Zou Qiang, Liang Qi, Zhou Henggang, Guo Yongqiang, Xue Ji, Luo Mingkai, Jia Songyu, Liu Wenlong, Wang Sizhe
School of Food and Biological Engineering, Chengdu University, Chengdu, 610106, P. R. China.
Yangtze Delta Region Institute (Quzhou), University of Electronic Science and Technology of China, Quzhou, 313002, P. R. China.
Small. 2024 Oct;20(40):e2402344. doi: 10.1002/smll.202402344. Epub 2024 Jun 3.
Lithium-sulfur batteries (LSBs) are still limited by some issues such as polysulfides shuttle and lithium dendrites. Recently, the concept "high-entropy" has been considered as the research hotspot and international frontier. Herein, a high entropy MXene (TiVCrMoCT, HE-MXene) doped graphene is designed as the modified coating on commercial separators for LSBs. The HE-MXene affords multiple metal active sites, fast Li diffusion rate, and efficient adsorption toward polysulfide intermediates. Furthermore, strong lithophilic property is favorable for uniform Li deposition. The combination of in situ characterizations confirms TiVCrMoCT effectively promotes the LiS nucleation/dissolution kinetics, reduces the Li diffusion barrier, and exhibits favorable lithium uniform deposition behavior. This TiVCrMoCT/G@PP provides a high-capacity retention rate after 1000 cycles at 1 C and 2 C, with a capacity decay rate of merely 0.021% and 0.022% per cycle. Surprisingly, the cell operates at a low potential of 48 mV while maintaining at 5 mA cm/5 mAh cm for 4000 h. Furthermore, it still maintains a high-capacity retention rate under a high sulfur loading of 4.8/6.4 mg cm and a low E/S ratio of 8.6/7.5 µg mL. This work reveals a technical roadmap for simultaneously addressing the cathode and anode challenge, thus achieving potential commercially viable LSBs.
锂硫电池(LSBs)仍然受到多硫化物穿梭和锂枝晶等问题的限制。最近,“高熵”概念已成为研究热点和国际前沿。在此,设计了一种高熵MXene(TiVCrMoCT,HE-MXene)掺杂的石墨烯作为锂硫电池商用隔膜的改性涂层。HE-MXene提供多个金属活性位点、快速的锂扩散速率以及对多硫化物中间体的有效吸附。此外,强亲锂性有利于锂的均匀沉积。原位表征的结合证实TiVCrMoCT有效地促进了锂硫的成核/溶解动力学,降低了锂扩散势垒,并表现出良好的锂均匀沉积行为。这种TiVCrMoCT/G@PP在1C和2C下1000次循环后提供了高容量保持率,每循环的容量衰减率仅为0.021%和0.022%。令人惊讶的是,该电池在48mV的低电位下运行,同时在5mA cm/5mAh cm下保持4000h。此外,在4.8/6.4mg cm的高硫负载和8.6/7.5µg mL的低E/S比下,它仍保持高容量保持率。这项工作揭示了一条同时解决正极和负极挑战的技术路线,从而实现具有潜在商业可行性的锂硫电池。