REPURPOSING OF LITHIUM-ION BATTERIES - Technology & Market Insights - A Joint Report by
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REPURPOSING OF
LITHIUM-ION BATTERIES
Technology & Market Insights
A Joint Report by
About IPI IPI is an innovation catalyst that creates opportunities for enterprises to grow beyond boundaries. As a subsidiary of Enterprise Singapore, IPI accelerates the innovation process of enterprises through access to its global innovation ecosystem and advisory services. For more information, please visit: www.ipi-singapore.org About SBC The Singapore Battery Consortium (SBC) aims to foster strategic R&D partnerships amongst public research performers and industry players in the development and advancement of battery technologies. We aim to develop and catalyze the local ecosystem in battery related technologies through this platform. For more information, please visit: www.batteryconsortium.sg About NTU SCARCE Singapore CEA Alliance for Research in Circular Economy (SCARCE) is a joint center established between Nanyang Technological University (NTU) and the French Alternative Energies and Atomic Energy Commission (CEA), France. The centre’s focus is on research on e-Waste Recycling with an aim to develop advanced technologies in sorting, dismantling, dissolution, separation and materials reuse processes in order to enable innovative solutions for the management of wastes. The initial focus of the SCARCE will be on e-waste and more specifically lithium ion batteries, solar panels, printed circuit boards and e-plastics. For more information, please visit: https://research.ntu.edu.sg/scarce/Pages/Home.aspx
About Authors • Steven Lee Sooi Joo (IPI) • Chiam Sing Yang (SBC) • Ren Yi (SBC) • Jason Luo Yuanhong (SBC) • Madhavi Srinivasan (NTU, SCARCE) Disclaimer This report is provided as is, with no warranties of any kind, express or implied, including but not limited to the warranties of merchantability, fitness for a particular purpose and non-infringement of any third party rights. This report is not a Freedom to Operate (FTO) check for any product or services. The company is strongly recommended to engage competent IP lawyers to carry out FTO checks on their Intellectual Property that is associated with the product or services they plan to commercialize. The report is provided to the company as a source of information. The final decision is still for the company to make. The authors shall not be liable for any indirect, incidental, special, punitive, or consequential damages or expenses (including loss of profits or revenue, business interruption, loss of data, or failure to realize anticipated savings or benefits) arising from or related to the report.
CONTENTS
06 Executive Summary
07 Introduction
08 Global Trend and Market Overviews
10 Key Challenges and Gaps
14 Standards for Battery Repurposing
17 Innovation Landscape and Technology Review
36 Examples of SLB Implementations
42 Battery Recycling
46 Opportunities for Singapore
48 Appendix
REPURPOSING OF LITHIUM-ION BATTERIES | Technology & Market Insights 4
Acronym Full Form ESS Energy Storage System SLB Second Life Battery LIB Lithium-Ion Battery EOLB End-of-life Battery OEM Original Equipment Manufacturer SOC State of Charge SOH State of Health BMS Battery Management System HF Hydrogen fluoride SOP State of Power OCV Open Circuit Voltage EIS Electrochemical Impedance Spectroscopy TRA Transient Response Analysis EMS Energy Management System TMS Thermal Management System SEI Solid Electrolyte Interface ERP Extended Producer Responsibility
EXECUTIVE SUMMARY
In this study, we identified the key drivers and barriers for adoption of Second Life
Batteries (SLB). The challenges highlighted in this report include handling the diversity
of electric vehicle (EV) battery packs in the market, costly battery transportation,
development of grading and disassembly processes, difficulty in accessing historical
data of used batteries, and the lack of unified standards for used battery repurposing.
We examined 33 case studies for SLB implementations in various applications, such as
reuse by EV OEMs, energy storage systems (ESS) for grid stabilization, back-up power
systems, smart grids, home ESS, EV chargers, and portable power.
Along with the implemented projects, this study also pinpoints the key market players
that lead these developmental and commercial projects. This include battery makers,
EV OEMs, ESS providers and start-ups. Players that focus on technologies that facilitates
battery repurposing for first life battery systems are listed in Appendix A.
A total of 18 emerging technologies are identified from patent landscape study and
open-source scan, specifically in battery diagnostic and grading, and non-invasive
battery rejuvenation and regeneration. In addition, a total of 22 patented technologies
are highlighted in the area of battery disassembly and automation.
The study also includes details for UL 1974, Evaluation for Repurposing Batteries, the
most established standard adopted by commercial player (4R Energy) for sorting,
grading and repurposing of used batteries for second life applications, as well as GB/T
33598-2017, Dismantling Specification for the Recycling of Traction Battery used in
Electric Vehicle, the first national standard on the end-of-life reusing/recycling of EV
batteries in China.
The study covers a unique overview of battery repurposing and recycling in the local
landscape, and highlights some prospective opportunities for Singapore to explore in
these areas.
Finally, the technologies and economical gaps and opportunities of battery recycling
are also included, as battery recycling is considered as the last resort for handling SLB
after their repurposed lives.
REPURPOSING OF LITHIUM-ION BATTERIES | Technology & Market Insights 6
INTRODUCTION
WHY LITHIUM ION BATTERIES?
Lithium ion battery (LIB) is a mature technology used in portable electronic devices, stationary energy storage
and electric vehicles (EVs)1. Generally, they constitute a cathode (metal oxide), an anode (graphite), an organic
electrolyte, and a separator. LIB’s advantages include long-term stability, high energy density, good safety &
stability, and low cost of production2. However, many parameters such as storage and cycling conditions have
an impact on battery life –time and performance. Depending on the cell chemistry, both high and low state of
charge can deteriorate performance and shorten battery life3. These issues become increasingly urgent as EVs
production is expected to reach between 125 million and 220 million units by 20304. Consequently, 250,000
metric tons of EVs batteries are expected to reach their end-of-life by 20255.
The consequent increase in end-of-life LIBs is likely to present itself as a challenge for waste management.
Direct disposal of end-of-life LIBs poses severe environmental concerns. Toxic Heavy metals like Co, Ni, and
Mn will contaminate soil and water, with the potential release of corrosive hazardous gas such as hydrogen
fluoride, CO, CO2, etc.
Since purchase of EVs is driven by environmental concerns, it is therefore important to consider the
environmental and ethical impacts of the entire life-cycle of LIB. Ensuring proper end-of-life management of
LIB e.g. via repurposing and recycling can help present companies with a marketing advantage.
[1] Armand, M., & Tarascon, J. (2008). Nature, 451, 2–7.
[2] Dunn, B., Kamath, H., & Tarascon, J. (2011). Science, 334, 928–936.
