阅读说明：本技术 新能源车用电池模组端板制备方法、电池模组及端板 (Preparation method of battery module end plate for new energy vehicle, battery module and end plate ) 是由 朱尚辉 黄景护 于 2021-09-28 设计创作，主要内容包括：本发明属于新能源车用电池模组技术领域,具体涉及一种新能源车用电池模组端板制备方法、电池模组及端板。所述新能源车用电池模组端板制备方法包括：S1：将原料熔化,得到铝液；S2：除气；S3：压铸成型得到毛坯料；S4：对毛坯料进行固溶和时效处理。本发明的有益效果是,选用A356.2铝合金作为主要原料,通过对铝合金进行隋性气体精炼除气,设置相应的热处理参数,克服了现有合金材料工艺不合理导致力学性能低的问题,提高了铝合金材料的力学性能,可以实现压铸铝合金电池端板与挤压型材侧板的焊接要求。(The invention belongs to the technical field of battery modules for new energy vehicles, and particularly relates to a preparation method of an end plate of a battery module for a new energy vehicle, a battery module and an end plate. The preparation method of the battery module end plate for the new energy vehicle comprises the following steps: s1: melting the raw materials to obtain aluminum liquid; s2: degassing; s3: performing die-casting to obtain a blank; s4: and carrying out solid solution and aging treatment on the blank material. The invention has the advantages that the A356.2 aluminum alloy is selected as the main raw material, the aluminum alloy is subjected to inert gas refining and degassing, and corresponding heat treatment parameters are set, so that the problem of low mechanical property caused by unreasonable process of the conventional alloy material is solved, the mechanical property of the aluminum alloy material is improved, and the welding requirement of the die-casting aluminum alloy battery end plate and the extruded profile side plate can be met.)

1. The preparation method of the battery module end plate for the new energy vehicle is characterized by comprising the following steps of:

s1: melting the raw materials to obtain aluminum liquid;

s2: degassing;

s3: performing die-casting to obtain a blank;

s4: carrying out solid solution and aging treatment on the blank material; wherein

Step S1, the raw material includes aluminum ingot;

the aluminum ingot comprises the following main components in percentage by weight: si: 6.5 to 7.0 percent; fe: less than or equal to 0.10 percent; cu: less than or equal to 0.08 percent; mn: less than or equal to 0.05 percent; mg: 0.30-0.45%; ti: 0.07-0.20%; zn is less than or equal to 0.05 percent; the balance being Al; and

the step of degassing in step S2 includes:

s21: blowing the slag removing agent into the aluminum liquid through nitrogen in a graphite rotor according to 0.05-0.1% of the weight of the aluminum liquid, setting the refining rotation speed of 400-600rpm, and requiring the nitrogen flow to be 12-18L/min;

s22, refining 1, parameters: the pretreatment time is 10 s; the vortex time is 10-15 s; the adding time of the slag removing agent is 15 +/-3 s; the reaction time of the slag removing agent is 15 +/-3 s; degassing time is 130 +/-10 s; cleaning the pipeline for 3 s; after finishing, fishing out the surface scum;

s23, refining 2, parameters: the degassing time is 480-600 s; the pipeline cleaning time is 3 s; cleaning the aluminum slag scum on the surface after finishing; and

in the step S4, the solid solution temperature is 490-560 ℃, the heat preservation time is 2-4 hours, the quenching treatment in 60S, the aging treatment temperature is 160-210 ℃, and the heat preservation time is 4 hours.

2. The method according to claim 1, wherein the reaction mixture,

step S1, the raw material also comprises scrap returns;

the weight percentage of the returning charge in the raw materials is less than or equal to 30 percent.

3. The method according to claim 1, wherein the reaction mixture,

the melting temperature in step S1 is: 730 and 760 ℃.

4. The method according to claim 1, wherein the reaction mixture,

step S2 also includes that the density index of the aluminum liquid is less than or equal to 0.05 percent after degassing.

5. The method according to claim 1, wherein the reaction mixture,

the step of press-casting and forming to obtain a blank material in step S3 includes:

forming the alloy liquid into a part through a special die and an ultra-low speed process;

the temperature of the die-casting aluminum alloy liquid is 700-720 ℃.

6. A battery module end plate produced by the production method according to any one of claims 1 to 5.

7. A battery module, comprising:

side plates and end plates of the battery module of claim 6;

the side plates are connected with the battery module end plates in a welding mode.

Technical Field

The invention belongs to the technical field of battery modules for new energy vehicles, and particularly relates to a preparation method of an end plate of a battery module for a new energy vehicle, a battery module and an end plate.

