Nonaqueous electrolytic solution secondary battery, current collector and vehicle
A nonaqueous electrolytic solution secondary battery includes an electrode body that contains a positive electrode and a negative electrode. An upper limit operating potential of the positive electrode is 4.5 V or more based on metallic lithium. The positive electrode includes a current collector and an active material layer formed on the current collector. The current collector includes a base material and a surface layer disposed on a surface of the base material. The surface layer is disposed at least in a region where the active material layer is not formed on the surface of the base material. The surface layer is formed of an aluminum material having an aluminum content of 99.85% by mass or more. The base material is formed of a conductive material having strength larger than strength of the surface layer.
1. A nonaqueous electrolytic solution secondary battery comprising an electrode body that contains a positive electrode and a negative electrode, wherein
an upper limit operating potential of the positive electrode is 4.5 V or more based on metallic lithium,
the positive electrode includes a current collector and an active material layer formed on the current collector,
the current collector includes a base material and a surface layer disposed on a surface of the base material,
the surface layer is disposed at least in a region where the active material layer is not formed on the surface of the base material,
the surface layer is formed of an aluminum material having an aluminum content of 99.85% by mass or more,
the base material is formed of a conductive material having strength larger than strength of the surface layer,
the conductive material that forms the base material is an aluminum material, and
the aluminum material that forms the base material has an aluminum content lower than the aluminum content of the aluminum material that forms the surface layer.
2. The nonaqueous electrolytic solution secondary battery according to claim 1 , wherein the current collector is a clad material.
3. The nonaqueous electrolytic solution secondary battery according to claim 1 , wherein
the positive electrode includes a lithium transition metal composite oxide having a spinel structure as a positive electrode active material, and
the lithium transition metal composite oxide includes at least nickel and manganese as transition metal elements.
4. The nonaqueous electrolytic solution secondary battery according to claim 1 , wherein
both the positive electrode and the negative electrode have a sheet form, and
the electrode body is a wound electrode body obtained by winding the positive electrode and the negative electrode.
5. The nonaqueous electrolytic solution secondary battery according to claim 1 , wherein tensile strength of a material that forms the base material is larger by 1 MPa or more than tensile strength of a material that forms the surface layer.
6. The nonaqueous electrolytic solution secondary battery according to claim 1 , wherein elongation of a material that forms the base material is larger by 0.1% or more than elongation of a material that forms the surface layer.
7. The nonaqueous electrolytic solution secondary battery according to claim 1 , wherein the upper limit operating potential is 5.5 V or less.
8. A vehicle comprising the nonaqueous electrolytic solution secondary battery according to claim 1 .
9. A current collector that is used in a positive electrode of which upper limit operating potential is 4.5 V or more based on metallic lithium, comprising:
a base material; and
a surface layer disposed on a surface of the base material, wherein
the surface layer is formed of an aluminum material of which aluminum content is 99.85% by mass or more,
the base material is formed of a conductive material of which strength is larger than strength of the surface layer,
the conductive material that forms the base material is an aluminum material, and
the aluminum material that forms the base material has an aluminum content lower than the aluminum content of the aluminum material that forms the surface layer.
10. The current collector according to claim 9 , wherein
the surface layer is disposed in a region on the surface of the base material to be an active material layer non-formed part, the active material layer non-formed part not including an active material layer.
11. The current collector according to claim 9 , wherein tensile strength of a material that forms the base material is larger by 1 MPa or more than tensile strength of a material that forms the surface layer.
12. The current collector according to claim 9 , wherein elongation of a material that forms the base material is larger by 0.1% or more than elongation of a material that forms the surface layer.