A strategy to achieve high loading and high energy density Li-S batteries

• 作者: Fei Yin Qi Jin Hong Gao XiTian Zhang ZhiGuo Zhang
• 来源期刊: 能源化学
• 年，卷（期）: 2021,（2）
• 页码范围: 340-346
• 页数: 7页
• 语种: 英文

摘要

Lithium-sulfur (Li-S) batteries are one of the most promising rechargeable storage devices due to the high theoretical energy density.However,the low areal sulfur loading impedes their commercial development.Herein,a 3D free-standing sulfur cathode scaffold is rationally designed and fabricated by coaxially coating polar Ti3C2Tx flakes on sulfur-impregnated carbon cloth (Ti3C2Tx@S/CC) to achieve high loading and high energy density Li-S batteries,in which,the flexible CC substrate with highly porous structure can accommodate large amounts of sulfur and ensure fast electron transfer,while the outer-coated Ti3C2Tx can serve as a polar and conductive protective layer to further promote the conductivity of the whole electrode,achieve physical blocking and chemical anchoring of lithium-polysulfides as well as catalyze their conversion.Due to these advantages,at a sulfur loading of 4 mg cm-2,Li-S cells with Ti3C2Tx@S/CC cathodes can deliver outstanding cycling stability (746.1 mAh g-1 after 200 cycles at 1 C),superb rate performance (866.8 mAh g-1 up to 2 C) and a high specific energy density (564.2 Wh kg-1 after 100 cycles at 0.5 C).More significantly,they also show the commercial potential that can compete with current lithium-ion batteries due to the high areal capacity of 6.7 rnAh cm-2 at the increased loading of 8 mg cm-2.