Remanufacturing
& Testing
Work Stream 4
The ideal aim for any ReLiB recycling or upcycling process is to ‘close the loop’ through the remanufacture of EV batteries. To evaluate processes developed in WS2 and WS3 the project must take resynthesised, regenerated and upcycled materials, and benchmark them electrochemically in a representative cell format i.e. pouch (or cylindrical) cell. Working at scale enables a full picture of the performance of the remanufactured cell, and a comparison to first-life cells.
This work is critical to battery manufacturers accepting resynthesized, regenerated and upcycled materials into their manufacturing processes and in validating ReLiB’s work and will underpin higher TRL work carried out and funded through the ReLiB Technology Platform Implementation Plan.
Long term performance is of concern for all batteries, especially those manufactured from recycled material. The potential for accumulated contamination from use and the recovery process needs to be better understood. Defects may only become apparent after long term stability testing. If issues are identified, root causes needs to be understood, followed by developing WS3 processes to improve long term stability. This work builds on preliminary but much shorter term testing in previous phases and is distinct from, but potentially complementary to, work in the Degradation project.
Design for disassembly is a concept that needs to be trialled on prototype cells, focussing on green solvents and fluorine free binders that will facilitate short-loop recycling. Other design concepts like redesigned current collectors can be trialled to gauge impact. Remanufacture be undertaken and these cells can be evaluated in ReLiB’s recycling processes to test the gains made by improved design.
WP4.1
Evaluation of WS3 Processes
Scope
This work package will look to close the loop by testing remanufactured materials and electrodes based on materials produced in WS3. The aim is to provide benchmarking of performance and validation for remanufactured new cells from upcycling, short-loop and direct recycling processes. Benchmarking will also seek to understand any reasons for changes of performance (capacity, power etc.) in remanufactured cells.
What is Involved
To realise the benefits and value in closing the loop in the life cycle of battery materials, materials produced within the project must be tested in remanufactured cells. The University of Birmingham can produce, test and optimise the manufacture of batteries up to batch scale reel-to-reel coating for multi-electrode pouch cells.
Validation testing will establish the viability of different recycling processes, ensuring it is possible to remanufacture batteries from the process, enabling down-selection of any processes / protocols / chemicals not conducive to remanufacturing to concentrate on those processes that are viable.
Benchmarking cells is essential to the credibility of recycling and remanufacturing of EV batteries to meet the demands set by the manufacturers. This work will be complementary to that of the Faraday Institution’s CATMAT project, with key CoIs currently on both projects.
Objectives
- Validate the performance of full cells remanufactured using short loop, directly recycled and upcycled materials
- Benchmark performance of different recycling routes developed within the project
- Understand any differences in processing characteristics of recycled materials compared to first-use materials
Pathways to Impact
Production of cells from pilot plant scale reel-to-reel coater will be used to demonstrate processes developed are commercially viable.
WP4.2
Design for Disassembly
Scope
Building on knowledge gained from work undertaken in ReLiB, previous phases and in parallel short projects, this work package will explore ideas for design for disassembly, focusing initially on the use of sustainable binder technology that enables effective rebinding and facilitates the transition to short-loop recycling.
The work will look at packing strategies for electrodes such as concertinaed current collectors to enable simple and rapid cell dismantling to obtain single electrodes needed for ultrasonic delamination and upcycling. Changes in adhesives used within the pack and module will also be examined, seeking to understand the impact on disassembly from pack to cell.
What is Involved
The implementation and realization of design for recycling and minimizing the environmental impact of battery (re)manufacture requires concepts, components and ideas to be tested within cells containing recovered material from different recycling processes. The adoption of green solvents and non-fluorinated binders will form the initial component of this work. The ability to short-loop recycle active material is dependent on obtaining binder free active material particles that can be treated and relithiated; these active particles can be printed onto a current collector forming new electrodes.
This process will form slurries of differing viscosities and properties, potentially requiring different printing techniques.
Current pouch cells are constructed of a series of individual electrodes separated by a plastic separator. To recover individual electrodes a one by one approach is needed. This could be transformed by developing current collector assemblies that are attached. These could take the form of concertina or other shape, that has a single point of contact to remove all anode or cathode assemblies, significantly improving the cell dismantling step.
The design of packs and modules with adhesives will be examined, and soluble adhesives will be investigated. This seeks to aid the rate of disassembly from pack to cell, whilst critically maintaining the structural integrity of cell casings. It will be important to retain a uniform shape to the recovered electrodes, making delamination easier and more consistent, whilst minimising operator exposure to the electrolyte vapours released from opened cells and potential thermal runaway.
Cells produced using the concepts of design for recycling will undergo electrochemical cycling to mimic use, before being subjected to recycling and recovery processes to ascertain the impact of the implemented changes to the cell design. This work will, in conjunction with WP5.1, quantify benefits.
Objectives
- Develop deposition techniques utilizing green solvents with non-fluorinated binder systems that produce the tailored microstructures needed to manufacture high performance electrodes from recovered, recycled and upcycled material
- Undertake teardown and recovery processes to evaluate the effectiveness of different binder systems designed to aid recycling
- Implement, test and validate designs identified together with WS5 that challenge conventional norms and manufacturing processes to enable effective recycling of cells
- Support and be informed by LCA and TEA within the project to minimize the environmental impact of the battery lifecycle and provide an economic incentive through minimizing recovery/recycling costs
Pathways to Impact
Production of test electrodes for use in pouch cells will demonstrate that the approaches developed in the project are capable of being commercialized.
WP4.3
Long Term Performance of Recovered Materials
Scope
This task will provide long term metrology and electrochemical characterization of cells made from recovered materials.
What is Involved
Recycled material, especially from Recycling 2.x routes may contain impurities accumulated from use and the recycling processes employed. Understanding what impact these have on remanufactured cells will indicate if recycling methodologies can be used to produce batteries capable of operating in high performance applications (e.g. EVs) or must be used in lower performance applications. Supporting metrology will probe the impact of impurities within cells and how they appear in use. This work will guide the refinement of recycling processes, set purity requirements for recycled and upcycled materials and generate an understanding of the origins of impurities generated during use.
Objectives
- Understand if there is any loss in performance of cells remanufactured using short-loop, directly recycled and upcycled materials to investigate the impact of impurities not removed or introduced during recycling processes
- Use a variety of metrology and characterization techniques to understand any underlying reasons for changes during long term use
Pathways to Impact
Production of cells from pilot plant scale reel-to-reel coater will be used to show that processes developed in the project are commercially viable.