Lithium secondary battery
AssigneeSK Innovation Co., Ltd.
InventorsKook-Hyun Han, Kyung-Bin Yoo, Duck-Chul Hwang
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Abstract
A lithium secondary battery including a cathode, an anode, and a separation film installed between the cathode and the anode, wherein the cathode includes a cathode active material containing lithium-metal oxide of which at least one of the metals has a continuous concentration gradient region between a core part and a surface part thereof, and the separation film includes a base film, and a ceramic coating layer formed on at least one surface of the base film, such that the lifespan property is significantly improved, while exhibiting excellent penetration safety.
Claims11
A lithium secondary battery, comprising a cathode, an anode, and a separation film installed between the cathode and the anode,
- wherein the separation film includes a base film, and a ceramic coating layer formed on at least one surface of the base film,
- wherein the cathode includes:
- a cathode active material consisting of:
- one or more lithium metal oxides containing Ni, Co, and Mn, at least one of the lithium metal oxides includes a compound represented by Formula 1:
- LixM1aM2bM3cOy, [Formula 1]:
- where 0<x≤1.1, 2≤y≤2.02, 0<a<1, 0<b<1, 0<c<1, and 0<a+b+c≤1;
- optionally including a coating layer or dopant including a metal, metal oxide, or alloy including Al, Ti, Ba, Zr, Si, B, or Mg, and
- M3 is Mn and has a concentration gradient range in which a concentration increases continuously from a core part of the cathode active material to a surface of the cathode active material;
- M1 is Ni and has a concentration gradient range in which a concentration decreases continuously from the core part of the cathode active material to the surface of the cathode active material;
- and
- M2 is Co and has a constant concentration from the core part of the cathode active material to the surface of the cathode active material;
- and
- a of Formula 1 is 0.7797 or more throughout an entire region of the cathode active material,
- wherein the ceramic coating layer formed on said at least one surface of the base film has a thickness of 2 to 20 μm.
A lithium secondary battery, comprising a cathode, an anode, and a separation film installed between the cathode and the anode,
- wherein the separation film includes a base film, and a ceramic coating layer formed on at least one surface of the base film;
- and
- the cathode includes a cathode active material consisting of one or more lithium metal oxides containing Ni, Co, and Mn, at least one of the lithium metal oxides includes a compound represented by Formula 1,
- LixM1aM2bM3cOy, [Formula 1]:
- where 0<x≤1.1, 2≤y≤2.02, 0<a<1, 0<b<1, 0<c<1, and 0<a+b+c≤1;
- M3 is Mn and has a concentration gradient range in which a concentration increases continuously from a core part of the cathode active material to a surface of the cathode active material;
- M1 is Ni and has a concentration gradient range in which a concentration decreases continuously from the core part of the cathode active material to the surface of the cathode active material, wherein a of Formula 1 is 0.7797 or more throughout an entire region of the cathode active material;
- and
- M2 is Co and has a constant concentration from the core part of the cathode active material to the surface of the cathode active material,
- wherein the ceramic coating layer formed on said at least one surface of the base film has a thickness of 2 to 10 μm.
Dependencies are inferred from the claim text.