CN-122025933-A - Heat insulation layer, preparation method thereof and battery

CN122025933ACN 122025933 ACN122025933 ACN 122025933ACN-122025933-A

Abstract

The application provides a heat insulation layer, a preparation method thereof and a battery, and belongs to the technical field of batteries, wherein the heat insulation layer comprises micro-nano ceramic particles, micro-nano aerogel particles, layered micro-nano sheets, microencapsulated phase change materials and an interfacial compatibility enhancer, the surfaces of the micro-nano ceramic particles contain first active groups, the surfaces of the layered micro-nano sheets contain second active groups, the surfaces of the microencapsulated phase change materials contain third active groups, the interfacial compatibility enhancer contains fourth active groups, and the interfacial compatibility enhancer enables at least two of the micro-nano ceramic particles, the micro-nano aerogel particles, the layered micro-nano sheets and the microencapsulated phase change materials to be mutually bonded. The application bonds micro-nano ceramic particles, micro-nano aerogel particles, layered micro-nano sheets and microencapsulated phase change materials, improves the mechanical strength, wear resistance and crack resistance of the heat insulation layer, and effectively prevents heat conduction and improves the heat insulation effect by a specific composite structure formed by different components.

Inventors

XUE JIEHUI
CAO FENGFENG
LI HEXIN
PENG YANQIU

Assignees

武汉亿纬储能有限公司

Dates

Publication Date: 20260512
Application Date: 20251231

Claims (11)

