A battery module with high safety

Abstract

The invention relates to a battery module with high safety. A plurality of battery cells are installed inside the battery module. Heat insulation and protective materials are pasted on the outer sides of the battery cells and between the battery cells. The heat insulation and protective materials are made of the following raw materials in percentage by mass: 40% to 50% of a binder, 20% to 30% of a foaming agent, 25% to 35% of a flame retardant, and 0.5% to 1.5% of a cross-linking agent. The heat insulation and protective materials have high expansion, flame retardancy, and flame impact resistance. When encountering high temperature, that is, in a thermal runaway reaction process, the heat insulation and protective materials will automatically expand, and the thickness can be increased by 10-30 times. By increasing the thickness and the characteristics of the structure itself, temperature conduction can be effectively isolated, and the time can be effectively delayed before thermal runaway occurs, so as to ensure that the battery cells are isolated from each other, and the modules are isolated from each other, so as to prolong the heat spread time or prevent the heat spread, thereby greatly improving the safety of the battery module.

Description

Technical Field

[0001] The present invention belongs to the field of new energy vehicle batteries, and in particular relates to a battery module with high safety. Background Art

[0002] With the development of green economy, new energy vehicles are becoming more and more popular. As an important component of new energy vehicles, battery safety is a problem that manufacturers and car owners are very concerned about. In recent years, a series of safety accidents caused by battery thermal runaway have occurred from time to time. Battery thermal runaway refers to the cumulative enhancement of current and battery temperature during constant voltage charging and gradual damage. When a battery cell has thermal runaway, the adjacent cells are affected, causing the thermal runaway to spread and eventually cause safety accidents. The existing solution to reduce battery thermal runaway is to install thermal insulation materials in the battery. This traditional thermal insulation material is achieved by using aerogel, but the defects of aerogel are that the thermal insulation performance is average, the thickness is large, the weight is relatively heavy, it fails in high temperature environment, the ability to resist flame impact is low, the processing cost is high, and the practical functionality is still insufficient. Summary of the invention

[0003] In view of the above defects in the prior art, the present invention provides a battery module with high safety, and the specific technical solution is as follows:

[0004] A battery module with high safety, wherein a plurality of battery cells are installed inside the battery module, and heat-insulating protective materials are pasted on the outside of the battery cells and between the battery cells. The heat-insulating protective materials are made of the following raw materials in the following mass percentages: 40% to 50% of a binder, 20% to 30% of a foaming agent, 25% to 35% of a flame retardant, and 0.5% to 1.5% of a cross-linking agent.

[0005] As a preferred embodiment of the present invention, the adhesive is composed of acrylic resin, rosin resin and modified chloroprene rubber resin.

[0006] As a preferred embodiment of the present invention, the mass percentage of acrylic resin in the thermal insulation protective material is 27% to 32%, the mass percentage of rosin resin in the thermal insulation protective material is 9% to 12%, and the mass percentage of modified chloroprene rubber resin in the thermal insulation protective material is 4% to 6%.

[0007] As a preferred solution of the present invention, the foaming agent consists of acrylic acid copolymer, n-hexane and isopentane.

[0008] As a preferred embodiment of the present invention, the mass percentage of acrylic copolymer in the thermal insulation protective material is 14% to 17%, the mass percentage of n-hexane in the thermal insulation protective material is 4% to 8%, and the mass percentage of isopentane in the thermal insulation protective material is 2% to 5%.

[0009] As a preferred embodiment of the present invention, the flame retardant is a phosphorus-nitrogen compound.

[0010] As a preferred embodiment of the present invention, the cross-linking agent is polyisocyanate.

