Environmental Benefit Assessment of Second-Life Use of Electric Vehicle Lithium-Ion Batteries in Multiple Scenarios Considering Performance Degradation and Economic Value

Second-life use of electric vehicle lithium-ion batteries(LIBs)is an inevitable trend; however, battery performance degradation increasesenvironmental loads. This study evaluated the life cycle environmentalimpacts of second-life use of LIBs in multiple scenarios, consideringperformance degradation and economic value. The results showed thata component replacement rate of retired LIBs below 50% made the batteriesworthy of repurposing. Reusing whole packs of retired LIBs was betterthan using only cells or modules owing to the environmental loadsfrom diagnosis, disassembly, replacement, and test processes. Thebattery energy density and performance degradation significantly affectthe maximum return on the environmental input. Compared with lithiumiron phosphate (LFP) batteries, new lithium nickel manganese cobaltoxide (NMC) batteries, or lead-acid batteries, using retired NMC-811batteries with capacities as low as 60.7% for energy storage systemsto store wind electricity rather than hybrid or photovoltaic electricity,had substantial environmental benefits, including a low global warmingpotential. Considering the costs of battery recycling, labor, andelectricity, using whole packs of retired LIBs could simultaneouslyachieve high economic and environmental values in energy storage andpeak shaving scenarios. Thisstudy reports on achieving environmental benefits andavoiding environmental loads by using retired lithium-ion batteriesfor energy storage, considering performance degradation and theirrelated economic potential.

Automated summary

This study evaluates the life cycle environmental impacts of second-life use of lithium-ion batteries (LIBs) and finds that a component replacement rate of retired LIBs below 50% makes them worthy of repurposing. Reusing whole packs of retired LIBs is better than using only cells or modules due to the environmental loads from diagnosis, disassembly, replacement, and test processes. The battery energy density and performance degradation significantly affect the maximum return on the environmental input.