An Yong, Yu Qianchuan, He Xiaoqin, Zheng He, Chen Jiguang, Zhu Sheng, Wu Qinghong, Zhao Zhiwei
Science and Technology Department, Chongqing Vocational Institute of Engineering, Chongqing 402260, China.
School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210023, China.
ACS Appl Mater Interfaces. 2024 Aug 28;16(34):44767-44779. doi: 10.1021/acsami.4c08006. Epub 2024 Aug 15.
Solid-state lithium-sulfur batteries (SSLSBs) have attracted a great deal of attention because of their high theoretical energy density and intrinsic safety. However, their practical applications are severely impeded by slow redox kinetics and poor cycling stability. Herein, we revealed the detrimental effect of aggregation of lithium polysulfides (LiPSs) on the redox kinetics and reversibility of SSLSBs. As a paradigm, we introduced a multifunctional hyperbranched ionic conducting (HIC) polymer serving as a solid polymer electrolyte (SPE) and cathode binder for constructing SSLSBs featuring high electrochemical activity and high cycling stability. It is demonstrated that the unique structure of the HIC polymer with numerous flexible ether oxygen dangling chains and fast segmental relaxation enables the dissociation of LiPS clusters, facilitates the conversion kinetics of LiPSs, and improves the battery's performance. A Li|HIC SPE|HIC-S battery, in which the HIC polymer acts as an SPE and cathode binder, exhibits an initial capacity of 910.1 mA h g at 0.1C and 40 °C, a capacity retention of 73.7% at the end of 200 cycles, and an average Coulombic efficiency of approximately 99.0%, demonstrating high potential for application in SSLSBs. This work provides insights into the electrochemistry performance of SSLSBs and provides a guideline for SPE design for SSLSBs with high specific energy and high safety.
固态锂硫电池（SSLSBs）因其高理论能量密度和固有安全性而备受关注。然而，其实际应用受到缓慢的氧化还原动力学和较差的循环稳定性的严重阻碍。在此，我们揭示了多硫化锂（LiPSs）聚集对固态锂硫电池氧化还原动力学和可逆性的不利影响。作为一个范例，我们引入了一种多功能超支化离子导电（HIC）聚合物，用作固体聚合物电解质（SPE）和阴极粘结剂，以构建具有高电化学活性和高循环稳定性的固态锂硫电池。结果表明，具有众多柔性醚氧悬链和快速链段弛豫的HIC聚合物的独特结构能够使LiPS簇解离，促进LiPSs的转化动力学，并提高电池性能。一种Li|HIC SPE|HIC-S电池，其中HIC聚合物用作SPE和阴极粘结剂，在0.1C和40°C下初始容量为910.1 mA h g，在200次循环结束时容量保持率为73.7%，平均库仑效率约为99.0%，显示出在固态锂硫电池中应用的高潜力。这项工作为固态锂硫电池的电化学性能提供了见解，并为设计具有高比能量和高安全性的固态锂硫电池的SPE提供了指导。
