A new organic silicon potting adhesive for lithium battery and a preparation and use method thereof

Abstract

The present application relates to lithium battery encapsulation glue material technical field, disclose a kind of new energy lithium battery with organic silicon potting adhesive, including equal quality A component and B component mixed solidification and become;Wherein A component includes the following components: silicone oil 35-55 mass fraction;Catalyst 0-5 mass fraction;Filler 45-65 mass fraction;Rheological auxiliary agent 0-5 mass fraction;B component includes the following components: silicone oil 10-30 mass fraction;Pigment 0-1 mass fraction;Crosslinking agent 5-30 mass fraction;Coupling agent 1-5 mass fraction;Filler 40-70 mass fraction;Rheological auxiliary agent 0-5 mass fraction;Dehydrating agent 0-5 mass fraction.The present application also discloses the preparation and use method of the above potting adhesive.The potting adhesive of the present application improves the bonding strength under the condition of guaranteeing elasticity, heat conduction, flame retardant and other requirements, avoids the risk of new energy battery pack due to vibration leading to degumming, cracking, effectively protects the battery cell and battery pack.

Description

Technical Field

[0001] This invention relates to the field of lithium battery encapsulation materials technology, and in particular to an organosilicon potting compound for new energy lithium batteries and its preparation and application method. Background Technology

[0002] With the increasing market demand for new energy power battery packs and new energy storage battery packs, the demand for lithium battery potting compounds is also increasing, and the performance requirements are becoming more stringent.

[0003] Currently, new energy battery packs use thermally conductive structural adhesives to bond the battery cells and structural adhesives to bond the modules. This solution uses two types of adhesives, requiring two applications and two curing cycles. Production efficiency is increasingly unable to meet the growing market demand, and carbon emissions are relatively high. Furthermore, the thermally conductive and structural adhesives on the market are mainly polyurethane-based, which has characteristics such as easy moisture absorption, poor high-temperature resistance, and poor aging performance.

[0004] Currently available silicone potting compounds, while having good elasticity, have low bonding strength (0.3MPa), which cannot meet the requirements of new energy batteries, especially new energy power battery packs.

[0005] Chinese Patent: A Silicone Encapsulant for New Energy Vehicle Heaters and Its Preparation Method (Publication No. CN121319865A). The disclosed encapsulant is only used in new energy vehicle heaters. It uses a platinum catalyst and is improved by addition-type silicone. However, its fire resistance, thermal conductivity, and shear strength cannot reach the performance of the encapsulant inside lithium batteries. Summary of the Invention

[0006] The purpose of this invention is to solve the above-mentioned problems and provide an organosilicon potting compound for new energy lithium batteries and its preparation and use method. While ensuring the requirements of elasticity, thermal conductivity, and flame retardancy, it improves the bonding strength and avoids the risk of delamination and cracking of new energy battery packs due to vibration, effectively protecting the cells and battery packs.

[0007] The technical solution adopted in this invention is:

[0008] An organosilicon potting compound for new energy lithium batteries is characterized by comprising equal masses of component A and component B mixed and cured.

[0009] Component A includes the following components: 35-55 parts by weight of silicone oil; 0-5 parts by weight of catalyst; 45-65 parts by weight of filler; and 0-5 parts by weight of rheology modifier.

[0010] Component B includes the following components: 10-30 parts by weight of silicone oil; 0-1 parts by weight of pigment; 5-30 parts by weight of crosslinking agent; 1-5 parts by weight of coupling agent; 40-70 parts by weight of filler; 0-5 parts by weight of rheology modifier; and 0-5 parts by weight of dehydrating agent.

[0011] Furthermore, the silicone oil is two or three of the following: hydroxyl-terminated polydimethylsiloxane, dimethyl silicone oil, modified silicone oil, and hydrogen-containing silicone oil.

[0012] The catalyst is one or two of organotin, organobismuth, organozirconium, and organotitanium catalysts;

[0013] The filler is one or more of aluminum hydroxide, aluminum oxide, boron nitride, flame retardant, and modified magnesium hydroxide;

[0014] The pigment is one or more of the following: red, yellow, blue, white, and black;

[0015] The crosslinking agent is one or more of methyltrimethoxysilane, methyltriethoxysilane, and vinyltrimethoxysilane;

[0016] The coupling agent is one or more of KH560, KH550, KH570, KH590, and aniline methyltriethoxysilane;

[0017] The dehydrating agent is a molecular sieve;

[0018] The rheology modifier is one or two of thixotropic rheology modifiers and fumed silica.

