Lithium secondary battery of high power property with improved high power density
View Patent ↗Disclosed is a high-output lithium secondary battery including: a cathode including a cathode active material having an average particle diameter (with respect to capacity) of 0.03 to 0.1 μm/mAh and a layered structure; an anode including crystalline graphite and amorphous carbon as anode active materials, wherein the amount of the amorphous carbon is between 40 and 100 wt % based on the total weight of the anode active materials; and a separator.
1. A high-output lithium secondary battery comprising:
a cathode comprising a cathode active material represented by Formula 1:
Li x (Ni v Mn w Co y M z )O 2-t A t (1)
wherein 0.8<x≦1.3, 0≦v≦0.9, 0≦w≦0.9, 0≦y≦0.9, 0≦z≦0.9, x+v+w+y+z=2, and 0≦t<0.2; M refers to at least one metal or transition metal cation having an oxidation number of +2 to +4; and A is a monovalent or divalent anion,
wherein the cathode active material has an average particle diameter with respect to capacity of 0.03 to 0.1 μm/mAh and has a powder conductivity of 1×10 −3 S/cm or greater to less than 10×10 −3 S/cm at a powder density of 2.65 to 2.85 g/cc, and has a layered structure;
an anode comprising crystalline graphite and amorphous carbon as anode active materials, wherein an amount of the amorphous carbon is between 40 and 100 wt % based on a total weight of the anode active materials, and wherein the amorphous carbon is one selected from the group consisting of a first carbon having a specific surface area with respect to capacity of 0.01 to 0.031 m 2 /mAh, a second carbon having a specific surface area with respect to capacity of 0.0035 to 0.0170 m 2 /mAh, and a mixture thereof;
and a separator.
2. The high-output lithium secondary battery according to claim 1 , wherein the crystalline graphite is one selected from the group consisting of a first graphite having a specific surface area with respect to capacity of 0.007 to 0.011 m 2 /mAh, a second graphite having a specific surface area with respect to capacity of 0.005 to 0.013 m 2 /mAh, and a mixture thereof.
3. The high-output lithium secondary battery according to claim 2 , wherein the first graphite has a powder conductivity of 100 S/cm or greater to less than 1000 S/cm at a powder density of 1.4 to 1.6 g/cc.
4. The high-output lithium secondary battery according to claim 3 , wherein the first graphite is surface-modified graphite and has 3R and 2H peaks distinguishable as a rhombohedral peak of a (101) plane at 2θ=43° based on XRD data.
5. The high-output lithium secondary battery according to claim 1 , wherein the first carbon has a powder conductivity of 15 S/cm or greater to less than 100 S/cm at a powder density of 1.0 to 1.2 g/cc.
6. The high-output lithium secondary battery according to claim 1 , wherein, in the Formula 1, M is at least one selected from the group consisting of Al, Mg and Ti.
7. The high-output lithium secondary battery according to claim 1 , wherein, in the Formula 1, A is at least one selected from the group consisting of halogens, S and N.
8. The high-output lithium secondary battery according to claim 1 , wherein the lithium secondary battery has a capacity with respect to volume of 0.03 to 0.05 Ah/cm 3 and an energy with respect to volume of 0.1 to 0.2 Wh/cm 3 .
9. The high-output lithium secondary battery according to claim 1 , wherein the separator is an organic-inorganic composite separator.
10. A battery module comprising the lithium secondary battery according to claim 1 as a unit battery.
11. An electric vehicle or hybrid electric vehicle comprising the battery module according to claim 10 .
12. A power storage device comprising the battery module according to claim 10 .