Synergistically enabling the interface stability of lithium metal batteries with soft ionic gel and garnet-type Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)ceramic filler

Lithium metal batteries based on solid electrolytes are considered as promising candidates with high energy density and safety.However,the weak solid-solid contact between electrolyte and electrode can easily lead to interface instability and lithium ions discontinuous migration,which seriously reduces the electrochemical performance of the battery.Herein,we construct a soft gel interfacial layer to improve the stability of the solid-solid interface between electrolyte and electrode by means of polyester-based monomers and imidazole-based ionic liquids.Based on this,garnet-type Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZTO)particles as inorganic ceramic filler were introduced in the layer to obtain composite electrolytes with high ionic conductivity(up to 1.1×10^(-3)S/cm at 25℃).As a result,the assembled lithium symmetric battery of Li|THCE-15%LLZTO|Li suggests excellent cycling stability with 700 h at 0.1 mA/cm^(2)at 50℃,and the lithium metal batteries of LFP|THCE-15%LLZTO|Li delivers high initial discharge capacity of 128.2 mA·h/g with capacity retain of 75.48%after 150 cycles at 2 C.This work paves a new route to build safe and stable lithium metal batteries with synergistic introduction of composite electrolytes between electrolyte and electrode using soft gel interfacial layer and inorganic filler.