Carbon-filament-entangled lithium iron phosphate/carbon composite produced in partially reductive atmosphere: Dual role of the iron as source material and catalyst

Various morphologies of carbon-LiFePO4 composites can be achieved via the reaction of the appropriate iron or iron oxalate and hydrated phosphates with sucrose as the source of carbon in the Ar/H2 or Ar atmosphere. When sintering in Ar condition, the resulting composite comprised a LiFePO4 core coated with a carbon shell. By contrast, Ar/H2-derived composites produced under a partially reductive atmosphere consisted of olivine particles enmeshed in a carbon filament matrix with the catalytic effect of Fe. Specific capacities as high as 140 mA h g−1 at 1 C and 93 mA h g−1 at 10 C were obtained in carbon-filament-entangled LiFePO4 composite.