Stabilizing Solid Electrolyte Interphase on Liquid Metal via Dynamic Hydrogel-Derived Carbon Framework Encapsulation.

Eutectic gallium-indium liquid metal (EGaIn-LM), with a considerable capacity and unique self-healing properties derived from its intrinsic liquid nature, has gained tremendous attention for lithium-ion batteries (LIBs) anode applications. However, the fluidity of the LM could trigger continuous consumption of the electrolyte, and its liquid-solid transition during the lithiation/de-lithiation process may result in the rupture of the solid electrolyte interface (SEI). Herein, we employed LM as an initiator to in-situ assemble the 3D hydrogel framework for dynamic encapsulating itself, the LM nanoparticles could be homogeneously confined into the hydrogel-derived carbon framework (HDC) after calcination. Such design effectively alleviates the volume expansion of LM, facilitates electron transportation, and improves the reaction kinetics, resulting in a superior rate capability (252.1 mAh g -1 at 20 A g -1 ) and long-term cyclability (248.1 mAh g -1 at 10 A g -1 after 10 000 cycles). Furthermore, we revealed the dual-layer SEI structure and its key components, including the robust LiF outer layer and corrosion-resistant and ionic conductive LiGaO x inner layer, confirming that the involvement of LM in the formation of SEI, as well as the important role of carbon framework in reducing interfacial side reactions and SEI decomposition. This work not only provides a distinct perspective for the formation, structural evolution, and composition of SEI at the liquid/solid interface but also demonstrates an effective strategy to construct a reliable matrix for stabilizing the SEI. This article is protected by copyright. All rights reserved.