Negative active material including manganese oxides, negative electrode including the same, lithium battery including negative electrode and method of preparing negative active material
Provided herein is a negative active material including an ordered porous manganese oxide, wherein pores of the ordered porous manganese oxide have a bimodal size distribution. Provided herein is a method of preparing a negative active material that includes the ordered porous manganese oxide. The invention also includes a negative electrode which includes the negative active material and a lithium battery which includes the negative electrode.
1. A negative active material comprising:
a carbonaceous conductive material; where the carbonaceous conductive material is selected from the group consisting of carbon black, acetylene black, carbon fibers, carbon nanotubes; and
an ordered porous manganese oxide, wherein the ordered porous manganese oxide comprises at least one of MnO, Mn 2 O 3 , and Mn 3 O 4 , wherein pores of the ordered porous manganese oxide have a first peak in a range of about 1 nm to about 5 nm and a second peak in a range of about 10 nm to about 20 nm,
wherein the negative active material has a discharge capacity per unit weight of 800 mAh/g or greater, wherein the ordered porous manganese oxide has a pore volume in a range of about 0.1 cm 3 /g to about 2 cm 3 /g.
2. The negative active material of claim 1 , wherein pores of the ordered porous manganese oxide have a bimodal size distribution.
3. The negative active material of claim 1 , wherein, in a low-angle X-ray diffraction spectrum of the ordered porous manganese oxide, a peak with respect to a (110) plane appears at a Bragg (2θ) angle of 0.6±0.2°.
4. The negative active material of claim 1 , wherein, in a low-angle X-ray diffraction spectrum of the ordered porous manganese oxide, an intensity ratio of a peak with respect to a (110) plane to a peak with respect to a (221) plane (I(110)/I(221)) is 0.1 or greater.
5. The negative active material of claim 1 , wherein, in a low-angle X-ray diffraction spectrum of the ordered porous manganese oxide, an intensity ratio of a peak with respect to a (110) plane to a peak with respect to a (221) plane (I(110)/I(221)) is in a range of about 0.1 to about 10.
6. The negative active material of claim 1 , wherein a framework of the ordered porous manganese oxide has a thickness of 5 nm or greater.
7. The negative active material of claim 1 , wherein a framework of the ordered porous manganese oxide has a thickness in a range of about 5 nm to about 20 nm.
8. The negative active material of claim 1 , wherein the ordered porous manganese oxide has a crystal size of 5 nm or greater.
9. The negative active material of claim 1 , wherein the ordered porous manganese oxide has a crystal size in a range of about 5 nm to about 30 nm.
10. The negative active material of claim 1 , wherein the ordered porous manganese oxide has a pore volume in a range of about 0.5 m 2 /g to about 1 cm 3 /g.
11. The negative active material of claim 1 , wherein pores of the ordered porous manganese oxide are connected to each other to form a channel.
12. The negative active material of claim 1 , wherein pores of the ordered porous manganese oxide each have a diameter of about 1 nm to about 20 nm, and a framework formed as a wall between the pores has a thickness of about 5 nm to about 20 nm.