Garnet based solid-state batteries have the advantages of wide electrochemical window and good chemical stability. However, at Li-garnet interface, the poor interfacial wettability due to Li2CO3 passivation usually causes large resistance and unstable contact.
In a study conducted by the research team led by Prof. LI Chilin at Shanghai Institute of Ceramics of Chinese Academy of Sciences, a Li2CO3-affiliative mechanism is proposed for air-accessible interface engineering of garnet electrolyte via facile liquid metal (LM) painting. The natural LM oxide skin enables a superior wettability of LM interlayer towards ceramic electrolyte and Li anode. Therein the removal of Li2CO3 passivation network is not necessary, in view of its delamination and fragmentation by LM penetration. This dissipation effect allows the lithiated LM nanodomains to serve as alternative Li-ion flux carriers at Li-garnet interface. This mechanism leads to an interfacial resistance as small as 5 Ω cm2 even after exposing garnet in air for several days. The ultrastable Li plating and stripping across LM painted garnet can last for 9930 h with a small overpotential.
△ Wetting behavior of LM in air on garnet surface
This work was published in Nature Communications. PhD student MENG Junwei at University of Chinese Academy of Sciences (institute: Shanghai Institute of Ceramics, Chinese Academy of Sciences) is the first author. This work was supported by National Key R&D Program of China, National Natural Science Foundation of China, and Shanghai Science and Technology Committee.
