Electrophoretically Deposited Na3V2(PO4)3 and its Carbonaceous Composites as Promising Cathode for Sodium-ion Batteries

Abstract

Sodium vanadium phosphate (NVP), a sodium ion super ionic conductor (NASICON), is one of the most attractive cathode materials for sodium ion batteries (SIBs). Electrophoretic deposition (EPD) is demonstrated to be an efficient synthesis tool to deposit strongly adhered and porous NVP carbonaceous material (viz. carbon nano tube (CNT) and reduced graphene oxide (rGO)) on aluminum current collector. EPD grown NVP delivers a stable reversible capacity ∼53.7 mAhg−1 at 0.1Ag−1 current density after 250 cycles. The introduction of CNT and rGO in the electrode significantly improves the electrochemical properties of NVP by providing better conduction pathways. Consequently, reversible capacities of 87 mAhg−1 and 70 mAhg−1 were obtained after 250 cycles at 0.1Ag−1 for NVP/RGO-CB and NVP/CNT-CB electrodes, respectively. These electrodes are able to deliver specific capacities of ∼70 mAhg−1 at a current density of 5Ag−1. Moreover, these electrodes were able to retain more than 80% of its initial capacity even after 2000 cycles at a high current density of 3Ag−1.