Hollow CoP nanoparticles embedded in Two–Dimensional N–doped carbon arrays enabling advanced Li–SeS₂ batteries with rapid kinetics

Selenium sulfide has been regarded as very promising alternatives to partially address the issues of Li–S batteries due to their better electrical conductivity than sulfur cathode; however, the serious dissolution of intermediate polyselenides and polysulfides still brings about the fast capacity decay and low coulombic efficiency in Li–SeS₂ batteries. Here, a flexible electrode composing of hollow CoP nanoparticles embedded in two–dimensional nitrogen doped carbon arrays supported on carbon cloth were employed as SeS₂ immobilizers for the first time. The integrated host not only provides a high adsorption ability for lithium polysulfides/polyselenides (LiPSs/LiPSes) through the unique physical confinement and strong chemical immobilization, but also facilitate the fast diffusion of LiPSs and LiPSes on the surface of CoP catalyst. It was demonstrated through the microstructural, chemical, and electrochemical characterization, CoP catalyst can greatly promote the nucleation of LiPSs and LiPSes, and fast convert into insoluble products. DFT calculations and ex–situ XPS measurements can interpret the fundamental mechanism for the fast polysulfide/polyselenide conversion. Therefore, our elaborate designed architecture and surface chemistry of CoP–N/C@CC with a high SeS₂ loading of 2.6 mg cm⁻² exhibit a large specific discharge capacity of 1026 mAh g⁻¹ at 0.2 A g⁻¹, high Coulombic efficiency, good rate capability, and excellent cycling performance with a reversible capacity of 778 mAh g⁻¹ at 1 A g⁻¹ after 300 cycles. Our work will give contributes to the research community to rationally encapsulate SeS₂ cathodes with unique hosts and architectures, providing fundamental understanding of the catalytic mechanism in Li–SeS₂ batteries.