[0011] Beneficial effects: Thermal insulation protective materials are pasted on the outside of the battery cells and between the battery cells. The thermal insulation protective materials have high expansion, flame retardant and flame impact resistance. When encountering high temperature, that is, thermal runaway reaction, the thermal insulation protective materials will automatically expand, and the thickness can be increased by 10-30 times. By increasing the thickness and the characteristics of its own structure, it can effectively isolate temperature conduction and effectively delay the time before thermal runaway occurs, ensuring that the battery cells are isolated from each other, the modules are isolated from each other, extending the heat spread time or blocking the heat spread, greatly improving the safety of the battery module. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a structural schematic diagram of the battery module of the present invention;

[0013] Figure 2 Schematic diagram of the structural evolution of the heat-insulating protective material of the present invention when it expands after being heated;

[0014] Figure 3 This is a performance index parameter table of the thermal insulation and protective material product of the present invention;

[0015] Figure 4 This is a picture of the test verification of the battery module of the present invention. DETAILED DESCRIPTION

[0016] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings:

[0017] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the positions or elements referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limitations on the present invention.

[0018] like Figures 1 to 4 A battery module with high safety is disclosed, wherein a plurality of battery cells 1 are installed inside the battery module, and heat insulating protective materials 2 are pasted on the outside of the battery cells 1 and between the battery cells 1. The heat insulating protective materials 2 are made of the following raw materials in the following mass percentages: 40% to 50% of a binder, 20% to 30% of a foaming agent, 25% to 35% of a flame retardant, and 0.5% to 1.5% of a cross-linking agent.

[0019] Thermal insulation and protective material embodiment 1: The thermal insulation and protective material is made of the following raw materials in mass percentage: 45% binder, 25% foaming agent, 29% flame retardant, 1% cross-linking agent. Thermal insulation and protective material embodiment 2: The thermal insulation and protective material is made of the following raw materials in mass percentage: 43% binder, 30% foaming agent, 26.9% flame retardant, 0.7% cross-linking agent. Thermal insulation and protective material embodiment 3: The thermal insulation and protective material is made of the following raw materials in mass percentage: 48% binder, 22.5% foaming agent, 28.3% flame retardant, 1.2% cross-linking agent.

[0020] Specifically, the adhesive is composed of acrylic resin, rosin resin and modified chloroprene rubber resin. The purpose of using three kinds of resins is mainly for bonding. The main distribution of glue can bond the different foaming powders below through these resins.

[0021] Specifically, the mass percentage of acrylic resin in the thermal insulation protective material is 27% to 32%, the mass percentage of rosin resin in the thermal insulation protective material is 9% to 12%, and the mass percentage of modified chloroprene rubber resin in the thermal insulation protective material is 4% to 6%. For example, the mass percentage of acrylic resin in the thermal insulation protective material is 28%, the mass percentage of rosin resin in the thermal insulation protective material is 10%, and the mass percentage of modified chloroprene rubber resin in the thermal insulation protective material is 5%. For example, the mass percentage of acrylic resin in the thermal insulation protective material is 30%, the mass percentage of rosin resin in the thermal insulation protective material is 11%, and the mass percentage of modified chloroprene rubber resin in the thermal insulation protective material is 5.5%. For example, the mass percentage of acrylic resin in the thermal insulation protective material is 31%, the mass percentage of rosin resin in the thermal insulation protective material is 12%, and the mass percentage of modified chloroprene rubber resin in the thermal insulation protective material is 5%. That is, the heat-insulating protective material is made of the following raw materials in the following mass percentages: 27% to 32% of acrylic resin, 9% to 12% of rosin resin, 4% to 6% of modified chloroprene rubber resin, 20% to 30% of foaming agent, 25% to 35% of flame retardant, and 0.5% to 1.5% of cross-linking agent.

[0022] Specifically, the foaming agent is composed of acrylic copolymer, n-hexane and isopentane. There is a coordination effect among the three. The acrylic copolymer is used as the matrix, and n-hexane and isopentane are used as the core. When heated, foaming produces pores to expand the thermal insulation protective material as a whole, and the volume becomes larger. The thickness can be increased by 10-30 times. By increasing the thickness and the characteristics of the structure itself, it can effectively isolate temperature conduction.