[3] Vetter, J., Nov, P., Wagner, M. R., & Veit, C. (2005). Journal of Power Sources, 147, 269–281.
[4] IAE. (2018). Global EV Outlook 2018, IAE, Paris. https://www.iea.org/reports/global-ev-outlook-2018
[5] Winslow, K. M., Laux, S. J., & Townsend, T. G. (2018). Resources, Conservation and Recycling,
REPURPOSING OF LITHIUM-ION BATTERIES | Technology & Market Insights 7
WHAT ARE ALTERNATIVES TO BATTERY DISPOSAL?
LIB can still find useful applications after removal from their first use in electric vehicles
Remanufacturing
End-of-Life batteries (EOLB) can be rebuilt to the specifications of a new battery for the original
application through replacing defective battery modules or cells, regenerating the electrodes,
or replacing the electrolytes.
Repurposing
If the specification of the original applications cannot be fulfilled, EOLB can also be redeployed
for other less demanding applications such as back-up power supply and energy storage system,
maximizing the residual capacity left in Li-ion batteries.
Recycling
The supply of key elements required to manufacture a LIB is not abundant. Recycling of EOLB,
as a final recourse, can recover valuable raw materials (such as lithium, nickel, manganese, and
cobalt along with other materials such as graphite, copper, and aluminum) to be refed into the
manufacturing supply chain.
Repurposing EOLB for second life applications could Furthermore, there is a high amount of variance in form
extend their lifetimes by another 5-10 years before factors and chemistries, complicating the grouping of old
they are recycled. However, reusing Li-ion cells is not as cells for large projects. Additionally, repurposing costs and
straightforward as plugging them into new applications. reduced resale prices could affect the economic viability of
Remaining capacity and performance depend on second-life batteries.
climate conditions, driving habits, and charging habits.
GLOBAL TREND & MARKET OVERVIEW
Market Size
The global electric vehicle reuse (second life) segment [1] Growth Opportunities in the Circular Economy for Global Electric Vehicle Battery
Reuse (Second-life) and Recycling Market, Forecast to 2025
generated a revenue of US$51.24 million in 2018, [2] https://www.evgo.com/about/news/evgo-announces-grid-tied-public-fast-
and this is expected to reach US$1,284.91 million by charging-system-second-life-batteries/
[3] https://www.mckinsey.com/~/media/mckinsey/industries/metals%20and%20
2025, recording a CAGR of 58.5%1. Global stockpile mining/our%20insights/lithium%20and%20cobalt%20a%20tale%20of%20two%20
of EV batteries is forecasted to exceed the equivalent commodities/lithium-and-cobalt-a-tale-of-two-commodities.ashx
of about 3.4 million packs by 2025, compared with [4] https://www.nissan.com.sg/news-promotions/news/worlds-number-one-elec-
tric-vehicle-Nissan-LEAF-arrives-in-Singapore.html
about 55,000 in 20182. Nissan Leaf (one of the most [5] https://insideevs.com/news/393890/nissan-leaf-sales-450000/
popular electric vehicles) had achieved over 450,000 [6] https://www.bloomberg.com/news/features/2018-06-27/where-3-million-elec-
tric-vehicle-batteries-will-go-when-they-retire
units in global sales (as of Jan 2020) since Dec 2010,
and this represents more than 10 GWh battery energy
on the road for future repurposing opportunities4,5.
Depending on the state-of-heath, not all EV EOLB
are suitable for second-life applications, and the
economic feasibility also depends on the repurposing
costs as well as the price of refurbished battery.
Technologically, repurposing EV EOLB is independent
of the future recycling process. Currently, EV Original
Equipment Manufacturers (OEMs) are repurposing
spent EV batteries for energy storage applications as
they are expected to retain 60-80% of initial capacity3,
and will continue to serve for another 7-10 years6.
REPURPOSING OF LITHIUM-ION BATTERIES | Technology & Market Insights 8
Value Chain & Key Players
Players that focus on diagnostic, design, and
manufacturing of second life battery consist of
battery makers, EV OEMs, ESS makers and start-ups.
There are players who focus on technologies that
facilitates battery repurposing, e.g. enhanced on-
board diagnostic and data collection (e.g. Akkurate,
Dukosi, ReJoule) to eliminate grading processes
during repurposing, as well as designs for easy
dismantling (e.g. Aceleron).
1] https://www.continental.com/en/press/press-releases/2018-03-07-jv-citc-123382
[2] https://www.envision-aesc.com/en/product.html , https://www.envision-aesc.
com/en/aiot.html
[3] http://autonews.gasgoo.com/new energy/70016265.html
BMS SUPPLIERS EV BATTERY MAKERS EV OEMS (first life) REPURPOSING
INTO SECOND LIFE
• Akkurate • A123 Systems • Audi BATTERY
• Bosch Mobility • Altairnano • Bayerische Motoren
Solutions • Beijing Pride Power3 Werke Diagnostic
• Continental1 • Boston-Power • BMW • 4R Energy
• GS Yuasa • BYD • BYD Auto • Aceleron
• Hitachi Vehicle Energy • CATL • Chengan • Ametek
• Indy Power Systems • Continental-CALB • Chevrolet • Bitrode
• Kisensum • Dow Kokam • Daimler • Goiku Battery
• LG Chem Power • Electrovaya • General Motors • LG Chem
• Lithium Balance • EnerDel • Great Wall Motors • Maccor
• Navitas Solutions • Envision AESC2 • Honda Motor • RePurpose Energy
• Nunam • E-One Moli Energy • Hyundai Motor • Relectrify
• Sumitomo Electric Ind. • Farasis Energy • Jaguar Land Rover • Panasonic
• Titan Advanced • GS Yuasa • Mitsubishi Motors • Primearth EV Energy
Energy Solutions • Hefei Guoxuan • Nissan Motors • Smartville Energy
• XALT Energy High-Tech • Porsche • Spiers New Technology
• Hitachi Vehicle • PSA Peugeot Citroen • Titan AES
Energy • Renault
• Johnson • SAIC Motor Design and
Controls-Saft • Tesla Manufacturing /
• LG Chem Power • Toyota Motor System Integrators
• Lithium Werks • Volvo Cars • 4R Energy
• Matsushita Battery • Volkswagen • Aceleron
• Microvast • Yin-Long • Belectric
• Northvolt • Betteries
• Panasonic • Bosch Energy Solutions
• Primearth EV Energy • Connected Energy
• Samsung SDI • Eaton
• SK Innovation • EcarACCU
• Sanyo • Itochu
• Sony • RePurpose Energy
• Tianjin Lishen • Spiers New Technology
• Tianneng Power Int. • The Mobility House
• Toshiba • Watt4Ever
• Valence Technology
• XALT Energy Technologies that
Facilitates Battery
Repurposing
• Aceleron
• Akkurate
• Dukosi
• ReJoule
• Rivian
• (See Appendix A)
REPURPOSING OF LITHIUM-ION BATTERIES | Technology & Market Insights 9
KEY CHALLENGES & GAPS
1 Diversity of EV Battery Packs in the Market
Different cell chemistries, types (pouch, prismatic
and cylindrical), sizes, and architectures adopted
by different manufacturers creates challenges for
processing and reconfiguring of the batteries for new
applications due to significant reverse-engineering
requirements.
