Tab lead including surface treatment film with polymer having carboxylic acid anhydride groups, and nonaqueous electrolyte secondary battery using the same
Provided is a tab lead for a secondary battery including tab lead metal that has an adhesion interface with sealing resin. The adhesion interface is provided with a surface treatment film formed of a material including a polymer with carboxylic acid anhydride groups. Further provided is a nonaqueous electrolyte secondary battery including the tab lead for the secondary battery as a leading terminal of at least one of a positive electrode and a negative electrode.
1. A tab lead for a secondary battery, comprising
tab lead metal,
the tab lead metal comprising an adhesion interface with a sealing resin,
wherein the adhesion interface is provided with a surface treatment film formed of a polymer with carboxylic acid anhydride groups and carboxylic groups,
wherein the polymer is formed by:
applying to the tab lead metal a solution consisting essentially of water and a polycarboxylic acid; and
heating the tab lead metal with the applied solution to form the polymer with carboxylic acid anhydride groups and carboxylic groups.
2. The tab lead for a secondary battery according to claim 1 , wherein the tab lead metal comprises at least one metal selected from nickel, copper, and aluminum.
3. The tab lead for a secondary battery according to claim 1 , wherein peak intensity of the carboxylic acid anhydride group is greater than peak intensity of the carboxylic group in a Raman spectroscopic analysis of the surface treatment film.
4. The tab lead for a secondary battery according to claim 1 , wherein the polycarboxylic acid is polyacrylic acid, polymethacrylic acid, or a salt thereof.
5. The tab lead for a secondary battery according to claim 1 , wherein the polymer is a crosslinked polyacrylic acid.
6. The tab lead for a secondary battery according to claim 1 , wherein the polymer is a crosslinked polymethacrylic acid.
7. The tab lead for a secondary battery according to claim 1 , wherein the surface treatment film comprises carbon in an amount greater than or equal to 10 μg/cm 2 when measured by a high-frequency combustion-infrared absorption method.
8. The tab lead for a secondary battery according to claim 1 ,
wherein the tab lead metal with the applied solution is heated on a hot plate.
9. The tab lead for a secondary battery according to claim 1 , wherein the number of the carboxylic acid anhydride groups in the polymer is greater than the number of the carboxylic groups.
10. The tab lead for a secondary battery according to claim 9 ,
wherein peak intensity of the carboxylic acid anhydride group is greater than peak intensity of the carboxylic group in a Raman spectroscopic analysis of the surface treatment film.
11. The tab lead for a secondary battery according to claim 9 ,
wherein the tab lead metal comprises at least one metal selected from nickel, copper, and aluminum.
12. A nonaqueous electrolyte secondary battery comprising the tab lead according to claim 1 as a leading terminal of at least one of a positive electrode and a negative electrode.
13. The nonaqueous electrolyte secondary battery according to claim 12 , comprising a package for the secondary battery including a laminated film.
14. A nonaqueous electrolyte secondary battery comprising
the tab lead according to claim 9 as a leading terminal of at least one of a positive electrode and a negative electrode.
15. The nonaqueous electrolyte secondary battery according to claim 14 , comprising a package for the secondary battery including a laminated film.