1. The heat insulation layer is characterized by comprising micro-nano ceramic particles, micro-nano aerogel particles, layered micro-nano sheets, microencapsulated phase change materials and interfacial compatibility enhancers; The surface of the micro-nano ceramic particle contains a first active group, the surface of the layered micro-nano sheet contains a second active group, the surface of the microencapsulated phase change material contains a third active group, the interfacial compatibility enhancer contains a fourth active group, and the interfacial compatibility enhancer enables at least two of the micro-nano ceramic particle, the micro-nano aerogel particle, the layered micro-nano sheet and the microencapsulated phase change material to be bonded with each other.
2. The thermal insulation layer according to claim 1, wherein the micro-nano ceramic particles account for 40% -50% of the mass of the thermal insulation layer, and/or, The micro-nano aerogel particles account for 5% -10% of the mass of the heat insulation layer and/or, The layered micro-nano sheet accounts for 8-12% of the mass of the heat insulation layer, and/or, The microencapsulated phase change material accounts for 12% -18% of the mass of the heat insulation layer and/or, The interfacial compatibility enhancer accounts for 2% -5% of the mass of the heat insulation layer.
3. The thermal insulation layer according to claim 1 or 2, wherein the micro-nano ceramic particles have a D50 particle size of 10nm to 50nm and/or, The D50 particle size of the micro-nano aerogel particles is 5 nm-20 nm, and/or, The lamellar micro-nano sheet has a sheet diameter of 1-3 μm and/or, The D50 particle size of the microencapsulated phase change material is 2-8 mu m.
4. A thermal insulating layer according to claim 1 to 3, comprising a thermal insulating body layer and a hydrophobic layer provided on at least one side surface of the thermal insulating body layer, and/or, The thickness of the heat insulation layer is 20-50 mu m.
5. The thermal barrier coating of any one of claims 1 to 4, wherein the first reactive group comprises at least one of an oxygen-containing reactive group, a nitrogen-containing reactive group, and a sulfur-containing reactive group, and/or, The second reactive group comprises at least one of an oxygen-containing reactive group, a nitrogen-containing reactive group and a sulfur-containing reactive group, and/or, The third reactive group comprises at least one of an oxygen-containing reactive group, a nitrogen-containing reactive group and a sulfur-containing reactive group, and/or, The fourth reactive group comprises at least one of an oxygen-containing reactive group, a nitrogen-containing reactive group and a sulfur-containing reactive group.
6. The thermal insulation layer according to any one of claims 1 to 5, wherein the micro-nano ceramic particles comprise at least one of micro-nano alumina particles, micro-nano zirconia particles, micro-nano silicon nitride particles and micro-nano aluminum titanate particles, and/or, The porosity of the micro-nano aerogel particles is higher than 80 percent, the micro-nano aerogel particles comprise at least one of micro-nano silica aerogel particles, micro-nano alumina aerogel particles, micro-nano silicon carbide aerogel particles, micro-nano silica-micro-nano alumina composite aerogel and polyurethane-micro-nano silica composite aerogel, and/or, The layered micro-nano sheet comprises at least one of a graphene oxide micro-nano sheet, a boron nitride micro-nano sheet, a reduced graphene oxide micro-nano sheet, a mica micro-nano sheet and a montmorillonite micro-nano sheet, wherein the content of oxygen-containing functional groups of the graphene oxide micro-nano sheet is more than or equal to 30at%, and/or, The microcapsule phase-change material comprises a core layer and a coating layer, the coating layer is arranged on the surface of the core layer, the core layer comprises at least one of polyethylene glycol phase-change material, paraffin phase-change material and fatty acid phase-change material, the coating layer comprises urea formaldehyde resin, and/or, The interfacial compatibility enhancer comprises at least one of hydroxyl-terminated polydimethylsiloxane, hydroxyl-terminated polyurethane prepolymer, carboxyl-terminated nitrile rubber, silane coupling agent and silane coupling agent modified polyethylene glycol.
7. The thermal insulation layer according to any one of claims 1 to 6, wherein the micro-nano ceramic particles are silane coupling agent and titanate coupling agent modified micro-nano ceramic particles, and/or, The layered micro-nano sheet is a silane coupling agent modified layered micro-nano sheet and/or, The microencapsulated phase change material is a hydroxyl-terminated polydimethylsiloxane modified microencapsulated phase change material.
8. A method for producing the heat insulating layer according to any one of claims 1 to 7, comprising: Dispersing micro-nano ceramic particles and micro-nano aerogel particles in a first solvent to obtain a first dispersion liquid; Dispersing the layered micro-nano sheet in a second solvent to obtain a second dispersion liquid; adding the second dispersion liquid into the first dispersion liquid, dispersing, then adding the microencapsulated phase change material and the interfacial compatibility enhancer into the first dispersion liquid, and dispersing to obtain dispersed slurry; and (3) coating and forming the dispersion slurry, and drying and curing to form the heat insulation layer.
9. The method for producing a heat insulating layer according to claim 8, wherein, And in the step of forming the heat insulation layer by coating and forming the dispersion slurry and drying and curing the dispersion slurry, the drying comprises the following steps: Firstly, drying for 5-7 hours at 50-70 ℃ to remove the solvent; Heating to 70-90 ℃ and drying for 5-7 hours to primarily crosslink the interfacial compatibility enhancer, the micro-nano ceramic particles, the layered micro-nano sheets and the microencapsulated phase change material to obtain an intermediate film layer; The curing includes: and (3) carrying out ultraviolet curing treatment on the intermediate film layer so as to further crosslink the interfacial compatibility enhancer, the micro-nano ceramic particles, the layered micro-nano sheets and the microencapsulated phase change material.
10. The method of preparing a thermal insulation layer according to claim 8 or 9, wherein the microencapsulated phase change material comprises a core layer and a coating layer, the coating layer is disposed on the surface of the core layer, and the coating layer comprises urea formaldehyde resin and silica; The preparation method of the coating layer comprises the following steps: Dispersing the core layer and the surfactant in deionized water to form emulsion; mixing a first monomer and a second monomer to obtain a mixed solution, adjusting the pH value of the mixed solution to be 8-9, and heating to react to obtain a urea resin prepolymer, wherein the first monomer comprises urea, and the second monomer comprises formaldehyde solution; and adding the prepolymer and nano silicon dioxide into the emulsion, so that the prepolymer is polymerized in situ and coated on the surface of the core layer, and the microencapsulated phase change material is obtained.
11. A battery, characterized by comprising the heat insulating layer according to any one of claims 1 to 7 or the heat insulating layer prepared by the preparation method of the heat insulating layer according to claim 8 to 10.

