Hierarchical Porous Carbon Embedded MoSe2 Effectively Improve Cycle Stability in K‐Se Battery

Abstract

AbstractIt is a crucial challenge to control the dissolution and diffusion of polyselenides in the K−Se system. Herein, a polar material MoSe2 was introduced into Chitosan‐derived hierarchical porous carbon (MoSe2‐HPC) for the first time by a simple freeze‐dried carbonization method, which was used as host materials of Se. The porous carbon plays a vital role in alleviating volume expansion from Se to K2Se and affording physical restriction effect for generating potassium polyselenides (KPSs). The adsorption experiment can prove that the additive MoSe2 as active site can effectively anchor soluble KPSs by remarkable polar interaction to achieve raising electrochemistry performance. Therefore, the Se@MoSe2‐HPC cathode presents superior cycling stability with a specific capacity of 323.2 mAh g−1 after 500 cycles at 1 C and satisfactory rate performance of 261.7 mAh g−1 at 5 C, demonstrating the great potential of MoSe2 as polar adsorption component for K−Se batteries cathode materials.