Heat Generation Power of the LiNi_0.8Co_0.1Mn_0.1O₂ Cathode at Higher Charging Cutoff Voltages

Lithium-ion batteries using the LiNi0.8Co0.1Mn0.1O2 (NCM811) cathodeusually exhibitahigh energy density, but structure fading and heat accumulation occurringduring charge/discharge are their drawbacks. Herein, the heat generationpower of the NCM811 cathode at relatively higher charging cutoff voltagesand elevated temperatures is studied systematically. Specifically,the heat generation powers of NCM811 after various charge/dischargecycles under charging cutoff voltages of 4.3, 4.5, and 4.8 V at 50 & DEG;C are measured. First-principles calculation results combinedwith experimental measurements show that more structural variationcan be generated at higher charging cutoff voltages, such as vacanciesof oxygen, lithium, and transition metal ions, as well as cation mixingof Li+/Ni2+, all of which can increase the energybarrier for Li+ diffusion and instantly enhance the heatgeneration power of the NCM811 cathode.