In this paper, solid polymer electrolytes consisting of chitosan, lithium bis (trifluoromethylsulfonyl) imide (LiTFSI) as a salt and succinonitrile as a plastic crystal are prepared by using the solution casting method. Electrochemical impedance spectroscopy is used to examine the ionic conductivity of the films at the temperature range of 303-383 K. Chitosan-LiTFSI containing 50 wt% succinonitrile exhibits high ionic conductivity at a room temperature of 0.4 x 10(-3) S cm(-1), a high lithium ion transference number (0.598) and wide electrochemical window. The solid polymer electrolyte with LiFePO4 as a cathode displays a stable discharge capacity of 160 mAh g(-1) for up to 50 cycles at a current density of 17 mA g(-1). The results demonstrate the potential for the solid polymer electrolyte system to be used as an electrolyte in lithium rechargeable batteries. (C) 2014 Elsevier B.V. All rights reserved.