Comparative study of operational parameters in high-voltage cathode materials.

Abstract

This work investigates the synthesis and characterization of the high-voltage Li-ion battery cathode material LiMn_1,5Ni_0,5O₄ (LMNO) prepared by a conventional solid-state reaction. The material was synthesized through a precursor mixing step followed by calcination at 800 °C. Structural characterization was carried out by Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD), complemented by Rietveld refinement. The XRD results confirmed the formation of the spinel phase with the (Fd3m) crystal structure as the dominant phase, together with a slight oxygen deficiency and minor impurity phases. Electrochemical characterization was performed in half-cells by cyclic voltammetry (CV) and galvanostatic charge–discharge cycling at C/2 using different voltage windows (2.0–5.2, 2.5–5.0, and 3.0–5.0 V vs. Li/Li⁺). The results enabled optimization of the electrochemical performance of the material, demonstrating that the 2.5–5.0 V operating window provides the best balance between cycling stability and reversible capacity, achieving a capacity retention of 81% after 175 cycles with a discharge capacity of approximately ∿80 mAh g⁻¹.