Investigating MA MX–NiSe2@C heterostructures to boost reaction kinetics in Lithium-Sulfur batteries

To address the severe challenges of sluggish reaction kinetics and shuttle effects in lithium-sulfur (Li–S) batteries, this study ingeniously employed an efficient microwave-assisted (MA) strategy to rapidly synthesize the MXene–NiSe 2 @C (denoted as MA MX–NiSe 2 @C) heterostructure, serving as a sulfur host material. This method offered key benefits such as rapid and uniform heating, along with high energy efficiency. Theoretical simulations validated that the MXene–NiSe 2 heterostructure interface promoted the electron transfer processes, enhanced polysulfides adsorption, catalyzed the multi-step reduction of sulfur, and significantly reduced the energy barrier for Li 2 S decomposition. Electrochemical experiments demonstrated that MA MX–NiSe 2 @C notably improved Li–ion diffusion kinetics, accelerated sulfur redox reactions, and effectively mitigated shuttle effects. As a result, Li–S batteries based on the MA MX–NiSe 2 @C cathode exhibited a high initial capacity of 1222 mA h·g −1 at 0.1C, enhanced rate performance of 619 mA h·g −1 at 2C, and remarkable cycling stability. Even after 1000 cycles at a high 2C rate, the average capacity decay rate per cycle remained at only 0.054 %. This efficient synthesis method for MXene–transition metal selenide electrocatalysts, coupled with a thorough investigation of their adsorption and catalytic mechanisms in the intricate multiphase electrochemical reactions of Li–S batteries, provides strong support for the ongoing advancement of Li–S battery technology.