| 摘要 |
PURPOSE: To provide a secondary battery with high energy density and long cycle life by increasing adhesion between positive active materials, between negative active material, and between the active material and a current collector. CONSTITUTION: A secondary battery contains a sheet-shaped positive electrode 5, a sheet-shaped negative electrode 3 both capable of repeating charge/ discharge, and an electrolyte serving as an ion conductive material. A binder having rubber-like elasticity or viscoelasticity comprising a copolymer of three kinds of different monomers of unsaturated aliphatic hydrocarbon fluoride is contained in the mix of the positive electrode 5 or in the mix of the negative electrode 3. The binder is made of a copolymer containing 30±5% to 60±5% tetrafluoroethylene, 10±5% to 30±5% hexafluoropropylene, and 10±5% to 40±5% vinylidene fluoride. |
