Surface-functionalized metal–organic framework with high specific surface area optimizing composite solid electrolyte for high-performance solid-state lithium metal batteries

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 501; p. 157704
• Main Authors: Chen, Guoqiang, Jin, Bo, Sun, Shitong, Jiang, Qing
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2024
• Subjects: Composite solid electrolyte; Solid-state lithium metal battery; Surface functionalization; Zeolitic imidazole framework; Surface functionalization; Zeolitic imidazole framework; Solid-state lithium metal battery; Composite solid electrolyte
• ISSN: 1385-8947
• DOI: 10.1016/j.cej.2024.157704

A composite solid electrolyte containing polydopamine-modified ZIF-8 (ZIF-8@PDA) as a filler is designed to approach the good electrochemical properties. The existing abundant surface functional groups of polydopamine promote the segment motion of polymer chain, and strengthen the interaction between polymer and filler, which lead to high performance of solid-state lithium metal batteries. [Display omitted] •ZIF-8 with high specific surface area is obtained and used in PHZP electrolyte.•Both LiN3 and LiF are in situ formed in electrolyte/electrode interface.•PHZP has a good interfacial stability and compatibility with Li anode.•Full cells with PHZP electrolyte show the good electrochemical performance. Solid-state lithium metal batteries (SSLMBs) are the potential candidates of next-generation batteries for safety and remarkable energy density against lithium ion batteries with liquid electrolyte widely applied these days. Even if composite solid electrolytes (CSEs), as the core of SSLMBs, have drawn much attention and devotion for the promising application potential, they are subject to low ionic conductivity, insufficient mechanical strength, and severe interfacial stability deficiency. Herein, we prepare a composite solid electrolyte containing poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) as a polymer matrix and polydopamine-modified ZIF-8 (ZIF-8@PDA) as a filler to tackle the challenges, and named as PHZP. The existing PDA on ZIF-8 particle’s surface is helpful to the uniform dispersal of filler in the whole composite solid electrolyte. Consequently, the PHZP membrane exhibits the good properties in ionic conductivity of 0.31 mS cm−1 at 25 ℃, enhanced lithium-ion transference number of 0.41, and extended electrochemical window of 4.8 V. More importantly, the PHZP membrane demonstrates the plating/stripping performance of Li in Li||PHZP||Li symmetric cell for over 2700 h with a small overpotential. LiNi0.5Co0.2Mn0.3O2||PHZP||Li (NCM523||PHZP||Li) cell possesses the first discharge capacity of 150 mAh/g and a capacity retention rate up to 95.8 % after 400 cycles at 0.5 C, and a capacity retention rate of 89 % after 800 cycles at 1 C. In the meantime, LiFePO4||PHZP||Li (LFP||PHZP||Li) cell also provides a capacity retention rate of 94.2 % after 100 cycles at 0.1 C. This work provides a simple and promising strategy to enhance the electrochemical performance of CSEs in SSLMBs, which would also be applied to the other energy storage/conversion fields.