Description

Heat insulation layer, preparation method thereof and battery Technical Field The application relates to the technical field of batteries, in particular to a heat insulation layer, a preparation method thereof and a battery. Background With the rapid development of the new energy automobile industry, power batteries become a research hotspot. With the requirements of lithium ion batteries on high energy density and rapid charge and discharge, the thermal management requirements of the lithium ion batteries are increasingly severe, and meanwhile, the batteries are easily threatened by high-temperature environments in the use process, so that the performance and the service life of the batteries are affected. Therefore, studies on the heat insulating layer are receiving a great deal of attention. The prior heat insulation material is difficult to meet the following key requirements: At present, the heat insulation layer of the power battery mainly adopts the technical means of traditional high polymer heat insulation films, ceramic coatings, single nano material coatings, aerogel materials and the like. The heat insulating layer has the following defects of (1) limited heat insulating performance, incapability of effectively blocking heat conduction and difficulty in preventing thermal runaway, (2) poor mechanical stability, easiness in cracking or falling off of the heat insulating layer due to thermal expansion and contraction or mechanical stress, and (3) poor interface bonding, weak interface between materials and influence on the stability and durability of the whole structure. Therefore, the existing insulation layer is relatively poor in heat insulating performance and mechanical strength. Disclosure of Invention The application provides a heat insulation layer, a preparation method thereof and a battery, and aims to solve the problem that the heat insulation performance and mechanical strength of the existing heat insulation layer are relatively poor. In a first aspect, the application provides a thermal insulation layer, which comprises micro-nano ceramic particles, micro-nano aerogel particles, layered micro-nano sheets, microencapsulated phase change materials and an interfacial compatibility enhancer, wherein the surfaces of the micro-nano ceramic particles contain first active groups, the surfaces of the layered micro-nano sheets contain second active groups, the surfaces of the microencapsulated phase change materials contain third active groups, the interfacial compatibility enhancer contains fourth active groups, and the interfacial compatibility enhancer enables at least two of the micro-nano ceramic particles, the micro-nano aerogel particles, the layered micro-nano sheets and the microencapsulated phase change materials to be bonded with each other. The surface of the micro-nano ceramic particles contains a first active group, the surface of the layered micro-nano sheet contains a second active group, the surface of the micro-encapsulated phase change material contains a third active group and the interface compatibility enhancer contains a fourth active group, and the first active group, the second active group, the third active group and the fourth active group can be mutually bonded or chemically reacted to be coupled, so that the micro-nano ceramic particles, the micro-nano aerogel particles, the layered micro-nano sheet and the micro-encapsulated phase change material in the heat insulation layer are uniformly distributed and strongly combined to avoid particle aggregation and form the heat insulation layer with a specific microstructure, and the obtained heat insulation layer has excellent mechanical strength, wear resistance and crack resistance. The micro-nano aerogel particles have extremely low heat conductivity and nanoscale porous structures, can form a multistage hole heat insulation framework with the micro-nano ceramic particles, and the layered micro-nano sheets can construct a continuous sheet layer supporting network in the heat insulation layer, so that the mechanical property of the heat insulation layer is improved, meanwhile, the layered micro-nano sheets can be mutually overlapped to form a labyrinth type heat conduction barrier, the heat transfer path is prolonged, the heat conductivity of the heat insulation layer is reduced, namely, the specific composite structure formed by the micro-nano ceramic particles, the micro-nano aerogel particles and the layered micro-nano sheets can effectively prevent heat conduction, remarkably reduce the heat conductivity and improve the heat insulation effect. The microencapsulated phase change material can absorb heat in a certain temperature range to change phase, so that temperature responsive heat management and intelligent temperature control are realized. The interfacial compatibility enhancer not only can promote the binding force among the micro-nano ceramic particles, the micro-nano aerogel particles, the layered micro-nano