Regulating adsorption ability toward polysulfides in a porous carbon/Cu3P hybrid for an ultrastable high-temperature lithium-sulfur battery

Lithium-sulfur batteries (LSBs) can work at high temperatures, but they suffer from poor cycle life stability due to the "shuttle effect" of polysulfides. In this study, pollen-derived porous carbon/cuprous phosphide (PC/Cu3P) hybrids were rationally synthesized using a one-step carbonization method using pollen as the source material, acting as the sulfur host for LSBs. In the hybrid, polar Cu3P can markedly inhibit the "shuttle effect" by regulating the adsorption ability toward polysulfides, as confirmed by theoretical calculations and experimental tests. As an example, the camellia pollen porous carbon (CPC)/Cu3P/S electrode shows a high capacity of 1205.6 mAh g(-1) at 0.1 C, an ultralow capacity decay rate of 0.038% per cycle after 1000 cycles at 1 C, and a rather high initial Coulombic efficiency of 98.5%. The CPC/Cu3P LSBs can work well at high temperatures, having a high capacity of 545.9 mAh g(-1) at 1 C even at 150 degrees C. The strategy of the PC/Cu3P hybrid proposed in this study is expected to be an ideal cathode for ultrastable high-temperature LSBs. We believe that this strategy is universal and worthy of in-depth development for the next generation energy storage devices.