Journal of Power Sources
Volume 272, 25 December 2014, Pages 837-844
Morphology control of lithium iron phosphate nanoparticles by soluble starch-assisted hydrothermal synthesis
ZhaoyongChenMingXuBinglinDuHuali ZhuTianXieWenhua Wang
Lithiumironphosphate(LiFePO4) is a potentially high efficiencycathodematerial forlithium ion batteries, but the low electronic conductivity and one-dimensional diffusion channel for lithium ions require small particle size and shape control during the synthesis. In this paper, well-crystallized and morphology-controlled LiFePO4cathode material for lithium-ion batteries is successfully synthesized via a soluble starch-assistedhydrothermal methodat 180 °C for 5 h, followed by calcining with phenolic resin at 750 °C for 6 h. In this study, we investigate the effect of five different concentrations of starch solution on controlling morphology of LiFePO4. Interestingly, the nano-sized LiFePO4particles obtained in 0.075 mol L−1starch solution exhibit a spheroidalmicrostructure, while theplateletshape LiFePO4particles are synthesized in lower or higher concentration of starch solution. The mechanism and process of forming such spheroidal microstructure is discussed. These unique structural and morphological properties of LiFePO4lead to high specific capacity and stable cycling performance. Analysis of theelectrochemical impedance spectroscopyreveals that nano-sized carbon/polyacene coated LiFePO4cathode materials play an critical role in achieving excellent electrochemical performance.