High-performance solid-state lithium-metal batteries (SSLMBs) require solid electrolytes displaying outstanding electrochemical stability, excellent ionic conductivity, and high Li⁺ ion transference number. On top of these, it should also be compatible with the electrodes applied and functionable under room temperature. To achieve these, a solution-casting technique is proposed herein to prepare a flexible composite polymer electrolyte (CPE), which is equipped with a high ionic conductivity and Li⁺ ion transference number, concurrently applicable in the construction of high-voltage solid-state Li batteries. The proposed CPE, which is made up of poly(vinylidene difluoride-co-hexafluoropropylene) (PVDF-HFP)/polypropylene carbonate (PPC) blend with an Al-doped Li₇La₃Zr₂O₁₂ (Al-LLZO) filler, was sandwiched between PVDF-HFP/PPC–lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) skin layers with SN plasticizer added. This formulation of PVDF-HFP/PPC/Al-LLZO/LiTFSI/SN was abbreviated as sandwich-PPA in our study. Such configuration permits notable resistance reduction at the electrode–electrolyte interface while suppressing Li dendrite growth throughout the robust charging–discharging process. This can be attributed to the excellent performance of the sandwich composite electrolyte membrane, which promises high ionic conductivity (ca. 4.04 × 10^–4 S cm^–1) and a high Li⁺ ion transference number (ca. 0.583) at room temperature. A CR2032 coin cell, which is assembled with Al₂O₃-C@NCA/Sandwich-PPA/Li, delivered a high specific capacity (186.20 mAh g^–1 at 0.1C at room temperature), along with its excellent rate performance and cycle stability (discharge capacity of 126.23 mAh g^–1; capacity retention of 80.03% after 100 cycles at a rate of 0.5C at room temperature). This verified the potential of our novelty-formulated solid-state electrolyte to secure excellent performance of SSLMBs.

中文翻译：

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用于高压固态锂电池的基于 PVDF-HFP/PPC/Al 掺杂 LLZO 的三明治结构复合聚合物电解质

高性能固态锂金属电池 (SSLMB) 需要具有出色的电化学稳定性、出色的离子电导率和高 Li ⁺离子转移数的固体电解质。除此之外，它还应该与所应用的电极兼容，并在室温下发挥作用。为实现这些目标，本文提出了一种溶液流延技术来制备柔性复合聚合物电解质 (CPE)，该电解质具有高离子电导率和 Li +^离子转移数，同时适用于构建高压固态锂电池。拟议的 CPE，由聚（偏二氟乙烯-co）制成-六氟丙烯) (PVDF-HFP)/聚碳酸亚丙酯 (PPC) 与掺杂铝的 Li ₇ La ₃ Zr ₂ O ₁₂ (Al-LLZO) 填料的混合物，夹在 PVDF-HFP/PPC-双（三氟甲磺酰基）亚胺锂之间(LiTFSI) 表层，添加了 SN​​ 增塑剂。这种 PVDF-HFP/PPC/Al-LLZO/LiTFSI/SN 的配方在我们的研究中缩写为三明治-PPA。这种配置可以显着降低电极-电解质界面的电阻，同时在整个充放电过程中抑制锂枝晶的生长。这可归因于三明治复合电解质膜的优异性能，它具有高离子电导率（约4.04 × 10 ^–4 S cm^–1 ) 和室温下的高 Li ⁺离子转移数 ( ca. 0.583)。_{由 Al 2} O ₃ -C@NCA/Sandwich-PPA/Li组装而成的 CR2032 纽扣电池具有高比容量（室温 0.1C 时186.20 mAh g ^–1 ），以及出色的倍率性能和循环稳定性（放电容量为 126.23 mAh g ^–1；室温下以 0.5C 倍率循环 100 次后容量保持率为 80.03%）。这验证了我们新颖配方的固态电解质在确保 SSLMBs 卓越性能方面的潜力。