[0019] Furthermore, the modified silicone oil is one or more of phenyl silicone oil, long-chain alkyl modified silicone oil, polyether modified silicone oil, and fluorosilicone oil.

[0020] A method for preparing an organosilicon potting compound for new energy lithium batteries, characterized by including a method for preparing component A and a method for preparing component B.

[0021] The preparation method of component A includes the following steps:

[0022] (a) Add silicone oil and catalyst to the stirred tank in the order of mass parts of each component, and stir for 30 minutes;

[0023] (b) Add the filler and rheology modifier in the order of mass parts, and stir for 2 hours;

[0024] (c) Vacuum stir for 30 minutes.

[0025] (d) Obtain the potting compound component A;

[0026] The preparation method for component B includes the following steps:

[0027] (a) Add silicone oil, pigment, crosslinking agent and coupling agent into the mixing tank in the order of their respective mass parts, and stir for 30 minutes;

[0028] (b) Add the filler and rheology modifier in the order of mass parts, and stir for 2 hours;

[0029] (c) Vacuum stir for 30 minutes;

[0030] (d) Obtain the potting compound component B.

[0031] Finally, the prepared components A and B are mixed in a 1:1 mass ratio to obtain the silicone potting compound.

[0032] A method for using an organosilicon potting compound for new energy lithium batteries, characterized in that the organosilicon potting compound is injected into the battery pack and cured at 25°C for 7 days to obtain a cured potting compound.

[0033] The beneficial effects of this invention are:

[0034] (1) It has good elasticity and can effectively protect the new energy battery pack;

[0035] (2) Low density (≤1.5g / cm³) provides lightweight new energy battery packs and reduces energy consumption;

[0036] (3) Good fluidity, the adhesive can flow effectively into the gaps of the battery pack, improving production efficiency;

[0037] (4) It has good thermal conductivity, reaching over 1.2 W / mK;

[0038] (5) The bonding performance is moderate, which not only achieves the purpose of protecting the battery pack, but also facilitates the disassembly and maintenance of the battery pack;

[0039] (6) It has good flame retardant properties and can withstand 1000℃ (butane torch outer flame) without burning through. It has passed the thermal runaway test of new energy battery packs.

[0040] (7) It has low corrosivity, good storage stability, and relatively low sensitivity to humidity in the air, making it more stable;

[0041] (8) It has a good balance in terms of overall performance, mechanical properties, electrical insulation and aging resistance. Detailed Implementation

[0042] The following is a detailed description of the specific implementation method of the organosilicon potting compound for new energy lithium batteries and its preparation and use method according to the present invention.

[0043] The organosilicon potting compound for new energy lithium batteries of the present invention comprises equal masses of component A and component B, which are mixed together.

[0044] The A component comprises the following components: 35-55 parts by weight of silicone oil; 0-5 parts by weight of catalyst; 45-65 parts by weight of filler; and 0-5 parts by weight of rheology modifier.

[0045] Component B comprises the following components: 10-30 parts by weight of silicone oil; 0-1 parts by weight of pigment; 5-30 parts by weight of crosslinking agent; 1-5 parts by weight of coupling agent; 40-70 parts by weight of filler; 0-5 parts by weight of rheology modifier; and 0-5 parts by weight of dehydrating agent.

[0046] Among them, the silicone oil is two or three of the following: hydroxyl-terminated polydimethylsiloxane (107 glue), dimethyl silicone oil, modified silicone oil (phenyl silicone oil, long-chain alkyl modified silicone oil, polyether modified silicone oil, fluorosilicone oil), and hydrogen-containing silicone oil.

[0047] The catalyst is one or two of organotin, organobismuth, organozirconium, and organotitanium catalysts;

[0048] The filler is one or more of aluminum hydroxide, aluminum oxide, boron nitride, flame retardant, and modified magnesium hydroxide;

[0049] The pigment is one or more of the following: red, yellow, blue, white, and black;

[0050] The crosslinking agent is one or more of methyltrimethoxysilane, methyltriethoxysilane, and vinyltrimethoxysilane;

[0051] The coupling agent is one or more of KH560, KH550, KH570, KH590, and anilinemethyltriethoxysilane;

[0052] The dehydrating agent is a molecular sieve;

[0053] The rheology modifier is one or both of thixotropic rheology modifiers and fumed silica.

