Towards Circular Economy: Technoeconomic assessment of second-life EV batteries for energy storage applications in public buildings

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Master of Science Thesis

KTH School of Industrial Engineering and Management Energy Technology: TRITA-ITM-EX 2021:77

Division of Heat & Power Technology SE-100 44 STOCKHOLM

Towards Circular Economy:

Technoeconomic assessment of second- life EV batteries for energy storage

applications in public buildings

Maria Gris Trillo

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Master of Science Thesis in Energy Technology

TRITA-ITM-EX 2021:77

Towards Circular Economy:

Technoeconomic assessment of second-life EV batteries for energy storage applications

in public buildings

Maria Gris Trillo

Approved 2021-03-26

Examiner Supervisor

Francisco Díaz González, UPC Barcelona

Abstract

With the accelerated tendency of renewable energy penetration in the electricity grid, energy storage becomes a crucial asset for matching generation and demand. The growth of energy storage systems requires adequate new policies and regulatory frameworks.

The battery value chain also requests for new ways of end-of-life management since battery recycling is not a viable single option yet. This is where circular economy offers different solutions and alternatives for prolonging the battery life and reducing the negative impact.

This study analyses the technoeconomic feasibility of giving electric-vehicle (EV) batteries a second life as stationary energy storage systems in buildings with integrated on-site renewable energy production, such as for instance PV panels. Four different scenarios have been considered, including the refurbishment of the battery or its direct reuse, taking into account the degradation of capacity and thus, the amortisation price; against the possible load shifting benefit and the reduction of contracted grid power for the building.

Results show that, effectively, the reuse of batteries for stationary energy storage is economically justified but may not be worth only in self-consumption applications, that is, for prosumers with some little renewable generation installed on site. The simulations reveal less than 2% relative energy cost savings on annual basis and up to 25% savings related to reduction of grid-contracted peak power, for the chosen case study of a mid-size office building.

Second-life battery applications are still dependent on the development of tools for estimating and monitoring the battery’s state of health and potential performance in the new setting, for the technology to succeed. The increasing interest and necessity for circular economy together with the high volume of EV batteries expected to be released on the second-hand market, not suitable for automotive purposes anymore but reasonably applicable for stationary energy storage, will place this topic in the spotlight in the near future.

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SAMMANFATTNING

Den fortsätta trenden för utvidgning av förnybar energi i elnätet gör att energilagring blir en ännu viktigare tillgång för balansen mellan elproduktion och efterfrågan. Nya policyer och regelverk krävs för att understödja en bredare tillämpning av småskaliga energilagringssystem.

Batteriets värdekedja kräver också nya sätt att hantera uttömda material eftersom batteriåtervinning ännu inte hunnit utvecklas som ett genomförbart alternativ. En cirkulär ekonomi borde erbjuda olika lösningar inte endast för materialåtervinning utan också gentemot förlängning av livslängden och fördröjning av återvinningsprocessen tills nya metoder och verktyg finns på plats för effektiv hantering med minimal miljöpåverkan.

Denna studie analyserar den teknoekonomiska genomförbarheten att ge begagnade batterier från elektriska fordon (EV) en andra tillämpning, typ en utvidgad livslängd, som stationära energilagringssystem för mellanstora kontorsbyggnader med integrerad lokal elproduktion såsom t.ex. solpaneler på taket. Fyra olika scenarier har beaktats, inklusive delvis renovering av batteriet eller dess direkta återanvändning, med hänsyn tagen till kapacitetsnedbrytningen och därmed amorteringspriset, som vägs mot fördelarna i form av en uppnåelig tidsförskjutning av elbehovet och minskning av kontrakterad nätkraft för byggnaden.

Resultaten visar att återanvändning av elfordonsbatterier för stationär energilagring är ekonomiskt motiverad men troligen inte alltid värt i applikationer med låg förbrukning och låg egenproduktion av förnyelsebar elkraft. Simuleringarna avslöjar mindre än 2% relativa energikostnadsbesparingar på årsbasis och upp till 25% besparingar relaterade till minskning av nätavtagen toppeffekt för den valda fallstudien av en medelstor kontorsbyggnad.

Praktiska tillämpningar av begagnade batterier är fortfarande beroende av utvecklingen av verktyg för uppskattning och övervakning av batteriets hälsotillstånd och potentiella prestanda i den nya installationen, för att konceptet skulle kunna bevisa sitt värde. Det ökande intresset och nödvändigheten för cirkulär ekonomi tillsammans med den stora volymen EV-batterier som förväntas släppas på den begagnade marknaden, inte längre lämpliga för fordonsändamål men rimligt användbara för stationära energilagringssystem, kommer att föra detta ämnesområde in i rampljuset inom en snar framtid.

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List of Figures

Figure.1: Total primary energy supply (TPES) by source, Worldwide 1990-2017……….1

Figure.2: Energy-related CO2 emissions and reductions in the sustainable Development Scenario by source………..2

Figure 3: Cumulative global energy storage deployments.……….………….3

Figure 4: Total final consumption (TFC) by sector, Europe 1990-2017.IEA……….5

Figure 5: Electric vehicle stock in the EV3030 scenario, 2018-2030.……….6

Figure 6: The Circular Economy System diagram……….9

Figure 7: Growth of materials use and GDP, 2011-2060……….10

Figure 8: Global resources outlook 2015-206………..10

Figure 9: Achieving resource decoupling as a result of policy packages………...12

Figure 10: Li-ion battery structure diagram……….13

Figure 11: Average Li-cobalt battery………....18

Figure 12: Pure Li-manganese battery ………18

Figure 13: Typical NMC battery………..18

Figure 14: Standard LFP battery……….18

Figure 15: Snapshot of NCA………...18

Figure 16: Chart of Li-titanate……….18

Figure 17: EV and Industry Batteries’ value chain………...19

Figure 18: Capital investment cell manufacturing vs. module and system assembly……… 22

Figure 19: schematic of the methods and processes involved in the consumed LIBs recycling…23 Figure 20: Closed loop for LIBs life………25

Figure 21: Virtual map of UPC campus Terrassa………26

Figure 22: Aerial picture of the building………..27

Figure 23: Picture of the building………27

Figure 24: Daily total consumption, HVAC consumption and PV generation……….27

Figure 25: Ri-SOC plot with different cycles………...28

Figure 26: Maximum charge storage capacity for each cycle number as a function of T………..29

Figure 27: Capacity degradation curves for different discharge C-rates………....30

Figure 28: Comparison of calendar aging and cyclic aging for three temperatures investigated…30 Figure 29: Alterations of the voltage vs. capacity at different cycles………31

