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 increases
environmental loads. This study evaluated the life cycle environmental
impacts of second-life use of LIBs in multiple scenarios, considering
performance degradation and economic value. The results showed that
a component replacement rate of retired LIBs below 50% made the batteries
worthy of repurposing. Reusing whole packs of retired LIBs was better
than using only cells or modules owing 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. Compared with lithium
iron phosphate (LFP) batteries, new lithium nickel manganese cobalt
oxide (NMC) batteries, or lead-acid batteries, using retired NMC-811
batteries with capacities as low as 60.7% for energy storage systems
to store wind electricity rather than hybrid or photovoltaic electricity,
had substantial environmental benefits, including a low global warming
potential. Considering the costs of battery recycling, labor, and
electricity, using whole packs of retired LIBs could simultaneously
achieve high economic and environmental values in energy storage and
peak shaving scenarios.