Copper collector for secondary battery comprising Cu-nitrile compound complex formed on surface thereof
View Patent ↗Disclosed are copper foil or net comprising a Cu-nitrile compound complex formed on the surface thereof, a method for preparing the same, and a lithium secondary battery that comprises an electrode using the same copper foil or net as a collector. The lithium secondary battery, which uses a copper collector comprising a Cu-nitrile compound complex formed on the surface thereof through the application of a certain voltage level, can prevent the corrosion of Cu occurring at a voltage of 3.6V or higher under overdischarge conditions away from the normal drive condition, and thus can significantly improve the capacity restorability after overdischarge.
1. An electrode comprising:
a copper foil or net;
a Cu-nitrile compound complex coating film on an entire surface of the copper foil or net; and
an electrode active material on the Cu-nitrile compound complex coating film.
2. The electrode according to claim 1 , wherein the Cu-nitrile compound complex coating film is formed by subjecting a nitrile compound, which is disposed on the copper foil or net, to a reduction potential of less than or equal to 1.9 volts to greater than about 0.2 volts versus lithium metal.
3. The electrode according to claim 1 , wherein the nitrile compound is a compound represented by the formula R—CN or CN—R—CN, wherein R is a C 2 to C 15 alkyl group or a C 2 to C 15 alkylene group.
4. A lithium secondary battery comprising:
a) a cathode capable of lithium ion intercalation/deintercalation;
b) an anode capable of lithium ion intercalation/deintercalation;
c) a porous separator; and
d) a non-aqueous electrolyte containing i) a lithium salt and ii) a solvent,
wherein either or both of the cathode and the anode are the electrode as defined in claim 1 .
5. The lithium secondary battery according to claim 4 , wherein the Cu-nitrile compound complex coating film is formed by subjecting a nitrile compound, which is disposed on the copper foil or net, to a reduction potential of less than or equal to 1.9 volts to greater than about 0.2 volts versus lithium metal.
6. The lithium secondary battery according to claim 5 , wherein the nitrile compound is a compound represented by the formula R—CN or CN—R—CN, wherein R is a C 2 to C 15 alkyl group or a C 2 to C 15 alkylene group.