Figure 30: Cycle life at different DoD……….32

Figure 31: Winter season typical sypply/demand scenario………...41

Figure 32: Spring season typical sypply/demand scenario ………...41

Figure 33: Summer season typical sypply/demand scenario ………....42

Figure 34: Autumn season typical sypply/demand scenario ………....42

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Figure 35: Peak reduction………....43

Figure 36: Peak reduction………...……….…………44

List of Tables

Table 1: Energy consumption by sector………4

Table 2: Characteristics of Lithium Cobalt Oxide………....15

Table 3: Characteristics of Lithium Manganese Oxide……….…15

Table 4: Characteristics of Lithium Nickel Manganese Cobalt Oxide………..16

Table 5: Characteristics of Lithium Iron Phosphate………16

Table 6: Characteristics of Lithium Nickel Cobalt Aluminium Oxide………..17

Table 7: Characteristics of Lithium Titanate………17

Table 8: Main characteristics of critical raw materials involved in a battery………..20

Table 9: Pretreatment methods comparison………23

Table 10: Comparison for metal-extraction processes……….24

Table 11: Gaia building electricity consumption and generation………..28

Table 12: Battery components’ prices………..33

Table 13: Invoice periods of the Spanish tariff 3.0A.………...34

Table 14: Retailer power pries for each invoice period………35

Table 15: Retailer consumption pries for each invoice period……….35

Table 16: Sets used in the simulation………...36

Table 17: Parameters used in the simulation.………...36

Table 18: Variables in the simulation………...37

Table 19: Peak reduction cases..……….……….………43

Table 20: Costs breakdown...……….……….………44

Table 21: Annual energy costs and savings.……….………45

Table 22: Power term invoice conditions………46

Table 23: Power savings………..46

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Abbreviations and Nomenclature

BESS: battery energy storage system BMS: battery management system CAES: compressed air energy storage DoD: Depth of Discharge

EGD: European Green Deal

EGDIP: European Green Deal Investment Plan EIB: European Investment Bank

EVs: electric vehicles

ICE: internal combustion engine LIBs: Lithium ion batteries

OEM: original equipment manufacturer SEIP: Sustainable Europe Investment Plan SoC: State of Charge

SoH: State of Health

UPC: Universitat Politécnica de Catalunya (BarcelonaTech) WEO: World Energy Outlook

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ACKNOWLEDGMENTS

I would like to acknowledge everyone who played a role in this Master Thesis. First of all, my supervisor, Francisco Díaz González, who has provided valuable guidance and advice during this research. Secondly, I would like to thank Pau Lloret for his help concerning the technical aspects.

Also I would like to express my gratitude to Miroslav Petrov, for making this project possible.

Additionally, many thanks to all the professors and PhD students in the electrochemistry department at KTH for introducing me to this topic and for being sources of inspiration in the classes and in the laboratory sessions they taught.

Finally, special thanks to my friends, family and Joel, who supported and encouraged me.

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1 INTRODUCTION

1.1 Background

Energy is of crucial importance in our society and it has penetrated in almost all facets of the social domain and is a pillar of the economy. In a world where the major primary energy supply is still lead by coal and oil as it can be observed in Fig.1, a general awareness of their harmful effects has been increasing the last few decades.

Fig.1: Total primary energy supply (TPES) by source, Worldwide 1990-2017. Source: IEA

One of the battles humanity is fighting nowadays is the climate crisis with the drawback of a constant raise of energy demand. The objective of the Paris Agreement focuses on the need of world CO2 emissions to be dropped drastically to reach a sustainable development scenario that maintains the average global temperature increase below 2ºC above preindustrial levels and trying to limit it to 1.5ºC (IEA, 2019). To achieve this goal both technology and policy need to take action and work aligned, since less effective scenarios are drawn if one or another fail to meet their goals.

The International Energy Agency (IEA) published the World Energy Outlook (WEO) 2019, which included The Sustainable Development Scenario. The WEO implies what should be done in order to meet climate goals also aligned to what new policies are establishing. The following graph shows different future scenarios depending on the amount of adopted measures:

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Fig.2: Energy-related CO2 emissions and reductions in the sustainable Development Scenario by source.

Source: IEA

As it can be observed from the graph above, current trends of energy-related CO2 emissions will lead to a scenario of 45 GT by 2040. However, integrating all the changes shown in the graph and thus following the opposite tendency 0 emissions leads to an incredible drop of CO2 emissions down to 10 GT in 2050. Although this is very promising it is not an easy task and even the current target is not consistent with new stated policies. According to up-to-date policies, the future emission scenario would flatter the rapid increasing curve tendency but it would not decrease the current emissions as it can be noticed in the graph. These divergences between different scenarios highlight the importance of the decisions made by governments in the few next months and years, which will determine the new policies and the investment in technology development crucial for accomplishing the lowest emission scenario.

Everything points to a huge investment in renewables replacing systems powered by fossil fuels, as it can be observed in the trends of the past years. However, their stochastic and low predictable nature dependant on weather and season together with their immediate consumption required makes it difficult to maintain a high reliability and security in the supply of those renewable energy sources.

Therefore, energy storage has grown drastically these past few years not only helping address the intermittency of renewables but also responding rapidly to large fluctuations in demand, making the grid more responsive and reducing the need to build backup power plants (Zablocki, 2019).

However, this growth of storage systems needs the adequate new policies and regulatory frameworks in the electricity sector since there will be many different scenarios not contemplated nor planned until now.

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This future electricity market will need new rules to beneficiate all parts involved and prevent any technological or legal right confusion (Bioenergy International, 2019).

In the upcoming years the energy storage market is going to experience a huge growth hitting the 741 GWh of global cumulative capacity in 2030 led by the U.S. and China, with 49 and 21 percent respectively (McCarthy & Xu, 2020).

Fig.3: Cumulative global energy storage deployments. Source: Wood Mackenzie

All the research efforts that are being focused towards this technology will make reduce its price.

Still, a huge investment will be required to reach that capacity. However, since energy storage will become a key grid asset, all market players will have to take part in this transition.

The success of an energy storage facility lies on the response capability in front of a demand variation, the amount of energy lost in the storage system, the overall energy storage capacity and the velocity in the recharging process rate (Zablocki, 2019).

