Effect of a self-assembling La2(Ni0.5Li0.5)O4 and amorphous garnet-type solid electrolyte composite on a layered cathode material in all-solid-state batteries

Abstract

In this article, we report the effect of a Li6_.75La₃Zr₂Al_0.25O₁₂ (LLZAO) composite Li(Ni_0.8Co_0.1Mn_0.1)O₂ (NCM811) cathode material on the performance of all-solid-state batteries (ASSBs) with oxide-based organic/inorganic hybrid solid electrolytes. The layered structure of Ni-rich cathode material Li(Ni_xCo_(1−x)/2Mn_(1−x)/2)O₂ (x > 0.6) (NCM) exhibiting a high specific capacity is among the suitable cathode materials for next-generation energy storage systems, particularly electric vehicles and portable devices for all-solid-state batteries. However, the ASSBs present a problem—the resistance at the interface between a cathode and solid electrolyte is larger than that with a liquid electrolyte because of point contact. To solve this problem, using a simultaneous co-precipitation method, we composited various amounts of LLZAO material and an ion conducting material on the cathode material's surface. Therefore, to optimize the value of the LLZAO material in the composite cathode material, the structure, cycling stability, and rate performance of the NCM–LLZAO composite cathode material in ASSBs with oxide-based inorganic/organic-hybrid electrolytes were investigated using powder X-ray diffraction analysis, field-emission scanning electron microscopy, electrochemical impedance spectroscopy, and galvanostatic measurements.