Nickel Niobate Anodes for High Rate Lithium-Ion Batteries

Fast charging is one of the key requirements for next-generation lithium-ion batteries, however, lithium-ion diffusion rates of typical electrode materials are limited. Nanosizing of active electrode material is a common strategy to increase the effective lithium-ion diffusion transport rate, but it also decreases the volumetric energy/power density and stability of the battery. In this work, nickel niobate NiNb₂O₆ is demonstrated for the first time as a new intrinsic high-rate anode material for lithium-ion batteries without the requirement of realizing nano-architectures. The NiNb₂O₆ host crystal structure exhibits only a single type of channel for lithium-ion intercalation and can be fully lithiated with a capacity of about 244 mAh g⁻¹ at low current densities. Interestingly, a high diffusion coefficient of 10⁻¹² cm² s⁻¹ at 300 K enables fast (dis)charging at high current densities resulting in high capacities of 140 and 50 mAh g⁻¹ for 10 and 100C respectively. The minimal volume change during lithiation is the origin of the stable reversible lithiation process in NiNb₂O₆ and leads to 81% capacity retention after 20 000 cycles at 100C. Finally, full cell systems against LiFePO₄ and Li[Ni_0.8Co_0.1Mn_0.1]O₂ (NCM811) cathodes demonstrate the promising energy storage performance of nickel niobate anodes in practical battery devices.