High performance LiFePO4electrode materials: influence of colloidal particle morphology and porosity on lithium-ion battery power capability

Abstract

Porous colloidal particles of LiFePO₄ have been prepared using water based synthesis methods in the presence of tri-block copolymer amphiphiles. A systematic investigation into the synthesis parameters revealed the importance of porosity, particle size, crystallinity and carbon content on the electrochemical properties. Mesopore formation and particle connectivity were critical for efficient electrolyte access for high power LiFePO₄ electrode materials. Samples performed well at high rates with discharge capacities of 124 mA h g⁻¹ at 5 C and 113 mA h g⁻¹ at 10 C achieved. Discharge capacities of 164 mA h g⁻¹ were obtained at 0.1 C rates which are close to the theoretical capacity for LiFePO₄ of 170 mA h g⁻¹.