Lithium secondary battery
AssigneeSK Innovation Co., Ltd.
InventorsKyung-Bin Yoo, Duck-Chul Hwang, Jin-Sub Lim, Kook-Hyun Han
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Abstract
A lithium secondary battery comprises a cathode, an anode and a non-aqueous electrolyte. The cathode includes a cathode active material containing lithium-metal oxide of which at least one of metals has a continuous concentration gradient from a core part to a surface part thereof, and is doped with transitional metal. The lithium-metal oxide includes elements M1, M2 and M3. One of M1, M2 and M3 has a concentration gradient range in which a concentration increases from the core part to the surface part.
Claims13
A lithium secondary battery, comprising a cathode, an anode and a non-aqueous electrolyte,
- wherein the cathode includes a cathode active material consisting of one or more lithium-metal oxides containing Ni, Co, and Mn,
- and wherein at least one of the lithium-metal oxides includes a compound represented by Formula 1 below which is doped with a dopant element,
- LixM1aM2bM3cOy Formula 1
- 0<x≤1.1, 2≤y≤2.02, 0<a<1, 0<b<1, 0<c<1, and 0<a+b+c≤1,
- wherein M3 is Mn and has a concentration gradient range in which a concentration increases continuously throughout the cathode active material from a center of the cathode active material to a surface of the cathode active material,
- wherein M1 is Ni and has a concentration gradient range in which a concentration decreases continuously from the center of the cathode active material to the surface of the cathode active material,
- wherein M2 is Co and has a constant concentration from the center of the cathode active material to the surface of the cathode active material,
- wherein the dopant element is in a concentration of 1,000 to 5,000 ppm relative to the compound of Formula 1 having the concentration gradient range, and
- wherein a of Formula 1 is 0.7797 or more throughout an entire region of the cathode active material.
A lithium secondary battery, comprising a cathode, an anode and a non-aqueous electrolyte,
- wherein the cathode includes a cathode active material consisting of one or more lithium-metal oxides containing Ni, Co, and Mn,
- and wherein, at least one of the lithium-metal oxides includes a compound represented by Formula 1 below which is doped with a dopant element,
- LixM1aM2bM3cOy Formula 1
- 0<x≤1.1, 2≤y≤2.02, 0<a<1, 0<b<1, 0<c<1, and 0<a+b+c≤1,
- wherein M3 is Mn, and has a concentration gradient range in which a concentration increases continuously throughout the cathode active material frog a center of the cathode active material to a surface of the cathode active material,
- wherein M1 is Ni and has a concentration gradient range in which a concentration decreases continuously from the center of the cathode active material to the surface of the cathode active material,
- wherein M2 is Co and has a constant concentration from the center of the cathode active material to the surface of the cathode active material, and
- wherein the dopant element is in a concentration of 1,000 to 5,000 ppm relative to the compound of formula I having the concentration gradient range,
- wherein a capacity of 0.5 C charging at −20° C. is 65% or more of that at room temperature, and a capacity of 0.5 discharging at −20° C. is 78% or more of that at room temperature, and
- wherein a of Formula 1 is 0.7797 or more throughout an entire region of the cathode active material.
A lithium secondary battery, comprising a cathode, an anode and a non-aqueous electrolyte, the cathode including a cathode active material, wherein the cathode active material includes a lithium-metal oxide containing Ni, Co, and Mn, represented by Formula 1 below,
- LixM1aM2bM3cOy Formula 1
- 0<x≤1.1, 2≤y≤2.02, 0<a<1, 0<b<1, 0<c<1, and 0<a+b+c≤1,
- wherein M3 is Mn and has a concentration gradient range in which a concentration increases continuously throughout the cathode active material from a center of the cathode active material to a surface of the cathode active material,
- wherein M1 is Ni and has a concentration gradient range in which a concentration decreases continuously from the center of the cathode active material to the surface of the cathode active material,
- wherein M2 is Co and has a constant concentration from the center of the cathode active material to the surface of the cathode active material,
- wherein the lithium-metal oxide includes a dopant element in a concentration of 1,000 to 5,000 ppm relative to the compound of Formula 1 having the concentration gradient range,
- wherein the concentration of Ni is 0.7 or more throughout an entire region of the cathode active material,
- wherein the cathode does not include a cathode active material containing a lithium-metal oxide having which has only one or two of the Ni, Co, or Mn, and
- wherein a of Formula 1 is 0.7797 or more throughout an entire region of the cathode active material.
Dependencies are inferred from the claim text.