Guo Xiaotong, Bi Xu, Zhao Junfeng, Yu Xinxiang, Dai Han
Laboratory of Advanced Light Alloy Materials and Devices, Yantai Nanshan University, Longkou 265713, China.
Yulong Petrochemical Co., Ltd., Longkou 265700, China.
Nanomaterials (Basel). 2022 Aug 11;12(16):2752. doi: 10.3390/nano12162752.
The Lithium sulfur (Li-S) battery has a great potential to replace lithium-ion batteries due to its high-energy density. However, the "shuttle effect" of polysulfide intermediates (LiS, LiS, LiS, etc.) from the cathode can lead to rapid capacity decay and low coulombic efficiency, thus limiting its further development. Anchoring polysulfide and inhibiting polysulfide migration in electrolytes is one of the focuses in Li-S battery. It is well known that polar metal oxides-manganese oxides (MnO) are normally used as an effective inhibitor for its polysulfide inhibiting properties. Considering the natural 1D tunnel structure, MnO with three kinds of typical tunnel-type were screened to study the effects of the tunnel size on the adsorption capacity of polysulfide. We found that MnO with larger tunnel sizes has stronger chemisorption capacity of polysulfide. It promotes the conversion of polysulfide, and corresponding cathode exhibits better cycle reliability and rate performance in the cell comparison tests. This work should point out a new strategy for the cathode design of advanced Li-S battery by controlling the tunnel size.
锂硫（Li-S）电池因其高能量密度而具有巨大潜力，有望取代锂离子电池。然而，来自阴极的多硫化物中间体（Li₂S、Li₂S₂、Li₂S₃等）的“穿梭效应”会导致容量迅速衰减和库仑效率低下，从而限制其进一步发展。在电解质中锚定多硫化物并抑制多硫化物迁移是锂硫电池研究的重点之一。众所周知，极性金属氧化物——锰氧化物（MnO）通常因其多硫化物抑制性能而被用作有效的抑制剂。考虑到天然的一维隧道结构，筛选出三种典型隧道型的MnO来研究隧道尺寸对多硫化物吸附能力的影响。我们发现，具有较大隧道尺寸的MnO对多硫化物具有更强的化学吸附能力。它促进了多硫化物的转化，并且在电池对比测试中，相应的阴极表现出更好的循环可靠性和倍率性能。这项工作应为通过控制隧道尺寸来设计先进锂硫电池的阴极指出一种新策略。
