Li^sup +^ transport channel size governing Li^sup +^ migration in garnet-based all-solid-state lithium batteries

Li+ transport channel size of garnet-type Li7La3Z2O12 (LLZO) solid electrolytes is continuously regulated to study its governing of Li+ migration in application of all-solid-state batteries. Results show that the Li+ migration activation energy decrease with the decrease of Li+ transport channel size and then increase with further decrease of Li+ transport channel size. With Li+ transport channel size of 12.954 Å, the Li+ migration activation energy reaches minimum of 0.28 eV. The cyclic voltammogram of Au/Li7La3-XCaXZr2-YTaYO12/Li cells show that, with Li+ transport channel size of 12.954 Å, the redox peaks is at ±0.23 V, which is more symmetrical and closer to 0 V compared to both larger and smaller Li+ transport channel size of 12.961 Å (0.38 V and −0.32 V) and 12.935 Å (0.50 V and −0.40 V). This suggests that LLZO with Li+ transport channel size of 12.954 Å has better charge-discharge reversibility of lithium deposition and dissolution and less energy consumption when used as solid electrolyte in all-solid-state lithium batteries.