Extensively Reducing Interfacial Resistance by Ultrathin Pt Layer between Garnet-type Solid-state-electrolyte and Li-metal Anode

Yu-Kai Liao^1*, Ru-Shi Liu*², Shu-Fen Hu*¹

¹Department of Physics, National Taiwan Normal University, Taipei, Taiwan
²Department of Chemistry, Nation Taiwan University, Taipei, Taiwan

* Presenter:Yu-Kai Liao, email:without013@gmail.com

All-solid-state Li-ion batteries (ASSLIBs), also known as next-generation batteries, have attracted much attention due to their high energy density and safety. The best advantage of ASSLIBs is the Li-metal anodes that could be used without safety issues. In this study, a highly conductive garnet solid electrolyte (Li6.75La3Zr1.75Ta0.25O12, LLZTO) was used in ASSLIB, and Pt film was used to modify the surface of LLZTO to prove the solution of Li-metal anode for LLZTO. Li-Pt alloy was synthesized to improve the wettability and contact of the interface. The interfacial resistance was reduced by 21 times, at only 9 Ω cm2. The symmetric cell could stably cycle over 3500 h at a current density of 0.1 mA cm−2. The full cell of Li | Li-Pt | LLZTO | LiFePO4 and Li | Li-Pt | LLZTO | LiMn0.8Fe0.2PO4 achieved high stability in terms of battery performance. Point-to-point contact transformed into homogeneous surface contact made the Li-ion flux faster and became more stable. This surface modification method could provide researchers with a new choice for fixing interface issues and promoting the application of high-performance ASSLIBs in the future.

Keywords: All-Solid-State Batteries, LLZO, Interfacial resistance, Ultra thin interlayer