Functional Passivation Interface of LiNi0.8Co0.1Mn0.1O2 toward Superior Lithium Storage

The fast capacity/voltage fading with a low rate capability has challenged the commercialization of layer-structured Ni-rich cathodes in lithium-ion batteries. In this study, an ultrathin and stable interface of LiNi0.8Mn0.1Co0.1O2 (NCM) is designed via a passivation strategy, dramatically enhancing the capacity retention and operating voltage stability of cathode at a high cut-off voltage of 4.5 V. The rebuilt interface as a stable path for Li+ transport, would strengthen the cathode-electrolyte interface stability, and restrain the detrimental factors for cathode-electrolyte interfacial reactions, intergranular cracking and irreversible phase transformation from layered to spinel, even salt-rock phase. The as-optimized NCM displays a higher cyclability (i.e., 206.6 mA h g(-1) at 0.25 C (50 mA g(-1)) with 92.0% capacity retention over 100 cycles) and a better rate capability (141.0 and 112.6 mA h g(-1) at 12.5 and 25 C, respectively) than pristine NCM (205.0 mA h g(-1) with 73.0% capacity retention at 0.25 C; 120.9 and 93.1 mA h g(-1) at 12.5 and 25 C, respectively).

Automated summary

By designing an ultrathin and stable interface, the capacity retention and operating voltage stability of the cathode at a high cut-off voltage are significantly enhanced, while detrimental factors are restrained, leading to improved cyclability and rate capability of the battery.