[0054] The method for preparing the silicone potting compound of this patent includes the following steps:

[0055] Component A is prepared by the following steps:

[0056] (a) Add silicone oil and catalyst to the stirred tank in the order of mass parts of each component, and stir for 30 minutes;

[0057] (b) Add the filler and rheology modifier in the order of mass parts, and stir for 2 hours;

[0058] (c) Vacuum stir for 30 minutes.

[0059] (d) Obtain the potting compound component A;

[0060] Component B is prepared by the following steps:

[0061] (a) Add silicone oil, pigment, crosslinking agent and coupling agent into the mixing tank in the order of their respective mass parts, and stir for 30 minutes;

[0062] (b) Add the filler and rheology modifier in the order of mass parts, and stir for 2 hours;

[0063] (c) Vacuum stir for 30 minutes;

[0064] (d) Obtain the potting compound component B.

[0065] The components A and B are mixed in a 1:1 mass ratio to form a potting compound. When used, it is injected into the lithium battery pack for potting and then cured at 25°C for 7 days to obtain the cured potting compound.

[0066] The properties of the potted and cured products were tested and are shown in the table below:

[0067] Test Project Test conditions index Reference Standard hardness Shore A 25℃ 60 Shore A Water absorption rate 25℃ % ≤0.5 GB / T 1034 Insulation strength KV / mm 25℃ ≥10 GB / T 1408.1 Volume resistivity Ω.cm 25℃ <![CDATA[≥1.0×10 13 ]]> GB / T 1410-2006 Dielectric constant 50Hz, 25℃ ≥2.0 GB / T 1409-2006 Body tensile strength MPa ≥1.50 GB / T 528-2009 Elongation at break % ≥100 GB / T 528-2009 Shear strength Al / Al MPa ≥1.50 GB / T 7124 Pull-out strength Al / Al MPa ≥1.50 GB / T 6329 thermal conductivity W / mK ≥1.20 ASTM D5470 Flame retardancy UL-94 1.5mm thick V0 GB / T 2408-2008 Fireproof and heat insulation performance 1000℃ (outer flame of a butane torch) 4.5mm sheet, no burn-through in 2 minutes; 10mm sheet, no burn-through in 10 minutes. Operating temperature range -50～150℃

[0068] The potting compound and its preparation method of this patent are described below through three examples.

[0069] Example 1

[0070] The silicone potting compound is made by mixing and curing equal masses of component A and component B.

[0071] The A component is composed of the following components: 55 parts by mass of silicone oil; 2.5 parts by mass of catalyst; 45 parts by mass of filler; and 2.5 parts by mass of rheology modifier.

[0072] The B component consists of the following components: 30 parts by weight of silicone oil; 1 part by weight of pigment; 30 parts by weight of crosslinking agent; 5 parts by weight of coupling agent; 70 parts by weight of filler; 2.5 parts by weight of rheology modifier; and 2.5 parts by weight of dehydrating agent.

[0073] in,

[0074] The silicone oil is two or three of the following: hydroxyl-terminated polydimethylsiloxane (107 glue), dimethyl silicone oil, modified silicone oil (phenyl silicone oil, long-chain alkyl modified silicone oil, polyether modified silicone oil, fluorosilicone oil), and hydrogen-containing silicone oil.

[0075] The catalyst is one or two of organotin, organobismuth, organozirconium, and organotitanium catalysts;

[0076] The filler is one or more of aluminum hydroxide, aluminum oxide, boron nitride, flame retardant, and modified magnesium hydroxide;

[0077] The pigment is one or more of the following: red, yellow, blue, white, and black;

[0078] The crosslinking agent is one or more of methyltrimethoxysilane, methyltriethoxysilane, and vinyltrimethoxysilane;

[0079] The coupling agent is one or more of KH560, KH550, KH570, KH590, and anilinemethyltriethoxysilane;

[0080] The dehydrating agent is a molecular sieve;

[0081] The rheology modifier is one or two of thixotropic rheology modifiers and fumed silica.

[0082] The preparation method of potting compound includes the following steps:

[0083] Component A is prepared by the following steps:

[0084] (a) Add silicone oil and catalyst to the stirred tank in the order of mass parts of each component, and stir for 30 minutes;

[0085] (b) Add the filler and rheology modifier in the order of mass parts, and stir for 2 hours;

[0086] (c) Vacuum stir for 30 minutes.

