High-performance Li-S batteries enabled by polysulfide-infiltrated free-standing 3D carbon cloth with CeO2 nanorods decoration
High-performance Li-S batteries enabled by polysulfide-infiltrated free-standing 3D carbon cloth with CeO2 nanorods decoration
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DOI：
10.1016/j.electacta.2021.138645
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发表时间：
2021-08
影响因子：
6.6
通讯作者：
Zhen Wei;Junhao Li;Yifan Wang;Ruigang Wang
中科院分区：
文献类型：
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作者：
Zhen Wei;Junhao Li;Yifan Wang;Ruigang Wang
为了实现锂硫电池的大规模商业化，必须有效地解决寄生穿梭效应，导致活性材料利用率低和容量衰减快。本文以含Li 2S 6的多硫化物为原料，通过简单的一步水热反应制备了CeO 2纳米棒修饰的三维碳布，成功地提高了Li-S电池的电化学性能。首先，极性CeO 2纳米棒成功地构建了与多硫化物的强化学相互作用，其表面大量的氧空位作为多硫化物的有效锚定位点，显著提高了活性物质硫的利用率。第二，交织的独立式碳布可以通过具有丰富的长程电子转移通道的3-D互连网络显著增强氧化还原动力学，并且可以通过容易接近电解质和丰富的离子传输途径显著改善氧化还原动力学。第三，使用含Li 2S 6的阴极电解液导致活性材料的均匀分布并提高硫利用率。受益于上述优点，具有CeO 2纳米棒装饰的独立式3-D碳布与含Li 2S 6的阴极电解液组合（CC@CeO2@Li2S6）电极在0.2C下的初始放电容量为1311 mA h g-1，并且在100次恒电流循环后保持约95%的初始放电容量，表现出卓越的上级容量保持能力，每周期容量衰减最小为0.050%。
To achieve scale-up commercialization of Li-S batteries, parasitic shuttle effect, leading to low utilization of active material and fast capacity decay, has to be resolved effectively. Herein, we prepared CeO2nanorods decorated interwoven 3-D carbon cloth via facile one-step hydrothermal reaction and Li2S6-containing polysulfide as starting material to successfully improve the electrochemical performance of Li-S battery. First, strong chemical interaction toward polysulfides was successfully constructed by polar CeO2nanorods and numerous oxygen vacancies on their surface acting as efficient polysulfides anchoring sites significantly enhanced the utilization of active material sulfur. Second, interwoven freestanding carbon cloth can considerably enhance redox kinetics through a 3-D interconnected network with abundant long-range electron transfer channels and can significantly improve redox kinetics by easy accessibility to electrolyte and abundant ion transport pathways. Third, the utilization of Li2S6-containing catholyte leads to uniform distribution of active material and improves sulfur utilization. Benefiting from the aforementioned advantages, free-standing 3-D carbon cloth with CeO2nanorods decoration combined with Li2S6-containing catholyte (CC@CeO2@Li2S6) electrode delivered an initial discharge capacity of 1311 mA h g−1at 0.2C and approximately 95% of the initial discharge capacity was remained after 100 galvanostatic cycles, manifesting superior capacity retention with minimal capacity fading of 0.050% per cycle.