Non-aqueous electrolyte secondary battery and method of manufacturing the same

Abstract

A non-aqueous electrolyte secondary battery has an insulating porous membrane, on at least one of a positive electrode, negative electrode, and separator thereof. The membrane contains an inorganic filler, and an active agent for dispersing the inorganic filler uniformly.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partially cutaway view in perspective of a non-aqueous electrolyte secondary battery in accordance with a first exemplary embodiment of the present invention.

FIG. 2 is an exploded view in perspective of the non-aqueous electrolyte secondary battery of FIG. 1.

FIG. 3 is a conceptual sectional view of a positive electrode of the non-aqueous electrolyte secondary battery of FIG. 1.

FIG. 4 is a flowchart showing a procedure of preparing a paste for forming an insulating porous membrane in accordance with the first exemplary embodiment.

FIG. 5 is a conceptual sectional view of a negative electrode of a non-aqueous electrolyte secondary battery in accordance with a second exemplary embodiment of the present invention.

FIG. 6 is a conceptual sectional view of a separator of a non-aqueous electrolyte secondary battery in accordance with a third exemplary embodiment of the present invention.

FIGS. 7A through 7C are conceptual sectional views of an insulating porous membrane which is different from the exemplary embodiments of the present invention and is provided on a separator.

Claims

1. A non-aqueous electrolyte secondary battery comprising: a positive electrode;a negative electrode;a separator and a non-aqueous electrolyte disposed between the positive electrode and the negative electrode; andan insulating porous membrane provided on a surface of at least one of the positive electrode, the negative electrode, and the separator, and having an inorganic filler, and an active agent for uniformly dispersing the inorganic filler.

2. The non-aqueous electrolyte secondary battery of claim 1, wherein the active agent has a hydrophobic group and a hydrophilic group.

3. The non-aqueous electrolyte secondary battery of claim 2, wherein the active agent is a silane coupling agent.

4. The non-aqueous electrolyte secondary battery of claim 3, wherein the positive electrode has a composite oxide containing nickel as an active material thereof, and the insulating porous membrane is provided at least on the surface of the positive electrode.

5. The non-aqueous electrolyte secondary battery of claim 3, wherein the negative electrode has an oxide as an active material thereof, and the insulating porous membrane is provided at least on the surface of the negative electrode.

6. The non-aqueous electrolyte secondary battery of claim 5, wherein the oxide is a silicon oxide.

7. A method of manufacturing a non-aqueous electrolyte secondary battery, the method comprising forming an electrode group by disposing a separator between a positive electrode and a negative electrode, and sealing the electrode group into an outer case together with an electrolyte solution, the method further comprising: adding a binder to a mixture of an inorganic filler and an active agent for uniformly dispersing the inorganic filler, and kneading the mixture, to prepare a paste; andapplying the paste on a surface of at least one of the positive electrode, the negative electrode, and the separator, and drying the paste.