Liu Jianwei, Wang Jianan, Zhu Lei, Chen Xin, Ma Qianyue, Xu Zhicheng, Sun Shiyi, Wang Ning, Chai Qinqin, Yan Wei
Department of Environmental Science and Engineering, State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, 28 Xianning West Road, Xi'an 710049, China; Zhejiang Research Institude of Xi'an Jiaotong University, 328 Wenming Road, Hangzhou 310000, China.
Department of Environmental Science and Engineering, State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, 28 Xianning West Road, Xi'an 710049, China; Zhejiang Research Institude of Xi'an Jiaotong University, 328 Wenming Road, Hangzhou 310000, China.
J Colloid Interface Sci. 2022 Jan 15;606(Pt 2):1111-1119. doi: 10.1016/j.jcis.2021.08.096. Epub 2021 Aug 18.
Lithium-sulfur (Li-S) batteries are considered to be promising candidates for next-generation storage systems. However, the practical applications are still hindered by the severe capacity decay, mainly caused by the large volume change, polysulfide shuttle and sluggish sulfur conversion kinetics. Herein, hollow urchin-like MnO (HU-MnO) microspheres as sulfur hosts have been synthesized by the hydrothermal method and calcination treatment, aiming to prevent the polysulfide dissolution (benefiting from the strong polysulfide anchoring effect of MnO) and alleviate the volume expansion of sulfur (benefiting from the special hollow structure). Meanwhile, the urchin-like thorny surface also facilitates the rapid ion/electron transfer and the abundant active sites for the fast sulfur redox kinetics. When used as the sulfur host in Li-S batteries, the S@HU-MnO cathode delivers a high initial capacity of 1137.4 mAh g with a slow capacity decay of 0.042% after 200 cycles at 0.2 C. Even under the conditions of lean electrolyte (E/S = 7 mL g) and low N/P ratio (N/P = 2.1), the S@HU-MnO cathode still enables a stable cycling performance with a high gravimetric energy density (202 Wh kg cell), demonstrating its great potential in the development of future practical Li-S battery materials.
锂硫（Li-S）电池被认为是下一代储能系统的有前景的候选者。然而，实际应用仍受到严重的容量衰减的阻碍，这主要是由大的体积变化、多硫化物穿梭和缓慢的硫转化动力学引起的。在此，通过水热法和煅烧处理合成了中空海胆状MnO（HU-MnO）微球作为硫宿主，旨在防止多硫化物溶解（受益于MnO对多硫化物的强锚定作用）并减轻硫的体积膨胀（受益于特殊的中空结构）。同时，海胆状的刺状表面也有利于快速的离子/电子转移以及丰富的活性位点，以实现快速的硫氧化还原动力学。当用作Li-S电池中的硫宿主时，S@HU-MnO阴极在0.2 C下200次循环后具有1137.4 mAh g的高初始容量，容量衰减缓慢，为0.042%。即使在贫电解质（E/S = 7 mL g）和低N/P比（N/P = 2.1）的条件下，S@HU-MnO阴极仍能实现具有高重量能量密度（202 Wh kg电池）的稳定循环性能，证明其在未来实用Li-S电池材料开发中的巨大潜力。
