Stoichiometric Li 4 Mn 5 O 12 spinel oxide has been synthesized by an oxidation of Mn 2 + by lithium peroxide in the presence of excess lithium hydroxide followed by firing at T ⩽ 500°C. The sample has been characterized by X‐ray diffraction, elemental and oxidation state analyses and thermogravimetric analysis. X‐ray results indicate that Li 4 Mn 5 O 12 begins to disproportionate at T > 500°C to give Li 1 + x Mn 2 − x O 4 ( x < 0.33) and Li 2 MnO 3 . The samples fired at 400 and 500°C show in the voltage range 3.3–2.3 V, an initial capacity of 160 and 153 mAh/g, respectively, which is close to the theoretical value. The sample fired at 500°C shows excellent cyclability with <2% capacity decline over 40 cycles.
No takes yet. Share an insight, caveat, or question.
Kim et al. (1998) studied this question.