接口"双端结合点"催化剂协同增强耐用硫电池的电催化Li2S再氧化
Huifang Xu1, Qingbin Jiang1, Kwan San Hui2
1Joint Key Laboratory of the Ministry of Education, Institute of Applied Physics and Materials Engineering, University of Macau, Avenida da Universidade Taipa, Macau SAR 999078, People's Republic of China.
ACS nano
|March 11, 2024
概括
一个具有双终端结合点的新型分离器提高了硫 (Li-S) 电池的耐用性. 这种设计有效地转化了聚硫化物,在苛刻的条件下提高了循环稳定性和容量.
科学领域:
- 材料科学 材料科学 材料科学
- 电化学 电化学 电化学
- 储能 储能 储能 储能 储能 储能
背景情况:
- 硫 (Li-S) 电池在理论上具有很高的能量密度,但受到多硫化物转移的影响,限制了其实际应用.
- 高硫载荷和稀缺电解质条件加剧了聚硫化物穿,降低了电池的性能.
- 聚硫化物的催化转化是改善Li-S电池动力学和稳定性的关键策略.
研究的目的:
- 开发具有双终端结合 (DTB) 站点的分离器架构,以提高Li-S电池的耐用性.
- 为了研究嵌入在添加碳框架 (Co/Co$_{0.85}$Se@NC) 中的极性Co$_{0.85}$Se和Co集群的催化活性,用于聚硫化物转化.
- 为了评估使用修改后的分离器在高硫负载和稀缺电解质条件下使用Li-S电池的性能.
主要方法:
- 用剂合碳框架分离器的制造,其中包含极性Co$_{0.85}$Se和Co集群.
- 使用密度函数理论 (DFT) 计算,现场拉曼和X射线衍射 (XRD) 材料的表征.
- 用修改的分离器对Li-S电池进行电化学测试,包括循环稳定性,速率能力和面积容量测量.
主要成果:
- 在Co/Co$_{0.85}$Se@NC分离器表现出大量的有效聚硫化物 (LiPS) 转换和定的活跃点.
- DFT计算和现场表征证实了DTB效应加强了聚硫化物结合,降低了氧化还原反应能量障碍.
- -S电池表现出异常的循环稳定性 (在2°C下1000个循环中每循环稳定性为0.042%),以及高速率 (849mAhg-1在3°C).
- 在高硫负载 (10.7 mg cm-2) 和稀疏电解质 (5.8 μL mg-1) 条件下,获得了令人印象深刻的10.0 mAh cm-2的面积容量.
结论:
- 使用Co/Co$_{0.85}$Se@NC的DTB站点策略有效地减轻了聚硫化物穿,并提高了Li-S电池的性能.
- 开发的分离器架构为实现耐用和高性能Li-S电池提供了一个有前途的途径.
- 这项工作为设计下一代储能系统的先进材料提供了宝贵的见解.
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