Toward high capacity and stable SnO2 hollow nanosphere electrode materials: A case study of Ni-substituted modification

To develop the urgent requirement for high-rate electrodes in next-generation lithium-ion batteries, SnO2-based negative materials have been spotlighted as potential alternatives. However, the intrinsic problems, such as conspicuous volume variation and unremarkable conductivity, make the rate capability behave badly at a high-current density. Here, to solve these issues, this work demonstrate a new and facile strategy for synergistically enhancing their cyclic stability by combining the advantages of Ni doping and the fabrication of hollow nanosphere. Specifically, the incorporation of Ni2+ ions into the tetragonal rutile-type SnO2 shells improves the charge transfer kinetics effectively, leading to an excellent cycling stability. In addition, the growth of surface grains on the hollow nanospheres are restrained after Ni doping, which also reduces the unexpected polarization of negative electrodes. As a result, the as-prepared Ni doped electrode delivers a remarkable reversible capacity of 712 mAh g-1 at 0.1 A g-1 and exhibits outstanding capacity of 340 mAh g-1 at 1.6 A g-1, about 2.58 times higher than that of the pure SnO2 hollow sample.