Effect of surface modification and oxygen deficiency on intercalation property of lithium nickel manganese oxide in an all-solid-state battery
Abstract LiNbO 3 -coated LiNi 0.5 Mn 1.5 O 4 powders were synthesized by a sol–gel method, and their intercalation property as a cathode material was investigated using all-solid-state batteries with Li 10 GeP 2 S 12 solid electrolyte and In–Li metal anode. The LiNbO 3 coating delivered reversible lithium intercalation of LiNi 0.5 Mn 1.5 O 4 through an electrochemical interface with the Li 10 GeP 2 S 12 . Oxygen-deficient LiNi 0.5 Mn 1.5 O 4 − δ with a higher electronic conductivity than LiNi 0.5 Mn 1.5 O 4 improved the intercalation activity. An all-solid-state battery consisting of 3 wt.%-LiNbO 3 -coated LiNi 0.5 Mn 1.5 O 4− δ /Li 10 GeP 2 S 12 /In–Li exhibited a discharge capacity of 80 mAh g − 1 at the first cycle with an average discharge voltage of 4.1 V (vs. In-Li), which demonstrates the possibility of 5 V class all-solid-state batteries with a high voltage spinel cathode.