Blending Layered Cathode with Olivine: An Economic Strategy for Enhancing the Structural and Thermal Stability of 4.65 V LiCoO2.

The intrinsic poor structural and thermal stability of high‐voltage layered cathodes are aggravated as the charging depth increases, which severely threatens the cycle life and safety of the battery. Herein, without modifying the high‐voltage layered cathode itself, a simple and economic blending strategy is introduced, and an olivine‐LiCoO2 blended cathode featuring superior comprehensive performance (energy, power, cycle‐life, and safety) at 4.65 V is fabricated. The strong bonding affinity at the olivine/LiCoO2 contact interface suppresses lattice O2 release of LiCoO2, thus significantly improving the structural and thermal stability at high delithiation states. Meanwhile, by contacting with high‐electron‐conductivity LiCoO2, the redox activity of olivine is further activated. Therefore, a stable operation of both olivine‐LiCoO2 and olivine‐LiNi0.8Co0.1Mn0.1O2 blended cathode is achieved under harsh cycling conditions (high voltage or elevated temperature) and long‐life pouch‐cell (91.6% capacity retention after 1000 cycles) is harvested, demonstrating the feasibility and universality of this economic blending strategy on heterogenous cathode candidates. [ABSTRACT FROM AUTHOR]