Among some of the different ways to store electricity the most relevant ones that are currently being investigated are hydrogen (fuel cells), supercapacitors, compressed air and batteries. In the hydrogen storage, electricity is used to convert water and oxygen into hydrogen, which can be easily stored and re-converted into the desired form (electricity, heat etc.). This technology presents many advantages. Thanks to the large amounts of power and low cost for storing once transformed into hydrogen, this technology is very suitable for industrial processes. Moreover, hydrogen storage is a long-term storage system, which can last as long as needed. Secondly, supercapacitors are a very high power-density storage system, being able to release high amounts of power in short periods of time. They also have unlimited lifetime as their capacity is not affected by the amount of cycles performed. However, supercapacitors are a short-term energy storage system only being able to store energy up to some minutes. Thus, they are used for system disturbances providing short electricity bursts when necessary. Furthermore, compressed-air energy storage (CAES) is a long- term energy storage system that can store energy up to a week. And finally, batteries are an energy storing system for comparatively short periods of time, from hours up to few days. They can be employed in the frequency and voltage stabilisation of the power system, also helping in the demand balance.

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Energy storage is already an essential mechanism in the power and transportation sectors. While there are several ways to store electricity nowadays, current tendency is pointing to Li-ion batteries as the most viable solution in the short term. The key points to make a technology a success and competitive are increasing their performance and reducing their cost. Li-ion batteries price has dropped drastically from 1000 $/kWh to 200 $/kWh in the last 6 years and their energy density has doubled. These aspects make them good enough for EVs industry and are already competitive compared to internal combustion engines (ICE) because the lifecycle and cost can beat that of fossil fuel vehicle. However, batteries haven’t hit in heavy vehicles and aviation yet. It is believed this will occur by 2030-2040. Batteries will first be used on smaller planes, possibly many small engines in one plane to provide more reliability and flexibility. In the aviation sector energy density plays a crucial figure since there is the need to keep a low weight without loosing power range.

Battery energy density is rising by a significant 2 to 3 per cent each year. However, Tesla’s cars still overcome these numbers with each iteration. “It’s not the same ballpark as Moore’s Law progress because it’s chemistry, not electronics, but it’s still very good.” (Adams, 2017).

1.2 Motivation

For the last seven years I have been studying engineering and for the past three focusing on renewable energy. My goal is to help society overcome the climate crisis providing the clean alternatives to maintain our current life style as much as possible, in terms of energy use. Clearly, there are some other aspects that need to be changed in order to successfully meet the goal of preserving the environment, such as plastic use and waste management. Going back to energy use, the current energy distribution in Europe is the following showed in Table 1 and the tendency evolution of each sector is presented in Figure 4:

Table 1: Energy consumption by sector. Source: IEA, data and statistics.

Sector ktoe MWh %

Industry 333.947 3.883.803.610 23,79

Residential 346.149 4.025.834.259 24,66

Transport 391.169 4.549.295.470 27,87

Commercial and public services 179.653 2.089.364.390 12,80

Agriculture/Forestry 32.469 377.614.470 2,31

Fishing 2.030 23.608.900 0,14

Non-energy use¹ 118.264 1.375.410.320 8,43

1 Non-energy use: Non energy use includes energy products used as raw materials in the different sectors;

that is not consumed as a fuel or transformed into another fuel.

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Fig. 4: Total final energy consumption (TFC) by sector, Europe 1990-2017.

Source: IEA World Energy Balances 2019.

The industrial sector, for its economic resources and cover surface [m²] in the buildings, is one of the main vectors to integrate renewables. In fact, it can generate more energy than its own building consumption depending on the hour of the day and the economic activity carried out.

Thus, in order to maximize the local generation, renewable, and a neutral CO2 industrial sector, batteries are fundamental tools.

The battery storage capacity of an EV is usually much larger than an industry storage system. The requirements for a battery used in the transport sector are more demanding given their main competitive characteristic. Once a little capacity is lost for the aging process, the car range is reduced, compromising their good performance and eventually being replaced for a new EV.

However, the old batteries are still at a very high percentage of their initial capacity although not being suitable for their original purpose. For instance, Tesla Model 3 has a battery degradation of 7% after 250.000 miles (Kane, 2017). Hence, a new employment needs to be found for these batteries that are far from being at the end of their life.

As mentioned before, industry storage systems are not as size and capacity demanding as EV. Thus, discarded EV batteries can be reused and given a second life in the industry sector, preventing the over production of batteries risking the Earth resources of Lithium, taking also into account that the scarcity of this material would eventually lead to a commercial fight and an important raise in the prices.

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Fig. 5: Electric vehicle stock in the EV3030 scenario, 2018-2030. Source: IEA Global EV Outlook 2019.

However, second life batteries will only be a considerable resource in 5-10 years time. Before being a substantial source of second life batteries, EVs need to experiment a great increase in the vehicles selling share. Current tendency points to a promising scenario, where there would be 250 million vehicles by 2030 as revealed in Fig. 5. As this number increases, so do will the potential second life batteries, with some years delay due to their improved first life performance.

Moreover, the batteries’ second life approach is particularly important due to the lack of recycling capacity of the Li-ion batteries, which is totally insufficient in Europe. This is why the concept of circular economy is interesting for the decarbonisation of the industrial sector and to reduce the impact of the use of batteries in the natural environment.

1.3 Objectives

This project considers this current situation and proposes two major objectives. First, a definition of the battery value chain from the cell manufacturer to the end user and secondly, a study of the synergies between these two sectors: electro mobility and industry in order to quantify the impact of giving a second life to these batteries, from an economic point of view. Such study will be done by analysing two scenarios for the second life battery with the help of a simulation tool to check the potential savings.

The concrete technical objectives are to significantly reduce the energy bill, both reducing the electricity costs and power costs. In terms of power, since the battery is thought to be able to reduce the demand peaks considerably, the target is to reduce 25% of the contracted power. Also, the battery degradation is key to determine the viability of the project proposal.

The main research focus herein is therefore related to the feasibility and profitability of installing second-life batteries from EVs to medium-scale energy storage applications in office buildings.

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1.4 Methods, analytical framework and research approaches

Research approaches and methods are procedures and strategies that define the way assumptions are done and detailed data is collected and analysed to subsequently reach conclusions and results.

The choice of approach depends on the nature of the topic of study or the research problem.

This study will account with quantitative as well as qualitative methods. In order to give the most accurate future scenario for batteries impact in their second life in the industrial sector, a quantitative study will be executed with data provided by the energy resources and water information system (SIRENA) from UPC campus and a simulation tool that accounts with a series of equations describing the battery model, the different constraints, etc.

