Unraveling the Atomic‐Level Manipulation Mechanism of Li2S Redox Kinetics via Electron‐Donor Doping for Designing High‐Volumetric‐Energy‐Density, Lean‐Electrolyte Lithium–Sulfur Batteries. Issue 33 (6th October 2022)

• Record Type: Journal Article
• Authors: Shan, Jiongwei; Wang, Wei; Zhang, Bing; Wang, Xinying; Zhou, Weiliang; Yue, Liguo; Li, Yunyong
• Is Part Of: Advanced science. Volume 9:Issue 33(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-10-06
• Subjects: Cu‐doped CoP/MXene -- dense sulfur cathodes -- Li2S redox kinetics -- lithium–sulfur batteries -- volumetric capacity; Science -- Periodicals; 505
• DOI: 10.1002/advs.202204192
• Languages: English
• ISSNs: 2198-3844

Abstract

Abstract: Designing dense thick sulfur cathodes to gain high‐volumetric/areal‐capacity lithium–sulfur batteries (LSBs) in lean electrolytes is extremely desired. Nevertheless, the severe Li2 S clogging and unclear mechanism seriously hinder its development. Herein, an integrated strategy is developed to manipulate Li2 S redox kinetics of CoP/MXene catalyst via electron‐donor Cu doping. Meanwhile a dense S/Cu0.1 Co0.9 P/MXene cathode (density = 1.95 g cm −3 ) is constructed, which presents a large volumetric capacity of 1664 Ah L −1 (routine electrolyte) and a high areal capacity of ≈8.3 mAh cm −2 (lean electrolyte of 5.0 µL mgs −1 ) at 0.1 C. Systematical thermodynamics, kinetics, and theoretical simulation confirm that electron‐donor Cu doping induces the charge accumulation of Co atoms to form more chemical bonding with polysulfides, whereas weakens CoS bonding energy and generates abundant lattice vacancies and active sites to facilitate the diffusion and catalysis of polysulfides/Li2 S on electrocatalyst surface, thereby decreasing the diffusion energy barrier and activation energy of Li2 S nucleation and dissolution, boosting Li2 S redox kinetics, and inhibiting shuttling in the dense thick sulfur cathode. This work deeply understands the atomic‐level manipulation mechanism of Li2 S redox kinetics and provides dependable principles for designing high‐volumetric‐energy‐density, lean‐electrolyte LSBs through integrating bidirectional electro‐catalysts with manipulated Li2 S redox and dense‐sulfur engineering. Abstract : The authors develop an integrated strategy to manipulate Li2 S redox kinetics of CoP/MXene catalyst via electron‐donor Cu doping and meanwhile construct a dense S/Cu0.1 Co0.9 P/MXene cathode, which presents large volumetric capacity of 1664 Ah L −1 and high areal capacity of ≈8.3 mAh cm −2 (lean electrolyte) at 0.1 C, and its atomic‐level manipulation mechanism of Li2 S redox kinetics is uncovered.