NaMoO2PO4 glass ceramic nanocomposite as a novel cathode material for magnesium-ion batteries

Abstract

Unlocking superior Mg-ion cells with good cycling performance as a future battery candidate is now crucial. However, structural instability is mainly reported in current oxide frameworks. Additionally, poor diffusion kinetics are typical due to the affinity of Mg²⁺ ions to interact with oxide anions. Herein, NMoP-0 glass was obtained according to the molar ratio 20 Na₂S to 40 MoO₃-40 P₂O₅ mol%. NMoP-0 was thermally treated to obtain NMoP-8 and NMoP-12 glass ceramic nanocomposites (GCN) to obtain the desired NaMoO₂PO₄. XRD identified the crystal structure of NMoP-12 to be NaMoO₂PO₄ with a crystallite size of 38 nm. The electrodes were tested by EIS, CV, and GCD in three and two electrode systems, both confirming their reversible electrochemical activity. The initial specific capacitance values of NMoP-0, NMoP-8, and NMoP-12 in Mg-ion cells were estimated to be 214, 82, and 130 mAh g⁻¹, respectively. Meanwhile, the NMoP-12 cells showed the best capacity retention behavior and a diffusion coefficient \(\sim\) 10⁻¹⁴, which means that Mg²⁺ ion diffusion in NMoP-12 is moderately favorable. This promising performance of NaMoO₂PO₄ GCN suggests its potential as a novel cathode material for magnesium-ion batteries, sparking hope for future advancements in battery technology.