Promoting the Transformation of Li2S2 to Li2S: Significantly Increasing Utilization of Active Materials for High‐Sulfur‐Loading Li–S Batteries

• DOI: 10.1002/adma.201901220
• Publication Date: 2019-05-07T09:56:50Z
• Authors: Xiaofei Yang; Xuejie Gao; Qian Sun; Sara Panahian Jand; Ying Yu; Yang Zhao; Xia Li; Keegan Adair; Liang‐Yin Kuo; Jochen Rohrer; Jianneng Liang; Xiaoting Lin; Mohammad Norouzi ...; Yongfeng Hu; Hongzhang Zhang; Xianfeng Li; Ruying Li; Huamin Zhang; Payam Kaghazchi; Tsun‐Kong Sham; Xueliang Sun
• Keywords: Polysulfide; Cobalt sulfide; Lithium–sulfur battery

Lithium-sulfur (Li-S) batteries with high sulfur loading are urgently required in order to take advantage of their theoretical energy density. Ether-based Li-S involve sophisticated multistep solid-liquid-solid-solid electrochemical reaction mechanisms. Recently, studies on have widely focused the initial solid (sulfur)-liquid (soluble polysulfide)-solid (Li2 S2 ) conversion reactions, which contribute first 50% capacity batteries. Nonetheless, sluggish kinetics solid-solid from solid-state intermediate product Li2 final discharge S (corresponding last capacity) leads premature end discharge, resulting low output and utilization. To tackle aforementioned issue, a catalyst amorphous cobalt sulfide (CoS3 is proposed decrease dissociation propel transformation S. The CoS3 plays critical role improving utilization, especially high-loading cathodes (3-10 mg cm-2 ). Accordingly, S/Li2 ratio products increased 5.60/1 1/1.63 catalyst, utilization increase 20% (335 mAh g-1 compared counterpart electrode without .