Ionic liquid functionalized electrospun gel polymer electrolyte for use in a high-performance lithium metal battery
Ionic liquid functionalized electrospun gel polymer electrolyte for use in a high-performance lithium metal battery
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用于高性能锂金属电池的离子液体功能化电纺凝胶聚合物电解质
DOI：
10.1039/c8ta06338a
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发表时间：
2018-10-14
影响因子：
11.9
通讯作者：
Zhang, Suojiang
中科院分区：
文献类型：
--
作者：
Cheng, Yuanyuan;Zhang, Lan;Zhang, Suojiang
抑制锂枝晶的形成和增殖的能力是锂金属电池作为高能量存储装置成功商业化的重要努力。使用凝胶聚合物电解质是解决这个问题并获得高性能的最有前途的途径之一。在这里，我们提出了一种新的凝胶聚合物电解质（GPE），其中纳米结构的离子液体（IL），二氧化硅纳米粒子栓系的1-甲基-1-丙基哌啶鎓双（三氟甲磺酰基）酰亚胺（SiO2 PPTFSI），首先引入到凝胶聚合物电解质基质的基础上聚（偏氟乙烯-共-六氟丙烯）（PVDF-HFP）通过静电纺丝制备，然后在氟代碳酸乙烯酯（FEC）电解质中塑化。在与纳米结构IL结合后，这种新型GPE表现出良好的机械性能、增强的电解质吸收（552wt%）和高离子电导率（0.64mS cm-1）和锂离子迁移数（tLi+ = 0.60）。此外，它抑制锂枝晶形成，并在对称锂电池中表现出超过1200小时的稳定镀覆/剥离循环。更重要的是，它在高达5.1 V（vs. Li/Li+）下电化学稳定，使其可用于LiNi0.5Mn1.5O4系统，相对于具有基于PVDF-HFP的液体电解质或GPE的Celgard系统，具有更好的循环稳定性和倍率性能。具有新型GPE的Li/LiNi0.5Mn1.5O4电池在1C下表现出119 mA h g−1的初始放电容量，460次循环后的容量保持率为92.1%，并且在6C下具有74 mA h g−1的高可逆容量。因此，使用纳米结构的IL-改性的GPE提供了增强锂金属电池的循环性能和安全性的有希望的方式。
The ability to suppress the formation and proliferation of lithium dendrites is an important endeavour towards the successful commercialization of lithium metal batteries as high energy storage devices. The use of gel polymer electrolytes is one of the most promising pathways to solving this problem and obtaining high performance. Here, we propose a novel gel polymer electrolyte (GPE), in which a nanostructured ionic liquid (IL), silica nanoparticle-tethered 1-methyl-1-propylpiperidinium bis(trifluoromethanesulfonyl)imide (SiO2PPTFSI), is first introduced into a gel polymer electrolyte matrix based on poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF–HFP) prepared by electrospinning, followed by plasticization in a fluoroethylene carbonate (FEC) electrolyte. After being incorporated with the nanostructured IL, this novel GPE exhibits good mechanical properties, an enhanced electrolyte uptake (552 wt%) and a high ionic conductivity (0.64 mS cm−1) and lithium ion transference number (tLi+ = 0.60). In addition, it suppresses lithium dendrite formation and exhibits stable plating/striping cycles over 1200 hours in a symmetric lithium cell. More importantly, it is electrochemically stable up to 5.1 V (vs. Li/Li+), making it practical for use in LiNi0.5Mn1.5O4 systems with a much better cycle stability and rate capability relative to those of Celgard with a liquid electrolyte or GPE based on PVDF–HFP. The Li/LiNi0.5Mn1.5O4 cell with the novel GPE exhibits an initial discharge capacity of 119 mA h g−1 at 1C, a capacity retention of 92.1% after 460 cycles, and a high reversible capacity of 74 mA h g−1 at 6C. Therefore, the use of a nanostructured IL-modified GPE presents a promising way to enhance the cycle performance and safety of lithium metal cells.