Design of Rubik's cube-like hollow bimetallic sulfide nanocomposite for high-energy battery application

Sodium-ion battery has attracted considerable attention because of its enhanced safety and low cost. Herein, SnS2 and CuS2 were combined to produce an advanced bimetallic sulfide composite material by using a simple solvothermal method. The Rubik's cube-like hollow structure can significantly improve Na-ion energy storage characteristics of the anode electrode on an experimental level, and when SnS2 was incorporated into CuS2 electrode, the abovementioned cited restrictions provided additional active sites for electrochemical reaction, thereby improving the overall electrochemical activity. The electrochemical results indicated that the discharge specific capacity of the SnS2@CuS2 anode material reaches up to 730 mAh g−1 at a current density of 100 mA g−1. The discharge specific capacity of the SnS2@CuS2 electrode material remains at 692 mAh g−1 with a capacity retention rate of 92% after 100 cycles. In addition, theoretical calculation data can infer that the improved electrochemical performance attributes to the unique hollow structure of the Rubik's cube, thereby enhancing electron mobility and providing sufficient space for ion diffusion. Furthermore, the remarkable properties of CuS2 and SnS2 heterostructures provide the electrode material doughty charge storage progression. Thus, the proposed design can accelerate the practical application of other active metal sulfide composites in energy devices.