Reactive flash synthesis and phase compositions of Li_x(CoCrFeMnNi)O_y (x = 0–1) oxides

In this paper, the reactive flash sintering method was adopted to synthesize a series of Li_x(CoCrFeMnNi)O_y oxides with x in the range of 0–1. The phase compositions and electrical conductivities of the oxides at different Li incorporation level were characterized. A single phase of spinel structure (Fd-3m) was obtained for the sample (CoCrFeMnNi)₃O₄. With incorporation of Li, the phase transformed into Rock-salt structure (Fm-3m) and then layered structure (R-3m). The ionic and electronic conductivities of the samples were characterized by impedance spectrometry. The ionic and electronic conductivities of the samples decreased with increasing Li incorporation level at first along with the spinel to Rock-salt structure transformation, and then increased with further increasing Li incorporation level along with the Rock-salt to layered structure transformation.