Lifetime evaluation of lithium-ion batteries under pulsed charging currents

The lifetime represents a major bottleneck in the widespread use of lithium-ion batteries. Pulse current charging strategy is widely considered as it can improve the charging performance of lithium-ion batteries and maximize their lifetime. However, the optimum parameters for pulse current charging to achieve the best charging performance remains to be studied. This paper, taking the positive pulse current mode as an example, comprehensively analyzes the effect of the charging current frequency and the duty cycle on two lifetime-related parameters, i.e., the capacity fade and internal resistance. Long-term aging experiments are conducted on NMC batteries, and the results demonstrate that all pulse charging strategies with different parameters helps to delay the battery degradation to varying degrees. The analysis results can hopefully provide suggestions for optimizing the charging strategy, thereby prolonging the batteries' lifetime.