From Li 2 NiO 3 to high-performance LiNiO 2 cathodes for application in Li-ion and all-solid-state batteries.

The synthesis of LiNiO 2 (LNO) typically involves oxidizing Ni(II) to Ni(III), thus leading to Ni Li point-defect formation. Here, materials containing Ni(IV) in the form of overlithiated Li 1+ x Ni 1- x O 2 (0 ≤ x ≤ 1/3) are converted into LNO. This method produces low defect-density samples at high temperatures, offering an attractive route toward coarse-grained particles that are naturally coated by the byproduct Li 2 O. In thiophosphate-based solid-state batteries, this kind of self-coating effect shows a direct correlation between residual lithium content and cycling performance.