Chemical compatibility at the interface of garnet-type Ga-LLZO solid electrolyte and high-energy Li-rich layered oxide cathode for all-solid-state batteries
Natalia B. Timusheva, Alexander A. Golubnichiy, Anatolii V. Morozov, Arseniy S. Burov, Dmitry A. Aksyonov, Aleksandra A. Savina, Roman G. Markopolskii, Artem M. Abakumov
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).