Synthesis of LiFePO4/C composite with high rate capability using spheniscidite as a facile precursor

• The spheniscidite, (NH4)Fe2(OH)(PO4)2·2H2O, was synthesized via a simple chemical precipitate method for the first time.
• LiFePO4/C cathode material was successfully synthesized by the as-prepared (NH4)Fe2(OH)(PO4)2·2H2O.
• The reversible capacity of LiFePO4/C composite remains about 130 mA h g−1 at 10 C after cycled 100 times.

The spheniscidite, (NH4)Fe2(OH)(PO4)2·2H2O, has been successfully synthesized by precipitation method using low-cost raw materials. This method is facile and easy to control, as well as scale-up. LiFePO4/C composite has been fabricated using spheniscidite as precursor by carbonthermal reduction. The as-prepared LiFePO4/C composite exhibits excellent electrochemical performance. The discharge capacities of LiFePO4/C composite are 155, 154, 151, 148, 140 and 130 mA h g−1 at the rates of 0.2, 0.5, 1.0, 2.0, 5.0 and 10.0 C, respectively. And the discharge capacity fades rarely after 100 cycles at the rate of 10 C. The XRD analysis and SEM observations indicate that the electrochemical performance of LiFePO4/C composite is governed by its microstructure. The micro-nano sized secondary particles are composed of the nano sized primary particles coated with carbon.