Nickel-decorated TiO2 nanotube arrays as a self-supporting cathode for lithium-sulfur batteries

Lithium-sulfur batteries are considered to be one of the strong competitors to replace lithium-ion batteries due to their large energy density. However, the dissolution of discharge intermediate products to the electrolyte, the volume change and poor electric conductivity of sulfur greatly limit their further commercialization. Herein, we proposed a self-supporting cathode of nickel-decorated TiO2 nanotube arrays (TiO2 NTs@Ni) prepared by an anodization and electrodeposition method. The TiO2 NTs with large specific surface area provide abundant reaction space and fast transmission channels for ions and electrons. Moreover, the introduction of nickel can enhance the electric conductivity and the polysulfide adsorption ability of the cathode. As a result, the TiO2 NTs@Ni-S electrode exhibits significant improvement in cycling and rate performance over TiO2 NTs, and the discharge capacity of the cathode maintains 719 mA·h·g−1 after 100 cycles at 0.1 C.