Electrochemical properties of LiMn0.8Fe0.2PO4 cathode were investigated with gel polymer electrolyte (GPE). To access fast and efficient transport of ions and electrons during the charge/discharge process, a pure and well-crystallized LiMn0.8Fe0.2PO4 cathode material was directly synthesized via spray-pyrolysis method. For high operation voltage, polyacrylonitrile (PAN)-based gel polymer electrolyte was then prepared by electrospinning process. The gel polymer electrolyte showed high ionic conductivity of 2.9 × 10-3 S cm-1 at 25 °C and good electrochemical stability. Li/GEP/ LiMn0.8Fe0.2PO4 cell delivered a discharge capacity of 159 mAh g-1 at 0.1 C rate that was close to the theoretical value (170 mAh g-1). The cell allows stable cycle performance (99.3% capacity retention) with discharge capacity of 133.5 mAh g-1 for over 300 cycles at 1 C rate and exhibits high rate-capability. PAN-based gel polymer is a suitable electrolyte for application in LiMn0.8Fe0.2PO4/Li batteries with perspective in high energy density and safety.