Preparation and Electrochemical Properties of the Spongelike Melamine Formaldehyde-Poly(vinyl alcohol)/LiFePO4 Porous Composite as the Lithium-Battery Cathode

The electrospun-based porous nitrogen-enriched carbon-coated olivine LiFePO 4 nanocomposites (MF-PVA/LFP) were prepared by employing the practical electrospin technique and using affordable polymers, melamine-formaldehyde (MF) with poly(vinyl alcohol) (PVA), as the nitrogen-containing carbon precursor, followed by carbonization at various temperatures. Uniform and good interfiber separation of electrospun MF-PVA/LFP composite nanofibers with a average diameter of about 150–200 nm were initially obtained and then transformed into the spongelike porous structure after carbonization. The observed conductive pyridinic-N and pyrrolic-N nitrogen functional groups within the carbon coating material combining with the enhanced specific surface and high void volume of the porous structure played a great impact on the rate capability and cycling performance under high current density cycles. The highest obtained discharging capacity of the porous MF-PVA/LFP composite was 105 mAh g –1 at 0.1 C . This promising concept can be further developed if the sustained fibrous structure after carbonization and the better LiFePO 4 crystallinity can be achieved.