Improving Interfacial Contact within Solid-State Lithium Batteries using the Composite Materials at the Cathode Produced by a Scalable Mechanofusion Process

Abstract

Even though PEO-based electrolytes have been interested as a solution for developing the next-generation lithium-based batteries, their performances are still far from the commercial need and requirement. One of the major challenges limiting the cycling performance of all-solid-state batteries is at the interfacial contact of the electrode and the ceramic electrolyte, not like in the case of liquid electrolyte. To address this poor solid-solid contact, we introduce a cathode composite concept by combining both ceramic filler and polymer with LiFePO4 (LFP) cathode material. Herein, the garnet (Li7La3Zr2O12, LLZO) ceramic is well mixed with LFP cathode material using a new solid-solid mixing process namely a mechano-fusion technique. PEO is also used as a binder during the cathode preparation. The PEO-based composited electrolyte layer (filled with LLZO) and the composite material used at the cathode are stacked layer-by-layer and hot-pressed. As a result, this composite concept produced by a scalable mechanofusion process could be useful for further develop high-performance the all-solid-state batteries.