Scalable synthesis of NiMoO4 microspheres with numerous empty nanovoids as an advanced anode material for Li-ion batteries

Abstract

Closely in line with advances in next-generation energy storage materials, anode materials for lithium-ion batteries (LIBs) with high capacity and long cycle life have been widely explored. As part of the current effort, nickel molybdate (NiMoO4) microspheres with empty nanovoids are synthesized via spray drying process and subsequent one-step calcination in air. Dextrin in the atomized droplet is phase segregated during the spray drying process and calcined in air atmosphere, resulting in numerous empty nanovoids well-distributed within a microsphere. The empty nanovoids alleviate volume expansion during cycling, shorten lithium-ion diffusion length, and facilitate contact between electrode and electrolyte materials. Along with the high discharge capacity of NiMoO4 material, as high as 1240 mA h g−1 for the 2nd cycle at a high current density of 1 A g−1, uniquity of the structure enables longer cycle life and higher quality performances. The discharge capacity corresponding to the 500th cycle is 1020 mA h g−1 and the capacity retention calculated from the 2nd cycle is 82%. In addition, a discharge capacity of 413 mA g−1 is obtained at an extremely high current density of 10 A g−1.