THERMAL INSULATION COMPOSITION AND PREPARATION METHOD AND APPLICATION

Abstract

The present invention provides a thermal insulation composition and a preparation method and application. The thermal insulation composition is composed of aerogel material and organic resin; the composite mass ratio of the aerogel material to the organic resin is 5 wt %:95 wt % to 50 wt %:50 wt %; the porosity of the aerogel material is greater than 95%, the pore diameter of the aerogel material is less than or equal to 100 nm, the particle size of each particle of aerogel material is 5 nm to 20 nm, and the organic resin is filled in the pores of the aerogel material. The thermal insulation module component prepared from the thermal insulation composition has mechanical strength and thermal conductivity at room temperature, and if the battery goes into thermal runaway, the material becomes a heat-insulating material, blocking the heat transfer between battery cells, greatly improving the safety performance of the battery.

Claims

1. A thermal insulation composition, wherein the thermal insulation composition comprises a composite of an aerogel material and an organic resin, and the composite mass ratio of the aerogel material to the organic resin is 5 wt %:95 wt % to 50 wt %:50 wt %; the porosity of the aerogel material is greater than 95%, the pore size of the aerogel material is less than or equal to 100 nm, and the particle size of each particle of the aerogel material is 5 nm to 20 nm; and the organic resin is filled in the pores of the aerogel material.

2. The thermal insulation composition according to claim 1, wherein the aerogel material is prepared by the steps of: preparing a precursor solution for forming the aerogel material; solating the precursor solution by a polycondensation reaction; aging the solated precursor solution at 45° C. to 60° C. for 8 to 24 hours; and performing supercritical drying to obtain the aerogel material.

3. The thermal insulation composition according to claim 2, wherein the supercritical drying is performed at a temperature of 30° C. to 60° C.

4. The thermal insulation composition according to claim 3, wherein the medium for the supercritical drying is carbon dioxide, methanol or ethanol.

5. The thermal insulation composition according to claim 3, wherein the duration of the supercritical drying is 2 to 5 hours.

6. The thermal insulation composition according to claim 3, wherein the supercritical drying is performed under a pressure of higher than 1.01 MPa.

7. The thermal insulation composition according to claim 2, wherein the solvent used in the precursor solution for forming the aerogel material is water, a mixture of water and ethanol, propylene carbonate, ethylene carbonate, diethyl carbonate, dimethyl carbonate or 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide.

8. The thermal insulation composition according to claim 1, wherein the raw material of the aerogel material comprises a precursor, and wherein the precursor is one or two or more of silica, titanium oxide, chromium oxide, iron oxide, vanadium oxide, neodymium oxide, carbon and oxides of carbon with a particle size of less than 500 nm.

9. The thermal insulation composition according to claim 8, wherein the precursor comprises one or two or more of silica, titanium oxide and carbon with a particle size of less than 500 nm.

10. The thermal insulation composition according to claim 9, wherein the precursor comprises silica with a particle size of less than 500 nm.

11. The thermal insulation composition according to claim 8, wherein the raw material of the aerogel material further comprises an additive, and the precursor is added in an amount of 60-90% by weight in the aerogel material.

12. The thermal insulation composition according to claim 11, wherein the additive is one or two or more of a glass fiber and an opacifier.

13. The thermal insulation composition according to claim 1, wherein the organic resin comprises any one or two or more of polymethyl carbonate, polyethyl carbonate, polypropylene carbonate, and polymethyl carbonate, poly ethyl carbonate, and polypropylene carbonate modified with a functional group.

14. The thermal insulation composition according to claim 13, wherein the functional group comprises hydroxyl, carboxyl, halogen or propylene oxide.

15. A method for preparing the thermal insulation composition of claim 1, comprising: heating the organic resin to the melt processing temperature or higher; fully impregnating the aerogel material in the organic resin under vacuum; fully infiltrating the organic resin into the aerogel material under 0.5 MPa to 2 MPa, holding the pressure for 10 to 60 minutes, and recovering the excess organic resin; cyclically repeating the operations of impregnation, infiltration and recovery so that the organic resin is completely infiltrated into the aerogel material; and removing a sample and curing it at normal temperature to obtain the thermal insulation composition.

16. A thermal insulation module component, wherein the thermal insulation module component is prepared from the thermal insulation composition of claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0071] FIG. 1 is a schematic diagram of the structure of the thermal insulation composition in the Examples of the present disclosure.

[0072] FIG. 2 is an exploded view of the pouch cell module in the Examples of the present disclosure.

[0073] FIG. 3 is a schematic diagram of the thermal runaway experiment in the Examples of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

[0074] In order to more clearly understand the technical features, objects and beneficial effects of the present disclosure, the technical solutions of the present disclosure are described below in details, which should not be construed as limiting the implementable scope of the present disclosure.

Comparative Example 1

[0075] A 100% PPC sheet with a thickness of 1 mm was used to test its thermal conductivity.