Afterwards, results will be analysed in order to reach conclusions about the feasibility, advantages and drawbacks of the model proposed.

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2 CIRCULAR ECONOMY

The key difference between the cradle-to-grave dynamic active throughout all modern production history and the cradle-to-cradle system intended to accomplish, is the same as in between current resources value chain and circular economy value cycles.

Two concepts arise from this difference: eco-efficiency and eco-effectiveness. The first one assumes a linear flow of resources and materials with only one-way direction. This involves the natural resources extraction, processing and transformation until the product desired, for finally discarding it. In this value chain, the eco-efficient methods pursue only to diminish the quantity and harmfulness of the material stream, but are unable to change the linear flow. Some of the materials in these products are not recycled nor reused but undergo a downcycling process, which downgrades material worth and thus, restricts its usage. This is only a transitional step since it does not prevent the cradle-to-grave line.

Contrary to this methodology of resource reduction, eco-effectiveness aims to convert the products and materials that have reached their end of life so they can be reused at the same value level for any another purpose. This would establish an ecologically friendly as well as an economically supportive system. It would be possible by creating a cradle-to-cradle cyclical strategic structure, were materials maintain their worth and are used again as resources for a different aim (Webster, Bleriot, & Johnson, 2012).

2.1 Concept definition

Current developed economies and societies are used to a fast use and throw away model that has already compromised a wide range of natural resources on Earth. The material extraction not only causes scarcity in natural resources, but also has an immense impact in the environment in terms of land, water and air pollution. Moreover, it affects the ecosystems of millions of animals that could be at risk of extinction with all its repercussions in the complex bionetworks.

As technology keeps evolving and our everyday life is more dependent on devices and material assets, this devastating trend will not improve. Demand and waste are still correlated in the resources equation governing our economy up to date. Following this model, the only way to reduce the resources and the waste would be directly reducing the resource extraction. However, this approach would not be considered an option from the consumer comfort point of view, as it would cost the loss of facilities. Subsequently, this model does not meet our new need of urgently turning eco-friendly maintaining our lifestyles. From a holistic perspective, modern lifestyle should be reconsidered as an attempt to help reduce our footprint, but this is not a technical issue and thus, is out of the scope of present work.

Hence, the new model needed is a circular economy, redefining growth decoupled from finite resources consumption and redesigning the waste management systems. Together with renewable energy sources transition, the circular model will bring benefits to the natural environment and societies besides boosting economic activity.

This new system concept diagram flows as a ‘value circle’ instead of a ‘value chain’. The outline of a circular economy could be sketch as follows:

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Fig. 6: The Circular Economy System diagram. Source:Ellen MacArthur Foundation.

At the highest and more general level, the main objectives of a circular economy is to preserve and regenerate natural capital by controlling finite stocks and balancing their use with renewable resource flows. In the circular value flow, the goal is to optimise the resources yields by reusing materials and components as much as possible and giving them different uses and shapes if needed to get all their potential in the loop. Finally, raise system effectiveness by minimizing negative externalities out of the value cycle.

2.2 Forecast of the environmental impact of material use (predictions)

With current trend of growth, global population could reach 9.600 million by 2050 and therefore more natural resources will be required to withstand living standards, up to the corresponding resources of three planets Earth (United Nations, 2020).

Also, socioeconomic trends will determine the future material use. The three main drivers are income convergence among countries, a structural change and technology developments (OECD, 2019).

All countries will face an improvement in living conditions and reach those of the wealthiest countries. Emerging and developing countries will grow at higher rates than in the OECD region (OECD, 2019). This may cause a boom in their construction demand and thus, a higher demand of materials. It is believed that demand for services coming from any kind of customer (from households, large companies or governments) will surpass that of agricultural or industrial supplies.

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This structural change will lead to a less intense material use since agricultural and industrial sectors have higher material intensity than the services ones.

Fig. 7: Growth of materials use and GDP, 2011-2060. Source:OECD.

As it can be seen in Fig. 7, GDP in developing countries will grow rapidly while Material Use will not experiment such a rapid increase due to the mentioned less material intensive structural change.

2.3 Global resource outlook (impacts)

There are a wide range of environmental impacts related to material extraction, processing and use, such as acidification, climate change, human toxicity, land use, photochemical oxidation, aquatic and terrestrial ecotoxicity among others. More concretely, the resource provision involves greenhouse gas (GHG) emissions from mining and treating raw materials, while the use (e.g. fossil fuels) can cause air pollution produced by their combustion.

Products of the primary resources can also have serious environmental impacts at the end of their useful life, if the waste management is not properly accomplished. The consequences of using iron, aluminum, copper, zinc, lead, nickel and manganese are estimated to more than double by 2060 (OECD, 2019).

Resource² extraction and processing cause half of the greenhouse emissions alongside 90% of biodiversity loss and water stress (European Commission, 2020).

Past and current trends point to the following evolution from 2015 to 2060:

Fig. 8: Global resources outlook 2015-2060. Source: International resource panel, 2019.

2Resource here encloses materials, fuels and food.

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2.4 Action

Given the negative projections related to material use there is a need for urgent action.

Governments face a truly difficult challenge where a big transformation has to be shaped in several new policies to address the dark resources forecast. All of the new political decisions and new policies have to pursue the transition to a circular economy, where natural resources consumption and environmental impacts disassociation from economic activity are key factors.

In a circular economy there exists a bidirectional correlation between mitigation of climate change and resource efficiency. Shifting to a low-carbon emissions economy already involves taking action in terms of resource-efficiency, and an enhancement of resource efficiency in policies will make a repercussion on the climate crisis.

Following this purpose, the European Commission disclosed a roadmap concerning a sustainable economy and with the goal of reaching a climate-neutral circular economy, where the economic progress is not linked to resources use. This initiative known as The European Green Deal (EGD) and presented on 11 December 2019 will be accompanied by a series of new policies, which are fundamental to establish the bases for accomplishing this environmental challenge.

President of the European Commission Ursula von der Leyen claimed that “the European Green Deal is our new growth strategy – for a growth that gives back more than it takes away”.

And as the First Vice-President of the European Commission Frans Timmermans added, “our plan sets out how to cut emissions, restore the health of our natural environment, protect our wildlife, create new economic opportunities, and improve the quality of life of our”.

Thus, the EGD main objectives are to cut to zero the GHG emissions by 2050, to make EU’s economy sustainable by disjoining it from resource use and to make sure it is an inclusive transition (European Comission, 2019). The actions postulated on its guideline comprised an enhancement of the resource use efficiency through a clean, circular economy and a recovery of biodiversity.

