Patent ID: 11949061
Assignee: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  Y | IPC H

Claim 3:
4. A secondary battery comprising:
a first film;
a second film; and
a stacked layer comprising:
a first negative electrode current collector;
a first negative electrode active material layer on the first negative electrode current collector;
a first separator on the first negative electrode active material layer;
a first positive electrode active material layer on the first separator;
a first positive electrode current collector on the first positive electrode active material layer;
a second positive electrode current collector on the first positive electrode current collector;
a second positive electrode active material layer on the second positive electrode current collector;
a second separator on the second positive electrode active material layer;
a second negative electrode active material layer on the second separator; and
a second negative electrode current collector on the second negative electrode active material layer,

wherein each of an inside surface and an outside surface of the first film has a first pattern of depressions or projections with a first pitch,
wherein each of an inside surface and an outside surface of the second film has a second pattern of depressions or projections with a second pitch,
wherein the first pitch is smaller than the second pitch,
wherein the stacked layer is positioned inside the first film and the second film.