Continuous flame aerosol synthesis of carbon-coated nano-LiFePO4 for Li-ion batteries

Core–shell, nano-sized LiFePO4-carbon particles were made in one step by scalable flame aerosol technology at 7 g/h. Core LiFePO4 particles were made in an enclosed flame spray pyrolysis (FSP) unit and were coated in-situ downstream by auto thermal carbonization (pyrolysis) of swirl-fed C2H2 in an O2-controlled atmosphere. The formation of acetylene carbon black (ACB) shell was investigated as a function of the process fuel-oxidant equivalence ratio (EQR). The core–shell morphology was obtained at slightly fuel-rich conditions (1.0

Figure optionsDownload high-quality image (174 K)Download as PowerPoint slideHighlightsContinuous and sequential flame synthesis of core–shell carbon-LiFePO4 nanoparticles.
► Oxygen stoichiometry in the coating flame controls formation of smooth or rough carbon shells.
► The core–shell morphology hinders core LiFePO4 particle growth during annealing.
► Upon annealing, cavities and even hollow carbon shells were formed by reduction of LiFePO4 to Fe2P.
► Battery electrodes made by such particles had near theoretical capacity and high cycle stability.