Li Zhenfeng, Li Yue, Fei Yue, Li Pengcheng, Hung Shin-Yu, Zhang Hao, Li Ge
Department of Mechanical Engineering, University of Alberta, Edmonton, AB, T6G 1H9, Canada.
Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, T6G 1H9, Canada.
Adv Mater. 2025 Jun 25:e2505196. doi: 10.1002/adma.202505196.
Due to the notorious shuttle effect and the uneven deposition of lithium ions under high current conditions, lithium-sulfur batteries with ultra-high sulfur loading struggle to achieve stable long-cycle performance. Herein, a novel MBene-based composite material is prepared using the ultrasonic freeze etching method as a cathode host. The shuttle effect is effectively inhibited, thanks to its unique structure and abundant active sites. Moreover, a small amount of NaSeO is introduced into the electrolyte to further enhance the long-cycle performance. Due to the "reverse tip effect," where sodium ions preferentially deposit over lithium ions, the growth of lithium dendrites is effectively suppressed. Remarkably, the cell with the novel cathode and electrolyte design exhibits an initial capacity of 778.2 mAh g and sustains stability for up to 850 cycles with a capacity retention rate of 93.6% and a sulfur loading of 10.62 mg cm. The synergistic strategy of optimizing both cathode and electrolyte systems effectively mitigates the shuttle effect and suppresses lithium dendrite growth, offering an innovative approach to designing ultra-high-sulfur-loading lithium-sulfur batteries with extended lifespans.
由于臭名昭著的穿梭效应以及在高电流条件下锂离子的不均匀沉积，具有超高硫负载量的锂硫电池难以实现稳定的长循环性能。在此，采用超声冷冻蚀刻法制备了一种新型的基于MBene的复合材料作为正极主体。由于其独特的结构和丰富的活性位点，穿梭效应得到了有效抑制。此外，向电解液中引入少量的NaSeO以进一步提高长循环性能。由于“反向尖端效应”，即钠离子优先于锂离子沉积，锂枝晶的生长得到了有效抑制。值得注意的是，采用新型正极和电解液设计的电池初始容量为778.2 mAh g，在硫负载量为10.62 mg cm的情况下，能够稳定循环850次，容量保持率为93.6%。优化正极和电解液体系的协同策略有效减轻了穿梭效应并抑制了锂枝晶生长，为设计具有更长寿命的超高硫负载锂硫电池提供了一种创新方法。
