多硫化物
硫黄
材料科学
法拉第效率
电解质
碳纤维
化学工程
电池(电)
阴极
离子
扩散
化学
有机化学
物理化学
电极
复合材料
热力学
功率(物理)
物理
复合数
工程类
冶金
作者
Zuobei Jiang,Na Li,Lingyi Li,Fei Tan,Jinsha Huang,Shaoming Huang
标识
DOI:10.1002/adma.202311127
摘要
Abstract Potassium‐sulfur (K‐S) battery has attracted attention in large‐scale energy storage system. Small‐molecule/covalent sulfur (SMCS) can help to avoid shuttle effect of polysulfide ions via solid‐solid sulfur conversion. However, content of SMCS is relatively low (≤40%), and solid‐solid reaction cause sluggish kinetics and low discharge potentials. Herein, SMCS was confined in turbo carbon layers with content of ∼74.1 wt% via a C/S co‐deposition process. In the K‐S battery assembled by using as‐fabricated SMCS@C as cathode and KFSI‐EC/DEC as electrolyte, anion‐regulated two‐plateau solid‐state S conversion chemistry and a novel high discharge potential plateau at 2.5‐2.0 V with remarkable reversible capacity of 384 mAh g −1 at 3 A g −1 after 1000 cycles were found. The SMCS@C||K full cell showed energy and power density of 72.8 Wh kg −1 and 873.2 W kg −1 , respectively, at 3 A g −1 . Mechanism studies reveal that the enlarged carbon layer space enables the diffusion of K+‐FSI‐ ion pairs, and the coulombic attraction between them accelerates their diffusion in SMCS@C. In addition, FSI − regulates sulfur conversion in situ inside the carbon layers along a two‐plateau solid‐state reaction pathway, which lowers the free energy and weakens the S‐S bond of intermediates, leading to faster and more efficient S conversion. This article is protected by copyright. All rights reserved
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