Exploration of Iron-Based Mixed Polyanion Cathode Material for Thin-film Sodium-ion Batteries

摘要

In this work, we have explored the iron-based mixed polyanion cathode material for sodium-ion thin film batteries. Thin films of mixed polyanion compound Na_4Fe_3(PO_4)_2P_2O_7 has been prepared by pulsed laser deposition (PLD). The bulk powder was synthesized by facile solution combustion synthesis and it crystallized into orthorhombic structure with Pn2_1a space group as confirmed by Rietveld refinement. The observed galvanostatic charge/discharge profiles of the thin film cathodes are characterised by features similar to those measured for the bulk powder samples. Thin film Na_4Fe_3(PO_4)_2P_2O_7 exhibited reversible Na~+ storage capacities in the range of 110-120 mAh g~(-1) for more than 100 cycles with various thickness of the thin film electrode.