WO2017193880A1

WO2017193880A1 - Thermal control device and cooling device for soft pack battery

Info

Publication number: WO2017193880A1
Application number: PCT/CN2017/083375
Authority: WO
Inventors: 谢彦君
Original assignee: 谢彦君
Priority date: 2016-05-08
Filing date: 2017-05-07
Publication date: 2017-11-16
Also published as: CN107346807A; CN107346806A; CN208173634U

Abstract

The present invention relates to a thermal control device for a soft pack battery, and in particular, to a thermal control device for a soft pack battery soaked in cooling water. Moreover, with respect to the defect in the prior art of insufficient corrosion resistance of a packaging material for a battery, a corresponding packaging material is provided. The packaging material is composed of an aluminum foil layer having corrosion resistance to cooling water and a plastic layer on the surface of the aluminum foil layer.

Description

Soft pack battery thermal control device and cooling method

Technical field

The invention relates to a soft pack battery thermal control device, in particular to a soft pack battery thermal control device which can be applied to immersion in cooling water, such as a water cooling system in the field of a vehicle power battery and an energy storage battery.

Background technique

Thermal management technology is one of the core technologies of soft-packed power batteries. There are many thermal management technology solutions and efforts in this field, but thermal management issues are still one of the bottlenecks that restrict the development of the industry, and the demand for efficient thermal management. Still very urgent. The existing soft pack battery cooling methods are more air-cooled, oil-cooled and water-cooled; as described in CN201210016348.0, the water-cooling scheme uses water-cooled plates or cooling tubes to contact the battery for heat exchange, and this heat exchange method The contact between the cooling water and the battery has high thermal resistance, many heat transfer links and low heat exchange efficiency; although the immersion oil cooling scheme introduced in CN202550023U has a certain degree of temperature uniformity, the fluidity of the insulating oil is poor. There are many problems such as low heat exchange efficiency and after-sales maintenance. In the prior art, there is no application for directly immersing the soft pack battery in water or antifreeze, and there is no special battery packaging material suitable for it.

In the prior art, the aluminum plastic film used for packaging the soft pack battery is usually made of 8 series aluminum alloy aluminum foil, and the aluminum foil is annealed to a soft aluminum foil, and the deep molding property is good. At present, the battery packaging material is mainly considered to be resistant to electrolyte corrosion. The main technical solution is to physically or chemically modify the corrosion-resistant layer on the side of the packaging material facing the electrolyte, which is to prevent the electrolyte from corroding the inner surface of the aluminum foil and causing aluminum plastic. Peeling between layers. The outermost layer of the existing aluminum plastic film contains a protective plastic film such as polyamide. These plastic protective films have poor hydrolysis resistance, and if they are in contact with water vapor, they are easily hydrolyzed.

In order to improve the hydrolysis resistance of the aluminum plastic film, the conventional means of the prior art is to improve the hydrolysis resistance of the outer protective film, for example, a PET film which is more water resistant than the nylon film is used as the outermost protective film. The use of PET film improves the corrosion resistance of water vapor or water droplets in the air, but it is still not suitable for long-term contact with water.

Summary of the invention

Based on the current power battery thermal management problem, it is still a bottleneck problem that restricts the development of the industry. The present invention starts from the demand of soft pack battery cooling, and in order to obtain higher battery cooling performance, the present invention boldly adopts the soft pack battery directly immersed in the cooling water. Cooling scheme. However, after in-depth research and long-term testing, it was discovered that the existing battery packaging materials could not meet the requirements of this immersed water cooling. The outermost nylon protective layer of the existing soft plastic battery packaging has anti-glycol antifreeze corrosion performance. Poor, the aluminum foil as the water-blocking layer is aluminum-iron alloy, and its mechanical strength and anti-glycol antifreeze corrosion performance (especially pitting resistance) are also poor, even if it adopts traditional technical means (such as aluminum foil surface for anti-corrosion coating) Layer treatment) is also prone to pitting corrosion, so the existing aluminum plastic film can not meet the requirements of long-term immersion water cooling system. In order to overcome the above drawbacks, the present invention creatively provides the following new Battery cooling system solutions and battery packaging materials solutions to solve the above series of technical problems and meet the thermal management needs of large-capacity battery systems such as new energy vehicles or energy storage.

