Graphite paper current collector, negative electrode and preparation method

A technology of graphite paper and current collector, applied in the direction of negative electrode, battery electrode, active material electrode, etc., can solve the problem of unable to continuously improve the specific capacity of the battery, achieve good cycle stability, improve the overall specific capacity, and stabilize the charge-discharge capacity. Effect

Active Publication Date: 2020-08-11
TSINGHUA UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The invention provides a graphite paper current collector, a negative electrode, and a method for preparing the current collector and the negative electrode, so as to solve the bottleneck in the prior art that cannot continue to increase the specific capacity of the battery when the positive and negative electrode materials reach the theoretical capacity. technical issues

Method used

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  • Graphite paper current collector, negative electrode and preparation method
  • Graphite paper current collector, negative electrode and preparation method
  • Graphite paper current collector, negative electrode and preparation method

Examples

Experimental program
Comparison scheme
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Embodiment A

[0054] The preparation method of embodiment A graphite paper:

[0055] Take the 100HN polyimide film of DuPont's Kapton series as an example, its basic parameters are as follows: 25um thick, the highest tensile strength is 231MPa, the maximum elongation is 72% (23°C) and the tensile modulus is 2.5GPa Wait.

[0056] Cut it into a specific shape (rectangle, square, circle, triangle, rhombus, hexagon, etc.) and size (depending on the situation) as needed. The following is an example of a square of 10 cm by 10 cm;

[0057] Next, the cut polyimide film was first cleaned with ultrapure water ultrasonic (frequency 40KHz, power range 120W) for 15 minutes, then ultrasonically cleaned with ethanol for 15 minutes, and repeated cleaning three times to remove impurities;

[0058] Next, place one or more pieces of the cleaned polyimide film between two flat graphite templates, pressurize and fix it with a pressure of 5MPa to prevent deformation caused by the subsequent high-temperature car...

Embodiment B

[0064] The preparation of embodiment B graphite paper current collector

[0065] The template used is a stainless steel metal plate, which is prepared by etching. The structural features are as follows: image 3 shown.

[0066] Spread the graphite paper prepared in Example A on the surface of the stainless steel template, place it in a roller press, adjust the rolling thickness, and prepare graphite paper with an array hole structure (the holes do not penetrate the graphite paper). Specifically, the prepared graphite paper is placed on the surface of a steel plate (such as image 3 Shown), the specific parameters in the above preparation process are: the thickness of the stainless steel template is 2 mm, the thickness of the graphite paper is 20um, and the rolling thickness can be adjusted to 2010um. The final highly oriented graphite paper current collector with array hole structure is as follows: Figure 4 shown.

Embodiment 1

[0068] At room temperature, the thickener carboxymethylcellulose (CMC) powder and ultrapure deionized water were mixed at a ratio of 1.5:98.5, and stirred at room temperature for 12 hours to obtain a transparent viscous colloidal solution. According to the mass ratio of active material nano-scale silicon / carbon:: carbon nanotube (CNT): CMC = 8:1:1, add each component material, and ball mill and mix for 4 hours to obtain the negative electrode aqueous slurry. According to the conventional production process of lithium-ion button batteries, the aqueous negative electrode slurry is coated on the highly oriented graphite paper current collector with array hole structure prepared in Example B by the method of wet film preparation, dried and desiccated. In the water deoxygenation process, the dry film is punched by the punching equipment to cut the graphite paper collector to obtain the negative electrode sheet. In the glove box, assemble the button-type half-battery with metal lith...

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Abstract

The invention discloses a graphite paper negative electrode, a graphite paper current collector and a preparation method thereof, and belongs to the field of lithium ion material manufacturing. The graphite paper current collector comprises a first surface and a second surface which are oppositely arranged; wherein the second surface is a surface acting with the active substance, the first surfaceis used for being connected with an external circuit, a plurality of holes are formed in the second surface, and the plurality of holes do not penetrate through the first surface. In addition, the invention also provides a preparation method of the current collector and a graphite paper negative electrode. The lithium ion battery half-cell assembled by the current collector provided by the invention has excellent cycling stability, also has good rate capability, and has excellent charging and discharging performance under large current. Compared with a copper foil and aluminum foil current collector used at present, under the condition of the same capacity, the mass of the whole electrode is greatly reduced, and the mass specific capacity can be improved by 100-200%.

Description

technical field [0001] The invention relates to the technical field of manufacturing lithium-ion battery materials, in particular to a graphite paper current collector, a negative electrode, and a method for preparing the current collector and the negative electrode. Background technique [0002] Since the advent of lithium-ion batteries, this system has received widespread attention in recent years for its high energy density, high operating voltage, stable cycle performance, good load characteristics, fast charge and discharge rates, safety and non-pollution. attention and use. Since Sony Corporation of Japan invented the first generation of commercial lithium-ion batteries in 1991, lithium-ion batteries have made great progress in terms of cycle stability, energy density, and safety in the past 20 years. [0003] A classic lithium-ion battery mainly includes the following components: positive electrode material, negative electrode material, separator, electrolyte, curren...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/66H01M4/80H01M4/133H01M4/134H01M10/0525H01M10/613H01M10/653H01M10/654B26F1/00
CPCB26F1/00H01M4/133H01M4/134H01M4/663H01M4/80H01M10/0525H01M2004/027H01M10/613H01M10/653H01M10/654Y02E60/10
Inventor 林贤清魏飞于春辉肖哲熙
Owner TSINGHUA UNIV
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