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

Abstract Li + transport channel size of garnet-type Li 7 La 3 Z 2 O 12 (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 A, the Li + migration activation energy reaches minimum of 0.28 eV. The cyclic voltammogram of Au/Li 7 La 3-X Ca X Zr 2-Y Ta Y O 12 /Li cells show that, with Li + transport channel size of 12.954 A, 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 A (0.38 V and −0.32 V) and 12.935 A (0.50 V and −0.40 V). This suggests that LLZO with Li + transport channel size of 12.954 A 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.