Wei Huiying, Li Qicheng, Jin Bo, Liu Hui
Key Laboratory of Automobile Materials, Ministry of Education, and School of Materials Science and Engineering, Jilin University, Changchun 130022, China.
Nanomaterials (Basel). 2023 Aug 3;13(15):2244. doi: 10.3390/nano13152244.
Lithium-sulfur batteries (LSBs) have become the most promising choice in the new generation of energy storage/conversion equipment due to their high theoretical capacity of 1675 mAh g and theoretical energy density of 2600 Wh kg. Nevertheless, the continuous shuttling of lithium polysulfides (LiPSs) restricts the commercial application of LSBs. The appearance of layered double hydroxides (LDH) plays a certain role in the anchoring of LiPSs, but its unsatisfactory electronic conductivity and poor active sites hinder its realization as a sulfur host for high-performance LSBs. In this paper, metal organic framework-derived and Ce ion-doped LDH (Ce-Ni/Fe LDH) with a hollow capsule configuration is designed rationally. The hollow structure of Ce-Ni/Fe LDH contains a sufficient amount of sulfur. Fe, Ni, and Ce metal ions effectively trap LiPSs; speed up the conversion of LiPSs; and firmly anchor LiPSs, thus effectively inhibiting the shuttle of LiPSs. The electrochemical testing results demonstrate that a lithium-sulfur battery with capsule-type S@Ce-Ni/Fe LDH delivers the initial discharge capacities of 1207 mAh g at 0.1 C and 1056 mAh g at 0.2 C, respectively. Even at 1 C, a lithium-sulfur battery with S@Ce-Ni/Fe LDH can also cycle 1000 times. This work provides new ideas to enhance the electrochemical properties of LSBs by constructing a hollow capsule configuration.
锂硫电池（LSBs）因其1675 mAh g的高理论容量和2600 Wh kg的理论能量密度，已成为新一代储能/转换设备中最具前景的选择。然而，多硫化锂（LiPSs）的持续穿梭限制了锂硫电池的商业应用。层状双氢氧化物（LDH）的出现对LiPSs的锚定起到了一定作用，但其不理想的电子导电性和较差的活性位点阻碍了其作为高性能锂硫电池硫宿主的实现。本文合理设计了具有中空胶囊结构的金属有机框架衍生的Ce离子掺杂LDH（Ce-Ni/Fe LDH）。Ce-Ni/Fe LDH的中空结构包含足量的硫。Fe、Ni和Ce金属离子有效捕获LiPSs；加速LiPSs的转化；并牢固锚定LiPSs，从而有效抑制LiPSs的穿梭。电化学测试结果表明，具有胶囊型S@Ce-Ni/Fe LDH的锂硫电池在0.1 C时的初始放电容量分别为1207 mAh g，在0.2 C时为1056 mAh g。即使在1 C时，具有S@Ce-Ni/Fe LDH的锂硫电池也能循环1000次。这项工作为通过构建中空胶囊结构来提高锂硫电池的电化学性能提供了新思路。
