RESEARCH ARTICLE

In-situ polymerized siloxane cages for an interface-stable gel polymer electrolyte in lithium-metal batteries

¹ College of Chemistry & Chemical Engineering, Central South University, Changsha 410083, China
² State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China
³ Changsha Research Institute of Mining and Metallurgy Co., Ltd., Changsha 410012, China

^* Corresponding authors (emails: This email address is being protected from spambots. You need JavaScript enabled to view it. (Benhua Wang); This email address is being protected from spambots. You need JavaScript enabled to view it. (Bowei Ju); This email address is being protected from spambots. You need JavaScript enabled to view it. (Libao Chen))

Received: 17 October 2025
Revised: 26 November 2025
Accepted: 29 November 2025

Abstract

The rising demand for high energy density and safe rechargeable batteries calls for alternatives beyond conventional lithium-ion systems. Lithium metal batteries (LMBs) offer ultrahigh theoretical capacity but face critical challenges, including interfacial instability, dendritic lithium growth, and degradation of high voltage cathodes. Herein, we design a gel polymer electrolyte (HPP) via in-situ polymerization, integrating a fluorinated polymer network with highly cross-linked polyhedral oligomeric silsesquioxane (POSS) cages. The three-dimensional network enhances mechanical strength and promotes uniform Li⁺ transport, effectively suppressing dendrite formation. Simultaneously, fluorine-rich components extend the electrochemical stability window and enable a robust lithium fluoride (LiF) rich interphase, stabilizing the cathode interface. Benefiting from this synergistic design, Li||Li symmetric cells exhibit stable cycling for over 4500 h, while full cells retain 79% capacity after 500 cycles at 0.5 C and 87% after 200 cycles at 1 C. This work offers a rational strategy for electrolyte design to regulate interfacial chemistry and accelerate the development of high-performance LMBs.