Lithium ion battery safety coating slurry and dispersion method thereof

Abstract

The invention discloses lithium ion battery safety coating slurry and a dispersion method thereof. The lithium ion battery safety coating slurry comprises, by weight, 87-95 parts of a ceramic material, 5-13 parts of a binder, 0.1-3.5 parts of a low molecular weight ionic polymer wetting dispersant and 140-550 parts of a solvent. According to the safety coating slurry for the lithium ion battery, on one hand, the content of ceramic powder is high, and a small amount of low-molecular-weight ionic polymer wetting dispersant is introduced to improve the stability of the slurry; and due to the fact that the ceramic powder has the nanoscale particle size, secondary aggregate is very easy to form, a dispersing agent containing some groups is added to adjust surface charges and surface acid-base adsorption of the ceramic powder, the dispersion effect of powder particles is improved, and then the slurry with good dispersity and stability is obtained. And meanwhile, the provided dispersion method can stabilize the viscosity of the ceramic slurry and reduce the time for optimizing the lamination of the production process.

Description

technical field

[0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a lithium ion battery safety coating slurry and a dispersion method thereof. Background technique

[0002] With the advancement of lithium-ion battery technology, especially the market's expectations for large-scale equipment such as high-power, long-range electric vehicles, such as hybrid electric vehicles (HEV) and plug-in hybrid electric vehicles (PHEV), battery energy is required to be 5~20KWh , while pure electric vehicles (EV) require a battery capacity of 15~50KWh. Although battery life anxiety and energy replenishment anxiety have always surrounded new energy vehicles, battery safety has always been the focus of the whole society. In Shanghai alone, there have been more than 400 fire accidents caused by electric bicycle charging in 2020, resulting in 20 deaths and 17 injuries, which has aroused strong concern from consumers. The technology and ...

Examples

Embodiment 1

[0032] The lithium-ion battery safety coating slurry in this embodiment consists of the following components in parts by mass:

[0033] Boehmite 90, polyvinylidene fluoride 10, alkoxy ammonium salt of acid group block copolymer 0.1, N-methyl-2-pyrrolidone 140, the dispersion method of the uniform and stable suspension is as follows;

[0034] (1) Preparation of pre-mixed glue: Sprinkle polyvinylidene fluoride evenly into weighed N-methyl-2-pyrrolidone, stir in a sealed container at 15 rpm and 1200 rpm for 6 hours, polyvinylidene fluoride Completely dissolved in N-methyl-2-pyrrolidone to obtain a premixed glue with a mass concentration of 10%;

[0035] (2) Preparation of anhydrous boehmite material: add boehmite into the grinding tank, and the grinding time is 0.5h; the particle size D50 of the boehmite after grinding is 100-3000nm, and keep the ground boehmite at -0.9~- 0.85MPa vacuum degree, keep high temperature 150℃±5℃ and bake for 4h;

[0036](3) Preparation of low-molecu...

Embodiment 2

[0042] The difference between Example 2 and Example 1 is that the lithium-ion battery safety coating slurry of this example is composed of the following components in parts by mass: boehmite 90, polyvinylidene fluoride 10, acid group block Alkoxyl ammonium salt of the copolymer 0.1, N-methyl-2-pyrrolidone 550; 15% N-methyl-2-pyrrolidone was added in step (5); the rest of the steps were the same as in Example 1.

Embodiment 3

[0050] The difference between embodiment 3 and comparative example 1 is to remedy the slurry with flocculation problem, and re-add 1% of acidic group block copolymer to the slurry in comparative example 1 that has been separated for 10d under the sealed state. Alkoxyl ammonium salts. First, stir and disperse for 4 hours according to the revolution of 25rpm and the rotation of 3500rpm; then transfer the mixed solution into the cone mill, with a flow rate of 10L / h and a linear velocity of 23m / s, and circulate 10 times;

[0051] By the solid content of embodiment 1~3 and comparative example 1~3 and viscosity variation data figure 1 and figure 2 It can be seen from the comparison that the solid content of the ceramic slurry prepared in Comparative Example 1 without adding a wetting and dispersing agent, Comparative Example 2 with magnetic stirring, and Comparative Example 3 with ultrasonic and magnetic stirring cycles decreased rapidly, and the viscosity of the slurry decreased ...

technical field

[0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a lithium ion battery safety coating slurry and a dispersion method thereof. Background technique

[0002] With the advancement of lithium-ion battery technology, especially the market's expectations for large-scale equipment such as high-power, long-range electric vehicles, such as hybrid electric vehicles (HEV) and plug-in hybrid electric vehicles (PHEV), battery energy is required to be 5~20KWh , while pure electric vehicles (EV) require a battery capacity of 15~50KWh. Although battery life anxiety and energy replenishment anxiety have always surrounded new energy vehicles, battery safety has always been the focus of the whole society. In Shanghai alone, there have been more than 400 fire accidents caused by electric bicycle charging in 2020, resulting in 20 deaths and 17 injuries, which has aroused strong concern from consumers. The technology and ...

Examples

Embodiment 1

[0032] The lithium-ion battery safety coating slurry in this embodiment consists of the following components in parts by mass:

[0033] Boehmite 90, polyvinylidene fluoride 10, alkoxy ammonium salt of acid group block copolymer 0.1, N-methyl-2-pyrrolidone 140, the dispersion method of the uniform and stable suspension is as follows;

[0034] (1) Preparation of pre-mixed glue: Sprinkle polyvinylidene fluoride evenly into weighed N-methyl-2-pyrrolidone, stir in a sealed container at 15 rpm and 1200 rpm for 6 hours, polyvinylidene fluoride Completely dissolved in N-methyl-2-pyrrolidone to obtain a premixed glue with a mass concentration of 10%;

[0035] (2) Preparation of anhydrous boehmite material: add boehmite into the grinding tank, and the grinding time is 0.5h; the particle size D50 of the boehmite after grinding is 100-3000nm, and keep the ground boehmite at -0.9~- 0.85MPa vacuum degree, keep high temperature 150℃±5℃ and bake for 4h;

[0036](3) Preparation of low-molecu...

Embodiment 2

[0042] The difference between Example 2 and Example 1 is that the lithium-ion battery safety coating slurry of this example is composed of the following components in parts by mass: boehmite 90, polyvinylidene fluoride 10, acid group block Alkoxyl ammonium salt of the copolymer 0.1, N-methyl-2-pyrrolidone 550; 15% N-methyl-2-pyrrolidone was added in step (5); the rest of the steps were the same as in Example 1.

Embodiment 3

[0050] The difference between embodiment 3 and comparative example 1 is to remedy the slurry with flocculation problem, and re-add 1% of acidic group block copolymer to the slurry in comparative example 1 that has been separated for 10d under the sealed state. Alkoxyl ammonium salts. First, stir and disperse for 4 hours according to the revolution of 25rpm and the rotation of 3500rpm; then transfer the mixed solution into the cone mill, with a flow rate of 10L / h and a linear velocity of 23m / s, and circulate 10 times;

[0051] By the solid content of embodiment 1~3 and comparative example 1~3 and viscosity variation data figure 1 and figure 2 It can be seen from the comparison that the solid content of the ceramic slurry prepared in Comparative Example 1 without adding a wetting and dispersing agent, Comparative Example 2 with magnetic stirring, and Comparative Example 3 with ultrasonic and magnetic stirring cycles decreased rapidly, and the viscosity of the slurry decreased ...

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