Moreover, battery pack dismantling is a complex and
manual process. A systematic workflow planning is INDUSTRY NEEDS - A standardised,
necessary to synergize the manual work and robot- automated process to sort, dismantle electric
supported activities.
vehicle (EV) battery packs into modules for
subsequent testing and refurbishment works.
2 Costly Transportation & Grading Process
Used LIBs need to be dismantled from EVs, transported,
and subsequently tested. LIBs are classified under UN
Class 9 as dangerous goods. Current UN regulations
require batteries to be tested prior to transportation
according to requirements of UN Manual of Test
and Criteria Part III Sub-Section 38.3 – T1: Altitude
Simulation, T2: Thermal Test, T3: Vibration, T4: Shock,
T5: External short circuit, T6: Impact, T7: Overcharge,
T8: Forced discharged1.
Batteries need to comply with stringent packaging,
labelling, marking and documentation requirements
– defective or waste batteries are forbidden for cargo
transport2,3.
Transporting used batteries to a centralised facility
is complex and not easy to scale. In South Korea, the
collection and transport of spent batteries contributes
up to 50% of their overall processing costs4.
INDUSTRY NEEDS - A method to rapidly
Traditional methods of grading are protracted (2-3 grade used batteries in-situ or ex-situ with
hours for cell tests) and expensive, as establishing the sufficient accuracy.
state of charge (SOC), state of health (SOH), internal
resistance, self-discharge, cell voltage and current
require additional time and energy5.
[1] https://www.unece.org/fileadmin/DAM/trans/danger/publi/manual/Rev5/English/03en_part3.pdf
[2] https://www.caas.gov.sg/docs/default-source/pdf/2---regulations-on-the-transport-of-lithium-batteies-by-air.pdf
[3] https://www.icao.int/safety/DangerousGoods/DGP26/DGP.26.WP.047.6.EN.pdf
[4] https://www.csiro.au/~/media/EF/Files/Lithium-battery-recycling-in-Australia.PDF?la=en&hash=924B789725A3B3319BB40FDA20F416EB2FA4F320
[5] http://www.element-energy.co.uk/wordpress/wp-content/uploads/2020/01/UKESL-Non-technical-Public-Report_2020.pdf
REPURPOSING OF LITHIUM-ION BATTERIES | Technology & Market Insights 103 Difficulty in Accessing Historical Data
Used batteries from different OEMs may have different
battery management systems (BMS) and control
software standards. It may not be possible to access
the historical data (depth of discharge, cycles) that
is critical for battery repurposing due to concerns
including potential competition, IP issues, etc.
Battery OEMs update their BMS software frequently.
There are also numerous CPU standards in BMS,
e.g. battery manufacturers in China adopt different
standards than Japan or South Korea battery
manufacturers.
INDUSTRY NEEDS - A common BMS standard
on how acquired data can be extracted for
battery repurposing which will be useful to
predict the remaining lifespan of used LIBs,
and methods to access historical data from the
BMS to facilitate incoming modules sorting by
capacity, power capability, and calendar age.
*Refer to Appendix A for solutions that facilitates access to historical data for battery repurposing
4 Lack of a Unified Standard for Used Battery Repurposing
UL 1974 covers procedures for sorting of used batteries
and their components as well as the test processes for
repurposing. Other certification bodies have yet to
release their standards and different parts of the world
may require the manufacturer to adhere to different
sets of standards.
Standards development in the Netherlands (sharing
by CEO of EcarACCU)1 has NEN 9140 describing how
batteries can be disconnected from EVs, but not
describing how to open and disassemble the battery in
a safe way (which requires a unified standard to govern
easy disassembling and reuse of the batteries1). The
PGS 37 guideline (Netherlands) describes how to store
used LIBs is still under development1.
INDUSTRY NEEDS - Standardised test and
grading procedures for repurposing and
re-certifying used batteries for second life
applications (e.g. in stationary ESS), and a
common standard for battery packs designs
that facilitates repurposing.
[1] https://www.youtube.com/watch?v=0pPHINgLrT4
REPURPOSING OF LITHIUM-ION BATTERIES | Technology & Market Insights 115 Challenges in Battery Disassembly
The key challenge in battery disassembly arises Disassembly of battery cell
from non-standardized structures for battery packs/ • Different cell structures
modules/cells, thereby demanding flexibility in the (pouch, cylindrical, pristine)
production line. There has been minimum input at
the battery design level for recyclability. Electrocution • Different/unknown cell chemistries require
hazards require high-voltage training and insulated different approaches
tools, and short-circuiting can result in fire or explosion • Contamination of anode and cathode
of flammable and toxic battery components, and the for direct recycling
release of noxious by-products such as hydrogen • Finely powdered materials (nanoparticles)
fluoride (HF). Damaged EOL components and fasteners present health risks
are also more difficult to remove. There are also specific
challenges associated with various stages of battery • Potential fire hazards and off gassing of HF
disassembly1. • Difficulty in unwinding spiral cylindrical cells
Disassembly of battery pack Disassembly automation
• Removal of tricky wiring looms • Robotics and automation rely on highly
• Difficult manipulation of connectors structured environments, where robots make
(especially where locking tabs fitted) preprogrammed repetitive actions with respect
to exactly known objects in fixed positions
• No high voltages until wiring
loom/module links removed • Battery disassembly is complex with uncertainties
(no standardization in battery pack, module
• Lack of module condition data or cell design)
• Lack of labelling and identifying marks • Absence of labeling (QR code or RFID tags
• Potential fire hazards and off gassing of HF to record battery information)
• Dismantling requires forceful interaction
Disassembly of module with pristine cells between robots and objects, engendering
• Welded aluminum bus-bars complex dynamics and control problems, such as
• Welded side plates to the pressure plates simultaneous force and motion control, which is
needed for robotic cutting or unscrewing
• Thermoformed polyethylene film
between cell and housing • Dismantled materials must be grasped and
manipulated, including fragmented or deformable
• Strong adhesive (cyanoactylate) between cells materials, which pose challenges both to vision
systems and autonomous grasp planners
Disassembly of module with cylindrical cells
[1] Harper et al. Nature 575, 75-86 (2019)
• Spot welded nickel plated steel cell connector
• Hot pressed pins between cell holder
and current collector
• Glued (epoxy) connections between
current collectors and bus-bars
Disassembly of module with pouch cells
• Cells are glued to one another and some cells
are glued to aluminium sheet metal parts using
thermal conductive pastes
• Welded cell tabs among cells or to the
intermediate bus-bars
• Cell tabs of 0.2-0.3mm thick are not usable
after separation
REPURPOSING OF LITHIUM-ION BATTERIES | Technology & Market Insights 126 Cost & Business Model
Cost contributors to repurpose Possible Business Models for Repurposed Battery
used batteries into ESS1,2 : Nissan: Adopted a battery leasing scheme followed
• Purchase of used batteries by second life application as ESS, which contributes to
• Transportation lowering of the total cost of ownership of an EV.
