Gel polymer electrolytes (GPEs), composed of poly(vinylidene fluoride) (PVdF), a ternary solvent of ethylene carbonate : propyylene carbonate : dimethyl carbonate, and LiBOB, which are characterized by a novel composition with a fluorine-free lithium salt, are here proposed. GPEs were firstly prepared through a solution casting procedure using the ternary carbonate solution as a solvent (named ex situ prepared membranes), and then activated by being immersed in a 0.7 M LiBOB-carbonate solution. Fundamental characterizations, including thermal, spectroscopical, mechanical, and electrochem-ical analyses, were carried out and compared before and after the activation. GPEs, having the same composition, were also prepared by using a novel procedure (named in situ prepared membranes), involving the formation of PVdF membrane and its activation by the LiBOB electrolyte, as well as subsequent electrochemical characterizations, in the same T-shape cell. Thus prepared lithium-ion batteries, employing SnÀ C and LiFePO 4 electrodes, were demonstrated to exhibit a high capacity of 150 mAh g À 1 through the course of cycling.