Abstract
Investigations into lithium-sulfur batteries (LSBs) has focused primarily on the initial conversion of lithium polysulfides (LiPSs) to Li(2) S(2) . However, the subsequent solid-solid reaction from Li(2) S(2) to Li(2) S and the Li(2) S decomposition process should be equally prioritized. Creating a virtuous cycle by balancing all three chemical reaction processes is crucial for realizing practical LSBs. Herein, amorphous Ni(3) B in synergy with carbon nanotubes (aNi(3) B@CNTs) is proposed to implement the consecutive catalysis of S(8(solid)) → LiPSs((liquid)) → Li(2) S((solid)) →LiPSs((liquid)) . Systematic theoretical simulations and experimental analyses reveal that aNi(3) B@CNTs with an isotropic structure and abundant active sites can ensure rapid LiPSs adsorption-catalysis as well as uniform Li(2) S precipitation. The uniform Li(2) S deposition in synergy with catalysis of aNi(3) B enables instant/complete oxidation of Li(2) S to LiPSs. The produced LiPSs are again rapidly and uniformly adsorbed for the next sulfur evolution process, thus creating a virtuous cycle for sulfur species conversion. Accordingly, the aNi(3) B@CNTs-based cell presents remarkable rate capability, long-term cycle life, and superior cyclic stability, even under high sulfur loading and extreme temperature environments. This study proposes the significance of creating a virtuous cycle for sulfur species conversion to realize practical LSBs.