Method for making lithium ion battery

Patent metadata

Field	Value
Publication number	US-9634352-B2
Application number	US-201213662718-A
Country	US
Kind code	B2
Filing date	Oct 29, 2012
Priority date	Jul 13, 2012
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

A method for making lithium ion battery is provided. A cathode material layer and an anode material layer are provided. A cathode current collector is formed on a surface of the cathode material layer to obtain a cathode electrode. The cathode current collector includes a graphene layer and a carbon nanotube layer stacked with the graphene layer. An anode current collector is formed on a surface of the anode material layer to obtain an anode electrode. A separator is applied between the cathode electrode and the anode electrode thereby forming a battery cell. At least one battery cell is encapsulated in an external encapsulating shell. An electrolyte solution is injected into the external encapsulating shell.

First claim

What is claimed is:

1. A method for making lithium ion battery comprising:
providing a cathode material layer and an anode material layer, wherein providing the cathode material layer comprises:
providing a carbon nanotube source, a cathode active material comprising a plurality of cathode active material particles, and a solvent, wherein providing the carbon nanotube source comprises:
providing a substrate and a carbon nanotube array formed on the substrate, wherein the carbon nanotube array comprises a plurality of carbon nanotubes, and a length of the plurality of carbon nanotubes is longer than 200 micrometers; and
scratching the carbon nanotube array from the substrate to form the carbon nanotube source;

adding the carbon nanotube source and the cathode active material into the solvent;
agitating the solvent with the carbon nanotube source and the cathode active material with ultrasonic waves to form a mixture free of adhesive in the solvent;
depositing the mixture at a bottom of the solvent; and
separating the carbon nanotube source and the cathode active material from the solvent to obtain the cathode material layer free of adhesive;

forming a cathode current collector on a surface of the cathode material layer to obtain a cathode electrode, wherein the cathode current collector comprises a graphene layer and a carbon nanotube layer stacked with the graphene layer; the carbon nanotube layer is located on a surface of the cathode material layer, the graphene layer located on a surface of the carbon nanotube layer, and the carbon nanotube layer is sandwiched between the cathode material layer and the graphene layer; and the graphene layer comprises at least one graphene, the graphene is a one-atom-thick planar sheet of SP 2 -bonded carbon atoms that are densely packed in a honeycomb crystal lattice, and the at least one graphene comprises a plurality of graphenes stacked with each other or located side by side;
forming an anode current collector on a surface of the anode material layer to obtain an anode electrode;
applying a separator between the cathode electrode and the anode electrode thereby forming a battery cell;
encapsulating at least one battery cell in an external encapsulating shell; and
injecting an electrolyte solution into the external encapsulating shell.

2. The method of claim 1 , wherein the solvent is ethanol, glycol, acetone, N-Methyl-2-pyrrolidone, water, or combination thereof.

3. The method of claim 1 , wherein a method for making the anode material layer comprises:
providing the carbon nanotube source comprising the plurality of carbon nanotubes, an anode active material comprising a plurality of anode active material particles, and the solvent;
adding the carbon nanotube source and the anode active material into the solvent, and agitating the solvent with the carbon nanotube source and the anode active material with ultrasonic waves; and
separating the carbon nanotube source and the anode active material from the solvent to obtain the anode material layer.

4. The method of claim 3 wherein the anode material layer consists of the anode active material and the plurality of carbon nanotubes.

5. The method of claim 1 , wherein the graphene layer is formed by:
providing a metal substrate having a surface;
disposing the metal substrate in a reacting chamber;
heating the metal substrate to a predetermined temperature; and
supplying a carbon source gas into the reacting chamber.

6. The method of claim 5 , wherein a hydrogen gas is imported in the reacting chamber through a gas inlet before heating the metal substrate.

7. The method of claim 5 , wherein a flow rate of the hydrogen gas is about 2 sccm, and a pressure of the reacting chamber is about 13.3 Pa.

8. The method of claim 1 , wherein a method for applying the carbon nanotube layer on the surface of the graphene layer comprises:
providing a carbon nanotube array;
transferring the carbon nanotube array to the surface of the graphene layer; and
pressing the carbon nanotube array.

9. The method of claim 1 , wherein the battery cell is pressed using a laminator.

10. The method of claim 1 , wherein the cathode material layer consists of the plurality of carbon nanotubes and the cathode active material particles.

11. The method of claim 1 , wherein in the process of agitating the solvent with the carbon nanotube source and the cathode active material with ultrasonic waves, the plurality of carbon nanotubes is entangled with each other to form a net structure, and the cathode active material particles are wrapped by the net structure.

12. The method of claim 1 , wherein a diameter of the plurality of cathode active material particles is less than 15 micrometers.

Assignees

• Wang Jia-Ping
• Jiang Kai-Li
• Fan Shou-Shan
• Univ Tsinghua
• Hon Hai Prec Ind Co Ltd

Inventors

• Wang Jia-Ping
• Jiang Kai-Li
• Fan Shou-Shan

Classifications

• H01M10/049 Primary

  Processes for forming or storing electrodes in the battery container · CPC title

• H01M4/623

  fluorinated polymers · CPC title

• H01M4/625

  Carbon or graphite · CPC title

• H01M4/366

  as layered products · CPC title

• B82Y30/00

  Nanotechnology for materials or surface science, e.g. nanocomposites · CPC title