Wang Xin, Luo Dan, Wang Jiayi, Sun Zhenghao, Cui Guoliang, Chen Yuxuan, Wang Tong, Zheng Lirong, Zhao Yan, Shui Lingling, Zhou Guofu, Kempa Krzysztof, Zhang Yongguang, Chen Zhongwei
South China Academy of Advanced Optoelectronics & International Academy of Optoelectronics at Zhaoqing, South China Normal University, Guangzhou, 510006, China.
Department of Chemical Engineering, University of Waterloo, Waterloo, ON, N2L 3G1, Canada.
Angew Chem Int Ed Engl. 2021 Feb 1;60(5):2371-2378. doi: 10.1002/anie.202011493. Epub 2021 Jan 4.
Tensile-strained Mxene/carbon nanotube (CNT) porous microspheres were developed as an electrocatalyst for the lithium polysulfide (LiPS) redox reaction. The internal stress on the surface results in lattice distortion with expanding Ti-Ti bonds, endowing the Mxene nanosheet with abundant active sites and regulating the d-band center of Ti atoms upshifted closer to the Fermi level, leading to strengthened LiPS adsorbability and accelerated catalytic conversion. The macroporous framework offers uniformed sulfur distribution, potent sulfur immobilization, and large surface area. The composite interwoven by CNT tentacle enhances conductivity and prevents the restacking of Mxene sheets. This combination of tensile strain effect and hierarchical architecture design results in smooth and favorable trapping-diffusion-conversion of LiPS on the interface. The Li-S battery exhibits an initial capacity of 1451 mAh g at 0.2 C, rate capability up to 8 C, and prolonged cycle life.
拉伸应变的MXene/碳纳米管（CNT）多孔微球被开发用作多硫化锂（LiPS）氧化还原反应的电催化剂。表面的内应力导致晶格畸变，Ti-Ti键扩张，赋予MXene纳米片丰富的活性位点，并将Ti原子的d带中心调节到更接近费米能级的位置，从而增强了LiPS的吸附能力并加速了催化转化。大孔框架提供了均匀的硫分布、强大有效的硫固定能力和大表面积。由CNT触手交织而成的复合材料提高了导电性，并防止了MXene片层的重新堆叠。这种拉伸应变效应和分级结构设计的结合，使得LiPS在界面上实现了平滑且良好的捕获-扩散-转化。该锂硫电池在0.2 C时的初始容量为1451 mAh g，倍率性能高达8 C，且循环寿命延长。