Under the premise of taking into account the aluminum-plastic film aluminum foil forming ability, the aluminum-plastic film-resistant antifreeze coolant for the packaging of the battery in the prior art (referred to as antifreeze, the main component of which is ethylene glycol and water) or resistant A defect that the corrosion resistance of the cooling water is insufficient, that is, a defect that is easily corroded and perforated. The present invention provides an aluminum-plastic composite film (hereinafter referred to as an aluminum plastic film) which can be used for packaging lithium ion secondary batteries, which has a higher Resistance to coolant corrosion.

A first aspect of the present invention provides a battery formed of a metal plastic composite film, preferably a packaging material for a soft pack battery (preferably an aluminum plastic film), comprising a metal foil layer (preferably an aluminum foil layer) and a composite metal foil A plastic layer on the inner surface of the layer, preferably an aluminum foil layer.

A second aspect of the present invention provides a soft pack battery comprising the electrode material and an electrolyte and the above-mentioned metal plastic composite film (preferably an aluminum plastic film) for outer wrapping, the metal foil layer (preferably an aluminum foil layer) The plastic layer of the inner surface isolates the electrolyte from the metal foil layer, preferably the aluminum plastic film. Preferably, the electrolyte comprises lithium hexafluorophosphate and/or lithium tetrafluoroborate (LiBF ₄ ).

A third aspect of the present invention provides a battery thermal control device, preferably a soft pack battery thermal control device, comprising the above-described soft pack battery. The soft pack battery may be packaged in a cooling liquid (such as an antifreeze coolant) after being packaged by the above-mentioned aluminum plastic film which is resistant to the immersion corrosion of the coolant, preferably, the metal plastic composite film is formed. The battery packaging material is immersed in the cooling liquid, and more preferably, the metal foil layer (preferably an aluminum foil layer) is immersed in the cooling liquid so that the metal foil layer can be directly exchanged with the cooling liquid. In this way, the heat exchange effect of the battery is better, and the temperature of the battery is more uniform around the top, bottom, left and right.

A fourth aspect of the invention provides a method of cooling a battery unit using a thermal control device.

A fifth aspect of the present invention provides a method of producing the battery packaging material, preferably an aluminum plastic film, formed of the metal plastic composite film.

In a preferred embodiment of the invention, the aluminum foil layer is a single layer, and more preferably, the aluminum foil layer is formed of a corrosion resistant aluminum alloy. Among them, the term "corrosion resistance" means resistance to cooling water or antifreeze corrosion. Unless otherwise specified, the term "corrosion resistance" as used in the present invention means resistance to cooling water or antifreeze, and does not mean resistance to electrolyte corrosion. The technical means for resisting the corrosion of the cooling water used in the present invention is also different from the conventional technical means for resisting the corrosion of the electrolyte.

In a preferred embodiment of the present invention, the aluminum foil layer is a composite layer, and the aluminum foil layer comprises a core material and a skin material located outside the core material, and the corrosion potential of the skin material of the aluminum foil layer is lower than the corrosion potential of the core material. More preferably, the core material is located between the plastic layer and the skin material inside the aluminum foil layer. More preferably, in the battery thermal control device, the aluminum-plastic film aluminum foil of the soft pack battery is directly immersed in the leather material. In the cooling liquid.

The aluminum plastic film of the present invention is a film composite material formed of a plastic film and an aluminum foil film, and is used as a packaging material for a polymer lithium battery.

Among them, preferably, only one side of the aluminum foil layer is composited with a plastic layer, and, more preferably, the plastic layer is only composited to the inner side of the aluminum foil layer. Wherein, the above solution includes the following case: the plastic layer compounded on one side surface of the aluminum foil layer may be a single layer plastic or a multilayer plastic.

Further, the inner plastic layer is preferably a thermoplastic resin film. For example, a polypropylene (PP) film or a polyethylene (PE) film. Wherein, the thickness of the inner plastic layer may be selected from 50 to 300 micrometers, preferably from greater than 60 to less than 100 micrometers, and more preferably from 70 to 90 micrometers. The inner plastic layer may also be referred to as a heat seal layer or a seal layer. Preferably, the inner plastic layer is a polyolefin resin or an acid-modified polyolefin resin. The inner plastic layer may also be blended with various additives such as one or more of a flame retardant, a lubricant, an anti-blocking agent, an antioxidant, a light stabilizer, and an adhesion-imparting agent.

Preferably, the inner plastic layer has better electrical insulation properties and thus has a higher withstand voltage value, such as a withstand voltage preferably greater than 1000V, more preferably greater than 2000V.

