Deng Zekun, Zheng Zhenyang, Ruan Wenhong, Zhang Mingqiu
Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, School of Chemistry, Sun Yat-sen University, Guangzhou 510275, China.
Guangdong Provincial Key Laboratory for High Performance Polymer-Based Composites, Guangzhou 510275, China.
Materials (Basel). 2021 Apr 15;14(8):1979. doi: 10.3390/ma14081979.
With a higher theoretical specific capacity (1675 mAh g) and energy density (2600 Wh kg), the lithium-sulfur (Li-S) battery is considered as a promising candidate for a next-generation energy storage device. However, the shuttle effect of polysulfides as well as the large interfacial impedance between brittle solid electrolyte and electrodes lead to the capacity of the Li-S battery decaying rapidly, which limits the practical commercial applications of the Li-S battery. Herein, we reported a facile in situ ultraviolet (UV) curing method to prepare a flexible quasi-solid-state composite electrolyte (QSSCE) of poly(propylene glycol)-co-pentaerythritol triacrylate/LiAlGe(PO) (PPG-co-PETA/LAGP). By combining the high Li-ion conductivity and mechanical strength of inorganic NASICON-structure LAGP and good flexibility of the crosslinked PPG-co-PETA with nanopore structure, the flexible QSSCE with 66.85 wt% LAGP exhibited high Li-ion conductivity of 5.95 × 10 S cm at 25 °C, Li-ion transference number of 0.83 and wide electrochemical window of ~5.0 V (vs. Li/Li). In addition, the application of QSSCE in the Li-S battery could suppress the shuttle effect of polysulfides effectively, thus the Li-S battery possessed the excellent electrochemical cyclic performance, showing the first-cycle discharge-specific capacity of 1508.1 mAh g, the capacity retention of 73.6% after 200 cycles with 0.25 C at 25 °C and good rate performance.
锂硫（Li-S）电池具有较高的理论比容量（1675 mAh g）和能量密度（2600 Wh kg），被认为是下一代储能设备的有前途的候选者。然而，多硫化物的穿梭效应以及脆性固体电解质与电极之间的大界面阻抗导致Li-S电池的容量迅速衰减，这限制了Li-S电池的实际商业应用。在此，我们报道了一种简便的原位紫外（UV）固化方法，用于制备聚（丙二醇）-共-季戊四醇三丙烯酸酯/LiAlGe(PO)（PPG-co-PETA/LAGP）的柔性准固态复合电解质（QSSCE）。通过结合无机NASICON结构LAGP的高锂离子电导率和机械强度以及具有纳米孔结构的交联PPG-co-PETA的良好柔韧性，含有66.85 wt% LAGP的柔性QSSCE在25 °C下表现出5.95 × 10 S cm的高锂离子电导率、0.83的锂离子迁移数和约5.0 V（相对于Li/Li）的宽电化学窗口。此外，QSSCE在Li-S电池中的应用可以有效抑制多硫化物的穿梭效应，因此Li-S电池具有优异的电化学循环性能，在25 °C下以0.25 C进行200次循环后，首次循环放电比容量为1508.1 mAh g，容量保持率为73.6%，并且具有良好的倍率性能。
