The Operation Dependence of C ? N Fatigue for Lithium-Ion Batteries

摘要

Lithium-ion batteries (LIBs) fatigue in repeated service, and their cycle-life, inresemblance to most materials subject to cyclic loading, scatters over a broadrange. The dependence of critical fatigue parameters on ambient temperatureand charging or discharging rate, along with the scattering nature of cycle-lifeis of practical significance. Through large-scale experimental investigations, itis shown how both temperatures and charging-discharging rates mayinfluence critical parameters in the C ? N fatigue dependence for LIBs. Thecycle-life N of a battery subject to an average charging rate C follows C = c_0(T)N~(b(D)), where c0 varies with temperature T and b is a function of thedischarging rate D. It is further shown that the cycle-life of LIBs follows alognormal distribution. The revealed cycle-life distribution of LIBs and theirfatigue law enable the construction of a probabilistic C ? N model, which canbe used to quantify the fatigue failure probability in LIBs. Results reportedhere are of compelling importance for the life-span evaluation and safetydesign of large-scale battery packing in electric vehicles and energy storagewhere tens of hundreds of batteries working in concert is desired.