Secondary battery and method of producing same
AssigneeZeon Corporation
InventorsYutaka Maruhashi, Masuhiro Onishi
Life of this patent
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Abstract
A secondary battery includes a laminate in which a positive electrode, a separator, and a negative electrode are stacked in stated order. Resistance A per unit area of a central region P that has a similar shape to a shape of a surface Z that is either or both of an affixing surface X of the positive electrode and the separator and an affixing surface Y of the negative electrode and the separator, that has a center at the same position as a center of the surface Z, and that has an area equivalent to 10% of area of the surface Z is larger than resistance B per unit area of a region Q other than the central region P at the surface Z.
Claims8
A secondary battery comprising a laminate in which a positive electrode, a separator, and a negative electrode are stacked in stated order, wherein
- an affixing surface of the positive electrode and the separator is called X and an affixing surface of the negative electrode and the separator is called Y, and that either or both of X and Y is called surface Z,
- a region that has a similar shape to a shape of a surface Z that has a center at the same position as a center of the surface Z, and that has an area equivalent to 10% of area of the surface Z is called a central region P,
- a region other than the central region P is called a region Q,
- a direct current resistance per unit area of the central region P is called as resistance A and a direct current resistance per unit area of the region Q at the surface Z is called resistance B,
- the resistance A is larger than the resistance B,
- an adhesive material is present at the surface Z,
- in the surface Z, either of the following conditions (i) or (ii) is satisfied,
- (i) a ratio of coverage E of the adhesive material in the central region P of the surface Z is larger than a ratio of coverage F of the adhesive material in the region Q other than the central region P of the surface Z, or
- (ii) the adhesive material, containing particulate polymers, contained in the central region P and the adhesive material in the region Q are different with each other, wherein
- in the condition (i), the adhesive material is arranged in a dotted pattern or a striped pattern, in the case of the dotted pattern, the ratio of coverage is adjustable by altering the radius and the distance between centers of dots of the adhesive material, while in the case of the striped pattern, the ratio of coverage is adjustable by altering a line width of application sections for the adhesive material and spacing of the application sections, in the condition (ii), a degree of swelling in electrolyte solution of the particulate polymers contained in the adhesive material that is applied in the central region P is larger than that of the particulate polymers contained in the adhesive material contained in the region Q;
- or
- at least a part of the particulate polymers contained in the region Q have the core-shell structure including a core portion and a shell portion partially covering an outer surface of the core portion, while the particulate polymers contained in the adhesive material that is applied in the central region P do not have the core-shell structure.
A method of producing a secondary battery including a laminate in which a positive electrode, a separator, and a negative electrode are stacked in stated order, comprising a step of applying an adhesive material at a surface Z that is either or both of an affixing surface X of the positive electrode and the separator and an affixing surface Y of the negative electrode and the separator, wherein
- an affixing surface of the positive electrode and the separator is called X and an affixing surface of the negative electrode and the separator is called Y, and that either or both of X and Y is called surface Z,
- a region that has a similar shape to a shape of a surface Z that has a center at the same position as a center of the surface Z, and that has an area equivalent to 10% of area of the surface Z is called a central region P,
- a region other than the central region P is called a region Q,
- a direct current resistance per unit area of the central region P is called as resistance A and a direct current resistance per unit area of the region Q at the surface Z is called resistance B,
- the resistance A is larger than the resistance B,
- an adhesive material is present at the surface Z,
- in the surface Z, either of the following conditions (i) or (ii) is satisfied,
- (i) a ratio of coverage E of the adhesive material in the central region P of the surface Z is larger than a ratio of coverage F of the adhesive material in the region Q other than the central region P of the surface Z, or
- (ii) the adhesive material, containing particulate polymers, contained in the central region P and the adhesive material in the region Q are different with each other, wherein
- in the condition (i), the adhesive material is arranged in a dotted pattern or a striped pattern, in the case of the dotted pattern, the ratio of coverage is adjustable by altering the radius and the distance between centers of dots of the adhesive material, while in the case of the striped pattern, the ratio of coverage is adjustable by altering a line width of application sections for the adhesive material and spacing of the application sections, in the condition (ii), a degree of swelling in electrolyte solution of the particulate polymers contained in the adhesive material that is applied in the central region P is larger than that of the particulate polymers contained in the adhesive material contained in the region Q;
- or
- at least a part of the particulate polymers contained in the region Q have the core-shell structure including a core portion and a shell portion partially covering an outer surface of the core portion, while the particulate polymers contained in the adhesive material that is applied in the central region P do not have the core-shell structure.
Dependencies are inferred from the claim text.