Isovalent multi-component doping strategy for stabilizing cubic-Li7La3Zr2O12 with excellent Li mobility

Stabilizing the cubic phase of Li7La3Zr2O12 (LLZO) through doping has been a challenging issue, as conventional aliovalent dopants often decrease Li ion mobility and induce unwanted phase transformations. In this study, a novel multi-component doping strategy is proposed that stabilizes the cubic phase of LLZO while maintaining high Li ion mobility. The practical isovalent ions and their combinations are screened using density-functional theory (DFT) calculations and ab-initio molecular dynamics (AIMD) simulations, identifying the most stable multi-component alloy configuration that can stabilize the robust cubic phase of LLZO. Our results demonstrate that the proposed Li7La3(Zr, Hf, Ce, Ru)2O12 composition has a stable cubic phase at low temperatures, which we validated through experimental synthesis. Our proposed doping strategy has the potential to advance the development of high-performance all-solid-state batteries.

Automated summary

This study proposes a novel multi-component doping strategy that stabilizes the cubic phase of LLZO while maintaining high Li ion mobility. Using DFT calculations and AIMD simulations, practical isovalent ions and their combinations were screened, and the most stable multi-component alloy configuration was identified. Experimental synthesis confirmed that the proposed Li7La3(Zr, Hf, Ce, Ru)2O12 composition maintains a stable cubic phase at low temperatures. This doping strategy has the potential to advance the development of high-performance all-solid-state batteries.