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DE-112012004538-B4 - Modified ternary cathode material and its precursor, as well as the manufacturing process of the cathode material and precursor

DE112012004538B4DE 112012004538 B4DE112012004538 B4DE 112012004538B4DE-112012004538-B4

Abstract

A precursor material for a modified ternary cathode material of a lithium-ion battery, characterized in that it has a composition of the following formula: Ni 1/3 Co 1/3 Mn 1/3 (OH) 2 ; and consists of three layers, including: an inner layer with a composition of the formula: (Ni 1/3-x Co 1/3+2x Mn 1/3-x )(OH) 2 , where 0<x<1/3 is; an outer layer with a composition of the formula: (Ni 0.5-y Co 2y Mn 0.5-y )(OH) 2 , where 0<y<1/6; and an intermediate layer made of a composite material with a concentration gradient between the composition of the inner layer and the composition of the outer layer.

Inventors

  • Jun Zhang
  • Jian Guo
  • Lianqi Zhang
  • Ruijuan Yang
  • Peiyu Hou

Assignees

  • HUBEI ZTE ADVANCED MATERIALS CO., LTD.

Dates

Publication Date
20260513
Application Date
20121026
Priority Date
20111031

Claims (7)

  1. A precursor material for a modified ternary cathode material of a lithium-ion battery, characterized in that it has a composition of the following formula: Ni 1/3 Co 1/3 Mn 1/3 (OH) 2 ; and consists of three layers, including: an inner layer with a composition of the formula: (Ni 1/3-x Co 1/3+2x Mn 1/3-x )(OH) 2 , where, 0<x<1/3; an outer layer with a composition of the formula: (Ni 0.5-y Co 2y Mn 0.5-y )(OH) 2 , where, 0<y<1/6; and an intermediate layer of a composite material with a concentration gradient from the composition of the inner layer and the composition of the outer layer.
  2. A manufacturing process for a precursor material for a modified ternary cathode material of a lithium-ion battery, characterized in that it comprises the following steps: a) Filling a ternary nickel, cobalt, and manganese salt solution A with a molar ratio Ni:Co:Mn = (1/3-x):(1/3+2x):(1/3-x), where 0<x<1/3, into a reaction vessel at a certain rate, wherein a solid-liquid mixture is obtained by a co-precipitation reaction with an alkaline solution, in which the precipitated solid has the formula (Ni 1/3-x Co 1/3+2x Mn 1/3-x )(OH) 2 with 0<x<1/3 and forms an inner layer of the precursor material; b) Adjusting the flow rate of the alkaline solution during the addition of ternary nickel, cobalt, and manganese salt solution A and ternary nickel, cobalt, and manganese salt solution B with a molar ratio Ni:Co:Mn=(0.5-y):2y:(0.5-y), where 0<y<1/6, to maintain the pH of the solution in the reaction vessel between 10 and 12; continuing to add solution A to the reaction vessel at a decreasing rate of 100-1000 ml per hour, while simultaneously adding solution B to the reaction vessel at an increasing rate of 100-1000 ml per hour from zero, thereby forming an intermediate layer of the precursor with a concentration gradient, connecting the inner layer and an outer layer of the precursor; c) when the rate of filling solution A drops to zero, fill the remaining solution B into the reaction vessel at a certain rate, thereby forming the outer layer of the precursor substance that surrounds the intermediate layer; d) separate the precipitated solid from the solid-liquid mixture after step (c) by centrifugal filtration, neutral washing and drying at 60-200°C for 4-10 hours, wherein the formula of the precipitated solid is (Ni 1/3 Co 1/3 Mn 1/3 )(OH) 2 and the precipitated solid is the precursor substance.
  3. The manufacturing process according to Claim 2 , characterized in that the total molar concentration of solution A and that of solution B are equal and the volume ratio of the two solutions in the reaction vessel is: 1 - 10.
  4. A modified ternary cathode material for a lithium-ion battery based on the precursor material according to Patent claim 1 .
  5. Manufacturing process of the cathode material according to Claim 4 , characterized in that the cathode material is produced by mixing the powdered precursor material according to Claim 1 , or of the powdered, by the manufacturing process according to Claim 2 obtained precursor material, with a lithium source and calcination, wherein the cathode material is produced by mixing and calcining the said powdered precursor material and the lithium source at 300-1200°C for 8-30 hours.
  6. Manufacturing process according to Patent claim 5 , characterized by the fact that the aforementioned The lithium source is lithium carbonate or lithium hydroxide.
  7. Manufacturing process according to Patent claim 6 , characterized in that it comprises the following steps: firstly, preparation of the precipitated solid with the formula (Ni 1/3 Co 1/3 Mn 1/3 )(OH) 2 by the manufacturing process according to Claim 2 , wherein the precipitated solid is the precursor material for the cathode material, followed by mixing the precursor material with the lithium source in a molar ratio of 1:1 to 1:1.2, multi-stage calcination in a muffle furnace at a calcination temperature of 300-1200°C and a calcination time of 8-30 hours, and obtaining the modified ternary cathode material after multi-stage calcination, cooling, pulverizing, and sieving.