• Labour and material handling e.g. forklifts
Consider an 8 years battery lease ($225 per month
• Testing and dismantling equipment
over 8 years) and 10 years second-life value from the
e.g. battery testers and hand tools
application as home energy storage (with cost of
• Raw materials and parts repurposing, installation and maintenance included).
(power conditioning, controls interface) It was determined that for a new 24 kWh Nissan Leaf
• Indirect costs e.g. warranty, insurance, facility battery pack (costing US$15,000), such a second life
space, taxes, capital and operation costs scheme generates a net profit of US$304011.
Among these contributors, Narula et al. suggested Some other considered business models include:
that used batteries and transportation are the most
• Connected Energy: Procure used EV battery
prominent expenses in battery repurposing.
packs directly from EV OEMs, then repurposing
them into containerised ESS with a proprietary
The National Renewable Energy Laboratory (NREL)
power control module equipped with remote
has developed a battery second-use repurposing
monitoring and operating capabilities. These
calculator to determine the repurposing cost (US$/
systems can be sold/leased to be integrated for
kWh)4. The calculator accounts for factors including
various applications12,13.
module properties, facility throughput, transportation,
module handling and testing time, staff, facility size, • Betteries: Procure used battery cells from EV
capital costs, employment cost, etc. OEMs, then repurposing them into portable
battery packs, and generate profits by offering
Competition from New Battery battery-as-a-service, i.e. battery rental or battery
swapping (e.g. for EV fleets)14,15.
As of end 2019, a new EV battery pack costs US$156/
kWh and is expected to fall below US$100/kWh by [1] https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=8718282
20245,6, according to BNEF & Reuters. [2] https://innovation.luskin.ucla.edu/wp-content/uploads/2019/03/Analysis_of_the_
Combined_Vehicle-and_Post-Vehicle-Use_Value_of_Lithium-Ion_PEV_-Propulsion_
Batteries.pdf
Depending on the source of new batteries, the cost [3] http://www.ehcar.net/library/rapport/rapport124.pdf
[4] https://www.nrel.gov/transportation/b2u-calculator.html
of repurposed batteries may not be attractive or
[5] https://about.bnef.com/blog/battery-pack-prices-fall-as-market-ramps-up-with-
competitive. market-average-at-156-kwh-in-2019/
[6] https://www.reuters.com/article/us-autos-tesla-batteries-exclusive/exclusive-
• Aceleron: A repurposed used battery from teslas-secret-batteries-aim-to-rework-the-math-for-electric-cars-and-the-grid-
Total Access to Energy Solutions (TATES) into idUSKBN22Q1WC
[7] https://www.energy-storage.news/news/recycled-lithium-battery-storage-in-
solar home systems prices at US$45/kWh with a kenya-to-come-in-at-half-the-cost-of-le
predicted lifespan of 7 years7. [8] https://www.idtechex.com/en/research-article/china-tower-can-absorb-2-million-
retired-electric-vehicle-batteries/15460
• China Tower: As of end-2018, second-life batteries [9] https://www.autonews.com/sales/nissan-leaf-buyers-dealers-worry-about-
replacing-worn-out-cells
are priced at the same level as lead-acid batteries [10] https://wicleancities.org/wp-content/uploads/2019/09/Ted-Bohn-Presentation-
at around US$100/kWh in China8. WCC-9-11-19.pdf
[11] https://innovation.luskin.ucla.edu/wp-content/uploads/2019/03/Analysis_
• Nissan: Offers Leaf owners in Japan exchanges of_the_Combined_Vehicle-and_Post-Vehicle-Use_Value_of_Lithium-Ion_PEV_-
Propulsion_Batteries.pdf
for a refurbished 24kWh battery at US$119/kWh [12] https://en.reset.org/blog/connected-energy-interview-repurposing-ev-batteries-
(2018)9, while new battery costs US$247/kWh10. drive-sustainable-energy-storage-11262018
[13] https://www.c-e-int.com
[14] https://cleantechnica.com/2020/05/20/berlin-based-betteries-wants-to-
Hence, it is important to conduct a techno-economic catalyze-adoption-of-sustainable-second-life-lithium-ion-batteries-with-stackable-
assessment on comparing reused batteries made from multipurpose-packs/
[15] https://betteries.com/
different OEMs against new batteries from different
OEMs to provide insights on the economic viability of
repurposed batteries.
REPURPOSING OF LITHIUM-ION BATTERIES | Technology & Market Insights 13STANDARDS FOR BATTERY REPURPOSING
UL 1974: EVALUATION 3. Gathering and analysis of BMS data
FOR REPURPOSING BATTERIES • Useful BMS data to be retrieved, e.g. capacity
UL 1974 (Edition Oct 25, 2018) covers the sorting and (Ah or kWh), current (A), voltage (Vdc), power
grading process of battery packs, modules and cells (kW), state of charge (SOC, %), temperature (°C),
and electrochemical capacitors that are originally time (h), internal resistance (Ω)
configured and used for other purposes (such as • Average and extreme values of voltage,
electric vehicle propulsion), and that are intended for a current, temperature and SOC
repurposed use application, e.g. ESS1,2.
