Copper, zinc, and manganese niobates (CuNb2O6, ZnNb2O6, and MnNb2O6): structural characteristics, Li(+)storage properties, and working mechanisms

Abstract

Niobium-based oxides are considered promising anode materials for Li-ion batteries due to their high capacities, good cyclability, and excellent safety. Here, CuNb2O6, ZnNb2O6, and MnNb(2)O(6)niobate nanoparticles were prepared using a solvothermal method followed by heat treatment, and their electrochemical properties as anode materials for Li-ion batteries were explored. These CuNb2O6, ZnNb2O6, and MnNb(2)O(6)nanoparticles have BET surface areas of 3.17-11.53 m(2)g(-1). As anode materials, these nanoparticles display high reversible capacities of 256, 309, and 352 mA h g(-1), respectively, at C/10; in particular, the excellent capacity retention rates of the CuNb(2)O(6)nanoparticle sample at 5C and 10C are 158 and 131 mA h g(-1), respectively. After the first cycle, the Li-ion diffusion coefficients lie between similar to 1.6 x 10(-7)and similar to 2.1 x 10(-10)cm(2)s(-1), which effectively promotes Li-ion uptake.Ex situX-ray diffractometry provides insight into the insertion reaction by monitoring the changes in the crystal structures of the niobate samples during charge-discharge processes. We demonstrate that these niobate nanoparticle samples are possible alternative anode materials for use in rechargeable batteries.