COMPLEX ELECTRODE AND SECONDARY BATTERY USING GEL-TYPE POLYMER ELECTROLYTE AND PREPARATION METHODS THEREOF

摘要

PURPOSE: A gel-type polymer electrolyte, a complex electrode using the electrolyte, a lithium secondary battery using the electrode and their preparation method are provided, to improve the energy density, cycle lifetime, characteristics at a low and high temperature, a charge/discharge efficiency and stability of a secondary battery. CONSTITUTION: The gel-type polymer electrolyte comprises 5-90 wt% of a function-I polymer selected from polyacrylonitrile-based polymer and poly(methyl methacrylate) (PMMA)-based polymer; 5-80 wt% of a function-II polymer selected from a poly(vinylidene-fluoride) (PVdF)-based polymer and a PMMA-based polymer; and 5-80 wt% of a function-III polymer selected from a PVC-based polymer and a PVdF-based polymer. Optionally the gel-type polymer electrolyte comprises further a plasticizer or an organic solvent; and/or a filler. The complex electrode comprises the gel-type polymer electrolyte which is contained in the pore of an anode or cathode, and a layer made of the gel-type polymer electrolyte with the thickness of 1-20 micrometers formed on the surface of an anode or cathode. The lithium secondary battery is provided with a laminated body which comprises a cathode, an isolation membrane, an anode, an isolation membrane and a cathode, wherein the anode and the cathode are made of the complex electrode and the isolation membrane is made of polyethylene, polypropylene or nonwoven; a terminal connected with the anodes and cathodes; and a case surrounding the laminated body.