Boosting sodium-ion battery performance using Na3(VO)2(PO4)2F microrods self-embedded in a 3D conductive interpenetrated framework.

Na 3 (VO) 2 (PO 4) 2 F (NVPOF) is considered as a promising cathode candidate for sodium-ion batteries (SIBs) owing to the high theoretical capacity and operating voltage. However, the challenges of its rate capability and cyclability limit its widespread application. Herein, the reduced graphene oxide decorated NVPOF microrods (NVPOF@G) are successfully synthesized by a facile hydrothermal-induced self-assembly procedure. It is found that the graphene oxides added act as a crystal nucleation growth regulator and provide rapid Na+ and electron transport in the electrodes. The prepared NVPOF@G microrods exhibit a superior rate capability of 82.2 mAh g−1 at 50 C (fast discharge in 72 s) as well as considerable long-term cycle stability with a capacity retention of 87.6% over 1000 cycles at 0.5 C. Even at 50 °C, the NVPOF@G still achieves a high reversible capacity of 109.4 mAh g−1 with a capacity retention of 87.7% after 1000 cycles. This microrod structure shows superior structural stability, even at high temperatures (50 °C). Such a cathode incorporates the benefits of batteries and supercapacitors. This work gives a way to fabricate microrod-structure phosphate-based materials for commercial applications in high-performance SIBs. [Display omitted] • An interpenetrated framework cathode of Na 3 (VO) 2 (PO 4) 2 F microrods and reduced graphene oxides is prepared. • The interpenetrated framework provides rapid Na+ and electron transport in the electrode. • The interpenetrated framework mitigates the crystalline stress and limits the subsequent corrosion by electrolytes. • The prepared cathode exhibits a superior rate capability of 82.2 mAh g−1 at 50 C. • The prepared cathode achieves a high capacity retention of 87.7% after 1000 cycles at 50 °C. [ABSTRACT FROM AUTHOR]