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Method for improving porosity of dry-method electrode

A porosity and electrode technology, which is applied in the field of increasing the porosity of dry-process electrodes, can solve the problems of low porosity and poor rate performance of dry-process electrodes, and achieve the effect of improving rate performance and increasing porosity

Pending Publication Date: 2021-09-07
四川启睿克科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] Aiming at the problems of low porosity and poor rate performance of dry-process electrodes, the present invention provides a method for increasing the porosity of dry-process electrodes. The pore is formed in situ in the pole piece through high-temperature thermal decomposition of the pore-forming agent into gas release. , increasing the porosity of the pole piece, thereby improving the rate performance of the electrode

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0016] Polymethyl methacrylate was used as a pore-forming agent. According to the thermogravimetric test, the thermal decomposition temperature of polymethyl methacrylate is 300°C, and the thermal decomposition temperature of PVDF is 410°C. NCM523, SP, PVDF, polymethyl methacrylate (D 50 =5um) according to the mass ratio of 7:1:1:1 and mixed evenly, and then mixed by ball milling at 500r / min for 2h to obtain the above mixed powder. Cut aluminum foil with a diameter of 12mm and a thickness of 15um, weigh 40mg of the mixed powder, put them into a mold with a diameter of 12mm in turn, and heat press at 170°C and 2MPa pressure for 15 seconds to obtain a dry foil with a diameter of 12mm and a thickness of 120um. French electrode pole piece. Then put the dry-process electrode pole piece into a muffle furnace at 350°C for calcination for 1 hour to remove the polymethyl methacrylate pore-forming agent in the pole piece.

Embodiment 2

[0018] The difference between Example 2 and Example 1 is that the mixed powder does not contain polymethyl methacrylate pore-forming agent, and the mass ratio of NCM523, SP, and PVDF is 8:1:1.

Embodiment 3

[0020] The difference between Example 3 and Example 1 is that the mass ratio of NCM523, SP, PVDF, and polymethyl methacrylate is 7.5:1:1:0.5.

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PUM

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Abstract

The invention discloses a method for improving porosity of a dry-method electrode. A pore-forming agent is added when the active substance, the conductive agent and the binder dry powder are mixed, and the pore-forming agent is removed in the pole piece hot-pressing process or is removed through high-temperature calcination after the pole piece is formed. The method has the main advantages that the porosity of the electrode is improved while the peeling strength of the pole piece is considered, and the rate capability of the battery cell is further improved.

Description

technical field [0001] The invention belongs to the field of batteries, and in particular relates to a method for increasing the porosity of dry-process electrodes. Background technique [0002] Currently, electrode tabs for commercial lithium-ion batteries are produced by applying a wet coating to the collector. The slurry generally contains active materials, conductive agents and binders dissolved in organic solvents or water, and the specific material types and proportions depend on the binder system. For the common system of electrode preparation, the electrode drying process is the most energy-consuming link in the production process of lithium-ion batteries. Moreover, in the drying process, harmful substances such as NMP waste gas need to be treated. The above processes all increase the manufacturing cost of the lithium battery. Due to the fact that the dry electrode does not need coating, baking and other processes, the preparation process is simple, the preparatio...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/1391H01M4/04H01M10/0525
CPCH01M4/1391H01M4/0471H01M10/0525H01M2004/021Y02E60/10
Inventor 高剑汤争耀张婧宇周雪
Owner 四川启睿克科技有限公司