BOX 1 Key terms –State of health (SOH): A measure of a battery’s capacity, expressed as a percentage of the battery’s original capacity. –Battery management system (BMS): An electronic system that monitors the operating state of modules and cells in a battery pack; calculates and reports performance data; and manages the performance of individual cells and modules. –Experimental SOH diagnostics: A method of evaluating a battery’s SOH by directly testing it. –Model-based SOH diagnostics: A method of evaluating a battery’s SOH by monitoring physical parameters such as the current, voltage, temperature, number of cycles and charge/discharge behaviour of cells, modules and the battery pack over time, and then using these parameters to predict not only current SOH but also the battery’s degradation rate and remaining useful life. Source: Mobility Open Blockchain Initiative21Battery design that prioritizes first-life performance, combined with limited access to battery management system data, hinders repair, second life and recycling. Recycling, reusing and repurposing EOL batteries have significant environmental benefits. Extending the lifespan of LIBs through reuse and repurposing increases the resource efficiency and reduces the need to produce new batteries, reducing the environmental and social impacts associated with battery production and EOL management. Second- life batteries can also fulfil numerous roles in energy and mobility applications, as outlined on the following page, providing enormous potential benefit to markets around the world. When the battery reaches end of second life, recovering the battery minerals and using the recycled content in new batteries can potentially reduce the carbon footprint of battery manufacturing by 20-30%.16 Batteries have traditionally been designed to maximize performance (durability, vehicle range, battery safety and battery lifespan) during their first life, while minimizing cost. These design choices influence everything from selection of battery chemistry to battery weight to form factors,17 and necessitate trade-offs between how the battery performs in its first life and how the battery lends itself to repairability, second-life use and recyclability. A battery cell is the basic building block for EVBs; these cells are combined into modules, which are then assembled into battery packs, which are fitted into EVs. The materials, form factor and assembly technique chosen determine performance, weight, safety and ease of repair, recycling and second life. For example, permanent bonding techniques like irreversible adhesives and welding provide batteries more structural integrity and make them more compact, but also make their disassembly difficult. This poses a challenge for repair and second life and can potentially lead to premature recycling, as recycling via shredding may be the only feasible option at the end of first life if the battery cannot be disassembled.18 The diversity of battery designs also impacts management at end of first life. Automation could be helpful in avoiding the inherent safety risks of disassembly and saving time – but it is made more challenging because there is little battery standardization.19 Additionally, the range of battery designs makes screening, safety evaluation and certification of EVBs for second life challenging and increases the cost of transport and warranties for second life. Given that this is a nascent field, there is a lack of standardized tests, performance standards and statistical information that can provide end customers the confidence to support second- life products. For example, accessing data about a battery’s health and usage in first life can help evaluate viability of second life; but concerns about data privacy and liability often prevent sharing of this data via the battery management system (BMS). The design issues described above, paired with limited or no access to original BMS data, can lead to significant remanufacturing efforts and costs. Finally, in addition to design choices, battery labelling – or the lack thereof – impacts second life and EOL management. The lack of clear labelling indicating key battery components and substructures, and limited or non-existent access to information about the battery’s SOH hinder the safe and effective handling of retired batteries. While safety and performance during first life are critical priorities, batteries must also be designed (and labelled) with consideration for repair, second life, and eventually, recycling. This will help extend battery life and avoid premature recycling, improper disposal and unsafe handling.20 2.2 Battery design and data access Powering the Future: Overcoming Battery Supply Chain Challenges with Circularity 12

Powering the Future 2025