Lithium Trithiocarbonate as a Dual‐Function Electrode Material for High‐Performance Lithium–Sulfur Batteries
Lithium Trithiocarbonate as a Dual‐Function Electrode Material for High‐Performance Lithium–Sulfur Batteries
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DOI：
10.1002/aenm.202200680
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发表时间：
2022-04
影响因子：
27.8
通讯作者：
Hyunki Sul;A. Bhargav;A. Manthiram
中科院分区：
文献类型：
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作者：
Hyunki Sul;A. Bhargav;A. Manthiram
具有延长的循环寿命和高库仑效率的实用锂硫（Li-S）电池的开发受到来自溶解的多硫化物的寄生反应和苔藓状锂沉积的限制。为了应对这些挑战，本文采用三硫代碳酸锂（Li 2CS 3）涂覆的硫化锂（Li 2S）作为双功能阴极材料，以改善Li-S电池的循环性能。有趣的是，在阴极处，Li 2CS 3在表面上形成低聚物结构层以抑制多硫化物穿梭。Li 2CS 3的存在改变了传统的硫反应途径，这一点得到了材料表征和密度泛函理论计算的支持。在阳极处，在Li金属表面上形成具有较低Li离子扩散屏障的稳定的原位固体电解质界面层，以在循环时产生增强的锂电镀/剥离性能。因此，所获得的具有Li 2CS 3的无阳极全电池在125次循环中表现出51%的上级容量保持率，而常规Li 2S电池仅保持26%。这项研究表明，Li 2CS 3夹杂物是设计具有延长循环寿命的高能量密度Li-S电池的有效策略。
The development of practical lithium–sulfur (Li–S) batteries with prolonged cycle life and high Coulombic efficiency is limited by both parasitic reactions from dissolved polysulfides and mossy lithium deposition. To address these challenges, here lithium trithiocarbonate (Li2CS3)‐coated lithium sulfide (Li2S) is employed as a dual‐function cathode material to improve the cycling performance of Li–S batteries. Interestingly, at the cathode, Li2CS3 forms an oligomer‐structured layer on the surface to suppress polysulfide shuttle. The presence of Li2CS3 alters the conventional sulfur reaction pathway, which is supported by material characterization and density functional theory calculation. At the anode, a stable in situ solid electrolyte interphase layer with a lower Li‐ion diffusion barrier is formed on the Li‐metal surface to engender enhanced lithium plating/stripping performance upon cycling. Consequently, the obtained anode‐free full cells with Li2CS3 exhibit a superior capacity retention of 51% over 125 cycles, whereas conventional Li2S cells retain only 26%. This study demonstrates that Li2CS3 inclusion is an efficient strategy for designing high‐energy‐density Li–S batteries with extended cycle life.