Highly Stabilized Ni-Rich Cathode Material with Mo Induced Epitaxially Grown Nanostructured Hybrid Surface for High-Performance Lithium-Ion Batteries.

Capacity fading induced by unstable surface chemical properties and intrinsic structural degradation is a critical challenge for the commercial utilization of Ni-rich cathodes. Here, a highly stabilized Ni-rich cathode with enhanced rate capability and cycling life is constructed by coating the molybdenum compound on the surface of LiNi0.815Co0.15Al0.035O2 secondary particles. The infused Mo ions in the boundaries not only induce the Li2MoO4 layer in the outermost but also form an epitaxially grown outer surface region with a NiO-like phase and an enriched content of Mo6+ on the bulk phase. The Li2MoO4 layer is expected to reduce residential lithium species and promote the Li+ transfer kinetics. The transition NiO-like phase, as a pillaring layer, could maintain the integrity of the crystal structure. With the suppressed electrolyte-cathode interfacial side reactions, structure degradation, and intergranular cracking, the modified cathode with 1% Mo exhibits a superior discharge capacity of 140 mAh g-1 at 10 C, a superior cycling performance with a capacity retention of 95.7% at 5 C after 250 cycles, and a high thermal stability.