Description

The invention relates to a precursor material for a modified ternary cathode material of the lithium-ion battery. It belongs to the field of technical application for cathode materials of the lithium-ion battery. Its formula is: Ni 1/3 Co 1/3 Mn 1/3 (OH) 2 ; it consists of three layers, including: the inner layer of the precursor is a ternary material whose cobalt content is greater than 1/3 and whose nickel and manganese content are equal. The formula of said inner layer of the precursor is: (Ni 1/3-x Co 1/3+2x Mn 1/3-x )(OH) 2 , including, 0<x<1/3; The outer layer of the precursor is a ternary material with a cobalt content of 0 to 1/3 and equal nickel and manganese content. The formula of this outer layer is: (Ni 0.5-y Co 2y Mn 0.5-y )(OH) 2 , where 0 < y < 1/6. The intermediate layer of the precursor is a composite material with a concentration gradient between the aforementioned inner and outer layers of the precursor. The formula of the modified ternary cathode material is Li(Ni 1/3 Co 1/3 Mn 1/3 )O 2 . The internal microscopic particles consist of an inner layer, an intermediate layer, and an outer layer. The cycle strength, thermal stability, and knock resistance are effectively improved by the modified ternary material of the invention, resulting in a high performance-cost ratio. Technical field The invention relates to the technical field for cathode material of the lithium-ion battery, in particular to a cathode material and its precursor of the lithium-ion battery, as well as the manufacturing process of the cathode material and the precursor. Background technology Energy is a key issue in the context of sustainable development in China, and the search for and development of alternative secondary energy sources is an important national policy. Lithium-ion batteries have been rapidly developed over the last decade, offering high energy efficiency due to their advantages such as high voltage, high energy density, long cycle life, and low pollution. They represent a significant direction for the development of China's new energy industry. The cathode material is a crucial component of lithium-ion batteries and also accounts for the largest share of their cost. From the US 2009/0068561 A1 A cathode material of a lithium battery is known which comprises an inner main part and an outer main part that surrounds the inner main part, wherein a metal composition is distributed in a continuous concentration gradient from the interface between the inner main part and the outer main part to the surface of the cathode material. As a novel cathode material for lithium-ion batteries, LiNi 1/3 Co 1/3 Mn 1/3 O 2 exhibits superior electrochemical properties due to the interaction of nickel, cobalt, and manganese compared to the single-component oxides LiCoO 2 , LiNiO 2 , and LiMnO 2. Furthermore, this ternary material is being considered as a replacement for LiCoO 2 in smaller lithium-ion batteries and is highly likely to be used as a power battery material and cathode material in EV and HEV lithium-ion batteries. The material is already a major research focus in the field of lithium-ion batteries worldwide. Contents of the invention One purpose of the invention is to offer a modified ternary material as well as its precursor according to the current need for performance improvement of the ternary cathode material of the lithium-ion battery; by adjusting the components and improving the production technology, the cycle life, thermal stability and knock resistance are effectively improved without increasing raw material costs. Another purpose of the invention is to offer a manufacturing process for the aforementioned modified ternary material and its precursor. The previous manufacturing process using a single salt solution is replaced by the manufacturing process of the precursor to the cathode material of the lithium-ion battery. Initially, the cobalt content is increased, resulting in a compact microstructure within the material. During the modification of the salt solution component, the material grows according to the original crystal structure, thereby increasing its compactness; simultaneously, the migration rate of lithium ions within the material is increased. During the increase of the external nickel-manganese elements, the Ni 0.5 Mn 0.5 structure is partially formed, thereby increasing the cycle life and thermal stability of the modified ternary material. To solve the aforementioned technical problems, the invention provides the technical solutions as defined in the following patent claims. Compared to current technology, the invention has the following advantages: The modified precursor with different internal structure LiNi 1/3 Co 1/3 Mn 1/3 O 2 is replaced by the modified ternary material and its A precursor to the invention was produced according to different mixing ratios and volumes with different combinations of ternary nickel, cobalt, and manganese salt solution A and ternary nickel, cobalt, and