Nasicon material NaZr2(PO4)3: a novel storage material for sodium-ion batteries

Abstract

A new type of anode material for sodium-ion batteries is proposed which has been synthesized through solid state reaction. The galvanostatic charge/discharge cycling is carried out with a voltage range of 0.01–2.5 V vs. Na⁺/Na. First-principles calculations are also employed to theoretically investigate the crystal structure change and the insertion–extraction mechanism of Na ions in the NaZr₂(PO₄)₃ structure. The Nasicon material exhibits an excellent reversible charge/discharge capacity under different current densities, which is mainly attributed to the open and strongly bonded NaZr₂(PO₄)₃ structure, allowing the high mobility of the Na ions tunnelling through the PO₄–ZrO₆ polyhedra chain.