Economic potential assessment of multi-cell testing in lithium-ion cell production and electric vehicle application

Abstract

Lithium-ion cells for electric vehicles are evaluated for their performance at different stages of their life cycle, with the initial characterization in cell production as part of an end-of-line test being the most crucial due to the quality classification and scope. This paper presents an economic potential analysis of a novel multi-cell testing method for the use in sustainable and smart cell quality testing which economizes on the number of test channels required. Using a cost comparison and net present value method assessed for two feasible deployment scenarios, it is shown that the cost parity point compared to conventional single-cell procedures can be reached with only four series-connected cells. Overall, both multi-cell scenarios yield a cost reduction of ∼42 % per tested cell. The percentage shares of the cost categories redistribute moderately when switching from single-cell to multi-cell testing in a smart factory, with procurement costs of the battery cyclers with up to 43 % of the total costs representing the most significant share. Additional benefits can be expected with the method assuming maintenance schedules on a per-device basis. At 5% to 31 % of the costs, the energy expenses represent a significant lever for the profitability of the characterization and the thus economically viable scope of cell characteristics examined. Prospects are given for multi-cell testing in later life cycle phases, considering the re-evaluation of battery performance in operation during service checks and the remanufacturing at the original equipment manufacturers or service providers in 2nd life applications.