Electrochemical Alkali Metal Intercalation into the 3D-framework of MP₂O₇ (M = Mo, W)

抄録

Lithium and sodium insertions into pyrophosphates MP₂O₇ (M = Mo, W) were investigated electrochemically as possible cathodes for ion-transfer batteries. Lithium and sodium were reversibly incorporated in the 3D-framework of pyrophosphates MP₂O₇ (M = Mo, W) with liquid organic electrolytes at room temperature. The first discharge capacities were 95 mAhg⁻¹ for A_1.0MoP₂O₇ (A = Li, Na) and 295 mAhg⁻¹ for A_4.0WP₂O₇ (A = Li, Na), respectively. The guest (Li or Na) insertion into WP₂O₇ induced a transition to the amorphous phase, whereas the insertion into MoP₂O₇ proceeded topotactically with a smooth single phase reaction.