Protecting lithium anode with ionic liquid modified poly(vinylidene fluoride) single ion conducting separators for iodide-assisted lithium oxygen batteries
Protecting lithium anode with ionic liquid modified poly(vinylidene fluoride) single ion conducting separators for iodide-assisted lithium oxygen batteries
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DOI：
10.1016/j.est.2022.104580
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发表时间：
2022-04-20
影响因子：
9.4
通讯作者：
Luo, Kun
中科院分区：
文献类型：
--
作者：
Chen, Wenxiang;Luo, Zhihong;Luo, Kun
据报道，氧化还原介质（RM）可以有效促进Li-O-2电池（LOB）中放电产物的缓慢分解，然而，氧化的RM和其他有害物质的攻击对锂阳极仍然是一个挑战。本文制备了离子液体改性磺化聚偏二氟乙烯（MSP）单锂离子导电膜，该膜仅允许Li + 的传输并阻止阴离子和其他分子的通过。离子液体改性明显增强了膜的电导率，同时又不损失其不渗透性和离子选择性。与使用玻璃纤维隔膜的电池相比，MSP 隔膜的使用显着延长了 LOB 的循环寿命，在 1.0 A g(+1 ) 和 1000 mAh g(+1 ) 容量下的循环寿命从 60 次延长至 210 次。在2.0、3.0和5.0 A g(+1)倍率下，倍率性能分别从44、31和23次循环明显提高到152、129和107次循环。满放电容量也从3700mAh g(+1)扩大到17,000mAh g(+1)。 MSP 隔膜实现了碘化物辅助阴极过程，并改善了锂阳极的沉积/溶解，这对于非质子 LOB 性能的增强至关重要。
Redox mediators (RMs) have been reported to effectively promote the sluggish decomposition of discharge products in Li-O-2 batteries (LOBs), however, the attack of the oxidized RMs and other harmful species remains challenging to Li anodes. Herein, an ionic liquid modified sulfonated poly(vinylidene fluoride) (MSP) single lithium-ion conducting membrane was fabricated, which only allows the transfer of Li+ and blocks the pass-through of anions and other molecules. The ionic liquid modification apparently strengthened the conductivity of the membrane without losing its impermeability and ionic selectivity. The utility of the MSP separator signifi-cantly extended the cycle life of the LOB in comparison to the cell using a glass fiber separator, from 60 to 210 rounds at the 1.0 A g(+1 )and the capacity of 1000 mAh g(+1 ). The rate performance was obviously enhanced from 44, 31 and 23 cycles to152, 129 and 107 cycles at the rates of 2.0, 3.0 and 5.0 A g(+1 ), respectively. The full-discharge capacity was also enlarged from 3700 to 17,000 mAh g(+1 ). The MSP separator enables the iodide-assisted cathode process and improves the deposition/dissolution of the Li anode, which are essential for the performance enhancement of aprotic LOBs.