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

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.

Automated summary

The accuracy of conventional battery life prediction models for lithium-ion batteries (LiBs) with Ni-rich cathode materials is greatly reduced as the nickel content increases due to the neglect of degradation parameters such as crack formation and propagation. In this study, an advanced prediction model that includes both crack propagation and solid electrolyte interphase (SEI) growth is proposed and verified using experimental data of over 50 commercial 18650 LiB cells. The proposed model predicts capacity retention values with less than 5% error, providing a standard solution for predicting the cycle life of LiBs with Ni-rich cathode materials even in practical operations.