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

This is the authors' abstract. We don't add key points for this paper.

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. Herein, we design a gel polymer electrolyte (HPP), 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, fluorinated 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 3500 hours, 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.