• Total numbers at extreme values and out of
Procedures for examination of sorting of specification values for voltage, current and
used batteries and their components: temperature (rejection depends on length of
exposure)
1. Procedures for examination of sorting of
used batteries and their components • Total numbers under charge and discharge
over the lifetime and throughput
• Information gathering and review as part
of initial sorting procedure 4. Disassembly and examination
• Storage of batteries in accordance with local fire • Discharging of the battery pack
and building codes for hazardous material storage
• Disassembly into modules or individual cells
• Transporting of battery – refer to SAE J2950
Recommended Practices for Shipping Transport 5. Storage condition tracking
and Handling of Automotive-Type Battery System
- Lithium Ion • Record the temperature and humidity conditions
during storage on a daily basis
• Battery / modules / cells markings, date of
manufacturing, specifications, battery chemistry, • Record charging or discharging conducted
construction and configuration, cooling system, as part of the storage procedures
date of removal from service, etc. • Record the initial and final open circuit voltage
• Cell specification sheet indicating ratings for (OCV), any sorted parts that have self-discharge
nominal voltage of cells at start of life, calendar rate outside the repurposing manufacturer’s
expiration date of cells established acceptable limits are discarded
• BMS specifications, algorithms for charging and 6. Grading of batteries for repurposing
discharging, manufacturer, part number, etc.
• Batteries to be assigned grade upon completion
• Storage condition after removal from of the testing, and sorted into their specific grades
previous application that are equivalent with regard to remaining
usable energy and state of health (other criterion,
2. Visual inspection of incoming samples e.g. OCV, capacity, internal resistance, mass,
Visible signs of damage such as cracks, swelling, dimensions, etc.), prior to being re-assembled
notable odour, discolouration, or burn marks, shall be into a module or battery assembly
noted and documented.
REPURPOSING OF LITHIUM-ION BATTERIES | Technology & Market Insights 14Testing for the sorting and grading process 5. Check of BMS controls & protection components
1. Incoming open circuit voltage • Review of data including error messages to
(OCV) measurements determine if the BMS can be utilise for
• Performed on the battery pack, modules and cells repurposing – out of specification limits indicators
may be a signal for rejection of the battery for
• Devices with OCVs below the minimum voltage repurposing
limit shall be rejected
6. Discharge/charge cycle test
2. Incoming high voltage isolation check
• Battery pack, module or cells shall be discharged
• Insulation resistance test between the positive and charged for at least 1 cycle at room ambient
terminal and dead metal parts, and between the temperature, while monitoring temperatures,
negative terminal and dead metal parts voltage and current on the individual cells or
• Measured after a minimum 60-s using 500 Vdc modules
• Measured insulation shall be at least 100 Ω/V for
7. Self-discharge
dc circuit and at least 500 Ω/V for ac circuit or ac
• Performed at cell and module levels
combined circuit
• DUTs shall be charged to full and stored in a
3. Capacity check controlled environment at room ambient for at
least 1 day. The OCV of the fully charged DUT shall
• Performed at battery pack, modules
be recorded at 5 min, 1 h and 24 h
and cell levels
• Charge the device under test (DUT) to full at 8. Cell performance and safety characterisation
room ambient temperature. Rest for 1-4 hours
• The repurposing manufacturer shall have a
• Subject to a constant current / power discharge program for long term data gathering on aged cell
• Record capacity of the aged DUT and samples representative of samples for repurposing
compared with manufacturer rating or available
capacity data
Testing of assembled repurposed batteries
according to end use application and their
4. Internal resistance check
applicable standards
• Performed at battery pack and module levels
Disposal of damaged and rejected parts
• DUT is charged to full, then sit for 30 minutes procedures
to 4 hours
• Discharge the DUT at constant current rate I1 for a [1] https://www.ul.com/news/ul-issues-world%27s-first-certification-repurposed-ev-
batteries-4r-energy
specified duration T1 (typically a discharge time to [2] https://standardscatalog.ul.com/standards/en/standard_1974
reach 80-90% SOC). Record discharge voltage, V1
• Then, discharge the DUT at constant current SAE J2997: STANDARDS FOR
rate I2 = 5I1 for a specified duration T2 (typically BATTERY SECONDARY USE
a discharge time between 1 s to 10 s). Record SAE J2997 is currently under development by SAE In-
discharge voltage V2. ternational. The objective is to develop standards for
• Calculate the resistance R = (V1-V2)/(I2-I1) (Ω) a testing & identifying regimen to select batteries for
• Continue discharging the DUT to 20% SOC, sit safe reuse in various applications, including stationary
for 30 min to 4 hours, then measure the internal storage. It states battery state of health (SOH), label-
resistance at 20% SOC ling, and transportation as the evaluating criteria for
determining the reuse safety1.
[1] https://www.sae.org/standards/content/j2997/
REPURPOSING OF LITHIUM-ION BATTERIES | Technology & Market Insights 15GB/T 33598-2017: DISMANTLING SPECIFICATION Battery pack disassembly
FOR THE RECYCLING OF TRACTION BATTERY 1. Use specialize lifting tool to move the battery pack
USED IN ELECTRIC VEHICLE on to the disassembly platform
Since 2017, China has been introducing a series of 2. Dismantle the battery pack casing
regulations on recycling of retired EV batteries, and
one of them is the Dismantling Specification for the • For bolt, unscrew with appropriate tools
Recycling of Traction Battery used in Electric Vehicle • For welding and plastic packaging, use
(GB/T 33598-2017) proposed by the Ministry of Industry specialized cutting tools and control cutting
and Information Technology (MIIT) position and depth
• For embedded connection, use specialized
This specification is the first national standard on the
mechanical cutting tools
end-of-life reusing/recycling of EV batteries in China,
and clarifies the qualifications for battery dismantling 3. Dismantle connectors, separators and
and recycling companies, as well as the requirements other fixtures
in terms of the safety, operating procedures, storage, 4. Remove wiring, electronics, BMS, circuit breaker
and management of end-of-life EV battery packs and using insulated tools
module level dismantling.
