The Influence of Primary Particle Size and Secondary Particle Size on Performances of LiFePO_4

The influences of primary particle size and secondary size on the performance of lithium iron phosphate were studied.Scanning electron microscope(SEM) and laser particle size analyzer were employed to characterize the primary particle size and secondary size of lithium iron phosphate samples.The lithium iron phosphate samples were assembled to form the button batteries for the test of the electrochemical features of the samples,such as charge-discharge cycle performance,oxidation-reduction potentials and impedance.At last,it was concluded as following: primary particle size is significant for discharge capacity,discharge potential and impedance except for tap density;the tap density dependents on secondary particle size essentially.And for a high volumetric energy density lithium iron phosphate,what requirements must be met was proposed.