Key Laboratory of Engineering Dielectric and Applications, Ministry of Education, School of Electrical and Electronic Engineering, Harbin University of Science and Technology, Harbin 150080, China.
ACS Appl Mater Interfaces. 2023 May 3;15(17):21526-21536. doi: 10.1021/acsami.3c02678. Epub 2023 Apr 18.
Lithium-ion batteries (LIBs) have achieved a triumph in the market of portable electronic devices since their commercialization in the 1990s due to their high energy density. However, safety issue originating from the flammable, volatile, and toxic organic liquid electrolytes remains a long-standing problem to be solved. Alternatively, composite solid electrolytes (CSEs) have gradually become one of the most promising candidates due to their higher safety and stable electrochemical performance. However, the uniform dispersity of ceramic filler within the polymer matrix remains to be addressed. Generally, all-solid-state lithium metal batteries without any liquid components suffer from poor interfacial contact and low ionic conductivity, which seriously affect the electrochemical performance. Here we report a CSE consisting of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), polydopamine (PDA) coated LiLaZrTaO (LLZTO) (denoted as PDA@LLZTO) microfiller, polyacrylonitrile (PAN), and poly(vinylidene fluoride--hexafluoropropylene) (PVDF-HFP). Introducing only 4 μL of liquid electrolyte at the electrode|electrolyte interface, the CSE-based cells exhibit high ionic conductivity (0.4 × 10 S cm at 25 °C), superior cycle stability, and excellent thermal stability. Even under low temperatures, the impressive electrochemical performance (78.8% of capacity retention after 400 cycles at 1 C, 0 °C, and decent capacities delivered even at low temperature of -20 °C) highlights the potential of such quasi-solid-state lithium metal batteries as a viable solution for the next-generation high-performance lithium metal batteries.
锂离子电池（LIB）自 20 世纪 90 年代商业化以来，由于其高能量密度，在便携式电子设备市场取得了巨大成功。然而，由于易燃、易挥发和有毒的有机液体电解质，安全问题仍然是一个亟待解决的长期问题。相比之下，复合固态电解质（CSE）由于其更高的安全性和稳定的电化学性能，逐渐成为最有前途的候选者之一。然而，陶瓷填料在聚合物基体中的均匀分散性仍然是一个待解决的问题。一般来说，没有任何液体成分的全固态锂金属电池由于界面接触不良和离子电导率低，严重影响了电化学性能。在这里，我们报告了一种由双（三氟甲烷磺酰）亚胺锂（LiTFSI）、聚多巴胺（PDA）包覆的 LiLaZrTaO（LLZTO）（记为 PDA@LLZTO）微填料、聚丙烯腈（PAN）和聚（偏二氟乙烯-六氟丙烯）（PVDF-HFP）组成的 CSE。在电极|电解质界面仅引入 4 μL 液体电解质，基于 CSE 的电池表现出高离子电导率（25°C 时为 0.4×10 S cm）、优异的循环稳定性和良好的热稳定性。即使在低温下，令人印象深刻的电化学性能（在 1 C、0°C 下 400 次循环后容量保持率为 78.8%，甚至在低温-20°C 下也能提供良好的容量）突出了这种准固态锂金属电池作为下一代高性能锂金属电池的可行解决方案的潜力。
