To provide a secondary battery good in battery characteristic such as a cycle characteristic, by coating at least one of a positive electrode material and a negative electrode material with nonaqueous electrolyte containing ionic metallic salt whose relation between coating speed and viscosity is under a specific condition, and depressurizing treatment of the coated electrode material and a porous film.
An electrode material and/or a porous film is coated with nonaqueous electrolyte under a condition that viscosity η (cP) of nonaqueous electrolyte and coating speed V (mm/sec) satisfy formula. The coating speed V is preferably 10-15,000. Ionic metallic salt such as LiPF6, polar monomer such as acrylic acid having a reactive unsaturated group as a gelling agent, and a polymer initiator are dissolved in high dielectric constant solvent such as ethylene carbonate to form the nonaqueous electrolyte. After coating and depressurizing processes, the polymeric gelling agent is polymerized, and is cut in a prescribed size, and is used for a secondary battery. Positive and negative materials having a clearance with 0.1-10 μm average narrow hole diameter and 20-60% porosity.
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