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 (Ni 2 Nb 34 O 87 ) is rationally designed and synthesized as a safe anode material for lithium‐ion storage. Ni 2 Nb 34 O 87 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 Ni 2 Nb 34 O 87 with a shear ReO 3 ‐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.