Cathode pole piece, preparation method thereof, and lithium ion battery

A cathode and pole piece technology, applied in battery electrodes, secondary batteries, non-aqueous electrolyte battery electrodes, etc. Can not protect the cathode active material and other problems, to achieve the effect of improving electrochemical performance, strong operability, and good uniformity of film formation and coating

Active Publication Date: 2020-04-07
NINGDE AMPEREX TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, polymers with good film-forming properties are mostly insulating materials, so the thickness and density of the coating layer must be strictly controlled, otherwise it will affect the ion conductance and electron conductance of the lithium-ion battery, and then affect the capacity of the lithium-ion battery. and cycle performance
[0005] Considering the electrolyte, most of them are cathodic film-forming additives that can self-polymerize under high voltage and form a protective layer on the surface of the cathode active material. However, this method can only form a protective layer on the surface of the cathode sheet. It cannot protect the cathode active material inside the pole piece well, so the durability is poor, and there is also the risk of deteriorating the performance of the anode and the full battery

Method used

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  • Cathode pole piece, preparation method thereof, and lithium ion battery
  • Cathode pole piece, preparation method thereof, and lithium ion battery
  • Cathode pole piece, preparation method thereof, and lithium ion battery

Examples

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preparation example Construction

[0045] Next, the preparation method of the cathode electrode sheet according to the second aspect of the present invention is described, which is used to prepare the cathode electrode sheet described in the first aspect of the present invention, including the steps of: uniformly mixing the conductive agent, the binder and the solvent to obtain a conductive agent solution ; After stirring and mixing the additive and the cathode active material, add the conductive agent solution, stir evenly to obtain the cathode slurry, then place the cathode slurry on the cathode current collector, and obtain the cathode electrode sheet after drying, wherein the cathode slurry is dried After removing the solvent, a cathode active material layer is formed.

[0046] The conventional mixing process is to add cathode active materials, conductive agents, binders, additives, solvents, etc. into the mixing tank in sequence, and stir them together to make cathode stirring materials, which cannot ensure...

Embodiment 1

[0054] (1) Preparation of additives

[0055] The molecular structure of the additive is as follows:

[0056]

[0057]

[0058] Prepare the Grignard reagent by reacting monomer 1 and Mg in anhydrous ether environment, then add the monomer 2 mixed with KOH into the Grignard reagent dropwise, and react for 1.5h at 30°C under the protection of nitrogen. ~2h, the monomer before polymerization was obtained. Then transfer the monomer before polymerization to another reaction vessel, using AlEt 3 / NiOct / BF 3 ·Et 2 O catalyst system, using benzene as a solvent, reacting at 40°C to 55°C for 2 hours to obtain the additive represented by formula I. In formula I, the degree of polymerization n is 15-20.

[0059] (2) Preparation of cathode sheet

[0060] The cathode active material lithium cobalt oxide (LiCoO 2 ), the additive shown in formula I, and the solvent N-methylpyrrolidone (NMP) were mixed and stirred for 2 hours, then the conductive agent solution composed of conducti...

Embodiment 2

[0068] A lithium-ion battery was prepared according to the method of Example 1. The difference is that the molecular structure of the additive is as follows:

[0069]

[0070]

[0071] Prepare the Grignard reagent by reacting monomer 1 and Mg in anhydrous ether environment, then add the monomer 2 mixed with KOH into the Grignard reagent dropwise, and react for 1.5h at 30°C under the protection of nitrogen. ~2h, the monomer before polymerization was obtained. Then transfer the monomer before polymerization to another reaction vessel, using AlEt 3 / NiOct / BF 3 ·Et 2 O catalyst system, using benzene as a solvent, reacting at 40° C. to 55° C. for 2 hours to obtain the additive represented by formula II. In formula II, the degree of polymerization n is 15-20.

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PUM

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Abstract

The invention provides a cathode plate and a preparation method thereof and a lithium ion battery. The cathode plate consists of a cathode current collector and a cathode active substance layer. The cathode active substance layer consists of a cathode active material, a conductive agent; a binder; and an additive. The additive of the cathode plate disclosed by the invention can coat the surface of the cathode active material well after catalytic polymerization under voltage, so that a layer of uniformly distributed protective film is formed, and thereby the objective of improving the electrochemical properties of lithium ion batteries is achieved.

Description

technical field [0001] The invention relates to the technical field of lithium ion batteries, in particular to a cathode pole piece, a preparation method thereof, and a lithium ion battery. Background technique [0002] Lithium-ion batteries have become the mainstream development direction of secondary batteries due to their excellent performance. However, with the development of battery technology, the requirements for battery energy density are getting higher and higher. The battery energy density is determined by the theoretical energy density of the battery and the proportion of inactive materials (such as conductive agents, binders, etc.). Therefore, in order to continue to improve the energy density of batteries, in addition to reducing the specific gravity of inactive materials, more efforts should be made to develop active materials based on high voltage, especially cathode active materials, so as to increase the lithium intercalation and desorption potential of cat...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01M4/13H01M4/139H01M4/62H01M10/0525
CPCH01M4/13H01M4/139H01M4/62H01M10/0525Y02E60/10
Inventor 刘会会魏增斌孙成栋钟泽郑义李红举
Owner NINGDE AMPEREX TECH
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