Positive active material for a lithium secondary battery with higher performance and preparation method of the same
AssigneeLG Chem, Ltd.
InventorsHong-Kyu Park, Yong-Hoon Kwon, Seong-Yong Park, Mi-Seon Kwak, Jong-Moon Yoon, Jong-Sung Bae, Jin-On Kim
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Abstract
Disclosed is a positive active material for a lithium secondary battery and a preparation method of the same that can improve cycle-life characteristics and storage characteristics at a high temperature by improving structural safety characteristics and electrochemical characteristics, by forming an overlayer comprising an oxide glass phase on the surface of the positive active material, and a lithium secondary battery comprising the positive active material.
Claims10
A positive active material for a lithium secondary battery comprising
- a) a lithium metal complex oxide described by the following Formula 1;
- and
- b) a glass phase overlayer of a non-crystalline oxide described by the following Formula 2 coated on the a) lithium metal complex oxide:
- LiA1-xBxO2 [Formula 1]
- wherein,
- A is Co or Ni;
- B is selected from the group consisting of Al, B, Ni, Co, Ti, Sn, Mn, and Zr;
- and
- x is a real number of 0˜0.5,
- CsOt.yDzOw [Formula 2]
- wherein,
- C is selected from the group consisting of Na, K, Mg, Ba, Sr, Y, Sn, Ga, In, Th, Pb, Li, Zn, Ca, Cd, Rb, Sc, Ti, Zn, Al, Be, and Zr;
- D is selected from the group consisting of Al, B, Si, Ge, P, V, As, Sb, Zr, Nb, Ti, Zn, Zr, and Pb;.
- y is a real number of 0.5˜3;
- and
- s and t, and z and w, are respectively with respect to an oxidation number of C and D.
A preparation method of positive active material for a lithium secondary battery comprising the steps of:
- a) preparing lithium metal complex oxide as core particles described by Formula 1;
- b) providing an overlayer material compound described by Formula 2 for forming an oxide glass phase;
- c) coating the lithium metal complex oxide of the a) step with the overlayer material compound of the b) step;
- and;
- d) sintering the coated lithium metal complex oxide of the c) step.
- LiA1-xBxO2 [Formula 1]
- wherein,
- A is Co or Ni;
- B is selected from the group consisting of Al, B, Ni, Co, Ti, Sn, Mn, and Zr;
- and
- x is a real number of 0˜0.5,
- CsOt.yDzOw[Formula 2]
- wherein,
- C is selected from the group consisting of Na, K, Mg, Ba, Sr, Y, Sn, Ga, In, Th, Pb, Li, Zn, Ca, Cd, Rb, Sc, Ti, Zn, Al, Be, and Zr;
- D is selected from the group consisting of Al, B, Si, Ge, P, V, As, Sb, Zr, Nb, Ti, Zn, Zr, and Pb;
- y is a real number of 0.5˜3;
- and
- s and t, and z and w, are respectively with respect to an oxidation number of C and D.
Dependencies are inferred from the claim text.