The structure of Work Stream 1 (WS1), Gateway Testing and Dismantling, within the ReLiB project models the actual processes which will be required for a recycling facility to safely and efficiently receive, assess and process vehicle batteries for reuse or recycling at significant scale. Batteries arriving at a facility will, for the most part, have unknown providence, be of varied age and condition and will likely come from a number of different manufactures or models.
The first task is to assess the condition of the pack particularly looking for any defects which may mean the safety of downstream processing is jeopardised. At this stage, it is essential to understand whether the pack itself could be reused in either a primary or secondary application. WS1 is exploring the merits of various methods of either communicating with the on-board pack analysis tools (via the BMS for example) or making direct measurements of the battery performance. Where a pack can be “saved” and made available for re-use before it is processed it will remove the costs of any further processing.
Little is known about the performance of second life EVs in off highway applications, a key part of WS1 is to gain a better understanding of where the operational limits of these batteries are within the scope of providing energy storage to non-automotive loads. The variations in these load profiles will greatly affect the degradation of the energy storage asset and will change how and when an operator might chose to run it.
Where packs cannot, either in their entirety or in part, be reused as full packs then they must be disassembled to groups of modules or cells. However, the state of charge of packs which arrive at sorting/recycling facilities will be widely variable and it is required, particularly for most proposed recycling purposes to discharge the pack to a safe level. We are exploring the capability of fast-dischargers in order to recapture this energy as assessing the technoeconomic impact of such an activity to evaluate both the environmental and commercial benefits of recouping this energy.
When considering dismantling of the pack, it is understood that presently, manual dismantling is an onerous and potentially hazardous activity and can take many hours. Although workshops and even the manufacturing facilities do have some robotically assisted processes, the actual pack disassembly is largely a manual process. WS1 is exploring the use of artificial intelligence and robotic manipulation, not simply to dismantle packs as if they were somehow a reverse of the manufacturing process but to include the sensory capability and intelligence as part of the robotic system to recognise parts and fixings from packs which they may never have seen before and manipulate these in the way that a human operator would. The goal is not designing robotics to disassembly a battery pack, it’s to design them to disassemble any battery pack.
There will be some instances where only some parts of a pack are not suitable for reuse and therefore other parts may be reclaimed and put to use. In order to do this condition assessments of individual cells and modules will be required. Accurate and fast assessment methods will be required to understand the condition of these cells and must be performed and data processed, automatically with no human interface. WS1 will be integrating advanced measurement and sensor technologies within the robotic manipulation hardware. Cells will be graded with feedback from the re-use as well as the materials characterisation activities in order to recommend them for re-use or to warn the downstream materials processes that a battery may be dangerous to operate.
Finally, there is an overarching safety theme to WS1. Every aspect of the work stream has a safety element and the WS1 team are engaging with industrial, other academic and even emergency response partners in order to develop industry wide standards and good practice where the input from the project has been extremely warmly received.