Transformation of Undesired Li ₂ CO ₃ into Lithiophilic Layer Via Double Replacement Reaction for Garnet Electrolyte Engineering

Garnet-type solid-state electrolytes (SSEs) are a remarkable Li-ion electrolyte for the realization of next-generation all-solid-state lithium batteries due to their excellent stability against Li metal as well high ionic conductivities at room temperature. However, garnet always contain undesired and hardly removable Li2CO3 contaminations that have persistently large resistance unstable interface contact with metal. This is critical bottleneck practical application electrolytes. Here, we design novel strategy completely root out both inside on surface garnet. achieved by so-called double replacement reaction between SiO2 during one-step hot press process densification. It leads in-situ transformation LixSiOy (LSO) mostly locating around grain boundaries Due higher ion conductivity better electrochemistry LSO than Li2CO3, modified shows much improved electrochemical performance. Moreover, wettability metals was significantly enhanced in absence Li2CO3. As proof concept, an assembled symmetric cell displays current density (CCD) 0.7 mA cm−2 low interfacial impedance (5 Ω cm2) 25 °C. These results indicate upcycling promising well-address degradation issue associated