Lithium ion secondary battery and preparation process of same
A separator-type lithium ion secondary battery having large capacity and charge-discharge performance not destroying the separator, even with an active material layer having concavo-convex structure of high aspect ratio. The battery comprises a first electrode comprising a first current collector, and a first active material layer formed by plural convex first active material parts provided on the first current collector, a second electrode comprising a second current collector, and a second active material layer formed by plural convex second active material parts provided on the second current collector, and a separator provided between the first electrode and the second electrode, wherein the first electrode and the second electrode are integrated so that the convex first active material part is faced between the adjacent convex second active material parts, and the convex first active material part does not enter between the convex second active material parts.
1. A lithium ion secondary battery, comprising
a first electrode comprising a first current collector and a first active material layer formed by a plural of convex first active material parts which is provided on the first current collector,
a second electrode comprising a second current collector and a second active material layer formed by a plural of convex second active material parts which is provided on the second current collector, and
a separator provided between the first electrode and the second electrode,
wherein the first electrode and the second electrode are integrated so that the convex first active material part is faced between the adjacent convex second active material parts,
a size of the convex first active material part is larger than a space between the convex second active material parts, and the convex first active material part does not enter between the convex second active material parts, and
an electrolytic layer formed by charging a space between the first electrode and the second electrode with an electrolytic solution or gel;
wherein widths Wa 1 and Wa 2 between the two adjacent sides of the top surface of the convex first active material part, and distances Wb 1 and Wb 2 between the top surfaces (spaces) of the convex second active material parts corresponding to the above two adjacent sides satisfies
Wa 1 >Wb 1 , the relational inequality (1): and
Wa 2 >Wb 2 . the relational inequality (2):
2. The lithium ion secondary battery of claim 1 , wherein the convex first active material part and the convex second active material are both linear.
3. The lithium ion secondary battery of claim 1 , wherein the convex first active material part and the convex second active material are both prismatic.
4. The lithium ion secondary battery of claim 1 , wherein the widths Wa 1 and Wa 2 of the convex first active material part are 100 to 150 μm and the distances Wb 1 and Wb 2 between the top surfaces of the convex second active material parts are 50 to 90 μm.
5. The lithium ion secondary battery of claim 1 , wherein a height Ha of the convex first active material part and a height of the second active material part are both 50 to 100 μm.