| 摘要 |
PURPOSE: Provided are a lithium secondary battery and its preparation method. The battery is characterized by the separator between a cathode and an anode, which is made of fabricated fiber material with a multi porous coating layer. The separator has excellent mechanical property, discharge capacity, cycle characteristics and an improved property of ion conductivity because this separator can contain much electrolyte. CONSTITUTION: The battery comprises: a cathode, an anode, electrolyte including lithium salts in organic solvents and a separator between the above electrodes consisting of one or more multi-porous fabricated fiber materials, with permeability of 20-2000cfm and thickness of 5-200μm, selected from polyethylene phthalate, polypropylene, polyethylene and fiber glass, coated with layer of vinylidenefluoride-hexafluoropropylene copolymer with not more than 25% of hexafluoropropylene monomer. The battery is made by: coating the above copolymer on the above fabricated fiber material, drying, eliminating the low boiling plasticizer to make a multi-porous separator; introducing electrolyte into the above porous separator; and installing anode and cathode on both side of the separator to assemble the battery. |