If the outer plastic layer is contained, the outer plastic layer is preferably a heat resistant resin film. For example, a polyamide (PA) or nylon (Ny or ON) film, or a polyester (PET) film, or a polyimide (PI) film.

Further, the composite layer aluminum alloy preferably includes at least a core material and a skin material composited on the outer side of the core material. The composite layer aluminum alloy may be an aluminum alloy having two layers of different compositions, or may be an aluminum alloy having different layers.

The above aluminum plastic film of the present invention may be of any one of the structures A) to B):

A) The aluminum plastic film has a laminate composed of an inner plastic heat seal layer, an intermediate aluminum foil layer, and an outer plastic protective layer, wherein the intermediate aluminum foil layer is formed of a composite layer aluminum foil having a sacrificial anode protection function. For example, the composite layer aluminum foil is formed of a core material and a skin material having a corrosion potential lower than that of the core material.

B) The aluminum plastic film has a laminate composed of an inner plastic heat seal layer and an outer aluminum foil layer, wherein the outer aluminum foil layer is formed of a composite layer aluminum foil having a sacrificial anode protection function. The aluminum plastic film does not contain an outer plastic protective layer.

The inner plastic heat seal layer may also be referred to as a thermoplastic resin film layer, and the outer plastic protective layer may also be referred to as a heat resistant resin film layer.

The corrosion potential of the sheath material in the composite aluminum foil is 5 mV-500 mV lower than the corrosion potential of the core material. Further, the corrosion potential of the skin material is 50 mV-500 mV lower than the corrosion potential of the core material. Preferably, the corrosion potential of the sheath material is 70 mV-200 mV lower than the corrosion potential of the core material. More preferably, the corrosion potential of the sheath material is from 100 mV to 170 mV lower than the corrosion potential of the core material. The above potential difference means a potential difference before or before the recombination.

In the present invention, unless otherwise specified, the corrosion potential is referred to as a corrosion potential in a water-based coolant environment. Through this The reasonable potential matching between the leather material and the core material in the composite aluminum foil is beneficial to avoid pitting corrosion of the aluminum foil (especially the core material).

In the present invention, unless otherwise specified, both the cooling water and the cooling liquid refer to a water-based cooling liquid. The water-based coolant refers to a coolant containing water as a basic component. The water-based coolant may also contain various antifreeze agents (such as ethanol, ethylene glycol, propylene glycol, etc.) to form an antifreeze solution having an antifreeze function. Therefore, the cooling liquid of the present invention contains the following types: pure water, a mixed liquid of ethylene glycol and water, and the like.

Further, the core material of the above composite aluminum foil layer is formed of a corrosion-resistant aluminum alloy or pure aluminum. The pure aluminum includes industrial pure aluminum and high purity aluminum. The purity of aluminum in the pure aluminum is preferably ≥99.0%, more preferably 99.0%-99.99%.

The corrosion-resistant aluminum alloy according to the present invention means that the aluminum alloy and the aluminum plastic film can maintain a normal function for a long period of time without failure in an environment in direct contact with the cooling liquid, for example, the aluminum alloy is not corroded and perforated by the cooling liquid. The "non-failure" includes that the electrical insulation function of the aluminum plastic film does not fail and the water vapor barrier function does not fail. Although its performance is attenuated, it can still meet the basic requirements. The term "long-term" refers to the normal life cycle duration of a product (such as a car or an automobile power battery), such as a life of more than 5 years, preferably more than 10 years, more preferably more than 15 years. The corrosion-resistant aluminum alloy according to the present invention may be selected from the following rust-proof aluminum or an aluminum alloy having good corrosion resistance: a 1 series aluminum alloy, a 3 series aluminum alloy, a 5 series aluminum alloy, and a 6 series aluminum alloy. Since the corrosion-resistant aluminum alloy (such as aluminum-manganese alloy AA3003, etc., omitted AA below) or pure aluminum has good resistance to coolant corrosion, it can be used as an aluminum foil layer of aluminum plastic film, which can be applied to direct contact with coolant. Application.

