Material of case for storage cell

Abstract

There is provided a casing material for a storage cell having sufficient corrosion resistance and strength even under a charging environment of a high voltage exceeding 2.8 V. This casing material for the storage cell comprises C: not more than 0.03 mass%, Si: 0.01-0.50 mass%, Mn: not more than 0.20 mass%, P: not more than 0.04 mass%, S: not more than 0.0010 mass%, Ni: 20.0-40.0 mass%, Cr: 20.0-30.0 mass%, Mo: 5.0-10.0 mass%, Al: 0.001-0.10 mass%, N: 0.10-0.50 mass%, Ca: not more than 0.001 mass%, Mg: 0.0001-0.0050 mass%, O: not more than 0.005 mass%, provided that contents of Cr, Mo and N satisfy Cr+3.3×Mo+20×N ‰¥ 43, and the balance being substantially Fe and inevitable impurities, in which a content of CaO as an oxide inclusion in steel is not more than 20 mass%.

Description

[0001] Description of the relevant application [0002] This application claims priority based on Japanese Patent Application No. 2003-432492 filed on December 26, 2003 as an earlier application. technical field [0003] This application relates to a case material used for a coin-type storage battery such as a small-sized and large-capacity electric double layer capacitor, and particularly proposes a high-corrosion-resistant, high-strength positive electrode case material. Background technique [0004] Generally, as a material for a positive electrode case used in a coin-type storage battery such as an electric double layer capacitor, metal is mainly used when a non-aqueous electrolyte is used, and a conductive synthetic resin is mainly used when an aqueous electrolyte is used. . As the nonaqueous electrolytic solution, an electrolytic solution obtained by dissolving a solute such as tetraethylammonium tetrafluoroborate in a thermally stable polar organic solvent such as pr...

AI Technical Summary

Problems solved by technology

However, these positive electrode case materials do not have sufficient corrosion resistance as a material for a positive electrode case for charging at 2.8V.

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