The performance of sodium ion battery with NaFePO4 cathode prepared from local iron sand

Abstract

Abstract The performance of Sodium-Ion Battery, SIB, with NaFePO4 cathode prepared from local iron sand was investigated. The NaFePO4 was prepared through electrochemical sodiation to FePO4 layer on aluminium substrate. NaFePO4 prepared from local iron sand (from NTB, Indonesia) is named as NFP_A. The result is compared to the performance of SIB with NaFePO4 cathode prepared from a commercial FePO4, which is named as NFP_B. The SIB was fabricated in a split cell test type and a pouch type. Battery performance was measured by Cyclic Voltammetry (CV) analysis, Galvanostatic Charge-Discharge (GCD) testing, and Electrochemical Impedance Spectroscopy (EIS) measurements. CV analysis found that sodium intercalation and de-intercalation curve in NFP_A is similar to the CV curve of NFP_B. The reduction peak presents at -2.98 V and -2.99 V for NFP_A and NFP_B, respectively. Those peaks represent Na+ intercalation into FePO4 layer. The oxidation peaks, that represent deintercalation from NaFePO4 appears at 3.31 and 3.96 V. Split cell SIB with NFP_A as cathode provides 100 cycles under 1 C and 3 C current drawn. Meanwhile, the pouch type only provides 50 cycles before the capacity loss under 1 C current drawn. Each type has 100 % Coulombic efficiency indicates that all of the charged-ion can be completely discharged.