北京大学庞全全团队报道了具有快速固-固硫反应的全固态锂电池。相关研究成果于2025年1月15日发表在《自然》。

全固态锂硫电池（ASSLSB）具有高比能、高安全性和低成本的承诺，是下一代储能的理想选择。然而，三相边界处固体-固体硫氧化还原反应（SSSRR）缓慢造成的速率性能差和循环寿命短的问题仍有待解决。

该文中，研究人员演示了一种由碘化硫代硼磷酸锂（LBPSI）玻璃相固体电解质（GSEs）实现的快速SSSRR。基于I和I₂/I₃之间的可逆氧化还原，固体电解质（SE）同时作为超离子导体起着表面氧化还原介质的作用，促进了固-固两相边界的缓慢反应，从而大大增加了活性位点的密度。

通过这种机制，ASSLSB表现出超快充电能力，在2C（30°C）下充电时显示出1497mAhg^-1硫的高比容量，同时在20C下仍保持784mAhg^-1硫。值得注意的是，在60°C下以150C的极端速率充电时，可实现432mAhg^-1硫的比容量。此外，该电池在25000次循环中表现出优异的循环稳定性，在5C（25°C）下容量保持率为80.2%。

该氧化还原介导的SSSRR方面的工作，将为开发高能量和安全的先进ASSLSBs铺平道路。

附：英文原文

Title: All-solid-state Li–S batteries with fast solid–solid sulfur reaction

Author: Song, Huimin, Mnch, Konrad, Liu, Xu, Shen, Kaier, Zhang, Ruizhuo, Weintraut, Timo, Yusim, Yuriy, Jiang, Dequan, Hong, Xufeng, Meng, Jiashen, Liu, Yatao, He, Mengxue, Li, Yitao, Henkel, Philip, Brezesinski, Torsten, Janek, Jrgen, Pang, Quanquan

Issue&Volume: 2025-01-15

Abstract: With promises for high specific energy, high safety and low cost, the all-solid-state lithium–sulfur battery (ASSLSB) is ideal for next-generation energy storage1,2,3,4,5. However, the poor rate performance and short cycle life caused by the sluggish solid–solid sulfur redox reaction (SSSRR) at the three-phase boundaries remain to be solved. Here we demonstrate a fast SSSRR enabled by lithium thioborophosphate iodide (LBPSI) glass-phase solid electrolytes (GSEs). On the basis of the reversible redox between I and I2/I3, the solid electrolyte (SE)—as well as serving as a superionic conductor—functions as a surficial redox mediator that facilitates the sluggish reactions at the solid–solid two-phase boundaries, thereby substantially increasing the density of active sites. Through this mechanism, the ASSLSB exhibits ultrafast charging capability, showing a high specific capacity of 1,497mAhg1sulfur on charging at 2C (30°C), while still maintaining 784mAhg1sulfur at 20C. Notably, a specific capacity of 432mAhg1sulfur is achieved on charging at an extreme rate of 150C at 60°C. Furthermore, the cell demonstrates superior cycling stability over 25,000 cycles with 80.2% capacity retention at 5C (25°C). We expect that our work on redox-mediated SSSRR will pave the way for developing advanced ASSLSBs that are high energy and safe.

DOI: 10.1038/s41586-024-08298-9

Source: https://www.nature.com/articles/s41586-024-08298-9