Platinum Electrocatalyst Promoting Redox Kinetics of Li₂S and Regulating Li₂S Nucleation for Lithium–Sulfur Batteries

Abstract

The development of lithium–sulfur batteries (LSBs) is impeded by the shuttle effect of polysulfides (LiPSs) and the sluggish nucleation of Li2S. To address these challenges, incorporating electrocatalysts into sulfur host materials represents an effective strategy for promoting polysulfide conversion, in tandem with the rational design of multifunctional sulfur host materials. In this study, Pt nanoparticles are integrated into biomass‐derived carbon materials by solution deposition method. Pt, as an electrocatalyst, not only enhances the electrical conductivity of sulfur cathodes and effectively immobilizes LiPSs but also catalyzes the redox reactions of sulfur species bidirectionally. Additionally, Pt helps regulate the 3D deposition and growth of Li2S while reducing the reaction energy barrier. Consequently, this accelerates the conversion of LiPSs in LSBs. Furthermore, the catalytic ability of Pt for the redox reactions of sulfur species, along with its influence on the 3D deposition and growth of Li2S, is elucidated using electrochemical kinetic analyses and classical models of electrochemical deposition. The cathodes exhibit a high initial specific capacity of 1019.1 mAh g−1 at 1 C and a low decay rate of 0.045% over 1500 cycles. This study presents an effective strategy to regulate Li2S nucleation and enhance the kinetics of polysulfide conversion in LSBs.

High-Entropy Alloy Electrocatalysts Bidirectionally Promote Lithium Polysulfide Conversions for Long-Cycle-Life Lithium–Sulfur Batteries

“…These intricate processes present some challenges. 4,5 A critical problem is the slow redox kinetics and well-known LiPS shuttling, which invariably restrict sulfur utilization and cause rapid capacity attenuation, particularly at a high current density, high sulfur loading, and long cycling conditions. 6−8 Therefore, we propose to develop bidirectional catalysts for LSBs to accelerate the electrocatalytic transformation and mitigate polysulfide accumulation.…”

“…Lithium–sulfur batteries (LSBs) become one of the most promising next-generation electrochemical storage energy systems. − LSBs involve multiple stages of electrochemical reactions and phase changes: solid sulfur (S 8 ) was first converted into liquid lithium polysulfides (LiPSs) and eventually to solid lithium sulfide (Li 2 S). These intricate processes present some challenges. , A critical problem is the slow redox kinetics and well-known LiPS shuttling, which invariably restrict sulfur utilization and cause rapid capacity attenuation, particularly at a high current density, high sulfur loading, and long cycling conditions. − Therefore, we propose to develop bidirectional catalysts for LSBs to accelerate the electrocatalytic transformation and mitigate polysulfide accumulation. − …”