An Organic/Inorganic Composite Gel Electrolyte Inducing Uniformly Lithium Deposition at High Current Density and Capacity

Abstract Although gel polymer electrolytes (GPEs) have attracted tremendous attention for lithium metal batteries due to their high ionic conductivity, high safety, and excellent adaptability, it is still challenging to suppress the uncontrollable lithium dendrite growth for GPEs. Here, an organic/inorganic composite gel electrolyte (PPPL) as GPEs is proposed, which is formed by ring‐opening polymerization reaction of poly(methyl vinyl ether‐alt‐maleic anhydride) (PMVE‐MA) and polyethylene glycol (PEG) in polymer matrix of poly(vinylidene fluoride‐hexafluoropropylene) (PVDF‐HFP) embedded with Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12 (LLZTO) particles. The PMVE‐MA participates in the formation of a stable solid electrolyte interface (SEI) and the PEG greatly improves the flexibility of PPPL. The PPPL exhibits excellent performance in terms of a wide electrochemical window (4.7 V), high lithium transference number (0.59), and satisfactory mechanical strength (11 MPa). Besides, the PPPL contributes to the formation of stable and flexible SEI containing organic components and LiF on lithium metal, and constructs fast and uniform lithium transport channels to effectively suppress the lithium dendrite growth. The Li/PPPL/Li symmetric batteries can stably cycle 800 h at the high current density of 5 mA cm –2 and capacity of 5 mAh cm –2 . The outstanding electrochemical performance of the PPPL will provide important insights for design of advanced GPEs.