Reversible Calcium-Ion Insertion in NASICON-Type NaV2(PO4)(3)

Abstract

The recent discovery of reversible plating and alloying of calcium has invoked considerable interest in calcium-based rechargeable batteries toward overcoming the limitations of conventional Li-ion batteries. However, only a few cathode materials have been tested thus far, and these exhibit low energy-storage capability and poor cyclability. Herein, the highly reversible Ca-intercalation capability of NASICON-type NaV2(PO4)3 makes it a potential cathode material for nonaqueous Ca-ion batteries, with high capacity and voltage and good cyclability (90 mA h g-1 and ∼3.4 V at 11.7 mA g-1 and 75 °C; 70 mA h g-1 and ∼3.2 V at 5.85 mA g-1 and 25 °C). Although this work shows only the capability of the cathode, not a full-cell performance, it does demonstrate experimentally that a poly-oxyanionic material can provide an outstanding host structure for Ca diffusion at room temperature with high energy-storage capability. © 2020 American Chemical Society.