The circular economy plan will highlight the reduction and reuse of materials before recycling them.

Also, the first sectors to be tackled are those with major resource intensity such as textiles, construction, electronics and plastics. Another crucial strategy proposed by the Commission is the support to business models based on renting services (e.g. cars, bycicles, scooters) that will enlarge the use rate of those goods and lower their consumption from the levels they would have as if they were an owned product (European Comission, 2019).

To set a long-term direction to meet the targets stated above and make this plan a reality, all sectors of the economy will have to join the transition. It will require taking some actions from their side involving investing in environmentally friendly technologies and transport, reinforcing industry innovation, strengthening the decarbonisation of the energy sector, guaranteeing the buildings’

energy efficiency trend and collaborating internationally to expand sustainable standards. In order to truly meet these commitments, the European Climate Law has been announced to make a legal obligation and activate investment towards the European Green Deal (European Commission, 2019).

A fair transition fund will leverage private and public money including with the help of the European Investment Bank (EIB), which will deliver a sustainable investment plan. The European Green Deal Investment Plan (EGDIP), also known as Sustainable Europe Investment Plan (SEIP), is the financing support of the EGD, which will employ at least 1 trillion euros in the following

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decade. This plan includes the Just Transition Mechanism that accounts with minimum 100 billion euros destined for funding the regions most impacted by the green transition throughout the period 2021-2027 (European Comission, 2019).

All in all, achieving the EU’s climate neutrality demands a new industrial policy based on circular economy. The most important part of the EGD together with the financing is the new policy framework, which will determine the actions required to accomplish by the different actors involved in this huge transition.

Further, the OECD has raised a project for resource efficiency and circular economy as well. The OECD’s RE-CIRCLE project goal is to predict the effects of unceasing natural resources use, and forecast the outcome of applying new policies to recognize which ones would have the highest impact to encourage circular economy transition (OECD, 2018).

Succeeding in the decoupling of resources and economy will bring significant improvement in human well-being and environmental pressure, even restoring ecological impacts made in the past, as well as boosting the economic growth. The most substantial change of trends could be glimpsed in the increase of global GDP and area of forest and natural habitat, and decrease of global material extraction, greenhouse gas emissions, area of agricultural land and global pastureland as shown in Fig. 9.

Fig. 9: Achieving resource decoupling as a result of policy packages. Source: International resource panel, 2019.

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3 BATTERY VALUE CHAIN

3.1 Working principle

The cell, which is the core element of a battery, can take different shapes and sizes but its working principle remains the same. During the charge and discharge process lithium atoms split into ions and electrons, which migrate between the two electrodes and circulate across the external circuit respectively. In the discharge, the oxidation takes place in the anode and the lithium ions travel from the anode to the cathode, where the reduction occurs, while the electrons circulate through the external circuit providing energy. Contrary, the charge process absorbs energy, the lithium ions travel form the cathode to the anode as well as the electrons in the external circuit. Lithium is a critical component in a battery but it is not the limiting one. The greater volume of lithium, the higher the capacity, and the larger the potential difference among anode and cathode, the higher the voltage.

The cell comprises three main layers. At the anode, there is a current collector commonly made of copper and covered with a film of active material, usually natural graphite with some mixture of chemical additives used to increase the conductivity. At the cathode, there is also a metallic current collector in this case made of aluminium and again coated with active material³, conductive additives and binder, which acts as an adhesive between the active material and conductive additive.

And the third layer consists of a membrane between anode and cathode known as separator.

These three layers are wetted with the electrolyte, a high ionic conductive mixture of solvents, salts and additives that increases efficiency in lithium ions movement through the active material and separator.

Fig. 10: Li-ion battery structure diagram. Source: U.S. Department of Energy. Office of Basic Energy Sciences

3 Active material: depends on the type of Lithium-ion battery. Usually consists of a mixture of several transition metals such as cobalt, nickel, manganese, iron, and/or aluminium.

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Before batteries are ready for commercialisation, an electrical insulation layer known as solid electrolyte interface (SEI) has to be built for the good functioning of the battery. The creation of this layer is carried out under specific conditions of battery cycling. It provides sufficient ionic conductivity (lowering a bit the capacity) for an adequate performance but prevents the electrons to circulate through the electrodes, which is crucial for the battery working principle.

SEI growth is a consequence of irrecoverable decomposition of the electrolyte forming a solid layer on the surface of the negative electrode active material.

Given that the electrolyte is almost unable to penetrate the SEI, once the first layer has formed, it will not reach the active material and thus, will not promote further SEI growth. However, if there was an enduring SEI growth there would be an unceasing loss of lithium, which would lead to a slow capacity decline (Pinson & Bazant, 2012).

Most of current research is focusing on battery performance during discharge and much little attention is put in increasing battery lifespan, which is limited by the irreversibilities that occur in the electrochemical reactions.

3.2 Main Lithium-ion battery types

In order to understand the batteries value chain properly, a deep study of the activities and agents involved in each of the stages is carried out. Considering the amount of diverse types of batteries and all their end purposes and end-users, the focus will specifically be put in Lithium ion batteries (LIBs). This kind of batteries is widely adopted in several sectors such as phone devices and EVs among the most important ones.

However, the demand on the industry sector as an energy storage device is gaining weight nowadays thanks to the already mentioned raise of renewables mostly.

There are some requirements that need to be meet for a battery to be viable and reach basic functioning. As an electric storage device the following eight characteristics are of major relevance:

- High specific energy [Ah/kg] - Long life - Low toxicity

- High specific power - Safety - Fast charging

- Affordable price - Wide operating range

In addition, it is very important for a battery to have low self-discharge and instant start-up when required. However, all batteries have some self-discharge, which is aggravated and intensified with age and temperature (Battery University, 2017).

There are many different types of Lithium-ion batteries. This kind of batteries is named after the active materials of what they are composed of. The most common ones are Lithium Cobalt Oxide (LiCoO2) — LCO, Lithium Manganese Oxide (LiMn2O4) — LMO, Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO2) — NMC, Lithium Iron Phosphate (LiFePO4) — LFP, Lithium Nickel Cobalt Aluminium Oxide (LiNiCoAlO2) — NCA and Lithium Titanate (Li2TiO3) — LTO.

Each of them has different characteristics such as voltages; specific energy; cycle life, which depends on the cycling conditions; cost and applications. The following tables summarize the main features of these types of batteries:

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15 Lithium Cobalt Oxide (LiCoO2) – LCO

Table 2: Characteristics of lithium cobalt oxide. Source: Battery University.

