Ni-rich LiNixCoyM1-x-yO2 (NCM; M=Mn, Al) cathode materials for lithium-ion batteries: Challenges, mitigation strategies, and perspectives

Ni-rich LiNixCoyM1-x-yO2 (NCM; M = Mn, Al) cathodes have attracted much attention owing to their ability to provide high specific capacity of > 200 mAh g−1, high working potential (∼3.8 V vs. Li/Li+), and low cost, hence they are considered as preferred candidates for electric vehicle applications. Nevertheless, the commercialization of Ni-rich NCM cathodes is limited due to challenges of surface instability, structural mechanical failure and deteriorated thermal instability leading to cycling capacity fading. Cation mixing, gas release, residual of lithium, and dissolution of transition metals will also affect the electrochemical performance of Ni-rich cathodes which need to be addressed. The mitigation strategies to solve these challenges are doping to suppress the structural degradation and surface coating to improve interface stability. Herein, we present the recent comprehensive research works on Ni-rich cathodes for LIB, regarding challenges, mitigating strategies, and future perspectives to improve their electrochemical performance.