Enthalpy of formation of Li1+xMn2−xO4 (0 < x < 0.1) spinel phases

• The enthalpies of formation of Li1+xMn2−xO4 spinels were measured.
• High temperature oxide melt drop solution calorimetry was used.
• One commercial and two sol–gel synthesized samples were investigated.
• The enthalpies of formation depend on the value of x in Li1+xMn2−xO4.
• The Li-rich boundary of Li1+xMn2−xO4 in air was confirmed.

The enthalpies of formation of Li1+xMn2−xO4 (0 < x < 0.1) spinel phases were measured using high temperature oxide solution calorimetry in a sodium molybdate solvent at 701 °C. One commercially available LiMn2O4 powder and two Li1+xMn2−xO4 samples synthesized using the sol–gel method were used for the measurements. The enthalpies of formation of the spinels from the binary constituent oxides and from the elements become more exothermic with increasing lithium content and increasing average oxidation state of the manganese cation in the range 0 < x < 0.1. Additionally, the lithium-rich boundary of the Li1+xMn2−xO4 phase for 0 < x < 0.1 was re-investigated using differential thermal analysis combined with thermogravimetric analysis.