5. Based on the positioning and fixing battery
modules, dismantle the fixtures and cooling
system, and remove the battery module using
specialized tools
6. Avoid the contact of detached metal parts and
bolts with the electrical terminals, use magnetic
tools to extract metal parts and bolts
Battery module disassembly
1. Use specialized dismantling tools to conduct safe
and environmentally friendly module disassembly
2. Use specialized lifting tools to move the battery
module onto the disassembly platform or feed
inlet
3. Dismantle the battery module casing
Pretreatment • For bolts, fix the module with specialized
1. Collect battery information (model, manufacturer, clamp and unscrew with appropriate tools
voltage, capacity, dimension, weight, etc.) • For welding and plastic packaging, based
2. Extract coolant using specialized extracting on the location and angle of welding spot,
system, store the coolant in specialized container use specialized cutting tools in an enclosed
3. Conduct insulation inspection, discharge and chamber and control the cutting position and
insulate the battery for safety purpose depth to avoid short circuit and fire
4. Remove external cables and detached • For embedded connections, use specialized
attachments mechanical cutting tools
5. Label the battery and upload information on the 4. Remove wiring and connectors using insulated
recycling and traceability management system tools, and remove the battery cell
5. Based on the arrangement and fixture of the
battery cells, dismantle the battery module
under insulated conditions. Insulate the electrical
terminals immediately once exposed and avoid
dismantling without tools
REPURPOSING OF LITHIUM-ION BATTERIES | Technology & Market Insights 16UN GUIDELINES ON THE TRANSPORTATION OF LI BATTERIES
The transport of EOL LIBs presents risks to the handlers spent batteries are UN packaging requirements that
and transporters. There have been restrictions on the need to be met for battery transportation in Europe on
transportation of new Li-ion batteries, and these will the road.
be further emphasized when transporting EOL LIBs,
where the unknown SOH and history of use/abuse Because of the above considerations, transportation
present further challenges. costs are likely to account for a significant portion of
EOL battery management and can serve to hinder
UN Model Regulations classify Li-ion batteries as widespread LIB reuse & recycling.
miscellaneous dangerous goods and must therefore
comply with safety, packing, labelling, and certification Guidelines are provided globally for air travel by the
methods to be transported as cargo. International Air Transport Association, and for marine
transport by the International Maritime Dangerous
P908 for defective and damaged batteries and P909 for Goods.
INNOVATION LANDSCAPE & TECHNOLOGY REVIEW
Battery repurposing requires technology in battery disassembly, sorting and rejuvenation.
Battery sorting is based on grading which require advance battery diagnostic
Conduct initial
EV battery Disconnect & voltage and
Transport to Dismantle battery Examine data
packs reaches resistance
remove battery repurposing pack to obtain from BMS or from
end of life measurements
pack from EV facility battery modules cloud, if any
capacity to identify failed
modules
Technology that facilitates
First life battery application battery repurposing
Remove failed
Process Flow Non-invasive modules for
for EV Battery rejuvenation of possible
Repurposing Emerging technologies Recycling
weak cells in refurbishment,
selected modules cell reconditioning
or recycling
Test battery Re-package Sort modules by Perform
Second life packs according to modules with new Replacement of capacity, power Rapid
characterisation
application application specific BMS/EMS systems weak cells, if any capability & diagnostic
tests on modules
requirements into battery packs calendar age
Rapid diagnostic of
state of health (SOH)
We identify
three areas
of emerging Non-invasive
rejuvenation of
technologies
weak cells
for battery
repurposing:
Battery disassembly
& automation
REPURPOSING OF LITHIUM-ION BATTERIES | Technology & Market Insights 17Battery Repurposing -
Diagnostic, Grading, Sorting & Rejuvenation
Origin of Patent Applicants
China 106
Japan 94
S Korea 56
United States 21
China Taiwan 6
Germany 4
Belgium 2
France 2
Great Britain 2
Canada 1
Czech Republic 1
Denmark 1
China Hong Kong 1
Ireland 1
Portugal 1
Patent Families
Overview of the Patent Applicants
Among the patent applicants, 7 are LIB manufacturers, 6 are BMS manufacturers,
4 are research institutes, 2 are EV OEMs and 1 is a grid operator
LIB BMS RESEARCH
MANUFACTURERS MANUFACTURERS INSTITUTES EV OEMS GRID OPERATOR
* * * * *
LG Chem 37 Sumitomo Changsha Toyota 43 State Grid
5 Advanced 5
Panasonic EV Electric Industries Corporation 7
9 Materials Ind Res Honda 2
Energy Co Ltd Mitsubishi Electric 3 of China
GS Yuasa 7 Nihon Denso 3 State Grid Henan
4
Electric Power
Samsung SDI 4 Beijing
3 Doshisha 2
Hefei Guoxuan Hyperstrong Tech
High Tech Power 3 Shenzhen Smart Zhengzhou
Energy Li Ion Energy 2 2
University of Light
Pylon Tech Co
Technologies 3 Goiku Battery
2
Co Ltd Co Ltd Patent Application Trend
天津津泽新能源 2 * Patent families Number of patents
科技有限公司
80 74
70 63
60
59
49
50
40
29
30 26
20
10
5
0
2014 2015 2016 2017 2018 2019 2020
Note: Year 2020 number is partial due to the cut-off date
(5 Aug 2020) of the patent search.
REPURPOSING OF LITHIUM-ION BATTERIES | Technology & Market Insights 18Technology Categories
Diagnostic 134
BMS 68
Grading & sorting 53
Non-invasive capacity restoration 11
Invasive repair method 9
BMS with diagnostic feature 8
ESS design 8
Diagnostic - service life prediction 4
BMS with cloud based data 4
Battery design that facilitates reuse 4
Battery storage 1
Key technologies from a total of 305 patent families are categorised based on the following definitions:
TECHNOLOGY CATEGORY DEFINITION
Battery cell/module design with reusable structure, or with means to reinject or
Battery design that facilitates reuse
replenishing the electrolyte
Battery storage Container for storage and transportation of lithium ion batteries
BMS for charge/discharge control and battery parameters monitoring during operation
BMS
in-vehicle or energy storage systems
BMS with cloud based data Cloud based battery management system for full lifecycle monitoring
BMS for in-vehicle / in-operation diagnostic of battery parameters (e.g. voltage, current,
temperature) and determination of remaining capacity with ultrasound, or estimation of
BMS with diagnostic feature
degree of degradation with equivalent circuit model benchmarking or through wireless
communication feature, so as to facilitate the replacement and reuse of end of life modules
Measurement of battery parameters (e.g. voltage, current, temperature, internal resistance,
Diagnostic state of charge state (SOC), state of health as well as degree of degradation through cycling
test, EIS, ultrasound or other emerging methods, during in-vehicle use or offline setting
Methods and mathematical models to estimate the remaining service life of lithium ion
Diagnostic – Service life prediction
battery
ESS design using second life lithium-ion batteries, or ESS design for
ESS design
grid-stabilisation applications
Screening and grouping into different categories based on a set of pre-defined criteria
