The diffusion polarization model of lithium-ion battery relaxation effect

Lithium-ion battery capacity fades with the cycle number increment, and regenerates after a relaxation period. This phenomenon is called the relaxation effect of lithium-ion batteries. Studies have confirmed the relaxation effect is a key element within the remaining useful life prediction. However, due to the lack of related mechanism analysis for the relaxation effect, it´s hard to deduce a convincing model. This paper tries to deduce a diffusion polarization model to describe relaxation effect by mechanism analysis. Subsequently, the model parameters are estimated and the simulation experiment is conducted to verify the model. The result is found to be satisfactory to quantify regeneration capacity and reflect the attenuation of relaxation effect.