[0087] (d) Obtain the potting compound component A;

[0088] Component B is prepared by the following steps:

[0089] (a) Add silicone oil, pigment, crosslinking agent and coupling agent into the mixing tank in the order of their respective mass parts, and stir for 30 minutes;

[0090] (b) Add the filler and rheology modifier in the order of mass parts, and stir for 2 hours;

[0091] (c) Vacuum stir for 30 minutes;

[0092] (d) Obtain the potting compound component B.

[0093] The components A and B are mixed in a 1:1 mass ratio and cured at 25°C for 7 days to obtain the cured potting compound.

[0094] The properties of the cured product are shown in the table below:

[0095] Test Project Test conditions index Reference Standard hardness Shore A 25℃ 62 Shore A Water absorption rate 25℃ % 0.3 GB / T 1034 Insulation strength KV / mm 25℃ 12 GB / T 1408.1 Volume resistivity Ω.cm 25℃ <![CDATA[3.0×10 13 ]]> GB / T 1410-2006 Dielectric constant 50Hz, 25℃ 2.6 GB / T 1409-2006 Body tensile strength MPa 2.1 GB / T 528-2009 Elongation at break % 120 GB / T 528-2009 Shear strength Al / Al MPa 2.13 GB / T 7124 Pull-out strength Al / Al MPa 2.06 GB / T 6329 thermal conductivity W / mK 1.28 ASTM D5470 Flame retardancy UL-94 1.5mm thick V0 GB / T 2408-2008 Fireproof and heat insulation performance 1000℃ (outer flame of a butane torch) 4.5mm sheet, no burn-through in 2 minutes; 10mm sheet, no burn-through in 10 minutes. Operating temperature range -50～150℃

[0096] Example 2

[0097] The potting compound is made by mixing and curing equal masses of component A and component B.

[0098] The A component is composed of the following components: 35 parts by mass of silicone oil; 2.5 parts by mass of catalyst; 65 parts by mass of filler; and 2.5 parts by mass of rheology modifier.

[0099] The B component consists of the following components: 10 parts by weight of silicone oil; 1 part by weight of pigment; 5 parts by weight of crosslinking agent; 5 parts by weight of coupling agent; 40 parts by weight of filler; 2.5 parts by weight of rheology modifier; and 2.5 parts by weight of dehydrating agent.

[0100] in,

[0101] The silicone oil is two or three of the following: hydroxyl-terminated polydimethylsiloxane (107 glue), dimethyl silicone oil, modified silicone oil (phenyl silicone oil, long-chain alkyl modified silicone oil, polyether modified silicone oil, fluorosilicone oil), and hydrogen-containing silicone oil.

[0102] The catalyst is one or two of organotin, organobismuth, organozirconium, and organotitanium catalysts;

[0103] The filler is one or more of aluminum hydroxide, aluminum oxide, boron nitride, flame retardant, and modified magnesium hydroxide;

[0104] The pigment is one or more of the following: red, yellow, blue, white, and black;

[0105] The crosslinking agent is one or more of methyltrimethoxysilane, methyltriethoxysilane, and vinyltrimethoxysilane;

[0106] The coupling agent is one or more of KH560, KH550, KH570, KH590, and anilinemethyltriethoxysilane;

[0107] The dehydrating agent is a molecular sieve;

[0108] The rheology modifier is one or both of thixotropic rheology modifiers and fumed silica.

[0109] Its preparation method includes the following steps:

[0110] Component A is prepared by the following steps:

[0111] (a) Add silicone oil and catalyst to the stirred tank in the order of mass parts of each component, and stir for 30 minutes;

[0112] (b) Add the filler and rheology modifier in the order of mass parts, and stir for 2 hours;

[0113] (c) Vacuum stir for 30 minutes.

[0114] (d) Obtain the potting compound component A;

[0115] Component B is prepared by the following steps:

[0116] (a) Add silicone oil, pigment, crosslinking agent and coupling agent into the mixing tank in the order of their respective mass parts, and stir for 30 minutes;

[0117] (b) Add the filler and rheology modifier in the order of mass parts, and stir for 2 hours;

[0118] (c) Vacuum stir for 30 minutes;

[0119] (d) Obtain the potting compound component B.

[0120] The components A and B are mixed in a 1:1 mass ratio and cured at 25°C for 7 days to obtain the cured potting compound.

