Electrospun LiFe1−yMnyPO4/C Nanofiber Composites as Self-Supporting Cathodes in Li-Ion Batteries

LiFe1−yMnyPO4/C nanofiber composites are applied as cathode materials in Li‐ion batteries and their electrochemical properties are explored. Nanofiber meshes are synthesized via electrospinning of commercially available precursors (LiOH·H2O, FeSO4·7H2O, MnSO4·H2O, H3PO4, and polyvinylpyrrolidone). Nanofibers calcined at 850 °C under Ar/H2 (95/5 vol%) atmosphere are directly used as self‐supporting electrodes in Swagelok half cells without the need for any conductive additive or polymer binder. The morphology, phase, and chemical composition of as‐prepared and heat‐treated samples are analyzed by means of X‐ray powder diffraction, thermogravimetric analysis, and electron and scanning microscopy techniques. Brunauer–Emmett–Teller gas adsorption–desorption measurements show a high specific surface area (111m2 g−1) for LiFe0.5Mn0.5PO4. The influence of different Fe/Mn ratios on the morphology, electrical, and electrochemical performances are analyzed. Self‐supporting electrodes of electrospun LiFe1−yMnyPO4/C nanofibers are presented as cathodes for Li‐ion batteries. The dependence of the electrochemical properties on the phase composition of the solid–solution (Fe/Mn ratio) are characterized. The nanofiber meshes provide a porous high surface area and display a 1D–2D architecture, which shows high rate capabilities up to 8C with a capacity retention of nearly 50%.