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

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 degrees C. At 25 degrees 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 degrees 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 degrees 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.