If the aluminum foil layer is a composite layer, the core material and the leather material are compositely formed, the core material is located on the inner side, the leather material is located on the outer side, and the corrosion potential of the leather material is lower (or negative) than the corrosion potential of the core material. When in contact with a corrosive medium, electrochemical corrosion is formed, and the skin material acts as a sacrificed anode to protect the core material as a cathode, thereby ensuring that the aluminum foil layer in the aluminum plastic film can corrode with water-based coolant for a long period of time, thereby ensuring the battery. Service life. Among them, the leather material may be a single layer material or a multilayer material. If the skin material is a plurality of layers, it is preferred that the multilayer skin material is sequentially lowered from the inside to the outside. The thickness of the skin material preferably accounts for 8 to 20%, more preferably 10 ± 2%, of the entire aluminum foil layer. The inner side of the present invention refers to the side close to the electrolyte inside the battery when applied to the soft pack battery; the outer side refers to the side away from the electrolyte inside the battery when applied to the soft pack battery.

Among them, the core material may also be referred to as an aluminum substrate. The plastic layer may be a plastic layer of various mature applications in the prior art, such as a cast polypropylene film (CPP) for the inner layer, a nylon film (ON) or/and a polyester film (PET) for the outer layer, and a plastic layer. The dry-bonding or thermal compounding of the adhesive in the prior art can be used between the aluminum foil layer and the aluminum foil layer.

Further, the corrosion-resistant aluminum alloy is selected from the group consisting of aluminum manganese aluminum alloy, or aluminum magnesium aluminum alloy, or aluminum magnesium silicon aluminum alloy, or aluminum silicon aluminum alloy. The corrosion-resistant aluminum alloy is more preferably an aluminum manganese aluminum alloy or an aluminum magnesium aluminum alloy.

Alternatively, further, the corrosion-resistant aluminum alloy is selected from the group consisting of a 3 series aluminum alloy, or a 1 series aluminum alloy, or a 5 series aluminum alloy, or a 6 series aluminum alloy, or a 4 series aluminum alloy. Or these aluminum alloys have good corrosion resistance. Corrosion resistant aluminum alloy It is preferably a 3-series aluminum alloy or a 1-series aluminum alloy.

The aluminum alloy of the present invention is named using the corresponding standards of the American Aluminum Association.

Further, if the aluminum foil layer is a composite layer, the skin material of the aluminum foil layer is selected from the group consisting of aluminum zinc aluminum alloy, or aluminum copper aluminum alloy. The leather material of the aluminum foil layer is more preferably an aluminum zinc aluminum alloy. The zinc element content in the aluminum-zinc alloy is preferably from 1% to 10%, more preferably from 4% to 7%.

Preferably, the composite layer aluminum foil is formed by compounding a core material which is an aluminum alloy containing the following components (mass percentage): Si ≤ 0.25 wt%; Cu ≤ 0.05 wt%; Mg ≤ 0.05 Wt%; Zn ≤ 0.05 wt%; Mn ≤ 0.05 wt%; Ti ≤ 0.03 wt%; V ≤ 0.05 wt%; Fe ≤ 0.4 wt%;

Or; the core material is an aluminum alloy containing the following components (mass percentage): Si ≤ 0.25 wt%; Cu ≤ 0.05 wt%; Mg ≤ 0.05 wt%; Zn ≤ 0.05 wt%; Mn ≤ 0.05 wt%; Ti ≤0.03wt%; V≤0.05wt%; Fe≤0.4wt%; Sm 0.1-0.3wt%; the balance is aluminum;

The skin material is an aluminum zinc aluminum alloy containing the following components (mass percentage): Zn 4-7 wt%; Si 0.5-1.0 wt%; Ti 0.1-0.2 wt%; Fe 0.5-1.5 wt%;

Alternatively, the skin material is an aluminum zinc aluminum alloy containing the following components (mass percentage): Zn 4-7 wt%; Si 0.5-1.0 wt%; Ti 0.1-0.2 wt%; Fe 0.5-1.5 wt%; Sm 0.1-0.3 wt%.

Another preferred embodiment is that the composite layer aluminum foil is formed by combining a core material and a skin material, the core material being an aluminum alloy containing the following components (mass percentage):

Si≤0.9wt%; Fe≤1.7wt%; Cu≤0.1wt%;Mn≤0.2wt%;M≤0.05wt%;Zn≤0.1wt%;Ti≤0.08wt%;Cr≤0.05wt%;Other impurities The element is ≤0.05% single; the other impurity elements are ≤0.15% in total; the rest is aluminum;

The leather material is an aluminum zinc aluminum alloy containing the following components (mass percentage):

Zn 4-7 wt%; Fe 0.5-1.5 wt%.

