Abstract
All-solid-state batteries (ASSBs) with a garnet-type solid electrolyte have been considered promising alternatives to traditional batteries with a liquid organic electrolyte, due to their enhanced safety and ability to accommodate high energy density electrodes. In this study, we conducted a comprehensive investigation of the high-temperature chemical compatibility between the garnet-like Li(6.4)Ga(0.2)La(3)Zr(2)O(12) (Ga-LLZO) electrolyte and high-energy-density Li-rich layered Li(1.2)Ni(0.2)Mn(0.6)O(2) cathode (LNM). Our findings suggest that a high temperature reaction between the Li-rich cathode and Ga-LLZO occurs at 700-900(o)C depending on the form of reactants. This reaction results in the formation of La(Ni, Mn)O(3) and Li(2)ZrO(3) as the two main products, as confirmed by powder X-ray diffraction and transmission electron microscopy analysis. Li(2)ZrO(3) was discovered for the first time as a reaction product, and its formation in the case of Li-rich layered cathode material was rationalized with DFT + U calculations. The results were also compared with those obtained for a typical layered high-energy-density cathode material LiNi(0.8)Mn(0.1)Co(0.1)O(2) (NMC811).