Porosity echelon distribution pole piece, preparation method and application thereof

A technology of porosity and pole piece, which is applied in the field of pole piece with graded distribution of porosity and its preparation field, which can solve the problem of increasing the window of porosity distribution of active material layer and functional layer, difficult control of porosity distribution, unfavorable lithium Ion diffusion and other issues, to achieve the effect of improving diffusion capacity, low cost, and small porosity increase

Pending Publication Date: 2020-06-19
HUBEI JINQUAN NEW MATERIALS CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although the invention rationally configures the combination of the negative electrode active material layer and the functional layer, and designs the porosity distribution structure of the functional coating, the design of the multi-layer active material layer and the functional layer makes it difficult to control the porosity distribution. The active material layer and the functional layer are not conducive to the diffusion of lithium ions; in addition, it is difficult to increase the distribution window of the porosity of the active material layer and the functional layer by only using the accumulation of particles of different particle sizes. , resulting in a large proportion of the functional layer and a small increase in energy density

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  • Porosity echelon distribution pole piece, preparation method and application thereof

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Embodiment 1

[0074] This embodiment provides a pole piece, the thickness sum of the first film layer and the second film layer of the pole piece is 190 μm, wherein, the thickness of the first film layer is 95 μm, and the porosity is 8%; the thickness of the second film layer The thickness is 95 μm and the porosity is 20%.

[0075] The preparation method of the pole piece comprises the following steps:

[0076] (1) Mix nickel-cobalt lithium manganese oxide, conductive carbon black, PVDF and NMP with a particle diameter D50 of 12 μm to obtain the first film layer slurry, and take the mass of the solid content in the first film layer slurry as 100% Calculate, control nickel cobalt lithium manganate 80%, conductive carbon black 10% and PVDF10%, the quality of NMP is 30% of above-mentioned solid component quality;

[0077] (2) the particle diameter D50 is 12 μ m nickel cobalt lithium manganese oxide, conductive carbon black, PVDF and NMP and the particle diameter D50 is the paraffin microspher...

Embodiment 2

[0080] This embodiment provides a pole piece, the thickness sum of the first film layer and the second film layer of the pole piece is 300 μm, wherein the thickness of the first film layer is 200 μm, and the porosity is 16%; the thickness of the second film layer It is 100 μm and the porosity is 35%.

[0081] The preparation method of the pole piece comprises the following steps:

[0082] (1) Graphite, conductive carbon black, SBR binder and deionized water are mixed with the particle diameter D50 of 10 μm to obtain the first film layer slurry, and the quality of the solid component in the first film layer slurry is 100 In terms of %, control graphite 90%, conductive carbon black 5%, SBR binder 5%, deionized water is 40% of the above-mentioned solid component quality;

[0083] (2) Graphite, conductive carbon black, SBR binding agent and deionized water and particle diameter D50 are mixed with refined naphthalene of 13 μm by the particle diameter D50 to obtain the second film ...

Embodiment 3

[0086] This embodiment provides a pole piece, the thickness sum of the first film layer and the second film layer of the pole piece is 400 μm, wherein the thickness of the first film layer is 200 μm, and the porosity is 25%; the thickness of the second film layer It is 200 μm and the porosity is 60%.

[0087] The preparation method of the pole piece comprises the following steps:

[0088] (1) Graphite, conductive carbon black, SBR binding agent and deionized water solvent are mixed for particle diameter D50 of 8 μm, obtain the first film layer slurry, with the quality of solid component in the first film layer slurry as 100% meter, control graphite 99%, conductive carbon black 0.3%, SBR binder 0.7%, the quality of deionized water is 50% of the above-mentioned solid component quality;

[0089] (2) Graphite, conductive carbon black, SBR binder and deionized water and particle diameter D50 are mixed with polyethylene oxide of 10 μm to obtain the second film layer slurry, and the...

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Abstract

The invention relates to a porosity echelon distribution pole piece, a preparation method and application thereof. The pole piece comprises a current collector, and a first film layer and a second film layer which are sequentially arranged on the current collector, and the porosity of the first film layer is lower than that of the second film layer. According to the method, a pore-forming agent isused for improving the porosity of the second film layer, and furthermore, a distribution window of the porosity is controlled in a multi-dimensional manner through accumulation of different particlesizes, cold pressing and low-temperature vacuum baking processes, so that the porosity of the pole piece is improved, the influence on the thickness of the pole piece is relatively small, and the pole piece has the characteristics of high industrialization degree, low cost and high yield and has a wide application prospect.

Description

technical field [0001] The invention relates to the technical field of lithium-ion batteries, in particular to a pole piece with graded porosity distribution, a preparation method and application thereof. Background technique [0002] As the world's petroleum energy is depleted day by day, the demand for new energy is becoming more and more urgent. Lithium-ion batteries have a high voltage platform and a long cycle life, and have been widely used in consumer electronics, new energy vehicles and energy storage fields. [0003] At present, consumers have increased their requirements for the energy density and cruising range of new energy vehicle power battery systems, and lithium-ion batteries, as the core components of new energy vehicles, are also moving towards the era of high energy density. [0004] Under the condition of fixed cell size and material chemical system, there are two main methods to increase the energy density of lithium-ion batteries: 1. Indirectly increas...

Claims

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Application Information

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IPC IPC(8): H01M4/04H01M4/13H01M4/139H01M10/0525
CPCH01M4/0404H01M4/13H01M4/139H01M10/0525H01M2004/021Y02E60/10
Inventor 连朋飞谭明胜李倩伟何巍刘金成
Owner HUBEI JINQUAN NEW MATERIALS CO LTD
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