Asymmetric Polymer Electrolyte Constructed by Metal–Organic Framework for Solid‐State, Dendrite‐Free Lithium Metal Battery
Asymmetric Polymer Electrolyte Constructed by Metal–Organic Framework for Solid‐State, Dendrite‐Free Lithium Metal Battery
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DOI：
10.1002/adfm.202007198
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发表时间：
2020-10
影响因子：
19
通讯作者：
Guoxu Wang;P. He;Li-zhen Fan
中科院分区：
文献类型：
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作者：
Guoxu Wang;P. He;Li-zhen Fan
固态聚合物电解质（SPE）具有灵活性、易加工性和低成本，被认为是下一代高安全性锂金属电池中传统液体电解质的有前途的替代品。然而，SPE在充/放电过程中通常具有较差的强度以阻止Li枝晶生长，这严重限制了其广泛的实际应用。在这里，提出了一种在一侧用金属有机框架（MOF）层改性的3D交联网络不对称SPE的合理设计，并通过原位聚合工艺制备。在这种独特的非对称SPE中，纳米级的MOF层起到了屏蔽的作用，有效地抑制了Li枝晶的生长并调节了Li+的均匀传输，并且聚合物电解质可以分散在整个电池中，以赋予Li+的平滑传输。因此，不对称SPE表现出高离子电导率、宽电化学窗口、高热稳定性和安全性，这赋予Li/Li对称电池优异的循环稳定性（在0.1 mA cm-2的电流密度下运行超过800 h，容量为0.1 mAh cm-2）。
Solid‐state polymer electrolytes (SPEs) with flexibility, easy processability, and low cost have been regarded as promising alternatives for conventional liquid electrolytes in next‐generation high‐safety lithium metal batteries. However, SPEs generally suffer poor strength to block Li dendrite growth during the charge/discharge process, which severely limits their wide practical applications. Here, a rational design of 3D cross‐linked network asymmetric SPE modified with a metal–organic framework (MOF) layer on one side is proposed and prepared through an in‐situ polymerization process. In such unique asymmetric SPEs, the nanoscale MOF layer acts as a shield that effectively suppresses the growth of Li dendrites and regulates the uniform Li+ transport, and the polymer electrolyte can be scattered in the whole cell to endow the smooth transmission of Li+. As a result, the asymmetric SPE exhibits high ionic conductivity, wide electrochemical window, high thermal stability and safety, which endows the Li/Li symmetrical cell with outstanding cyclic stability (operate well over 800 h at a current density of 0.1 mA cm−2 for the capacity of 0.1 mAh cm−2).