[0076] The temperature of the heating plate was adjusted to 60° C. The PPC sheet was placed on the heating plate so that one side of the PPC sheet was in contact with the heating plate, and the temperature of the other side of the PPC sheet was recorded after the PPC sheet was heated for 1 minute and 5 minutes. The results are listed in Table 1.

Example 1

[0077] A composite thermal insulation material with a thickness of 1 mm was used, which had a structure as shown in FIG. 1, with an organic resin (100% PPC) filled in the pores of the aerogel material. The thermal conductivity thereof was tested. It should be noted that the organic resin can be randomly filled into the pores of the aerogel material without a regular filling as shown in FIG. 1, which is only a schematic illustration.

[0078] The temperature of the heating plate was adjusted to 60° C. The above composite thermal insulation material was placed on the heating plate so that one side of the composite thermal insulation material was in contact with the heating plate, and the temperature of the other side of the composite thermal insulation material was recorded after the composite thermal insulation material was heated for 1 minute and 5 minutes. The results are listed in Table 1.

[0079] The aerogel material of the Example was prepared by the steps of:

[0080] preparing a precursor solution for forming the aerogel material (the solvent was a mixed solution of water:ethanol=1:1, and the precursor was ethyl orthosilicate);

[0081] solating the precursor solution by a polycondensation reaction.

[0082] aging the solated precursor solution at 45° C. to 60° C. for 8 to 24 hours.

[0083] performing supercritical drying (at a temperature of 40° C. to 45° C. and a pressure of 7.38 MPa, holding for 2 to 3 hours) to obtain the aerogel material.

[0084] The composite thermal insulation material was prepared through the steps of:

[0085] heating the organic resin to the melt processing temperature or higher (105° C. to 130° C.);

[0086] fully impregnating the aerogel material in the organic resin under vacuum;

[0087] fully infiltrating the organic resin into the aerogel material under 1.2 MPa, holding the pressure for 30 minutes, and recovering the excess organic resin;

[0088] cyclically repeating the impregnation, infiltration and recovery steps three times so that the organic resin was completely infiltrated into the aerogel material;

[0089] removing a sample and curing it at normal temperature to obtain the thermal insulation composition.

Example 2

[0090] A composite thermal insulation material with a thickness of 2 mm (the preparation method and the composition of the composite material were the same as those in Example 1, and only the thickness was changed) was used to test its thermal conductivity.

[0091] The temperature of the heating plate was adjusted to 60° C. The above composite thermal insulation material was placed on the heating plate so that one side of the composite thermal insulation material was in contact with the heating plate, and the temperature of the other side of the composite thermal insulation material was recorded after the composite thermal insulation material was heated for 1 minute and 5 minutes. The results are listed in Table 1.

TABLE-US-00001 TABLE 1 Heating Material surface plate surface Heating temperature Example Thickness temperature time after heating Comparative 1 mm 60° C. 1 minute 60° C. Example 1 .sup. 5 minutes 60° C. Example 1 1 mm 60° C. 1 minute 60° C. .sup. 5 minutes 61° C. Example 2 2 mm 61° C. 1 minute 55° C. .sup. 5 minutes 60° C.

[0092] Table 1 shows that the pure PPC of Comparative Example 1 has a good thermal conductivity. The 1 mm adiabatic material mixed with PPC of Example 1 also has the same thermal conductivity, and 61° C. was within the experimental error range. The 2 mm adiabatic material mixed with PPC of Example 2 is poorer than the 1 mm material, but still has an ideal performance.

Comparative Example 2

[0093] A mica sheet (IEC-60371-2, AXIM MICA) with a thickness of 1 mm was used as a thermal insulation sheet to test its thermal insulation performance.

[0094] The temperature of the heating plate was adjusted to 60° C. The above mica sheet was placed on the heating plate so that one side of the mica sheet was in contact with the heating plate, and the temperature of the other side of the mica sheet was recorded after the mica sheet was heated for 5 minutes. The results are listed in Table 2.

Example 3

[0095] The composite thermal insulation material of Example 1 with a thickness of 1 mm was used as a thermal insulation sheet to test its thermal insulation performance.

[0096] The temperature of the heating plate was adjusted to 600° C. The above composite thermal insulation material was placed on the heating plate so that one side of the composite thermal insulation material was in contact with the heating plate, and the temperature of the other side of the composite thermal insulation material was recorded after the composite thermal insulation material was heated for 5 minutes. The results are listed in Table 2.

Example 4

[0097] The composite thermal insulation material of Example 2 with a thickness of 2 mm was used as a thermal insulation sheet to test its thermal insulation performance.

[0098] The temperature of the heating plate was adjusted to 600° C. The above composite thermal insulation material was placed on the heating plate so that one side of the composite thermal insulation material was in contact with the heating plate, and the temperature of the other side of the composite thermal insulation material was recorded after the composite thermal insulation material was heated for 5 minutes. The results are listed in Table 2.

TABLE-US-00002 TABLE 2 Heating plate Material surface surface Heating temperature Example Thickness temperature time after heating Comparative 1 mm 600° C. 5 minutes 600° C. example 2 Example 3 1 mm 601° C. 5 minutes 204° C. Example 4 2 mm 600° C. 5 minutes 176° C.

