High Cycling Performance Li-S Battery via Fenugreek Gum Binder Through Chemical Bonding of the Binder with Polysulfides in Nanosulfur@CNFs Cathode
High Cycling Performance Li-S Battery via Fenugreek Gum Binder Through Chemical Bonding of the Binder with Polysulfides in Nanosulfur@CNFs Cathode
复制标题
通过胡芦巴胶粘合剂与纳米硫@CNFs正极中的多硫化物进行化学键合，实现高循环性能的锂硫电池
DOI：
10.1002/slct.202002471
复制
发表时间：
2020-08-07
期刊：
影响因子：
2.1
通讯作者：
Sun, Shi-Gang
中科院分区：
文献类型：
--
作者：
Mo, Yu-Xue;Wu, Yi-Jin;Sun, Shi-Gang
The dissolution and diffusion of lithium polysulfides are one of the main intrinsic bottlenecks in the development of lithium-sulfur (Li-S) batteries with long term cycling stability. Appropriate binders could play a key role of anchoring the lithium polysulfides in S-cathode through strong chemical bonds, thus boosts the electrochemical performance of Li-S battery. Herein, we report a new binder (fenugreek gum, FG) that has enhanced significantly the cycling performance of Li-S batteries with S@CNFs composite as cathode. The Li-S cell with FG binder delivers a large initial capacity of 900 mAh g(-1)at 2 C, and a reversible capacity retention of 45.6 % after 1300 cycles, superior to the cycling performance of Li-S cell with conventional PVDF or previous reported guar gum (GG) binder. This enhancement in cycling performance of Li-S batteries could be attributed to the formation of the S-O and Li-O bonds between the O-relevant functional groups in the binder and the polysulfides in S-cathode as manifested by XPS data of the discharged and charged electrodes. Furthermore, the tensile strain rate of the FG binder is as high as 32 %, which can effectively restrain the volume expansion of the S-cathode during the discharge/charge process and ensure the integrity of the electrode.
