POSITIVE ACTIVE MATERIAL FOR RECHARGEABLE LITHIUM BATTERY
First Claim
Patent Images
1. A cathode active material for a lithium secondary battery, comprising:
- a core comprising a compound represented by Formula 1; and
a shell comprising a compound represented by Formula 2,wherein the core and the shell have different material compositions,wherein
Lix1M1y1M2z1PO4-w1Ew1
[Formula 1]
Lix2M3y2M4z2PO4-w2Ew2
[Formula 2]in the Formulas 1 and 2,M1, M2, M3 and M4 are the same or different, and each is independently selected from the group consisting of Ni, Co, Mn, Fe, Na, Mg, Ca, Ti, V, Cr, Cu, Zn, Ge, Sr, Ag, Ba, Zr, Nb, Mo, Al, Ga, B and a combination thereof,E is selected from the group consisting of F, S, and a combination thereof,0<
x1≦
1, 0≦
y1≦
1, 0≦
z1≦
1, and 0<
x1+y1+z1≦
2,0≦
w1≦
0.5,0<
x2≦
1, 0≦
y2≦
1, 0≦
z2≦
1, and 0<
x2+y2+z2≦
2 and,0≦
w2≦
0.5.
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Abstract
Disclosed are a cathode active material for a lithium secondary battery, and a lithium secondary battery including the same. The disclosed cathode active material includes a core including a compound represented by Formula 1; and a shell including a compound represented by Formula 2, in which the core and the shell have different material compositions.
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Citations
33 Claims
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1. A cathode active material for a lithium secondary battery, comprising:
-
a core comprising a compound represented by Formula 1; and a shell comprising a compound represented by Formula 2, wherein the core and the shell have different material compositions, wherein
Lix1M1y1M2z1PO4-w1Ew1
[Formula 1]
Lix2M3y2M4z2PO4-w2Ew2
[Formula 2]in the Formulas 1 and 2, M1, M2, M3 and M4 are the same or different, and each is independently selected from the group consisting of Ni, Co, Mn, Fe, Na, Mg, Ca, Ti, V, Cr, Cu, Zn, Ge, Sr, Ag, Ba, Zr, Nb, Mo, Al, Ga, B and a combination thereof, E is selected from the group consisting of F, S, and a combination thereof, 0<
x1≦
1, 0≦
y1≦
1, 0≦
z1≦
1, and 0<
x1+y1+z1≦
2,0≦
w1≦
0.5,0<
x2≦
1, 0≦
y2≦
1, 0≦
z2≦
1, and 0<
x2+y2+z2≦
2 and,0≦
w2≦
0.5.- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 33)
in Formula 3, M5 and M6 are the same or different, and each is independently selected from the group consisting of Ni, Co, Mn, Fe, Na, Mg, Ca, Ti, V, Cr, Cu, Zn, Ge, Sr, Ag, Ba, Zr, Nb, Mo, Al, Ga, B, and a combination thereof, E is selected from the group consisting of F, S, and a combination thereof, 0≦
x3≦
1, 0≦
y3≦
1, 0≦
z3≦
1, and 0<
x3+y3+z32, and0≦
w3≦
0.5.
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13. The cathode active material for the lithium secondary battery, as claimed in claim 12, wherein M1, M3, and M5 are the same materials, and M2, M4, and M6 are the same materials, in which x1=x2=x3, y1<
- y3<
y2, and z1>
z3>
z2.
- y3<
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14. The cathode active material for the lithium secondary battery, as claimed in claim 13, wherein M1, M3, and M5 are selected from the group consisting of Fe, Co, Ni, Mn, and a combination thereof, and M2, M4, and M6 are selected from the group consisting of Mn, Ni, Co, Fe, and a combination thereof.
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15. The cathode active material for the lithium secondary battery, as claimed in claim 12, wherein M1, M3, and M5 are different materials.
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16. The cathode active material for the lithium secondary battery, as claimed in claim 12, wherein M2, M4, and M6 are different materials.
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17. The cathode active material for the lithium secondary battery, as claimed in claim 12, wherein M5 is different from M6,
the interlayer has a structure in which in a direction away from the core, a concentration of M5 increases, and a concentration of M6 decreases, M5 is selected from the group consisting of Fe, Co, Ni, Mn, and a combination thereof, and M6 is selected from the group consisting of Mn, Ni, Co, Fe, and a combination thereof. -
18. The cathode active material for the lithium secondary battery, as claimed in claim 12, wherein the interlayer has a thickness of about 100 nm to 24 μ
- m.
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19. The cathode active material for the lithium secondary battery, as claimed in claim 1, which has a diameter of about 5 μ
- m to 25 μ
m.
- m to 25 μ
-
20. The cathode active material for the lithium secondary battery, as claimed in claim 1, which has a tap density of about 1 g/cm3 to 2 g/cm3.
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33. A lithium secondary battery comprising:
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a cathode comprising a cathode active material; an anode comprising an anode active material; and an electrolyte, wherein the cathode active material is the cathode active material for the lithium secondary battery as claimed in any one of claims 1 to 18.
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21. A method for preparing a cathode active material for a lithium secondary battery, the method comprising the steps of:
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forming a core precursor by mixing an M1 source, an M2 source, and a phosphoric acid source; forming a core-shell precursor by mixing the core precursor with an M3 source, an M4 source, and a phosphoric acid source, the core-shell precursor comprising a shell precursor formed on a surface of the core precursor; forming a core-shell composite by performing a heat treatment on the core-shell precursor; and mixing the core-shell composite with a lithium source, followed by calcination, wherein M1, M2, M3, and M4 are the same or different, and each is independently selected from the group consisting of Ni, Co, Mn, Fe, Na, Mg, Ca, Ti, V, Cr, Cu, Zn, Ge, Sr, Ag, Ba, Zr, Nb, Mo, Al, Ga, B and a combination thereof. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29)
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30. A method for preparing a cathode active material for a lithium secondary battery, the method comprising the steps of:
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forming a core precursor by mixing an M1 source and an M2 source; forming a core-shell precursor by mixing the core precursor with an M3 source, and an M4 source, the core-shell precursor comprising a shell precursor formed on a surface of the core precursor; and mixing the core-shell precursor with a lithium source and a phosphoric acid source, followed by calcination, wherein M1, M2, M3, and M4 are the same or different, and each is independently selected from the group consisting of Ni, Co, Mn, Fe, Na, Mg, Ca, Ti, V, Cr, Cu, Zn, Ge, Sr, Ag, Ba, Zr, Nb, Mo, Al, Ga, B and a combination thereof. - View Dependent Claims (31, 32)
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Specification