Comparative Example 3

[0099] The component of the organic resin binder was 100% PPC (25511-85-7, Sigma-Aldrich). Thermogravimetric analysis was used to measure the thermal degradation temperature of the above organic resin binder. The results are listed in Table 3.

Example 5

[0100] The component of the organic resin binder was 90% PPC (25511-85-7, Sigma-Aldrich) and 10% potassium hydroxide (1310-58-3, Sigma-Aldrich). Thermogravimetric analysis was used to measure the thermal degradation temperature of the above organic resin binder. The results are listed in Table 3.

Example 6

[0101] The component of the organic resin binder was 90% PPC (25511-85-7, Sigma-Aldrich) and 10% benzyl glycidate (Sigma-Aldrich). Thermogravimetric analysis was used to measure the thermal degradation temperature of the above organic resin binder. The results are listed in Table 3.

TABLE-US-00003 TABLE 3 Thermal degradation Component temperature Comparative 100% PPC 208° C. Example 3 Example 5 90% PPC + 10% KOH 178° C. Example 6 90% PPC + 10% C.sub.11H.sub.13O.sub.3 158° C.

Comparative Example 4

[0102] Mica with a thickness of 1 mm was used as a thermal insulation sheet. As shown in FIG. 3, a battery module with 4 pouch cells (250 Wh/kg, 550 Wh/L) was used as the test carrier. Cell 1, cell 2, cell 3 and cell 4 were arranged in parallel as shown in FIG. 3. The mica sheet was inserted as a thermal insulation sheet between two cells. A total of 3 mica sheets were used in this module.

[0103] During the test, Cell 1 was forced to undergo thermal runaway. The time for thermal runaway of cell 2, cell 3 and cell 4 was recorded. The 4 pouch cells were placed in a large enough open space so that the hot gas generated by the thermal runaway of the cells will not affect adjacent cells. Thermal runaway can only be caused by heat transfer between adjacent cells. The experimental results are listed in Table 4.

Example 7

[0104] The composite thermal insulation material of Example 1 with a thickness of 1 mm was used as a thermal insulation sheet.

[0105] As shown in FIG. 2, picture A in FIG. 2 is an exploded view of the pouch cell module; picture B in FIG. 2 is the core structure of the module including aluminum plate.fwdarw.plastic frame.fwdarw.pouch cell.fwdarw.foam.fwdarw.pouch cell.fwdarw.plastic frame.fwdarw.aluminum plate in order; picture C in FIG. 2 is the aluminum plate and frame in picture B, which were prepared with the composite thermal insulation material.

[0106] As shown in FIG. 3, a battery module with 4 pouch cells (250 Wh/kg, 550 Wh/L) was used as the test carrier. Cell 1, cell 2, cell 3 and cell 4 were arranged in parallel as shown in FIG. 3. The composite thermal insulation sheet was inserted as a thermal insulation sheet between two cells. A total of 3 composite thermal insulation sheets were used in this module.

[0107] During the test, cell 1 was forced to undergo thermal runaway. The time for thermal runaway of cell 2, cell 3 and cell 4 was recorded. The 4 pouch cells were placed in a large enough open space so that the hot gas generated by the thermal runaway of the cells will not affect adjacent cells. Thermal runaway can only be caused by heat transfer between adjacent cells. The experimental results are listed in Table 4.

Example 8

[0108] The composite thermal insulation material of Example 2 with a thickness of 2 mm was used as a thermal insulation sheet.

[0109] As shown in FIG. 3, a battery module with 4 pouch cells (250 Wh/kg, 550 Wh/L) was used as the test carrier. Cell 1, cell 2, cell 3 and cell 4 were arranged in parallel as shown in FIG. 3. The composite thermal insulation sheet was inserted as a thermal insulation sheet between two cells. A total of 3 composite thermal insulation sheets were used in this module.

[0110] During the test, cell 1 was forced to undergo thermal runaway. The time for thermal runaway of cell 2, cell 3 and cell 4 was recorded. The 4 pouch cells were placed in a large enough open space so that the hot gas generated by the thermal runaway of the cells will not affect adjacent cells. Thermal runaway can only be caused by heat transfer between adjacent cells. The experimental results are listed in Table 4.

TABLE-US-00004 TABLE 4 Thermal insulation Time when thermal runaway occurs sheet thickness Cell 2 Cell 3 Cell 4 Comparative 1 mm 2 m 3 s  5 m 25 s 7 m 39 s Example 4 Example 7 1 mm 14 m 23 s 35 m 36 s No runaway Example 8 2 mm 27 m 49 s No runaway No runaway

[0111] The above examples illustrates that the module component formed from the thermal insulation composition of the present disclosure, when used in lithium-ion batteries, not only has both mechanical strength and functionality, but also can play the role of fire prevention and thermal insulation when thermal runaway occurs, blocking heat propagation and greatly improving the safety performance of the batteries.