Grading and sorting (e.g. SOC, calendar age) through physical inspection, historical data, SOC/OCV
measurement, self-discharge test, or cycling tests, so as to facilitate battery reuse
Capacity restoration by means of electrolyte removal and re-injection, perform lithium
Invasive repair method supplementation discharging from an external lithium rich electrode, removal of gases
generated within battery cell
Capacity restoration for lithium ion cells with ultrasound, x-ray, pressurised storage,
Non-invasive capacity restoration novel charging method or other emerging methods in a non-invasive manner
REPURPOSING OF LITHIUM-ION BATTERIES | Technology & Market Insights 19Emerging Technologies for
Battery Diagnostic, Grading & Sorting
EV battery makers, i.e. Toyota, LG Chem and Panasonic EV Energy filed
the most number of patents in battery diagnostic, but most of these
diagnostic methods are used in new battery manufacturing lines or
embedded as part of the BMS for in-vehicle battery diagnostic
Patent owners involved in used battery diagnostic are mainly start-ups,
A total of 165 in which the SOH/SOC of used batteries are rapidly measured based on:
patent families Dynamic internal resistance (Goiku Battery Co., Ltd)
are filed in the Coulometry measurement (Xilectric Inc)
area of battery Ultrasound (Feasible Inc)
diagnostic Electrochemical impedance spectroscopy (EIS) and
Transient response analysis (TRA) (MinTech Co., Ltd)
The EIS/TRA method has been commercialised by MinTech while
the dynamic internal resistance and ultrasound methods are near
commercialisation
Patent Families
Toyota 24
LG Chem 20
Panasonic EV Energy Co Ltd 6
Changsha Advanced Materials Ind Res 5
State Grid Henan Electric Power 3
State Grid Corporation of China 3
GS Yuasa 3
Goiku Battery Co Ltd 3
天津津泽新能源科技有限公司 2
Honda 2
Doshisha 2
Dukosi Litd 1
Feasible Inc 1
Xilectric Inc 1
Min Tech 1
REPURPOSING OF LITHIUM-ION BATTERIES | Technology & Market Insights 201 Instantaneous TRL 6 - 7 3 Battery Diagnostic TRL 6 - 7
SOH/SOC Detection with Ultrasound
Goiku Battery Co. Ltd (Start-up based in Japan, Feasible Inc (Spin-off from Princeton University based
founded in 2014) developed a device to perform the in US, founded in 2016) developed a battery inspection
deterioration diagnosis (SOH) of battery in 1 second device based on ultrasound, which measures acoustic
based on dynamic internal resistance, a parameter data (including time-of-flight displacement, total
calculated at the time of charge using measured signal amplitude, frequency distribution) of a battery
voltage and a given formula, and comparing with cell. The measured data is then transferred to a
the dynamic internal resistance of a new battery to machine learning model that calculates the SOH and
determine its SOH. The battery diagnostic device need SOC, based on an established acoustic data set and the
to be customised to the specifications of the batteries cell’s physical properties and its voltage, current and
to be analysed. temperature.
Goiku Battery collaborated with Mitsubishi Materials Their EchoStat software platform provides insights
Corporation to perform verification tests of their including SOC, SOH, construction quality, or remaining
deterioration diagnosis technology for in-vehicle service life of a cell. The system can handle common
lithium-ion battery. types of battery cells (pouch, prismatic and cylindrical),
regardless of size and chemistry. The technology can be
Goiku Battery also developed proprietary battery integrated as part of a cell-level production workflow,
management systems and battery chargers, which for in-use monitoring, or for assessment for second life
utilise “advanced interrupted charge & check” charging reuse.
methods, and periodic monitoring of the battery’s
electromotive force to enable rapid charging without Patent: CN111344894A Using acoustic signals to
overcharging the battery. determine the characteristics of electrochemical
systems (published 26 June 2020).
Patent: WO2020149288A1 SOH/SOC detecting device
for power storage element, and power storage element
managing unit (published 23 July 2020) 4 Characterisation of TRL 8 - 9
SOH/SOC with EIS/TRA
2 Characterisation of TRL 3 - 4 MinTech Co., Ltd (Start-up based in South Korea,
SOH/SOC with Coulometry founded in 2015) developed a battery diagnostic
system that estimates the SOC, SOH and state of power
Xilectric Inc (Start-up based in US, founded in 2012) (SOP, defined as ratio of peak power to nominal power,
developed a new coulometer device, used for precision i.e. the amount of power available for a defined time
measurement of charge during the charge or discharge interval given the current power usage, temperature
cycle to determine the SOC or SOH of cells, without the and other conditions) based on a combination of
need to perform a full depth of discharge cycling. The (a) open circuit voltage (OCV) measurement, (b)
device allows measuring of capacity loss rates of LIBs, electrochemical impedance spectroscopy (EIS) to
whereby the information can be used to develop better measure the AC impedance (0.1-1kHz) and (c) transient
BMS algorithms, improve cell design, and to select response analysis (TRA) to measure the DC resistance.
Li-ion formulations for a specific application.
MinTech also developed a high-voltage AC impedance
Xilectric received more than US$4.3mil funding analyser which can be used for on-line inspection
from US Department of Energy under the SBIR of batteries in EV (including fuel cell) or high voltage
programme to develop the new coulometry technique energy storage system (~1,000V). The analyser works
for LIB durability analysis, additives for improve by measuring the impedance, charge, and mass transfer
cell reliability, and a low cost rechargeable battery from the reacting current/voltage after applying an AC
chemistry. voltage/current that have various ranges of frequencies
to the working electrode.
Patent: US10705152 Systems and apparatus of cyclic
coulometry (granted 7 July 2020). Patent: KR101944751B1 Remaining life evaluation
method for reusing of battery (granted 28 Jan 2019).
REPURPOSING OF LITHIUM-ION BATTERIES | Technology & Market Insights 215 Rapid Test of Degraded Cells TRL 6 - 7 7 Fast Battery Grading TRL 8 - 9
at Module Level
RePurpose Energy (Spin-off from UC Davis, California,
led by Prof Jae Wan Park, raised a total of US$9 million Ametek is in collaboration with Warwick Mfg Group
to date) focused on reuse of batteries from EVs to store (WMG), Nissan and Element Energy. WMG’s Energy
solar energy. Work includes disassembling of used EV Innovation Centre developed a rapid workflow for
batteries (e.g. from Nissan, GM), SOH measurement, grading used automotive LIBs at pack level, which is
and then reassembling them with new controls and scaled to Nissan’s second-life facility in the UK.
safety equipment.
Ametek and WMG have co-developed a fast testing
RePurpose developed proprietary methods to test for method at module level using EIS, which applies a
cell degradation in under 90 seconds, including an current over a range of frequencies to determine
online SOC and SOH estimation algorithm as part of module’s SOH with proprietary algorithm from
BMS for LFP and NMC battery and a load-classifying WMG1,2. This reduces the grading time from 4 hours
neural network model for SOC estimation with 3.8% to 65% are deemed
sufficient for use in energy storage applications.
