A microcrack propagation-based life prediction model for lithium-ion batteries with Ni-rich cathode materials

Abstract

The formation and growth of solid electrolyte interphase (SEI) on the anode are key parameters governing battery life prediction models of lithium-ion batteries (LiBs). However, as conventional battery life prediction models do not reflect other degradation parameters such as crack formation and propagation in Ni-rich cathode materials, their accuracy is greatly reduced as the nickel content increases in layered oxide cathode materials. Herein, we propose an advanced prediction model that includes both crack propagation and SEI growth. The reliability of this microcrack propagation-based life prediction model is verified using experimental data of over 50 commercial 18650 LiB cells, which are tested under depths of discharge and current rates, from 500 to 5000 cycles. The proposed model predicts capacity retention values with less than 5 % error, even in practical operations of energy storage systems and electric vehicles, providing a standard solution for predicting the cycle life of LiBs with Ni-rich cathode materials.