Alternatively, if the aluminum foil layer is a composite layer, the skin material of the aluminum foil layer is selected from a 7-series aluminum alloy or a 2-series aluminum alloy. That is, the leather material is selected from the aluminum alloy of the 7-series or 2-series aluminum alloy whose corrosion potential is lower than the corrosion potential of the core material, such as the 7072 aluminum alloy or the Al clad 2024 aluminum alloy. The skin material of the aluminum foil layer is more preferably a 7-series aluminum alloy. For example, the corrosion potential of 3003 aluminum alloy is about -0.72V, the corrosion potential of 7072 aluminum alloy is about -0.88V, and the corrosion potential of 2024 aluminum alloy is about -0.83V. In addition, in addition to the basic type of the 7072, the skin material can also be used with other improvements of the 7072.

Alternatively, further, if the aluminum foil layer is a composite layer, the skin material of the aluminum foil layer is selected from the group consisting of a modified aluminum alloy to which zinc is added. Among them, the sheath material is preferably a zinc-based 1 series aluminum alloy or a zinc-added 3 series aluminum alloy, such as a 3003 aluminum alloy modified type in which a mass percentage of 1.0% to 2.5% zinc is added. The 3003 potential drop of zinc added is about -0.82 to -0.88V, so it is lower than the potential of the 3003 core material. Alternatively, the skin material is preferably an aluminum alloy formed by adding zinc to a 1 series aluminum alloy (pure aluminum), such as adding quality. A modified 1050 aluminum alloy with a percentage of 4% to 7% zinc.

Further, the corrosion-resistant aluminum alloy is preferably 3003 aluminum alloy, or 3004 aluminum alloy, or 3005 aluminum alloy, or 3105 aluminum alloy, or 3A21 aluminum alloy.

Further, the pure aluminum is 1050 aluminum alloy, or 1060 aluminum alloy, or 1070 aluminum alloy, or 1100 aluminum alloy.

Further, if the aluminum foil layer is a composite layer, the skin material of the aluminum foil layer is a 7072 aluminum alloy or a 7075 aluminum alloy.

The aluminum foil of the present invention generally refers to a film-like (or flaky) pure aluminum or aluminum alloy, so the aluminum foil of the present invention can also be said to be an aluminum film, and the thickness can be selected as an aluminum film within 200 micrometers, or alternatively 200. - 300 micron or 300-500 micron thick aluminum film. Alternatively, further, the thickness of the aluminum foil layer in the aluminum plastic film is preferably from 80 to 500 μm. The thickness is more preferably from 100 to 300 μm. The thickness is still more preferably from 100 to 200 μm.

Alternatively, further, the thickness of the aluminum foil layer in the aluminum plastic film is 80-100 microns, or 100-150 microns, or 150-200 microns, or 200-300 microns, or 300-500 microns.

Further, the heat treatment state of the aluminum foil layer is annealed (O state).

Further, the exterior of the aluminum foil layer is bonded to the plastic protective layer by a release agent. The plastic protective layer on the outside of the aluminum foil layer is thus easily separated.

Further, the heat seal layer material may be a polypropylene (PP) film or a polyethylene (PE) film.

Further, the material of the plastic protective layer may be a nylon (ON) film or a polyester (PET) film.

The above technical solution includes the following technical solutions: if the aluminum foil layer of the aluminum plastic film is a single layer (non-composite layer), the aluminum foil layer may be a 3 series aluminum alloy, or a 1 series aluminum alloy, or a 5 series aluminum alloy, or 6 series aluminum alloy. If the aluminum foil layer of the aluminum plastic film is a composite layer, the core material of the aluminum foil layer may be a 3 series aluminum alloy, or a 1 series aluminum alloy, or a 5 series aluminum alloy, or a 6 series aluminum alloy, or an 8 series aluminum alloy; The skin material of the aluminum foil layer may be a 7-series aluminum alloy or a 2-series aluminum alloy. Among them, the core material is more preferably a 1 series aluminum alloy or an 8 series aluminum alloy, and the composite layer aluminum foil having such a core material has better corrosion resistance and deformability.

The aluminum foil layer of the aluminum plastic film provided by the present invention has good corrosion resistance, and the aluminum foil layer and the aluminum plastic film containing the aluminum foil layer have long-term resistance to coolant corrosion.

