A Room‐Temperature Self‐Healing Liquid Metal‐Infilled Microcapsule Driven by Coaxial Flow Focusing for High‐Performance Lithium‐Ion Battery Anode

Abstract Liquid metals have attracted a lot of attention as self‐healing materials in many fields. However, their applications in secondary batteries are challenged by electrode failure and side reactions due to the drastic volume changes during the “liquid‐solid‐liquid” transition. Herein, a simple encapsulated, mass‐producible method is developed to prepare room‐temperature liquid metal‐infilled microcapsules (LMMs) with highly conductive carbon shells as anodes for lithium‐ion batteries. Due to the reasonably designed voids in the microcapsule, the liquid metal particles (LMPs) can expand freely without damaging the electrode structure. The LMMs‐based anodes exhibit superior capacity of rete‐performance and ultra‐long cycling stability remaining 413 mAh g −1 after 5000 cycles at 5.0 A g −1 . Ex situ X‐ray powder diffraction (XRD) patterns and electrochemical impedance spectroscopy (EIS) reveal that the LMMs anode displays a stable alloying/de‐alloying mechanism. DFT calculations validate the electronic structure and stability of the room‐temperature LMMs system. These findings will bring some new opportunities to develop high‐performance battery systems.