This battery excels on high specific energy but has low specific power (load capability) and limited life span.

Lithium-Manganese Oxide (LiMn2O4) – LMO

Table 3: Characteristics of Lithium Manganese Oxide. Source: Battery University.

LiMn2O4 cathode Graphite anode Since 1996

Voltages 3.70V, 3.80V nominal; typical operating range 3.0–4.2V/cell

Specific energy (capacity) 100–150Wh/kg

Cycle life Short

Applications Power tools, medical devices, electric powertrains

Lithium-manganese offers improvements in specific power and safety, but diminishes the capacity decreasing the performance with respect to Lithium-cobalt.

Cathode (~60% Co) Graphite anode Since 1991

Voltages 3.60V nominal; usual operating range 3.0–4.2V/cell

Specific energy (capacity) 150–200Wh/kg.

Cycle life Limited

Applications Mobile phones, tablets, laptops, cameras

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Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO2) – NMC

Table 4: Characteristics of lithium nickel manganese cobalt oxide (NMC). Source: Battery University.

LiNiMnCoO2 cathode Graphite anode Since 2008

Voltages 3.60V, 3.70V nominal; typical operating range 3.0–4.2V/cell

Cycle life Long

Applications E-bikes, medical devices, EVs, industrial

In this battery the addition of nickel and manganese play an important role. Nickel is recognised for its great specific energy but reduced stability while manganese establishes a spinel structure, which provides low internal resistance, but also provides low specific energy. However, the combination of both metals boosts each other advantages.

Thus, this battery offers high capacity and high power, serving as both energy cell and power cell, which is known as hybrid cell. Also, not using cobalt decreases the cost significantly and is making this relatively new battery the dominant for cathode chemistry.

Lithium Iron Phosphate (LiFePO4) – LFP

Table 5: Characteristics of lithium iron phosphate. Source: Battery University.

LiFePO4 cathode Graphite anode Since 1996

Voltages 3.20, 3.30V nominal; typical operating range 2.5–3.65V/cell

Cycle life Long

Applications E-bikes, medical devices, EVs, industrial

Lithium-phosphate battery is not stressed at sustained high voltage levels as it happens to other lithium-ion systems, making it a safe battery with a very high thermal runaway (270ºC). Low specific energy and high self-discharge but one of the fastest (high power) lithium-ion batteries.

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Lithium Nickel Cobalt Aluminium Oxide (LiNiCoAlO2) – NCA

Table 6: Characteristics of Lithium Nickel Cobalt Aluminium Oxide. Source: Battery University.

LiNiCoAlO2 cathode (~9% Co) Graphite anode Since 1999

Voltages 3.60V nominal; typical operating range 3.0–4.2V/cell

Specific energy (capacity) 200-260Wh/kg

Cycle life Short

Applications Medical devices, industrial, electric powertrain (Tesla) In this battery the addition of aluminium provides more stability than in nickel oxide. For its high capacity it is used as an energy cell.

Lithium Titanate (Li2TiO3) – LTO

Table 7: Characteristics of lithium titanate. Source: Battery University.

LMO or NMC cathode Li2TiO3 anode Commercially available since 2008

Voltages 2.40V nominal; typical operating range 1.8–2.85V/cell

Cycle life Very long

Applications

UPS, electric powertrain (Mitsubishi i-MiEV, Honda Fit EV),

solar-powered street lighting

In this case, the graphite anode is replaced by a lithium-titanate, which arranges into a spinel structure. With such configuration, zero-tension can be reached, SEI is not formed when fast charging at low temperature and consequently there is not lithium loss. For all these reasons the lifespan is the highest of all Li-ion types, it can be ultra-fast charged and discharged at a current of 10 times the rated capacity. However, the extremely high cost of this technology makes it only available for very specific and special applications, far from massive usage.

As it can be observed from the tables above, the trend in newer systems is to incorporate materials such as nickel, manganese and aluminium to benefit from their singular and distinctive characteristics to enhance batteries performance. The following radar or spider charts plot the

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values over a graded scale of the most important variables for each battery (Battery University, 2017)

LCO LMO

Fig. 11: Average Li-cobalt battery. Fig. 12: Pure Li-manganese battery.

Source: Cadex Source: Boston Consulting Group

NMC LFP

Fig. 13: Typical NMC battery. Fig. 14: Standard LFP battery.

Source: Boston Consulting Group Source: Cadex.

NCA LTO

Fig. 15: Snapshot of NCA. Fig. 16: Chart of Li-titanate.

Source: Cadex. Source: Boston Consulting Group.

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3.3 Battery value chain for EV and Industry

Since the objective of the present work is to study the effect of second life batteries in the value chain and explore the synergies between both first and end user in terms of bill and material management savings afterwards, only one general value chain will be considered to analyse the most important aspects relevant to the case study.

The value chain for lithium-ion batteries comprises several phases from the cell manufacturer to the end user. Depending on who the end user is, this value chain will be split at the application and integration point to reach each end user’s needs.

Regardless of the battery application the essential approach of the value chain is shared. The following diagram shows the main stages.

Fig. 17: EV and Industry Batteries’ value chain.

The firsts and common segments in the value chain of batteries are raw material mining and processing, cell manufacturing and system and module assembly. Although the energy storage system end use determines the following stages of the manufacturing and integration process, the final stage can also be common. When batteries reach the end of life for their first designed purpose, they can be recycled or reused for another application instead.

Also, it is worth noting that certain companies deal with various segments of the value chain such as some chemical industries covering the recycling and also the materials processing stages.

3.3.1 Raw materials

Natural resources are the departing point of the battery value chain journey. As previously mentioned, there is a wide variety of elements used for Li-ion battery cells, including lithium (Li), nickel (Ni), cobalt (Co), manganese (Mn), aluminium (Al), tin (Sn), titanium (Ti) and carbon (C) mostly in natural graphite form. All these elements are obtained from raw material mining or earth and water surface.

Some of these resources are of high importance to the EU economy and have a high supply-risk.

For both these features they are designated as “critical raw materials (CRMs)”. The European Commission published the first list of 14 CRMs in 2011 (European Commission, 2011), which is updated every 3 years to update production, technological progresses and market trends (European Comission, 2020). The first reviewed list in 2014 contained 20 CRMs and the third one in 2017 comprised 27 CRMs. Further, in January 2018, the Commission issued a document featuring the

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CRMs capacity for circular usage (Directorate-General for Internal Market, Industry, Entrepreneurship; European Commission, 2018) and finally, in May 2019 the 'Recovery of critical and other raw materials from mining waste and landfills - state of play on existing practices' was published presenting the existing methods and processes for raw material recovery from mining waste and landfills (Blengini, et al., 2019).