[0121] The properties of the cured product are shown in the table below:

[0122] Test Project Test conditions index Reference Standard hardness Shore A 25℃ 60 Shore A Water absorption rate 25℃ % 0.24 GB / T 1034 Insulation strength KV / mm 25℃ 12.5 GB / T 1408.1 Volume resistivity Ω.cm 25℃ <![CDATA[3.6×10 13 ]]> GB / T 1410-2006 Dielectric constant 50Hz, 25℃ 2.65 GB / T 1409-2006 Body tensile strength MPa 1.86 GB / T 528-2009 Elongation at break % 120 GB / T 528-2009 Shear strength Al / Al MPa 1.85 GB / T 7124 Pull-out strength Al / Al MPa 1.89 GB / T 6329 thermal conductivity W / mK 1.23 ASTM D5470 Flame retardancy UL-94 1.5mm thick V0 GB / T 2408-2008 Fireproof and heat insulation performance 1000℃ (outer flame of a butane torch) 4.5mm sheet, no burn-through in 2 minutes; 10mm sheet, no burn-through in 10 minutes. Operating temperature range -50～150℃

[0123] As can be seen from the examples, the potting compound of this patent satisfies both thermal conductivity and adhesive properties, while eliminating a step. It only requires one potting process to form the product, eliminating the need for two applications of adhesive and two curing processes, thereby improving production efficiency and reducing carbon emissions.

[0124] While ensuring the requirements of elasticity, thermal conductivity, and flame retardancy, the bonding strength has been improved, avoiding the risk of delamination and cracking of new energy battery packs due to vibration, and effectively protecting the cells and battery packs.

[0125] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make several improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A silicone potting compound for new energy lithium batteries, characterized in that: It consists of equal masses of component A and component B mixed and cured. Component A includes the following components: 35-55 parts by weight of silicone oil; 0-5 parts by weight of catalyst; 45-65 parts by weight of filler; and 0-5 parts by weight of rheology modifier. Component B comprises the following components: 10-30 parts by weight of silicone oil; 0-1 parts by weight of pigment; 5-30 parts by weight of crosslinking agent; and 1-5 parts by weight of coupling agent. 40-70 parts by weight of filler; 0-5 parts by weight of rheology modifier; 0-5 parts by weight of dehydrating agent.

2. The silicone potting compound for new energy lithium batteries according to claim 1, characterized in that: The silicone oil is two or three of the following: hydroxyl-terminated polydimethylsiloxane, dimethyl silicone oil, modified silicone oil, and hydrogen-containing silicone oil. The catalyst is one or two of organotin, organobismuth, organozirconium, and organotitanium catalysts; The filler is one or more of aluminum hydroxide, aluminum oxide, boron nitride, flame retardant, and modified magnesium hydroxide; The pigment is one or more of the following: red, yellow, blue, white, and black; The crosslinking agent is one or more of methyltrimethoxysilane, methyltriethoxysilane, and vinyltrimethoxysilane; The coupling agent is one or more of KH560, KH550, KH570, KH590, and aniline methyltriethoxysilane; The dehydrating agent is a molecular sieve; The rheology modifier is one or two of thixotropic rheology modifiers and fumed silica.

3. The silicone potting compound for new energy lithium batteries according to claim 2, characterized in that: The modified silicone oil is one or more of phenyl silicone oil, long-chain alkyl modified silicone oil, polyether modified silicone oil, and fluorosilicone oil.

4. A method for preparing an organosilicon potting compound for new energy lithium batteries as described in any one of claims 1 to 3, characterized in that: This includes the preparation methods for component A and component B. The preparation method of component A includes the following steps: (a) Add silicone oil and catalyst to the stirred tank in the order of mass parts of each component, and stir for 30 minutes; (b) Add the filler and rheology modifier in the order of mass parts, and stir for 2 hours; (c) Vacuum stir for 30 minutes. (d) Obtain the potting compound component A; The preparation method for component B includes the following steps: (a) Add silicone oil, pigment, crosslinking agent and coupling agent into the mixing tank in the order of their respective mass parts, and stir for 30 minutes; (b) Add the filler and rheology modifier in the order of mass parts, and stir for 2 hours; (c) Vacuum stir for 30 minutes; (d) Obtain the potting compound component B. Finally, the prepared components A and B are mixed in a 1:1 mass ratio to obtain the silicone potting compound.

5. A method of using an organosilicon potting compound for new energy lithium batteries as described in any one of claims 1 to 3, characterized in that: The silicone potting compound was injected into the battery pack and cured at 25°C for 7 days to obtain the cured potting compound.