Background

The new energy automobile adopts unconventional automobile fuel as a power source (or adopts conventional automobile fuel and a novel vehicle-mounted power device), integrates advanced technologies in the aspects of power control and driving of the automobile, and forms an automobile with advanced technical principle, new technology and new structure. The new energy automobile comprises four types of Hybrid Electric Vehicles (HEV), pure electric vehicles (BEV, including solar vehicles), Fuel Cell Electric Vehicles (FCEV), other new energy (such as efficient energy storage devices like super capacitors and flywheels) automobiles and the like. Unconventional automotive fuels refer to fuels other than gasoline, diesel.

The traditional square battery module outer frame is formed by enclosing and welding end plates and side plates, and the end plates are made of plastics, aluminum alloy and magnesium alloy in common use. Because the expansion force of the ternary battery core is large, a metal end plate is generally selected. When under the operating mode such as inflation, vibration, impact, for steel band tying up and the welding of extrusion section bar of traditional square battery module, the lightweight of car module is helped more to the welding of die-casting aluminum alloy end plate and extrusion section bar curb plate.

However, die-cast aluminum alloy and 5-series extruded aluminum material (different materials) are prone to hole bursting and cracking when welded by a laser welding process. And the battery core expansibility working condition of the outer frame of the lithium battery module can not be met.

Disclosure of Invention

The invention provides a preparation method of a battery module end plate for a new energy vehicle and the battery module end plate.

In order to solve the technical problem, the invention provides a method for manufacturing an end plate of a battery module for a new energy vehicle, which comprises the following steps:

s1: melting the raw materials to obtain aluminum liquid;

s2: degassing;

s3: performing die-casting to obtain a blank;

s4: and carrying out solid solution and aging treatment on the blank material.

Further, in step S1, the raw material includes an aluminum ingot;

the aluminum ingot comprises the following main components in percentage by weight: si: 6.5 to 7.0 percent; fe: less than or equal to 0.10 percent; cu: less than or equal to 0.08 percent; mn: less than or equal to 0.05 percent; mg: 0.30-0.45%; ti: 0.07-0.20%; zn is less than or equal to 0.05 percent; the balance being Al.

Further, in step S1, the raw material further includes scrap returns;

the weight percentage of the returning charge in the raw materials is less than or equal to 30 percent.

Further, the melting temperature in step S1 is: 730 and 760 ℃.

Further, the step of degassing in step S2 includes:

s21: blowing the slag removing agent into the aluminum liquid through nitrogen in the graphite rotor according to 0.05-0.1% of the weight of the aluminum liquid, setting the refining rotation speed of 400-600rpm, and requiring the nitrogen flow to be 12-18L/min.

S22, refining 1, parameters: the pretreatment time is 10 s; the vortex time is 10-15 s; the adding time of the slag removing agent is 15 +/-3 s; the reaction time of the slag removing agent is 15 +/-3 s; degassing time is 130 +/-10 s; cleaning the pipeline for 3 s; and after finishing, fishing out the surface scum.

S23, refining 2, parameters: the degassing time is 480-600 s; the line cleaning time is 3 s. And cleaning the aluminum slag scum on the surface after finishing.

Further, step S2 includes degassing to make the density index of the molten aluminum less than or equal to 0.05%.

Further, the step of press-casting and forming the blank in step S3 includes:

forming the alloy liquid into a part through a special die and an ultra-low speed process;

the temperature of the die-casting aluminum alloy liquid is 700-720 ℃.

Further, in the step S4, the solid solution temperature is 490-560 ℃, the heat preservation time is 2-4 hours, the water quenching treatment in 60S, the aging treatment temperature is 160-210 ℃, and the heat preservation time is 4 hours.

In a second aspect, the invention also provides a battery module end plate manufactured by the manufacturing method.

In a third aspect, the present invention further provides a battery module, including: side plates and the battery module end plates as described above; the side plates are connected with the battery module end plates in a welding mode.

The invention has the advantages that the A356.2 aluminum alloy is selected as the main raw material, the aluminum alloy is subjected to inert gas refining and degassing, and corresponding heat treatment parameters are set, so that the problem of low mechanical property caused by unreasonable process of the conventional alloy material is solved, the mechanical property of the aluminum alloy material is improved, and the welding requirement of the die-casting aluminum alloy battery end plate and the extruded profile side plate can be met.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

Fig. 1 is a flowchart of a method for manufacturing an end plate of a battery module for a new energy vehicle according to the present invention;

fig. 2 is a schematic die-casting diagram of a method for manufacturing an end plate of a battery module for a new energy vehicle according to the present invention.

In the figure: aluminum liquid 1 and a pouring gate 2.

