Freeze drying synthesis of Li₃MnO₄ cathode material for Li-ion batteries: A physico-electrochemical study

Highlights: • Facilitated synthesis of Li₃MnO₄ with a smaller thermal budget via freeze drying. • Electrochemical activity enhanced by micro- and nanostructure modifications. • Capacity increase of 30% at 1st discharge versus standard synthesis process. - Abstract: Li₃MnO₄, a lithium rich phase containing manganese (V), is a promising cathode material for Li-ion batteries due to its very high theoretical capacity (698 A h kg⁻¹). Li₃MnO₄ was synthesized from freeze dried precursors at 398 K. Combined structural, morphological and chemical characterization by XRD, TGA, SEM, TEM and XPS revealed improvements in the micro- and nanostructure in comparison to the material synthesized by a standard solid state chemistry route. The average particle size decreased from 10 μm to 3.5 μm and the average crystallite size from close to 100 nm to around 30 nm. These modifications enhanced the capacity (23% at 10 A kg⁻¹ and up to 31% at 50 A kg⁻¹ with a maximum discharge capacity of 290 A h kg⁻¹) and the rate capability