دانلود گزارش کارورزی و کار آموزی

چکیده : 

Lithium iron phosphate/carbon (LiFePO4/C) composites were prepared by aconvenient method with

water-soluble phenol-formaldehyde resin as the carbon precursor.The morphology,crystalline structure,

thermal stability, and composition of as-prepared LiFePO 4/C composites were investigated by scannin g

electron microscopy, X-ray diffraction,thermogravimetric analysis,and Raman spectrometry.Their elec-

trochemical performance was examined based on cyclic voltammogram with aLAND battery testing sys-

tem while the effect of carbon content and calcination temperature was highlighted.Results show that

carbon content and calcination temperature dramatical ly influencethe discharge capacities and rate per-

formance of LiFePO 4/C comp osites.The optimal calcination temperature is 700 C, and the optimal carbon

content (mass fraction)is 8.7%.The LiFePO 4/C composite prepared under the optimal conditions exhibits

an initial room temperat ure discharge capacity of 150.2 mA hg1 at a 0.2 Crate and aconstant discharge

capacity of about 105.7 mA hg1 at a 20.0 Crate after 50 cycles,showing promising potential as anovel

cathode material for lithium ion batteries.