According to the last CRMs list published September the 5th 2020, which enclosed a larger number of materials, among the 83 materials 63 where considered individually and the rest arranged in 3 groups: 10 in heavy rare earth (HREEs), 5 in light rare earth (LREEs) and 5 in platinum metals (PGMs) (European Commission, 2020). To compare with previous lists, in 2011 41 elements were assessed, 54 in 2014 and 61 in 2017. The final 2020 list identifies 30 Critical Raw Materials (European Commission, 2020):

Among the materials used in Li-ion cells, cobalt, lithium, phosphate and natural graphite are considered critical raw materials. In the following table the main global producer for each of them, the stages assessed as critical, the economic importance and supply risk indexes and the recycling rates are presented (European Commission, 2020):

Table 8: Main characteristics of critical raw materials involved in a battery. Source: European Commission.

CRM Main global

producers

Stages assessed as critical

Substitution indexes EI/SR⁴

EoL recycling input rate⁵

Cobalt

Congo, DR (59%) China (7%) Canada (5%) Australia (4%)

mining/

extraction 0.92 / 0.92 22%

Lithium Chile (44%) processing/

refining 0.93/0.93 0%

Natural graphite

China (69%) India (12%) Brazil (8%)

mining/

extraction 0.95 / 0.97 3%

Phosphorus

China (74%) Vietnam (9%) Kazakhstan (9%) United States (8%)

processing/

refining 0.99 / 0.99 0%

4 ‘Substitution index’ is a method to numerically determine the hardship in substituting the CRM. It is estimated for both Economic Importance (EI) and Supply Risk (SR) factors. The value ranges from 0 (substitutable) to 1 (irreplaceable).

5 ‘End-of-life recycling input rate’ calculates the ratio between the recycled scrap and the EU demand.

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21 3.3.2 Active materials synthesis

Active materials are the core elements of a battery since are those participating in the electrochemical reactions. These materials include anode, cathode (both electrodes) and the electrolyte.

For the synthesis of these materials there are many different techniques. For example, for lithium iron phosphate the process consists of continuous ball-milling⁶ at high temperature with shearing capability, whereas for lithium nickel manganese cobalt oxide entails a batch wet synthesis on organic or aqueous solvent.

Mechanochemichal (MC) methods have been widely used for preparing lithium-ion batteries materials over the last years. MC methods shorten the synthesis process, display enhanced cycling behaviour as well as diminish the energy used and material cost compared to previous procedures including high temperature solid state reactions. However, current trends are pointing to nanotechnology, as it will offer new options for the cathode synthesis materials (Uddin, Alaboina,

& Cho, 2017).

3.3.3 Cell manufacturing

The cell manufacturing process comprises four main steps: active material preparation, electrodes manufacturing, cell assembly and cell formation.

First, for the active material arrangement, cathode material and graphite anode material are separately placed into two tanks where they are mixed with binder, additives and solvents to produce an ink.

Then, two metallic substrates, copper for the anode and aluminium for the cathode are covered with the ink through a slot-die process. Once coated, these foils are put in an oven so that the solvent evaporates and thus, a metallic bar coated with a solid substrate is the remaining product.

This foil then goes through a calendaring process where it reduces its thickness by roller compression until a right porosity level is reached.

The next stage is to cut in smaller rolls the two large electrode rolls. If the cell assembly process involves electrode piling, in order to obtain the electrode sheets it is required a roll-notching⁷ step.

In third place, the cell assembly involves the compilation of the separators and electrodes together.

The technique to do so is to coil together a separator (insulating sheet), the anode, another separator and finally the cathode. Depending on the battery configuration these layers will be enclosed in a cylindrical or prismatic casing, or will be assembled in single-sheet stacking or Z- folding among other structures. Next, the battery is sealed and the metal contacts are adhered.

And finally, the cell formation or aging step consists of charging and discharging the new assembled cell under very specific parameters depending on the chemistry composition, format and future battery application. One of the objectives is to form the SEI, which is composed of lithium carbonate and lithium oxide and grows in the anode active material surface. These initial charging and discharging tests are also used to detect any faults errors and discard malfunctioning cells.

6Ball-milling: grinding process into extremely fine dust.

7Notching: metal cutting process.

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22 3.3.4 Module and system assembling

Once the cells are ready, the modules can be built. The system assembly entails a few steps to obtain the final module. The new cells are cabled and coupled together, and then inserted into a casing made of plastic or metal. Additionally, to conclude with the final module, a control card is connected, comprising a battery management system (BMS). Usually the modules account with 4 to 50 cells, reaching up to few kilowatt-hours.

Module and system assembly are way less capital intensive compared to cell manufacturing, around 5-7 times.

Fig. 18: Capital investment cell manufacturing vs. module and system assembly. Source: Saft 3.3.5 Application and integration

This stage is different for each battery end use. Depending on the battery first life purpose, the battery pack will be integrated into the vehicle structure, comprising the battery-car interface (connectors, plugs, mounts). This task is carried out by automotive OEMs (original equipment manufacturer), such as Chrysler (Fiat), Ford, GM, Nissan and Tesla among the most important ones (Lowe, Tokuoka, Trigg , & Gereffi , 2010).

In the other hand, stationary battery uses include off-grid applications, where storage is part of a bigger energy solution; utility application, where energy storage can provide system reliability, peaking capability, frequency response, regulation, power quality, forecast error mitigation and renewable restriction mitigation among other values; and finally behind the meter, providing the electricity consumer benefits determined by the tariff structure and in terms of power quality from the grid.

3.3.6 Recycling and second life

Once the battery has reached the end of its first purpose life due to a capacity loss that no longer satisfies the automotive industry needs, the objective is to repurpose the use of this battery instead of discarding it right away in order to create a circular economy around them. The next steps are conditioned by a series of economic and technical aspects that will be further discussed. However, if the battery has already reached the end of its second life, meaning it has already been used for a stationary purpose not as demanding as the first one, it will be recycled.

