Low temperature molybdenum oxide as host lattice for lithium intercalation

Abstract

The heat treatment of molybdenum oxide dihydrate resulting from the acidification of Na 2MoO 4 solution leads to various molybdenum trioxides MoO 3. Electrochemical Li insertion into these compounds varies depending on the temperature required for drying the MoO 3 · 2H 2O (250,400 and 500 °C). The lower the temperature of the heat treatment, the better is the electrochemical performance. The lowest temperature 250 °C induced the formation of a long-range disordered oxide characterized by a high surface area exhibiting the best performance both in terms of specific capacity (≈ 2F/MoO 3) and cycling efficiency, which were found to be significantly higher than that usually obtained for the conventional crystalline or amorphous MoO 3 or for the heat-treated form at 500 °C (≈ 1.5F/MoO 3). For example, when galvanostatic cycling experiments are performed at a C/10 discharge-charge rate within cycling limits 3.8/2 V, ∼ 300 Ah kg −1 oxide were still recovered after 10 cycles.