In situ soft-chemistry synthesis of β-Na_0.33V₂O₅ nanorods as high-performance cathode for lithium-ion batteries

β-Na_0.33V₂O₅ nanorods were prepared via a facile soft-chemistry strategy using Na⁺ intercalated (NH₄)_0.5V₂O₅ nanosheets as precursor. Based on X-ray diffraction, Fourier transform infrared spectra and scanning electron microscope analysis, the formation mechanism of β-Na_0.33V₂O₅ nanorods is proposed, which involves cation co-intercalation and crystal structure slip as well as a phase transformation process induced by cation release. When used as cathode for lithium-ion batteries, β-Na_0.33V₂O₅ nanorods calcined at 600 °C exhibited good stable cycling behaviour with high capacity retention of 81.3% after 50 cycles. Reversible discharge capacities of 237.8, 199.8, 183.5, 151.7 mA h g⁻¹ and 110.5 mA h g⁻¹ can be delivered at 30, 60, 150, 300 and 600 mA g⁻¹, respectively. It is expected that the Na_0.33V₂O₅ nanorods could be employed as a promising cathode material in rechargeable lithium-ion batteries.