Detailed Description

To make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is apparent that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

At present, die-cast aluminum alloy and 5-series extruded aluminum material (different materials) are easy to explode and crack when being welded by a laser welding process. And the battery core expansibility working condition of the outer frame of the lithium battery module can not be met. In addition, the general die-casting aluminum alloy liquid contains gas, so that the bubbling phenomenon is often generated in the heat treatment process (at high temperature), the strength of the material is greatly reduced, and the compressed air holes close to the surface layer in the casting are freely expanded, so that the defects of hole explosion and the like are generated in the welding process; in addition, the die-casting aluminum alloy has deformation in the solution treatment stage, and the deformation is accelerated in the quenching process.

In order to solve the technical problem, the invention provides a method for manufacturing an end plate of a battery module for a new energy vehicle, which comprises the following steps:

s1: melting the raw materials to obtain aluminum liquid;

s2: degassing;

s3: performing die-casting to obtain a blank;

s4: and carrying out solid solution and aging treatment on the blank material.

In step S1, optionally, the raw material may include an aluminum ingot and a scrap; the weight percentage of the returning charge in the raw materials is less than or equal to 30 percent.

Wherein the aluminum ingot may be ASTM B179: the cast aluminum alloy with the mark of A356.2 in the 2006 standard comprises the following main components in percentage by weight: si: 6.5 to 7.0 percent; fe: less than or equal to 0.10 percent; cu: less than or equal to 0.08 percent; mn: less than or equal to 0.05 percent; mg: 0.30-0.45%; ti: 0.07-0.20%; zn is less than or equal to 0.05 percent; the balance being Al. An a356.2 grade aluminum alloy was used, which had a Fe: less than or equal to 0.10 percent and can avoid cracks during welding when being matched with other element components of the alloy. The heat preservation can be carried out by adopting a rotatable AB heat preservation furnace. The AB holding furnace can be a rotatable double-furnace body electromagnetic holding furnace, one furnace is used for smelting, and the other furnace is used for holding the temperature after smelting for die casting.

In step S1, the melting temperature is optionally: 730 and 760 ℃.

The step of degassing in step S2 includes:

s21: blowing the slag removing agent into the aluminum liquid through nitrogen in the graphite rotor according to 0.05-0.1% of the weight of the aluminum liquid, setting the refining rotation speed of 400-600rpm, and requiring the nitrogen flow to be 12-18L/min.

S22, refining 1, parameters: the pretreatment time is 10 s; the vortex time is 10-15 s; the adding time of the slag removing agent is 15 +/-3 s; the reaction time of the slag removing agent is 15 +/-3 s; degassing time is 130 +/-10 s; cleaning the pipeline for 3 s; and after finishing, fishing out the surface scum.

S23, refining 2, parameters: the degassing time is 480-600 s; the line cleaning time is 3 s. And cleaning the aluminum slag scum on the surface after finishing.

Wherein, the slag remover comprises the following components in percentage by weight: less than or equal to 10 percent of calcium fluoride, less than or equal to 5 percent of sodium carbonate, less than 1 percent of potassium fluoroaluminate, less than 1 percent of sodium hexafluoroaluminate and less than 1 percent of sodium fluosilicate. Sodium fluosilicate and potassium fluoaluminate in the slag remover are easy to decompose at high temperature, and generated gas is easy to react with hydrogen, has strong adsorption force with slag inclusion and can quickly escape from a melt.

In step S2, it is preferable that the density index of the molten aluminum is less than or equal to 0.05% after degassing.

In step S3, optionally, the step of die-casting to obtain the blank includes: forming the alloy liquid into a part through a special die and an ultra-low speed process; wherein the filling speed of the aluminum liquid is 0.05-0.8 m/s.

Referring to fig. 2, the low-speed filling with a speed of 0.05-0.8m/s is adopted, so that the occurrence of air entrainment can be prevented, and the porosity can be reduced; the area of a pouring gate of the mold is large, the pouring gate is solidified at last, directional solidification and timely feeding can be realized, and pores and shrinkage cavities caused by cooling and shrinkage of materials in a casting are reduced; the release agent without carbon, graphite and paraffin components is adopted, but the release agent can be used for releasing the carbon, graphite and paraffin components, and the release agent is not limited to Nimi W-8001; carbon, graphite and the like can be sintered and remain on the surface of the casting, and the carbon is not liquefied during high-temperature welding, so that the strength of a welding seam has defects.

In step S4 of the present invention, the solid solution temperature is preferably 490-560 ℃, the heat preservation time is preferably 2-4 hours, the quenching treatment in 60S, the aging treatment temperature is 160-210 ℃, and the heat preservation time is preferably 4 hours.

Furthermore, the invention also provides a battery module end plate prepared by the preparation method.

Further, the present invention also provides a battery module, including: side plates and the battery module end plates as described above; the side plates are connected with the battery module end plates in a welding mode.

