A safe, high-rate and high-energy polymer lithium-ion battery based on gelled membranes prepared by electrospinning

In this paper we report on the characteristics of a polymer Li-ion battery based on a unique combination of innovative electrode and electrolyte materials. In particular, the electrolytic separator of this system is based on gelled membranes prepared by the electrospinning technique. Electrospinning of polymer fibers is usually realized by applying a strong electric field to a polymer solution in an appropriate solvent. Typical membranes (mats) consist of nanometre size fibers and have porosities of 56-85%. Here we describe the fabrication, physical chemistry and electrochemical properties of PVdF (poly(vinylidene difluoride))-based electrospun membranes and their use as gelled electrolyte in Li-ion battery. Moreover, we describe the performances of a battery formed by sandwiching a gelled membrane with a nanoscale engineered Sn-C based anode and a lithium nickel manganese oxide spinel cathode. The battery so obtained has an appealing performance in terms of energy density, power capability, cycle life and safety.