Preparation of Li2+xInxZn1−xCl4+2x (0 ≤ x ≤ 0.5) solid electrolyte and its application in all-solid-state Li-ion batteries

Abstract

Li_2+xIn_xZn_1−xCl_4+2x (0 ≤ x ≤ 0.5) solid electrolytes were synthesized using a mechanochemical method. XRD indicated that the prepared samples had a cubic structure. The lattice parameter was dependent on the value of x. The cold-pressed pellet of the sample with x = 0.45 had an ionic conductivity of about 2.4 × 10⁻⁴ S cm⁻¹ at 25 °C and an activation energy of about 0.446 eV. The equivalence circuit and distribution of the relaxation time indicated that grain boundary resistance was the main component of the total resistance of the sample. The hot-pressed pellet of the sample with x = 0.45 had an ionic conductivity of about 9.2 × 10⁻⁴ S cm⁻¹ at 25 °C and an activation energy of about 0.300 eV, which were comparable with those of the reported halide-based solid electrolyte. The solid-state cell employing the sample with x = 0.45 as a solid electrolyte and bare LiNi_0.5Mn_0.3Co_0.2O₂ as the active material showed good cyclic ability at room temperature.