Boosting the cycling and storage performance of lithium nickel manganese cobalt oxide-based high-rate batteries through cathode manipulation.

• A complexing strategy of polycrystalline and single crystal NCM was proposed to optimize the comprehensive performances of high-rate Li-ion batteries. • The capacity fading of polycrystalline NCM was demonstrated mainly due to the structural collapse and severe electrode/electrolyte interface parasitic reactions. • The capacity fading of single crystal NCM mainly arose from the sever heat accumulation and the accelerated parasitic reactions with electrolyte under high temperature. • Excellent high-temperature storage and cycling stability of prototype high-rate Li-ion batteries were achieved through dedicate manipulation of the cathode materials. Lithium Nickel Manganese Cobalt Oxide (NCM) is extensively employed as promising cathode material due to its high-power rating and energy density. However, there is a long-standing vacillation between conventional polycrystalline and single-crystal cathodes due to their differential performances in high-rate capability and cycling stability. Herein, a complexing strategy is proposed based on the investigation of capacity fading mechanism of both polycrystalline and single crystal NCM. A series of mixed cathodes containing both types of NCM particles with different mass ratio have been compared. The optimized NCM-37 cathode realized a balance between high-rate performances, high-temperature storage, and stable cycling. Specifically, the NCM-37 sustains a capacity retention of 98.4% after 300 cycles under 1 C charge/30 C discharge. Moreover, after storage at 60°C for 7 days, the capacity retention and recovery ratio are 91.73% and 95.02%, respectively. This work demonstrates an efficient approach to improve the comprehensive performances of prototype lithium-ion batteries by cathode manipulation, which can fully utilize the advantages and suppress the disadvantages of conventional polycrystalline and single crystal NCM particles. [Display omitted] [ABSTRACT FROM AUTHOR]