Polyether-based composite solid-state electrolyte to realize stable high-rate cycling for high-voltage lithium metal batteries at room temperature

• Published in: Materials today chemistry Vol. 40; p. 102219
• Main Authors: Li, Xinhao, Wang, Chen, Nan, Wenzheng, Peng, Sikan, Liu, Jin, Yan, Shaojiu
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.09.2024
• Subjects: Asymmetrical solid-state electrolyte; In situ polymerization; Poly(1,3-dioxolane); Polyether-based composite electrolyte; Solid-state lithium metal batteries; Poly(1,3-dioxolane); Asymmetrical solid-state electrolyte; Solid-state lithium metal batteries; In situ polymerization; Polyether-based composite electrolyte
• ISSN: 2468-5194; 2468-5194
• DOI: 10.1016/j.mtchem.2024.102219

Polyether electrolytes, which possess benefits in terms of lithium salt solubility, compatibility with lithium metal, and material availability, are promising candidate materials for solid-state lithium metal batteries with high safety and specific energy. However, achieving stable cycling at high rates under room temperature conditions for high-voltage lithium metal solid-state batteries is a significant challenge. In this study, a polyether-based composite solid-state electrolyte was fabricated via in situ polymerization, and a novel polyether matrix (PDSi) was synthesized by copolymerization of 1,3-dioxolane (DOL) and 3-(glycidoxypropyl)triethoxysilane (GPTES). The triethoxysilicon groups of PDSi improve the antioxidant capacity of polyether and interact with anionic groups, thereby enabling a wide electrochemical window of 5.5 V and a high lithium-ion transference number tLi+ of 0.56 at room temperature. In addition, a prepared PDSi@LLZTO electrolyte with an asymmetric structure mitigated the side reaction between the LLZTO ceramic filler and lithium. Here, PDSi@LLZTO exhibited a lithium-ion transference number of 0.67 and ionic conductivity of 1.28 × 10−4 S cm−1 at 20 °C. More importantly, the Li|PDSi@LLZTO|NCM523 cell demonstrated excellent capacity retention of 83.9 % after 200 cycles at a high-rate discharge of 3C. The proposed material and structure design provide a unique perspective for the development of an effective polymer-based electrolyte for high-voltage lithium metal batteries. A novel asymmetric electrolyte based on polyether-based modified with triethoxysilicon, enabling stable high-rate discharge of lithium metal solid-state batteries. [Display omitted] •A new asymmetric solid-state electrolyte was successfully prepared by in-situ polymerization•The electrolyte exhibits high ionic conductivity and a wide electrochemical stability window.•NCM523|Li cell exhibits excellent cycling stability at 3C.