Rational Design and Synthesis of Nickel Niobium Oxide with High‐Rate Capability and Cycling Stability in a Wide Temperature Range

Abstract Conductive nickel niobium oxide (Ni₂Nb₃₄O₈₇) is rationally designed and synthesized as a safe anode material for lithium‐ion storage. Ni₂Nb₃₄O₈₇ exhibits high‐rate capability and cycling stability in the temperature range between ‐10 and 60 °C. At 25 °C, it delivers reversible specific capacities of 339 mAh g^‐1 at 0.1C with 98.1% capacity retention after 1000 cycles at 20C. At ‐10 °C, it displays a reversible capacity of 207 mAh g^‐1 at 0.1C with 64.0% capacity retention when the C‐rate increases from 0.5C to 2C and no capacity decay after 1000 cycles at 2C. At 60 °C, it exhibits a reversible capacity of 224 mAh g^‐1 at 0.1C with 65.3% capacity retention when the C‐rate increases from 0.5C to 10C and 78.7% capacity is maintained after 1000 cycles at 10C. In‐situ X‐ray diffraction measurements combined with Rietveld refinements reveal that the interlayer spacing of Ni₂Nb₃₄O₈₇ with a shear ReO₃‐type layered structure is relatively large, effectively facilitating lithium‐ion transport and storage with 6.71% unit‐cell‐volume expansion upon lithiation. This new anode material holds great promise for lithium‐ion batteries working in a wide temperature range.