Researchers from China's Bohai University, Harbin Institute of Technology, Yanshan University and Xi’an Jiaotong University have developed a composite catalytic material based on CsPbBr3 halide perovskite quantum dots for use as the sulfur host for lithium-sulfur batteries (LSBs), which are seen as promising energy storage devices that face some challenges like low conductivity of the sulfur cathode and shuttle effect of polysulfides.
The team explained that CsPbBr3 perovskite quantum dots, as nanoscale perovskite materials, combine the inherent excellent charge transport properties and structural stability of perovskite with the unique size and surface effects of quantum dots.
The special octahedral framework structure chosen by the team reportedly results in a large number of unsaturated coordination sites on the surface, creating abundant active centers which is beneficial for enhancing the catalytic activity of the material.
Moreover, the small size of CsPbBr3 QDs effectively mitigates the significant polarization issues caused by larger grain sizes in traditional perovskite materials so as to exhibit excellent interactions with lithium polysulfides (LiPSs). Then, they can significantly reduce the activation energy of LiPSs decomposition reactions in order to accelerate the conversion reaction rate of LiPSs.
Therefore, the PTI-CsPbBr3/S composite cathode at a ratio to 30:1 exhibits excellent LiPSs adsorption and catalytic properties for high-performance lithium-sulfur batteries. Even at a high sulfur loading (6 mg·cm−2) and a current density of 0.5C, it still remains stable for 500 cycles with a capacity attenuation rate of only 0.15 % for a single cycle.
This novel approach offers a new perspective for developing more stable and efficient lithium-sulfur batteries using perovskite materials.
