Sun Hongguang, Ning Daze, Cheng Junmei, Guo Jian, Hou Hongbin, Wang Qinggang
School of Polymer Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042, People's Republic of China.
School of Polymer Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042, People's Republic of China.
J Colloid Interface Sci. 2022 Dec 15;628(Pt A):562-573. doi: 10.1016/j.jcis.2022.07.163. Epub 2022 Jul 28.
Lithium-sulfur battery(LSB)'s commercial manufacturing has been mainly retarded by the "shuttle effect" and low electrical conductivity of polysulfides (LiPSs). Designing a cathode with hollow and hierarchically porous structures was expected to solve the above problems. Herein, a kind of TiN particles with the hierarchical hollow double-shelled structures was synthesized and applied to cathodes of LSB. The Fig-like hollow TiO particles (FHTiOs) were firstly synthesized by the hard-template method. Subsequently, the Fig-like hierarchical hollow double-shelled TiN particles (FHTiNs) were synthesized by the template-free sequential transformation and separation approach (STSA). It was verified that the heating temperature and time were key parameters. Special Fig-like double-shell hollow structures could greatly increase the loading of S, and the excellent initial capacity of FHTiNs cathodes was up to 1159 mAh/g. On the one hand, the Fig-like framework in internal cavity and double-shell structures could promote the ultrahigh specific surface area, and the adsorption to LiPSs was improved by increasing active sites; On the other hand, the shuttle effect of LiPSs was weakened by the fig-like framework and double-shell structures, which slowed down the massive dissolution of sulfur in the electrolyte. As a result, the pleasant rate performance of FHTiNs cathodes was up to 400 mAh/g at 5C. This novel structures and synthesis method provided a new strategy for the designing of LSB cathodes.
锂硫电池（LSB）的商业化生产主要受到“穿梭效应”和多硫化物（LiPSs）低电导率的阻碍。设计具有中空和分级多孔结构的阴极有望解决上述问题。在此，合成了一种具有分级中空双壳结构的TiN颗粒，并将其应用于LSB的阴极。首先通过硬模板法合成了无花果状中空TiO颗粒（FHTiOs）。随后，通过无模板顺序转化和分离方法（STSA）合成了无花果状分级中空双壳TiN颗粒（FHTiNs）。验证了加热温度和时间是关键参数。特殊的无花果状双壳中空结构可以大大增加硫的负载量，FHTiNs阴极的优异初始容量高达1159 mAh/g。一方面，内腔中的无花果状框架和双壳结构可以促进超高比表面积，并通过增加活性位点来改善对LiPSs的吸附；另一方面，LiPSs的穿梭效应被无花果状框架和双壳结构削弱，减缓了硫在电解质中的大量溶解。结果，FHTiNs阴极在5C时的良好倍率性能高达400 mAh/g。这种新颖的结构和合成方法为LSB阴极的设计提供了一种新策略。
