Anode and lithium secondary battery comprising the same

1. A secondary battery comprising:

a negative electrode;

a positive electrode;

a separator disposed between the positive electrode and the negative electrode; and

an electrolyte, wherein a negative electrode comprising an active material layer which includes carbon-based particles having an oxygen content of 1,000 mg/kg to 1,600 mg/kg, wherein the carbon-based particles comprise natural graphite.

2. The secondary battery of claim 1 , wherein the electrolyte is an organic-based electrolyte.

3. A battery module comprising a secondary battery as a unit cell, said secondary battery comprising a negative electrode comprising an active material layer which includes carbon-based particles having an oxygen content of 700 mg/kg to 1,700 mg/kg wherein the carbon-based particles comprise natural graphite;

a positive electrode;

a separator disposed between the positive electrode and the negative electrode; and

an electrolyte.

4. A battery pack comprising the battery module of claim 3 and used as a power source of a device.

5. The battery pack of claim 4 , wherein the device comprises an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or a power storage device.

6. The second battery of claim 1 , wherein the carbon-based particles consist essentially of said natural graphite.

7. The secondary battery of claim 1 , wherein the carbon-based particles comprise at least one selected from the group consisting of a hydroxyl group, a carboxyl group, and an epoxy group.

8. The secondary battery of claim 7 , wherein the at least one selected from the group consisting of a hydroxyl group, a carboxyl group, and an epoxy group is disposed on a surface of the carbon-based particles.

9. The secondary battery of claim 1 , wherein the active material layer further comprises a binder.

10. The secondary battery of claim 9 , wherein a weight ratio of the carbon-based particles to the binder is in a range of 95:5 to 99:1.

11. The secondary battery of claim 9 , wherein the binder comprises at least one selected from the group consisting of a polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HFP), polyvinylidene fluoride, polyacrylonitrile, polymethylmethacrylate, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, polyacrylate, an ethylene-propylene-diene monomer (EPDM), a sulfonated EPDM, a styrene-butadiene rubber (SBR), a fluorine rubber, polyacrylic acid, and polymers in which hydrogen thereof is substituted with lithium (Li), sodium (Na), or calcium (Ca).

12. The secondary battery of claim 11 , wherein the binder comprises the carboxymethylcellulose and the styrene-butadiene rubber.

13. The secondary battery of claim 12 , wherein a weight-average molecular weight of the carboxymethylcellulose is in a range of 500,000 g/mol to 4,500,000 g/mol.

14. The secondary battery of claim 12 , wherein an amount of the styrene-butadiene rubber is in a range of 0.5 wt % to 1.5 wt % based on a total weight of the active material layer.

15. The secondary battery of claim 9 , wherein the active material layer further comprises a conductive agent, wherein a weight ratio of the carbon-based particles to the conductive agent to the binder is in a range of 94:1:5 to 99:0.01:1.