Effect of LLZTO Tablet Pressing Process on Electrochemical Properties of Button Batteries

Abstract

The garnet‐type Li_6.4La₃Zr_1.4Ta_0.6O₁₂ (LLZTO) is a widely studied solid‐state electrolytes (SSEs) due to its high ionic conductivity and electrochemical stability. However, the conventional preparation process of LLZTO electrolyte tablets has encountered several issues such as powder embedment in the mold gaps and inadequate bonding between powders, leading to fragile electrolyte tablets that are prone to cracking. In this study, the effects of LLZTO electrolyte tablet pressing process parameters, including mixed powder content, polyvinyl alcohol (PVA) content and cold pressing pressure, on the electrochemical properties of button cells were investigated. The results indicated that the produced solid‐state electrolyte tablets with high quality, low interfacial resistance and low surface passivation layer (Li₂CO₃) content was obtained by using 0.8 g of mixed powder content, 0.7 g of PVA content and 20Mpa pressure. The interface resistance decreased from 2927.1 Ω to 1069.7 Ω under these conditions. Additionally, the Li symmetric cell treated with adhesive exhibited stable cycling for over 400 hours at 25 °C under a current density of 0.1 mA ⋅ cm⁻².