[0023] Specifically, the mass percentage of acrylic copolymer in the thermal insulation protective material is 14% to 17%, the mass percentage of n-hexane in the thermal insulation protective material is 4% to 8%, and the mass percentage of isopentane in the thermal insulation protective material is 2% to 5%. For example, the mass percentage of acrylic copolymer in the thermal insulation protective material is 15%, the mass percentage of n-hexane in the thermal insulation protective material is 5%, and the mass percentage of isopentane in the thermal insulation protective material is 3%. For example, the mass percentage of acrylic copolymer in the thermal insulation protective material is 16%, the mass percentage of n-hexane in the thermal insulation protective material is 7%, and the mass percentage of isopentane in the thermal insulation protective material is 4%. For example, the mass percentage of acrylic copolymer in the thermal insulation protective material is 15.5%, the mass percentage of n-hexane in the thermal insulation protective material is 6.5%, and the mass percentage of isopentane in the thermal insulation protective material is 5%. That is, the heat-insulating protective material is made of the following raw materials in the following mass percentages: 40% to 50% of a binder, 14% to 17% of an acrylic copolymer, 4% to 8% of n-hexane, 2% to 5% of isopentane, 25% to 35% of a flame retardant, and 0.5% to 1.5% of a cross-linking agent.

[0024] Specifically, the flame retardant is a phosphorus nitrogen compound, which plays a flame retardant role, and the cross-linking agent is a polyisocyanate, which plays a curing role. Optimally, the above-mentioned thermal insulation protective material can be made by mixing 27% to 32% of acrylic resin, 9% to 12% of rosin resin, 4% to 6% of modified chloroprene rubber resin, 14% to 17% of acrylic copolymer, 4% to 8% of n-hexane, 2% to 5% of isopentane, 25% to 35% of flame retardant, and 0.5% to 1.5% of cross-linking agent according to mass percentage.

[0025] Figure 3 This is a product performance index table for testing multi-purpose thermal insulation and protective materials with a sampling thickness of 0.8mm and a width of 1070mm.

[0026] Figure 4 This is a picture of the actual test and verification of this battery module. The test method is as follows: 1. The module has been covered with heat-insulating protective materials; 2. The middle module of the packaging box is used as the heating trigger module; 3. After the test, the cover is opened to check the internal conditions of the module. Test conclusion: The trigger module has thermal runaway, while other modules in the box have not experienced thermal runaway and the voltage is normal.

[0027] In summary, the advantages of this battery module are:

[0028] 1. Good safety. The material has high expansion, flame retardancy, and flame impact resistance. When the thermal insulation material encounters high temperature during use, that is, when it is in a high temperature environment during the thermal runaway reaction, the thermal insulation material will automatically expand, and the thickness can increase by 10-30 times. By increasing the thickness and the characteristics of its own structure, it can effectively isolate temperature conduction and effectively delay the time before thermal runaway occurs, greatly improving safety;

[0029] 2. The material has strong adhesive properties, high viscosity and easy installation;

[0030] 3. Automatically control thermal runaway, no electronic sensors required, saving costs.

[0031] The above content is a further detailed description of the present invention in combination with specific preferred implementation modes. It cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as belonging to the protection scope of the present invention.

Claims

1. A battery module with high safety, characterized in that: Multiple cells are installed inside the battery module. Thermal insulation materials are pasted on the outside of the cells and between the cells. The thermal insulation materials are made of the following raw materials in percentage by mass: 40% to 50% of a binder, 20% to 30% of a foaming agent, 25% to 35% of a flame retardant, and 0.5% to 1.5% of a cross-linking agent. The binder is composed of acrylic resin, rosin resin, and modified chloroprene rubber resin. The foaming agent is composed of acrylic copolymer, n-hexane, and isopentane. The mass percentage of acrylic resin in the thermal insulation protective material is 27% to 32%, the mass percentage of rosin resin in the thermal insulation protective material is 9% to 12%, the mass percentage of modified chloroprene rubber resin in the thermal insulation protective material is 4% to 6%, the mass percentage of acrylic copolymer in the thermal insulation protective material is 14% to 17%, the mass percentage of n-hexane in the thermal insulation protective material is 4% to 8%, and the mass percentage of isopentane in the thermal insulation protective material is 2% to 5%. The flame retardant is a phosphorus-nitrogen compound, and the cross-linking agent is polyisocyanate.

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