Spirally would non-aqueous electrolyte secondary battery having insulating members
A battery including an electrode assembly is provided. The electrode assembly has first and second current collectors facing region disposed at a winding start end and at a winding terminal end, respectively. A positive electrode current collector exposed portion and a negative electrode current collector exposed portion face each other through the separator in each of the first and second current collector facing regions. At least one of the positive or negative electrode current collector exposed portion has a first insulating member formed thereon in the first current collector facing region at the winding start end and has a second insulating member formed thereon in the second current collector facing region at the winding terminal end. The second insulating member has a melting point lower than that of the first insulating member.
1. A battery, comprising:
an electrode assembly which includes
a positive electrode including a cathode active material layer and a positive electrode current collector,
a negative electrode including an anode active material layer and a negative electrode current collector,
a separator,
a first insulating member including at least a material different from the separator, and
a second insulating member,
wherein the electrode assembly has a winding start end at an innermost end of the electrode assembly and a winding terminal end at an outermost circumferential end of the electrode assembly, respectively,
wherein the first insulating member is attached to the winding start end of a first exposed portion of the positive electrode current collector at the innermost end of the electrode assembly,
wherein the second insulating member is attached to the winding terminal end of a second exposed portion of the negative electrode current collector at the outermost circumferential end of the electrode assembly, and
wherein a positive electrode terminal and a negative electrode terminal are disposed at the winding start end.
2. The battery according to claim 1 , wherein the first insulating member is formed on both sides of the first exposed portion of the positive electrode current collector at the winding start end of the positive electrode, and the second insulating member is formed on both sides of the second exposed portion of the positive electrode current collector at the winding terminal end of the positive electrode.
3. The battery according to claim 1 , wherein the first insulating member is not provided in the negative electrode.
4. The battery according to claim 1 , wherein the first insulating member and second insulating member are provided so that the first and second exposed portions of the positive electrode current collector and the first and second exposed portions of the negative electrode current collector do not face each other through only the separator.
5. The battery according to claim 1 , wherein the second insulating member is selected from the group consisting of low density polyethylene and high density polyethylene.
6. The battery according to claim 1 , wherein the first insulating member and the second insulating member each have a thickness of 10 μm to 100 μm.
7. The battery according to claim 1 , wherein a melting point of the first insulating member and a melting point of the second insulating member are different.
8. The battery according to claim 1 , wherein the second insulating member has a melting point lower than that of the first insulating member.
9. The battery according to claim 1 , wherein a difference between a melting point of the first insulating member and a melting point of the second insulating member is 20° C. or more.
10. The battery according to claim 1 , wherein a difference between a melting point of the first insulating member and a melting point of the second insulating member is 100° C. or more.
11. The battery according to claim 1 , wherein a difference between a melting point of the first insulating member and a melting point of the second insulating member ranges from 20° C. to 178° C.
12. The battery according to claim 1 , wherein a difference between a melting point of the first insulating member and a melting point of the second insulating member ranges from 100° C. to 178° C.
13. The battery according to claim 1 , wherein the first insulating member is selected from the group consisting of a polypropylene resin, a polyethylene terephthalate resin, a polyethylene naphthalate resin, a polyphenylene sulfide resin and a polyimide resin.
14. The battery according to claim 1 , wherein the second insulating member is selected from the group consisting of a low density polyethylene resin, a high density polyethylene resin, a polypropylene resin, a polyethylene terephthalate resin, a polyethylene naphthalate resin and a polyphenylene sulfide resin.
15. The battery according to claim 1 , wherein the positive electrode terminal protrudes from the electrode assembly, and wherein the first insulating member covers an end portion of the positive electrode terminal at the winding start end.