Non-aqueous electrolyte secondary battery and manufacturing method of the same
In a method for manufacturing a non-aqueous electrolyte secondary battery, a negative electrode having a current collector exposed portion in a portion corresponding to an outer winding end of an electrode body, metallic lithium piece is allowed to precipitate or be deposited on this current collector exposed portion, and this metallic lithium piece is joined to the other portion of the current collector exposed portion or one metallic lithium piece is joined to the other metallic lithium piece so as to fix two points of the negative electrode.
1 . A non-aqueous electrolyte secondary battery, comprising:
a negative electrode including a sheet-like negative electrode current collector made of a conductor, negative electrode active material layers formed on both surfaces of the negative electrode current collector, a current collector exposed portion provided on an end portion of the negative electrode current collector and exposed from the negative electrode active material layers, and a metallic lithium piece provided on at least one portion of the current collector exposed portion;
a positive electrode provided facing the negative electrode;
a non-aqueous electrolyte; and
a separator interposed between the negative electrode and the positive electrode and impregnated with the non-aqueous electrolyte;
wherein the negative electrode, the positive electrode and the separator are wound so as to form an electrode body, and the current collector exposed portion is provided on an outer winding end of the electrode body.
2 . The non-aqueous electrolyte secondary battery according to claim 1 , wherein the metallic lithium piece has a joined trace with respect to a position other than the metallic lithium piece in the negative electrode.
3 . The non-aqueous electrolyte secondary battery according to claim 1 , wherein the metallic lithium piece is one of two metallic lithium pieces, and the two metallic lithium pieces are provided on two different portions in the current collector exposed portion in a direction in which the electrode body is wound.
4 . The non-aqueous electrolyte secondary battery according to claim 1 , wherein the metallic lithium piece is provided in a vicinity of the negative electrode active material layer.
5 . The non-aqueous electrolyte secondary battery according to claim 1 , wherein the metallic lithium piece is provided at a winding end portion of the current collector exposed portion.
6 . A method for manufacturing a non-aqueous electrolyte secondary battery, the method comprising:
(A) producing a negative electrode including a sheet-like negative electrode current collector made of a conductor, negative electrode active material layers formed on both surfaces of the negative electrode current collector, and a current collector exposed portion provided on an end portion of the negative electrode current collector and exposed from the negative electrode active material layers;
(B) allowing metallic lithium piece to precipitate or be deposited on at least a part of the current collector exposed portion; and
(C) winding the negative electrode and the positive electrode via a separator therebetween so that the current collector exposed portion becomes an outer winding end so as to form an electrode body after step B, two portions of the negative electrode being fixed with the metallic lithium piece.
7 . The method according to claim 6 , wherein the metallic lithium piece is provided in a vicinity of the negative electrode active material layer in step B.
8 . The method according to claim 6 , wherein the metallic lithium piece is provided in a winding end portion of the current collector exposed portion in step B.
9 . The method according to claim 6 , wherein the metallic lithium piece is one of two metallic lithium pieces, and the two metallic lithium pieces are provided in two different portions in the current collector exposed portion in a direction in which the electrode body is wound in step B.