RePurpose is currently developing a non-destructive
fire suppression system that can detect an imminent Ametek has filed patent and commercialised the
battery failure and prevent the battery from battery analyser called the SI-9300R, which enables
overheating, without damaging any of the electrical fast grading at the cell level with EIS SOH algorithm
components. Refurbished battery with new BMS that developed for Nissan Leaf, in9 Life Extending TRL 6 - 7
Power Management
Warwick Manufacturing Group (WMG) and
Dr Truong from the Energy Management and Control
System group focuses on developing system level
control and energy management strategies, as well as
development of hardware and software for BMS, energy
management system (EMS), and thermal management
system (TMS). They also work on hardware-in-the-
loop testing and simulation, which includes functional
safety, characterisation and validation for energy
storage, smart grid and transportation applications.
WMG collaborated with Jaguar Land Rover and
Connected Energy for the design and commissioning
of a second life automotive system. The team
supported the design and integration of a BMS
and power management system to manage and
operate automotive batteries of varying voltages
and SOHs at the system level to prolong its
service life.
WMG’s engagement model is through contract
research funded by industry, and collaboration with
industry partners from UK to co-apply for funding e.g.
Eureka Globalstars-Singapore call.
Emerging Technologies for
Battery Rejuvenation & Regeneration
For all of the inventions, the regeneration is performed
A total of 11 patent families
at the cell level. The regeneration methods include
are filed in the area of
non-invasive battery rejuvenation Targeting radiant ray at dendrite growth areas or
and regeneration from disruption of solid electrolyte interphase (SEI) layer
2017 onwards with ultrasound
Cell pressurisation and storage at
elevated temperature
Developments of non-invasive capacity restoration Lithium supplementation through charging
technologies are still in the early stages (TRL 3-4). with lithium rich electrode
Patents are filed by EV battery makers, EV OEMs and Pulsed charging
start-ups.
LG Chem (KR), a large manufacturer of LIB cells /
modules / packs for EV applications. PATENT FAMILIES
Toyota (JP), an EV manufacturer. LG Chem 5
New market entrants such as Titan Advanced Toyota 3
Energy Solutions (US) and BRS Co. Ltd (JP).
Titan Advanced Energy Solutions Inc. 1
Farida Kasumzade, an adjunct instructor at the
University of St. Thomas, School of Engineering BRS Co., Ltd. 1
and founder of Max Consulting Firm Kasumzade Farida 1
REPURPOSING OF LITHIUM-ION BATTERIES | Technology & Market Insights 231 Rejuvenation of Lithium TRL 3 - 4 3 Rejuvenation of Cells through TRL 3 - 4
Cells with Radiant Ray Lithium Supplementation
LG Chem Battery cell capacity degradation is largely LG Chem The proposed method recovers the battery
caused by the increase in internal resistance due to capacity by completely discharging the negative
gas generation by side reactions, and formation of electrode to the discharge limit through an external
by-products in the form of plated lithium metal on lithium re-supply electrode (made of lithium metal)
the anode surface (dendrites) during charging of connected to the existing electrodes, without
the battery. The proposed method relates to non- disassembling the battery.
destructive regeneration of a lithium cell using high
capacity radiant rays for targeted removal of the plated The amount of lithium ion re-supply is regulated based
lithium metal to convert it to available lithium. on the battery’s degradation degree. The method
includes a step of applying a high current pulse of 1.0-
The steps include: 1) Inserting the battery cell into a 2.5 C during discharging to remove the solid electrolyte
magnetic resonance imaging device; 2) Measuring interface (SEI) layer formed on the cathode surface.
a location of a by-product formed in the battery cell In one example, the treated cells resistance is found
using the magnetic resonance imaging device; 3) to decrease by 23-40% across various SOC levels. The
Ionizing a material contained in the by-product by method is applicable to NMC, NCA cell types.
irradiating radiant rays by targeting the by-product
at the measured location (parallel to a surface of Patent: WO2019013536A1 Lithium secondary battery
anode) until the energy value that passed through the regeneration method (published 17 Jan 2019).
battery reaches the value of a new cell. A linear particle
accelerator with tungsten/lead collimator is used to
generate the radiant ray in the kV range, e.g. X-rays, 4 Regeneration of Lithium TRL 3 - 4
gamma rays, beta rays, visible rays, or infrared rays. The Cells with Applied Pressure
method is applicable to LCO, LMO and NMC cells.
Toyota The proposed method recovers the capacity
Patent: WO2019083183A1 Method for regenerating by applying pressure to a region where the spacer
battery cell (published 2 May 2019). was not in contact on the side surface of a cell, in
order to reduce the waviness of the electrode caused
by repeated charge and discharge and the increase in
2 Rejuvenation of Lithium Cells TRL 3 - 4 distance between the electrodes.
through Pressurised Storage
A flat pressing plate or a press board may be used
LG Chem The proposed method relates to storing to apply pressure. In one example, the treated cells
pressured EOL cells at elevated temperature condition, capacity retention was increased by 0.7-1.0% (relative
thereby forcing the gas present within the electrode to the initial SOC) with a pressure of 3.4-10kN for 1-30
assembly to move to the external portion of the mins.
electrode assembly, reducing the internal resistance
without damaging the EOL cell. Patent: JP2019114344A Method of recovering capacity
of secondary battery cell (published 11 Jul 2019).
The EOL cell is mounted on a pressurizing jig at 2,133-
3,555 psi and then left under a high temperature
chamber of 80-100°C for 20 minutes to 24 hours. In 5 Rejuvenation of Lithium TRL 3 - 4
one example, after storage at 85°C for 24 hours, it was Cells with Ultrasound
observed that the capacity retention rate is improved
from about 70% to 80% for an NMC cell that had Toyota Lithium-ion cell degrades due to decomposition
undergone 1000 cycles (0.5 C). A further 200 cycles of phosphate in the electrolytic solution containing
(0.5 C) usage sees the retention rate holding steady at LiPF6 during charging and discharging, and formation
about 76%. The method is applicable to pouch cells of the decomposition product (phosphorus atoms)
of LCO, LMO and NMC types. This techonology can on the cathode surface, which increases the battery’s
also be applied to a module unit with further design resistance.
customisation to the pressure jig.
The proposed method relates to applying an ultrasound
Patent: WO2019132403A1 Method for regenerating treatment to the lithium ion secondary battery
EOL cell (published 16 Apr 2020). immersed in water at >900 kHz for a continuous period
of >5 min, without disassembling the battery cell, to
REPURPOSING OF LITHIUM-ION BATTERIES | Technology & Market Insights 24You can also read
