Synergistically enabling the interface stability of lithium metal batteries with soft ionic gel and garnet-type Li6.4La3Zr1.4Ta0.6O12 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 Li6.4La3Zr1.4Ta0.6O12 (LLZTO) particles as inorganic ceramic filler were introduced in the layer to obtain composite electrolytes with high ionic conductivity (up to 1.1 x 10-3 S/cm at 25 degrees C). 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/cm2 at 50 degrees C, and the lithium metal batteries of LFP|THCE-15%LLZTO|Li delivers high initial discharge capacity of 128.2 mA center dot 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. (c) 2022 The Authors. Published by Elsevier B.V. on behalf of The Chinese Ceramic Society. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).