BATTERIES SAFETY, RECYCLING AND SECOND LIFE
The goal of this WP is to investigate into safety and resource efficiency of batteries in their whole battery life cycle. Therefore, the design and status of the battery is essential for further life cycle phases: transport, second life and recycling. The eMPROVE demonstrator should be basis for the developments and initiate new concepts.
The overall goal of this WP is to identify further relevant safety challenges of batteries and resulting design suggestions throughout their life cycle (from cradle to grave).
1. DESIGN A RECYCABLE AND ENVIROMENTAL FRIENDLY BATTERY SYSTEM
- Requirements: Elaboration on design rules aiming at recyclability and eco-friendly realisation of the battery pack and assessment of this rules
- Development: Scientific support in the design and development phase of the new modularized battery pack, virtual disassembly of the battery system
- Evaluation: Review of the implementation of design rules, evaluation which rules should be changed to implement, rules fulfilled and rules not possible to integrate (reason given).
2. ENABLE SECOND LIFE OF BATTERIES
- Requirements: Define second life enablers in design process (design rules) as well as discuss safety issues and cell status regarding to second life
- Development: Development of a cell status detection device and investigation on future battery design
- Evaluation: Minimize safety risks throughout the battery life
3. DEVELOP SAVE MECHANICAL RECYCLING PROCESS
- Requirements: Identify mechanical process options for battery recycling
- Development: Develop a pure mechanical recycling concept for energy storage systems based on lithium ion batteries, further treatment of output fractions
- Evaluation: Minimize safety risks throughout the battery life and reduce costs at recycling level
MAIN TARGETS & RESULTS
- Recycling process: Increase of energy efficiency of overall recycling process due to pure mechanical recycling step up to 20% + Cost reduction by 5% via re-design and re-design and increased output fraction quality (secondary materials)
- Development of design rules regarding future recycling concepts to include recycling already during the development process (à mass producibility)
- Extension of battery safety life cycle to logistics, second life, decommissioning and recycling, indicating potential influence factors on early battery design and risk mitigation measures (instructions)
- Logistics concept for batteries
- Virtual disassembly of existing and new developed systems
- Assessment of materials for second life handling and establishment of instructions for design compartments for future batteries suited for second life
Current Highlights of WP4
WP 4 takes a look at the whole battery life cycling and focuses four main topics:
- 1. Eco-Design,
- 2. Functional Safety and Second Life,
- 3. Recycling.
- Eco Design:
The design of a battery pack was observed from a life cycle perspective. Different technical workshops helped understanding the system structure and change major functionalities as well as materials. The main results of the workshops are an optimized structure to reduce the HV while disassembly and repair, screws are the main joining technology (instead of glue and other technologies, which force destructive disassembly), the module format is chosen to ease recycling and re-use. Two other points are highlighted: the same material characteristics are used to separate the different parts easily as well as the marking of materials (cell chemistry etc.) on system, and module level is identified as necessary.
- Functional Safety and Second Life:
Based on the HARA (hazard assessment and risk analysis) the requirements of a first life battery are identified. Therefore the ISO 26262 and other normative and legal requirements were collected and examined if they influence the functional safety. To assure a holistic safety concept the safety issues for automotive and stationary use as well as transport, storage and charging are demonstrated and validated. The results of the HARA of a first life battery are shown in the 6 requirements shown in the following table and will be compared to the results of a second life battery (IEC norm).
Figure 3: Main requirements of a first life battery identified by HARA according to ISO 26262
Based on the planed recycling concept, different experiments on laboratory and pilot scale were performed. The results help to dimension the aggregates for an industrial plant and optimize the process steps as well as the output fractions. A discharging station was established that will feed in the discharging energy in the internal energy net. Compared to the previous activities (discharging with a light bulb), the new approach will save energy and tries to reduce the discharging time. Concerning the output fractions the active materials fraction is optimized for industrial use by separation. Different cells were opened and chemically analyzed; these cells will be the basis for pilot scale tests in the second year. Due to the different pre-recycling steps, a comparison of LIBRES material and eMPROVE material is done. Different separation possibilities were evaluated and two of them were chosen for further experiments. The experiments with active materials show a potential to optimize the output on laboratory scale. An investigation on aggregates for a pilot/industrial plant was done to identify the important parameters. The activities will now lead to the build-up of a new recycling plant at our project partner REDUX as base for the development of an more energy- and cost efficient recycling process.