Promoting the conversion of Li2S by functional additives phenyl diselenide in Lithium-Sulfur batteries
Promoting the conversion of Li2S by functional additives phenyl diselenide in Lithium-Sulfur batteries
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功能添加剂苯基二硒化物促进锂硫电池中Li2S的转化
DOI：
10.1016/j.jpowsour.2020.228967
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发表时间：
2021
影响因子：
9.2
通讯作者：
Zhang Kai
中科院分区：
文献类型：
--
作者：
Zhang Xueya;Li Jie;Gao Chunhui;Shi Chenyang;He Liang;Xiang Qian;Hong Bo;Lai Yanqing;Zhang Zhian;Zhang Kai
锂硫电池以其高比容量和低成本的特点，在电化学储能领域具有广阔的应用前景。然而，不溶性Li2S转化效率低，电极上沉积不可控，导致硫利用率低，可逆性差，容量衰减快。因此，锂硫电池的实际应用受到了限制。本文将苯基二硒化物（PDSe）加入到传统的电解液中，试图提高电池的性能。结果表明，PDSe的Se-Se键断裂，Li2S中的Li-S键拉长。此外，PDSe促进了Li2S的转化，减少了Li2S在电极上的沉积。因此，使用含有PDSe的电解质的电池表现出增强的放电容量和改进的倍率性能。特别是，添加5.0 wt% PDSe的电池具有1585.6 mAh g−1的高初始放电容量，即使在0.5 C下循环300次后，电池仍保持916.5 mAh g−1，远高于常规电池的618.7 mAh g−1。
Lithium–Sulfur (Li–S) battery is a promising device in the field of electrochemical energy storage since its high specific capacity and low cost. However, the low insoluble Li2S conversion efficiency and uncontrollable deposition on the electrodes lead to low sulfur utilization, poor reversibility and rapid capacity decay. Consequently, the practical application of Li–S battery is limited. Herein, phenyl diselenide (PDSe) is added into the conventional electrolyte try to improve the batteries performance. The results show that the Se–Se bond in PDSe is broken and the Li–S bond in Li2S is elongated induced by PDSe. Moreover, PDSe promotes Li2S conversion and reduces Li2S deposition on the electrodes. As a result, the batteries using the electrolyte with PDSe exhibit enhanced discharge capacity and improved rate performance. Particularly, the batteries with 5.0 wt% PDSe additive exhibit a high initial discharge capacity of 1585.6 mAh g−1, even after 300 cycles at 0.5 C, the batteries still maintain 916.5 mAh g−1, which is much higher than conventional batteries of 618.7 mA h g−1.