Low salt dissociation and the unstable [Li(N,N-dimethylformamide (DMF))_x]⁺ solvent structure in poly(vinylidene fluoride) (PVDF)-based solid polymer electrolyte (SPE) remarkably restricts the high throughput ion transport and interfacial stability. Here, we designed a hybrid electrolyte (denoted as HFGP-SE) composed of fluorinated gel solid electrolyte (FG-SE) and poly(vinylidene fluoride-co-hexafluoropropylene) (PVHF)-based solid polymer electrolyte (PVHF-SPE). We found that in the HFGP-SE, the interface of FG-SE and PVHF-SPE effectively promotes lithium salt dissociation and creates a localized high-concentration (LHC) solvation structure. The developed HFGP-SE shows high ionic conductivity (0.84 mS cm⁻¹) and a remarkably improved lithium transference number (t_Li⁺ = 0.87). Meanwhile, the controlled LHC solvation structure formed at the interface between FG-SE and PVHF-SPE supports the formation of inorganic-rich solid electrolyte interphases (SEIs) derived from anions, allowing for stable lithium deposition and ultra-stable plating/stripping performance for over 1200 hours at a current density of 0.5 mA cm⁻². Additionally, HFGP-SE supported stable cycling in 4.5 V class Li||NCM811 full cells under practical conditions, with a 50 μm thick lithium metal anode and cathodes with a mass loading of 12 mg cm⁻², achieving an areal capacity >2 mA h cm⁻². This work proposes a novel strategy using interfaces existing in hybrid solid electrolytes to significantly enhance lithium salt dissociation, fast ion transport, and interfacial stability of solid-state electrolytes for lithium metal batteries.

中文翻译：

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氟化凝胶和聚合物固体电解质界面处的盐解离和局部高浓度溶剂化


在基于聚偏二氟乙烯 （PVDF） 的固体聚合物电解质 （SPE） 中，低盐解离和不稳定的 [Li（N，N-二甲基甲酰胺 （DMF））_x]⁺ 溶剂结构显著限制了高通量离子传输和界面稳定性。在这里，我们设计了一种由氟化凝胶固体电解质 （FG-SE） 和聚（偏二氟乙烯-共六氟丙烯） （PVHF） 基固体聚合物电解质 （PVHF-SPE） 组成的混合电解质（表示为 HFGP-SE）。我们发现，在 HFGP-SE 中，FG-SE 和 PVHF-SPE 的界面有效地促进了锂盐的解离，并产生了局部高浓度 （LHC） 溶剂化结构。开发的 HFGP-SE 显示出高离子电导率 （0.84 mS ^cm-1） 和显着改善的锂转移数 （t_Li⁺ = 0.87）。同时，在 FG-SE 和 PVHF-SPE 界面处形成的受控 LHC 溶剂化结构支持形成源自阴离子的富含无机物的固体电解质界面 （SEI），从而在 0.5 mA ^cm-2 的电流密度下实现超过 1200 小时的稳定锂沉积和超稳定的电镀/剥离性能.此外，HFGP-SE 还支持 4.5 V 级 Li||NCM811 全电池在实际条件下，具有 50 μm 厚的锂金属阳极和阴极，质量负载为 12 mg ^cm-2，达到面容量 >2 mA h ^cm-2。 这项工作提出了一种新的策略，利用混合固体电解质中存在的界面来显着增强锂盐解离、快速离子传输和锂金属电池固态电解质的界面稳定性。