Study on low-temperature cycle failure mechanism of a ternary lithium ion battery.

This study is focused on the changes in parameters such as discharge capacity, and the possible failure mechanism of a 25 Ah ternary lithium ion battery during cycling at -10 °C. A new battery and a battery after 500 cycles were disassembled. The morphology and structure of the cathode and anode electrodes were characterized. Transmission electron microscopy (TEM) and X-ray photoelectron absorption spectroscopy (XPS) were used to analyze the changes in the microstructure and chemical environment of the anode electrode interface. The results show that after 500 cycles at -10 °C, the capacity of the battery is only 18.3 Ah, and there is a large irreversible capacity loss. The battery samples after low-temperature cycling produced gas during storage at 25 °C. It is found that a large amount of lithium plating on the anode surface is an important factor for the reduction in battery capacity. The dissolution of transition metal elements in the cathode electrode and deposition on the anode electrode, and the catalytic decomposition of electrolyte at the anode interface are the main reasons for the gassing of the battery.