Example 1

Mixing an aluminum ingot and a foundry returns according to the proportion of 8: 2, putting into a smelting furnace in proportion, and smelting at 740 ℃ until the molten aluminum reaches the water discharge temperature of 750 ℃; detecting chemical components of aluminum water in the smelting furnace before discharging water, and introducing inert gas into the aluminum liquid to carry out rotary degassing so that the density index of the aluminum liquid is less than or equal to 0.05 percent; the temperature of the die-casting aluminum alloy liquid is 700 ℃, and the alloy liquid is molded into parts through a special die and an ultra-low speed process; and (3) carrying out solid solution and aging treatment on the die-cast blank material, wherein the solid solution temperature is 530 ℃, the heat preservation time is 4 hours, the quenching treatment is carried out in 60S, the aging treatment temperature is controlled at 160 ℃, and the heat preservation time is 4 hours.

Examples 2-5 and comparative examples 1-3 were prepared according to the procedure of example 1, with the process parameters shown in Table 1.

Comparative examples 4 and 5 use a354 and a356 brand starting materials, respectively, and the process parameters are shown in table 1.

TABLE 1 Process conditions for the examples

	Melting temperature/. degree.C	Density index of molten aluminum	temperature/deg.C of die-casting aluminum alloy liquid	Solid solution temperature/. degree.C	Solid solution heat preservation time/h	Temperature of aging treatment/. degree.C	Aging treatment heat preservation time/h
								Example 1	740	≤0.05%	700	530	4	160	4
Example 2	750	≤0.05%	720	500	3.5	180	4
								Example 3	730	≤0.05%	710	490	3.5	170	4
Example 4	760	≤0.05%	720	540	4	180	4
								Example 5	740	≤0.05%	700	560	4	210	4
Comparative example 1	730	≤0.05%	700	480	3.5	190	4
								Comparative example 2	750	≤0.05%	710	570	4	180	4
Comparative example 3	760	≤0.05%	700	580	4	170	4
								Comparative example 4	730	≤0.05%	710	535	4	170	4
Comparative example 5	750	≤0.05%	700	535	4	170	4

The performance of the battery module end plates manufactured in the above embodiments was tested, and the test results are summarized in table 2.

Table 2 performance data of battery module end plates

	Thickness/mm	Width/mm	Tensile strength/MPa	Rp0.2 yield strength/MPa	E modulus of elasticity/MPa	Elongation/percent
							Example 1	2.89	8.05	266	193	71	6.6
Example 2	2.82	8.02	273	199	72	6.4
							Example 3	2.84	8.02	255	188	80	6.2
Example 4	2.80	8.03	261	180	73	6.3
							Example 5	2.85	8.04	260	176	76	6.5
Comparative example 1	2.87	8.02	239	145	64	2.9
							Comparative example 2	2.84	8.01	245	153	75	3.1
Comparative example 3	2.80	8.03	236	168	69	2.4
							Comparative example 4	2.80	8.04	245	215	-	2
Comparative example 5	2.85	8.02	255	220	-	3

Example 6

The die casting prepared in example 1 (raw material a 356.2) was laser welded to an extruded profile side plate, and the weld was tested for properties: porosity 0.8%, and welding strength mean value 23 KN.

Comparative example 6

The die casting prepared in comparative example 4 (raw material a 354) was laser-welded to an extruded profile side plate, and the weld was subjected to performance testing: porosity was 1%, and welding strength mean value was 14 KN.

Comparative example 7

The die casting prepared in comparative example 5 (raw material a 356) was laser welded to an extruded profile side plate, and the weld was subjected to performance testing: porosity was 4%, and welding strength mean value was 16 KN.

In summary, the present invention is achieved by using the ASTM B179 in the United states: in the 2006 standard, the mark A356.2 is used as a main raw material, the content of iron is less than or equal to 0.10 percent, and the problem of cracks of a welding line can be effectively solved by proportioning the iron and other element components of the alloy; by carrying out inert gas refining degassing on the aluminum alloy, adopting a rotatable AB holding furnace for heat preservation, enabling the density index of the aluminum liquid to be less than or equal to 0.05 percent after degassing, adopting a release agent without carbon, graphite and paraffin components, and setting corresponding heat treatment parameters, the problem of low mechanical property caused by unreasonable process of the existing alloy material is solved, the mechanical property of the aluminum alloy material is improved, the mechanical property meets the requirements of the tensile strength of more than 235MPa, the yield strength of more than 160MPa and the elongation of more than 3 percent, and the laser welding process requirement of the end plate and the extruded section side plate of the die-cast aluminum alloy battery can be realized.

In light of the foregoing description of the preferred embodiment of the present invention, many modifications and variations will be apparent to those skilled in the art without departing from the spirit and scope of the invention. The technical scope of the present invention is not limited to the content of the specification, and must be determined according to the scope of the claims.