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Fig. 19: Schematic of the methods and processes involved in the consumed LIBs recycling. Source: (Zheng, et al., A Mini-Review on Metal Recycling from Spent Lithium Ion Batteries, 2018)

This process involves different stages, comprising pretreatments, metal-extraction and product preparation. Initially, the battery is discharged for security reasons, the BMS, the battery cooling system and packaging are disassembled, removed and handled separately. There are different pretreatment methods: solvent dissolution; NaOH dissolution; ultrasonic assisted separation, which allows stripping the cathode material thanks to cavitation effect; thermal treatment, to decompose the binder and thus, reduce the bonding force between particles; and mechanical methods including sieving, crushing and magnetic separation. Table 9 summarizes the advantages and disadvantages of each process.

Table 9: Pretreatment methods comparison. Source: (Zhang, He, Wang, Ge, & Zhu, 2014).

Technology Advantages Disadvantages

Solvent

dissolution High separation efficiency Expensive solvent, environmental hazards

NaOH dissolution

High separation efficiency Simple operation

Difficult aluminium recovery Alkali wastewater emission Ultrasonic-

assisted separation

Simple operation

Practically no exhaust emission

Noise pollution

High device investment

Thermal treatment

Simple operation High output quantity

High energy consumption High device investment Toxic gas release Mechanical

methods Simple and useful operation

Toxic gas release

Cannot separate all kind of components in spent LIBs completely

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Some of these techniques have a more efficient separation process such as solvent dissolution and NaOH dissolution whereas the others occur to be simpler operations.

Once opened, to inactivate the harmful substances, liquid nitrogen is used. Also, the cathode, anode and separator are removed and put in an oven for 24h in order to dry them.

Next, each electrode is further separated for the metal extraction, which is done by pyrometallury, hydrometallurgy, biometallurgy or a combination of these. This process consists on transforming the solid metals into their liquid state to enable the later separation and retrieval of the metal components. Again, the advantages and disadvantages are presented in a summary table:

Table 10: Comparison for metal-extraction processes. Source: (Georgi-Maschlera, Friedricha, Weyheb, Heegnc, & Rutzc, 2012)

Technology Advantages Disadvantages

Pyrometallurgy Great capacity Simple operation

High temperature and energy consumption

Low metal recovery rate Waste gas and dust

Hydrometallurgy

Low energy consumption High metal recovery rate High product purity

Long recovery process High chemicals consumption Waste water

Biometallurgy

Low energy consumption Mild operating conditions High metal recovery rate

Long reaction period

Bacteria are difficult to cultivate

This step of metal-extraction is critical to the whole process. The methods implemented are gaining efficiency and capacity but still are very harmful for the environment because of the wastewater, the management of chemicals involved and exhaust gas. Hence, further attention and research in secondary pollution is needed to achieve a successful recycling process.

Subsequently, in the preparation step metal components present in the liquid mixture can be recovered by a combination of solvent extraction, chemical precipitation and crystallization. For the cathode material preparation, since the dissolved metal ions such as Ni, Mn and Co are difficult to separate due to their nature similarity, a precursor material is used to ease the separation.

Then, the cathode material is regenerated through co-precipitation and sol-gel, both these are synthesizing methods.

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Further maturity in cathode recycling processes is key to produce elements that can already be used in new batteries lowering or eradicating additional expensive reprocessing (Green Car Congress, 2019). In general terms, new batteries will be design to ease the recycling process and therefore, reduce the whole battery life cost.

The final goal is to reach a close-loop, see Fig. 20, where spent batteries are recycled diminishing processing steps and thus, reducing waste and energy consumption and positively affecting battery production costs.

Figure 20: Closed loop for LIBs life. Source: Argonne National Laboratory

Currently Europe does not have the capacity to recycle all the batteries that are in use and thus, even more emphasis needs to be placed in the repurposing and second-life of batteries to give time to further develop the recycling industry.

The upcoming worldwide rise of EVs will certainly bring new strategies for the collection and waste batteries management. Once the batteries are removed from the EVs their categorization and testing are crucial for determining a suitable second-use.

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4 STUDY CASE

From the battery collection until the second-use there are different strategies and approaches to proceed. Depending on the state of the battery, the battery pack is tested without being disassembled and, if it is apt and meets the market requirements for the second-use proposed, directly reused; in the other hand, the battery pack can be dismantled at a module level involving more technical procedures, materials and components to rebuild a new battery pack that will rise the cost of the operation. However, this second repurposed battery would be more adaptable for particular uses. The first strategy is known as “direct reuse” while the second one as “battery repurposing/refurbishing” (Canals Casals & Amante García, 2016).

The objective of this chapter is to introduce two different ways of proceeding with second life batteries and the economic effects, pursuing the best scenario for the prosumer using the available flexibility. To do so, an algorithm will be used to perform a consumption profile calculation using a second life battery. This algorithm with the code for the calculation step will be taken from The European project INVADE (Smart system of renewable energy storage based on INtegrated EVs and bAtteries to empower mobile, Distributed and centralised Energy storage in the distribution grid) (INVADE, 2020).

INVADE is a 16 million euros budget project being one of the largest European research and innovation in the field of SmartGrid & Storage. Both the present work and INVADE project ultimately seek to increase renewable sources integration in the power system. However, while this project only includes stationary storage, INVADE project incorporates both mobile (EVs) as well as stationary storage and thus, those parts of the algorithm corresponding to EVs storage will have to be omitted.

In the present work UPC public consumption and generation data will be used to perform the case study. This data will be acquired from the UPC SIRENA (Sistema d’Informació de Recursos Energètics i Aigua) tool (UPC, 2007), which was launched in 2007. SIRENA platform offers publicly accessible data measured by the smart meters distributed throughout the installations of the UPC for research and dissemination purposes (UPC, 2007). SIRENA’s main purpose is to lead the new energy saving measures and get track of their implementation effect. UPC is a good model to carry out such study since it has a plan for reducing energy consumption and implementing renewable energy systems (solar PV) and thus, our second life batteries could benefit UPC both technically and economically.

The targeted building is TR14 Gaia in UPC campus Terrassa. This building is intended to locate university-company projects, technology-based companies, research centres and innovation units.

The solar power plant installed on the roof has 120 photovoltaic panels, with a power of 25kW.

Figure 21: Virtual map of UPC campus Terrassa. Source: UPC

Towards Circular Economy: Technoeconomic assessment of second-life EV batteries for energy storage applications in public buildings

Towards Circular Economy:

Technoeconomic assessment of second- life EV batteries for energy storage

applications in public buildings

Maria Gris Trillo

Abstract

SAMMANFATTNING

Contents

List of Figures

List of Tables

Abbreviations and Nomenclature

ACKNOWLEDGMENTS

1 INTRODUCTION

2 CIRCULAR ECONOMY

3 BATTERY VALUE CHAIN

4 STUDY CASE