Abstract：
Although polymer electrolytes have been regarded as potential separator materials for high energy density solid-state lithium-based batteries, their applications were significantly restricted by the low ionic conductivity, poor mechanical strength, and thermostability. Herein, a highly conductive and thermostable hybrid polymer electrolyte was developed by combining poly(vinylidene fluoride-co-hexafluoropropylene)-grafted polyrotaxane and nano-Al2O3 particles. In this unique hybrid, not only the Lewis acid-type Al2O3 and the fluorine groups of polyrotaxane branches exhibited strong integration with ionic species to accelerate the dissociation of lithium salt, improving the Li ionic conductivity, but also the abundant hydroxy functional groups on the surface of Al2O3 hydrogen-bonded with fluorine-containing branches, enhancing the mechanical strength. More importantly, the hybrid electrolyte exhibited superior thermal stability due to the heat resistance of the ceramic filler and the unique bead string structure of polyrotaxane. Consequently, a polymer electrolyte with a comprehensively improved performance was obtained, including high ionic conductivity and Li+ transfer number and superior tensile strength and thermostability. The hybrid electrolyte provided a dendrite-free lithium anode with a long life up to 1800 h and stable solid-state lithium-metal batteries at a high temperature of 80 °C.
摘要：
尽管聚合物电解质已被视为高能量密度固态锂基电池的潜在隔膜材料，它们的应用受到低离子电导率的显著限制，机械强度差，和热稳定性。在这里，通过结合聚偏氟乙烯-共-六氟丙烯接枝的聚轮烷和纳米Al2O3颗粒，开发了一种高导电性和热稳定性的杂化聚合物电解质。在这个独特的混合体中，不仅Lewis酸型Al2O3和聚轮烷分支的氟基团表现出与离子物种的强整合以加速锂盐的解离，提高Li离子电导率，而且Al2O3表面上丰富的羟基官能团与含氟支链氢键键合，提高机械强度。更重要的是,由于陶瓷填料的耐热性和聚轮烷独特的珠串结构，复合电解质表现出优异的热稳定性。因此,获得了性能全面改善的聚合物电解质，包括高离子电导率和Li+转移数和优越的拉伸强度和热稳定性。该混合电解质提供了一种无枝晶的锂阳极，具有长达1800小时的长寿命和在80°C的高温下稳定的固态锂金属电池。
