Feasibility Assessment of Differential Voltage Analysis to Detect Lithium Plating in Battery Modules for Electric Vehicles

Fast charging of Lithium-ion battery modules can lead to accelerated ageing caused by Lithium plating. The open-circuit voltage profile during post-charge relaxation has been utilized used to detect the onset of Li plating, while devising fast charging strategies. Yet the scope of this method is predominantly evaluated and utilized only for cells in open circuit. Cells in a module are not ideally in open circuit, and there exist balancing currents within the module after charging. The extension of this method to battery modules, with cells connected in parallel is presented in this article. The experiments conducted on individual cells and module, the results obtained, and analysis is presented in detail. The effectiveness of differential voltage profile or relaxation profile analysis for identifying Li plating and stripping characteristics for cells in parallel are highlighted.