College of Materials Science and Engineering , Zhejiang University of Technology , Hangzhou 310014 , People's Republic of China.
Nano Lett. 2018 May 9;18(5):3104-3112. doi: 10.1021/acs.nanolett.8b00659. Epub 2018 Apr 25.
High ionic conductivity, satisfactory mechanical properties, and wide electrochemical windows are crucial factors for composite electrolytes employed in solid-state lithium-ion batteries (SSLIBs). Based on these considerations, we fabricate MgBO nanowire enabled poly(ethylene oxide) (PEO)-based solid-state electrolytes (SSEs). Notably, these SSEs have enhanced ionic conductivity and a large electrochemical window. The elevated ionic conductivity is attributed to the improved motion of PEO chains and the increased Li migrating pathway on the interface between MgBO and PEO-LiTFSI. Moreover, the interaction between MgBO and -SO- in TFSI anions could also benefit the improvement of conductivity. In addition, the SSEs containing MgBO nanowires exhibit improved the mechanical properties and flame-retardant performance, which are all superior to the pristine PEO-LiTFSI electrolyte. When these multifunctional SSEs are paired with LiFePO cathodes and lithium metal anodes, the SSLIBs show better rate performance and higher cyclic capacity of 150, 106, and 50 mAh g under 0.2 C at 50, 40, and 30 °C. This strategy of employing MgBO nanowires provides the design guidelines of assembling multifunctional SSLIBs with high ionic conductivity, excellent mechanical properties, and flame-retardant performance at the same time.
高离子电导率、令人满意的机械性能和宽电化学窗口是用于固态锂离子电池 (SSLIB) 的复合电解质的关键因素。基于这些考虑因素，我们制备了 MgBO 纳米线增强的聚（环氧乙烷）（PEO）基固态电解质 (SSE)。值得注意的是，这些 SSE 具有增强的离子电导率和大的电化学窗口。离子电导率的提高归因于 PEO 链的运动得到改善以及在 MgBO 和 PEO-LiTFSI 界面上 Li 迁移路径的增加。此外，MgBO 和 TFSI 阴离子中的 -SO2-之间的相互作用也有助于提高电导率。此外，含有 MgBO 纳米线的 SSE 表现出改善的机械性能和阻燃性能，均优于原始的 PEO-LiTFSI 电解质。当这些多功能 SSE 与 LiFePO4 阴极和锂金属阳极配对时，SSLIB 在 50、40 和 30°C 下以 0.2 C 的倍率测试时，分别表现出更好的倍率性能和更高的循环容量，分别为 150、106 和 50 mAh g-1。这种使用 MgBO 纳米线的策略为组装具有高离子电导率、优异机械性能和阻燃性能的多功能 SSLIB 提供了设计指导。
