Solution combustion synthesis of LiMn1.5Ni0.5O4 cathode material for Li ion storage: Effect of solvent type

In this work, LiMn 1.5 Ni 0.5 O 4 (LMNO) powders were synthesized via solution combustion using methanol, ethanol, and distilled water as solvents to investigate the solvent-dependent effects on structure, morphology, and electrochemical performance. X-ray diffractometry confirmed the direct formation of the spinel LMNO phase for ethanol- and water-assisted syntheses, whereas methanol-derived powders contained secondary phases and required post-calcination treatment. All LMNO powders exhibited a spongy microstructure; however, ethanol-assisted samples showed higher specific surface area and larger pore volume. As a result, the ethanol-derived LMNO delivered a higher initial discharge capacity of 134 mAh g⁻¹ at 0.1C. In contrast, the water-derived LMNO exhibited superior electrochemical durability, achieving 99% capacity retention over 200 cycles at 1C and maintaining 81% capacity retention from 0.1C to 1C. These results demonstrate a solvent-dependent trade-off between capacity enhancement at low C-rates and long-term cycling stability at high C-rates in combustion-synthesized LMNO material.