Lithium Cathode Surface Area Control for Crack Prevention

The patent changes the physical and chemical parameters of the cathode active material by controlling the BET specific surface area (1.5-2.6 m2/g after 300 cycles) and pore volume (0.01-0.018 cm3/g after 300 cycles) of the lithium-transition metal composite oxide particles. These parameter controls prevent particle cracking during pressing while maintaining high capacity, resolving the contradiction between battery capacity and chemical stability.

The patent optimizes the pore volume parameter of the cathode active material to 0.01-0.018 cm3/g after 300 cycles, which provides sufficient space to accommodate volume changes during charge-discharge cycles without causing particle cracking. This parameter control maintains both high battery capacity and extended lifespan by preventing structural degradation.

The patent precisely controls the BET specific surface area parameter within the range of 1.5-2.6 m2/g after 300 cycles. This optimized parameter range provides a balance: it is low enough to prevent particle cracking and maintain chemical stability, yet high enough to ensure sufficient electrolyte impregnation for maintaining high battery capacity.

The patent optimizes the pore volume parameter to 0.01-0.018 cm3/g after 300 cycles, which provides sufficient pore space for electrolyte impregnation and ion transport while maintaining structural integrity of the particles. This prevents particle cracking and maintains both high battery capacity and chemical stability simultaneously.