Dry-method positive pole piece of lithium ion secondary battery and preparation method of dry-method positive pole piece

A technology for positive pole pieces and secondary batteries, which is applied in the field of dry-process positive pole pieces and its preparation, which can solve the problems of increasing battery resistivity, high battery manufacturing costs, and cracking battery performance, so as to improve the degree of dispersion and save manufacturing costs , Improve the effect of mixing degree

Pending Publication Date: 2021-06-25
DALIAN CBAK POWER BATTERY CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] (1) The amount of organic solvent NMP is large, the unit price is high, and the recovered NMP cannot be reused, resulting in high battery manufacturing costs;
[0005] (2) During the drying process, a part of the organic solvent NMP will be discharged in the form of waste gas, which may pollute the environment;
[0006] (3) After drying, there will be a small amount of organic solvent NMP remaining in the positive electrode sheet, cracking the performance of the battery;
[0007] (4) With the recovery of the organic solvent, the binder will float up during the drying process, which increases the battery resistivity and reduc

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0041] This embodiment provides a preparation of lithium iron phosphate positive pole piece of lithium ion secondary battery, the steps are as follows:

[0042] (1) Powder ingredients: the positive electrode main material powder and the conductive agent SP are uniformly mixed for 2 hours through a high-speed dispersing kneader, and the linear speed is 25m / s to obtain a powder; the positive electrode main material and the conductive agent in the obtained powder have a mass ratio of 96:4;

[0043] (2) Carrier preheating: 70% porosity, 10g / m 2 Heat the PTFE non-woven fabric with surface density to 120°C, and place it at a distance of 40mm directly below the high-speed jet machine;

[0044] (3) Preparation of electrode coating: The mixed powder is sprayed vertically downward at a speed of 10m / s in a high-speed jet machine, and sputtered on the inside and surface of the PTFE non-woven fabric to obtain a surface density of 170g / m 2 The electrode coating; the lower part of the PTFE n...

Embodiment 2

[0048] This embodiment provides a kind of preparation of lithium-ion secondary battery ternary nickel cobalt lithium manganese oxide positive pole piece, the steps are as follows:

[0049] (1) Powder ingredients: The positive electrode main material powder and the conductive agent SP are uniformly mixed for 2 hours through a high-speed dispersing kneader, and the linear speed is 30m / s to obtain a powder; the positive electrode main material and the conductive agent in the obtained powder have a mass ratio of 97:3;

[0050] (2) Carrier preheating: 80% porosity, 10g / m 2 Heat the PTFE non-woven fabric with surface density to 120°C, and place it at a distance of 60mm directly below the high-speed jet machine;

[0051] (3) Preparation of electrode coating: The mixed powder is sprayed vertically downward at a speed of 15m / s in a high-speed jet machine, and sputtered on the inside and surface of PTFE non-woven fabric to form a surface density of 180g / m 2 The electrode coating; the ...

Embodiment 3

[0055] This embodiment provides a preparation of lithium manganate positive electrode sheet for a lithium ion secondary battery, the steps are as follows:

[0056] (1) Powder ingredients: The positive electrode main material powder and the conductive agent SP are uniformly mixed for 2 hours through a high-speed dispersing kneader, and the linear speed is 30m / s to obtain a powder; the positive electrode main material and the conductive agent in the obtained powder have a mass ratio of 95:5;

[0057] (2) Carrier preheating: 80% porosity, 12g / m 2 Heat the surface density PTFE non-woven fabric to 120°C, and place it at a distance of 100mm directly below the high-speed jet machine;

[0058] (3) Preparation of electrode coating: The mixed powder is sprayed vertically downward at a speed of 20m / s in a high-speed jet machine, and sputtered on the inside and surface of PTFE non-woven fabric to form a surface density of 190g / m 2 The electrode coating; the lower part of PTFE is equippe...

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Abstract

The invention belongs to the technical field of preparation of positive pole pieces of lithium batteries, and particularly relates to a dry-method positive pole piece of a lithium ion secondary battery and a preparation method of the dry-method positive pole piece. The positive pole piece of the lithium ion secondary battery provided by the invention is of a sandwich structure and sequentially comprises an electrode coating, a metal foil and an electrode coating, wherein the electrode coating comprises a carrier as well as a positive electrode main material and a conductive agent which are loaded inside or on the surface of the carrier; and the carrier is a PTFE non-woven fabric. By changing the compounding mode of the positive pole piece, the loading capacity of an active substance in the pole piece and the dispersion uniformity of the active substance and PTFE in the pole piece are improved, so that the resistance of the pole piece is remarkably reduced, and the electrical property of the pole piece is improved; meanwhile, no organic solvent is involved, so that no NMP waste gas is discharged, and the material cost of the battery is saved by 5-10%; and as a drying process is omitted, the manufacturing cost is saved by 40-60%.

Description

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Claims

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Application Information

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Owner DALIAN CBAK POWER BATTERY CO LTD
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