Guo Wei, Zhang Wanying, Si Yubing, Wang Donghai, Fu Yongzhu, Manthiram Arumugam
College of Chemistry, Zhengzhou University, Zhengzhou, PR China.
Department of Mechanical Engineering, The Pennsylvania State University, University Park, PA, USA.
Nat Commun. 2021 May 28;12(1):3031. doi: 10.1038/s41467-021-23155-3.
The interfacial instability of the lithium-metal anode and shuttling of lithium polysulfides in lithium-sulfur (Li-S) batteries hinder the commercial application. Herein, we report a bifunctional electrolyte additive, i.e., 1,3,5-benzenetrithiol (BTT), which is used to construct solid-electrolyte interfaces (SEIs) on both electrodes from in situ organothiol transformation. BTT reacts with lithium metal to form lithium 1,3,5-benzenetrithiolate depositing on the anode surface, enabling reversible lithium deposition/stripping. BTT also reacts with sulfur to form an oligomer/polymer SEI covering the cathode surface, reducing the dissolution and shuttling of lithium polysulfides. The Li-S cell with BTT delivers a specific discharge capacity of 1,239 mAh g (based on sulfur), and high cycling stability of over 300 cycles at 1C rate. A Li-S pouch cell with BTT is also evaluated to prove the concept. This study constructs an ingenious interface reaction based on bond chemistry, aiming to solve the inherent problems of Li-S batteries.
锂硫（Li-S）电池中锂金属负极的界面不稳定性以及多硫化锂的穿梭效应阻碍了其商业应用。在此，我们报道了一种双功能电解质添加剂，即1,3,5-苯三硫醇（BTT），它通过原位有机硫醇转化在两个电极上构建固体电解质界面（SEI）。BTT与锂金属反应形成沉积在阳极表面的1,3,5-苯三硫醇锂，实现锂的可逆沉积/剥离。BTT还与硫反应形成覆盖在阴极表面的低聚物/聚合物SEI，减少多硫化锂的溶解和穿梭。含有BTT的Li-S电池具有1239 mAh g（基于硫）的比放电容量，并且在1C倍率下具有超过300次循环的高循环稳定性。还对含有BTT的Li-S软包电池进行了评估以验证这一概念。本研究基于键化学构建了一种巧妙的界面反应，旨在解决Li-S电池的固有问题。
