Improving the Interfacial Contact between Li7La3Zr2O12 and Lithium Anode by Depositing a Film of Silver

Cubic Li7La3Zr2O12 is a promising solid-state electrolyte as its high Li+ conductivity, wide electrochemical window, and good stability with lithium anode. However, the interfacial impedance between Li7La3Zr2O12 and lithium anode is high, which hinders the electrochemical performance of batteries. In this work, magnetron sputtering has been adopted to deposit a film of silver on two surfaces of LLZO to improve the interfacial contact between Li7La3Zr2O12 and lithium anode. The XRD, SEM, EDS and XPS show that a film of sliver is successfully deposited on LLZO. The EIS indicates the interfacial impedance between Li7La3Zr2O12 and lithium anode decreases from 661 Ω•cm2 to 26 Ω•cm2 after modification. In lithium plating and striping test, the modified symmetrical lithium battery exhibits a small and stable voltage at a current density of 0.4 mA cm−2, while the unmodified one presents a high and unstable voltage even at 0.05 mA cm−2.