The aluminum plastic film provided by the above invention, for example, the aluminum foil layer adopts a 3 series aluminum alloy (such as 3003), and more preferably a 3 series aluminum alloy and a 7 series aluminum alloy composite aluminum alloy composite layer (such as 3003/7072). Therefore, it has excellent resistance to coolant corrosion, and can be applied to a power pack battery system for a vehicle, and allows the aluminum plastic film of the soft pack battery to directly contact with the coolant for heat exchange.

The above-mentioned aluminum plastic film of the present invention is an aluminum plastic film for battery packaging, and the aluminum foil layer functions as a water blocking layer.

As an alternative, the inner side of the aluminum foil layer may further have an anti-corrosion treatment layer, and the anti-corrosion treatment layer is chromate treatment. Formed, or formed by treatment with rare earth oxides, but is not required. In the present invention, the aluminum plastic film containing only the inner plastic layer is immersed in the conductive coolant, and the aluminum foil layer is in electrical communication with the conductive coolant. In rare cases, when the battery electrolyte passes through the inner plastic layer to reach the aluminum foil layer, the electrolyte is in electrical communication with the aluminum foil layer, the conductive coolant and the external ground line, which can trigger the insulation resistance alarm and detect the hydrofluoric acid on the aluminum foil in time. Corrosion and prevention of electrolyte leakage and other hazards. Therefore, in the thermal management system of the present invention, the inner side of the aluminum-plastic film aluminum foil is not treated with a conventional anti-corrosion coating, and the safety performance of the battery and the entire system can be ensured.

The present invention provides an aluminum plastic film which has the following resistance to coolant corrosion: the corrosion resistance test method is an OY water solution corrosion test; the aluminum plastic film or its aluminum foil layer The corrosion life in the above test was greater than 500 hours. Further, the aluminum plastic film or the aluminum foil layer has a corrosion resistance life of more than 1000 hours. Further, the aluminum plastic film or its aluminum foil layer has a corrosion resistance life of more than 2000 hours.

The thickness of the aluminum foil of the above-mentioned aluminum plastic film which satisfies the requirements for the corrosion resistance of the aqueous solution of OY in the present invention is preferably more than 80 μm, further preferably more than 100 μm, still more preferably from 120 μm to 300 μm.

Alternatively, the aluminum plastic film or its aluminum foil layer has the following resistance to coolant corrosion: OY aqueous solution corrosion test, or internal corrosion resistance test in ASTM D2570 standard; resistance of the aluminum plastic film or its aluminum foil layer in the above test The corrosion life is greater than 150 hours, or greater than 200 hours, or greater than 336 hours. Further, the aluminum plastic film or the aluminum foil layer has a corrosion resistance life of more than 500 hours. Still further, the aluminum plastic film or its aluminum foil layer has a corrosion resistance life of more than 1000 hours. Further, the aluminum plastic film or the aluminum foil layer thereof has a corrosion resistance life of more than 2000 hours; further, the aluminum plastic film or the aluminum foil layer has a corrosion resistance life of more than 2,500 hours.

In the prior art, the 8-line (such as 8021 or 8079) aluminum foil with a thickness of 40 microns has a service life of about 98 hours in the OY aqueous solution corrosion test, and cannot meet the design life requirement of the vehicle at all, so it cannot meet the requirements of the antifreeze immersion cooling method. . Therefore, in order to have the above corrosion resistance, the aluminum foil in the aluminum plastic film needs to have a suitable aluminum alloy material composition and/or a suitable thickness.

The aluminum foil material satisfying the above requirements for resistance to coolant corrosion can be selected from a single layer of a 1 series aluminum alloy (pure aluminum), a single layer of a 3 series aluminum alloy, or a composite layer aluminum alloy having a sacrificial anode protection function.

The thickness of the aluminum foil which satisfies the above requirements for resistance to coolant corrosion can be selected from the following thicknesses: 80-120 micrometers, or 120-150 micrometers, or 150-200 micrometers, or 200-300 micrometers.

For example, pure aluminum AA1050 with a thickness greater than 150 microns, or a composite aluminum alloy formed by a combination of AA1050 with a thickness of 100 microns and AA7072 with a thickness of 20 microns (ie, a total thickness of the composite aluminum alloy of 120 microns), the above two aluminum foils are used to manufacture aluminum. The plastic film can meet the above-mentioned anti-freeze corrosion life requirements, so as to meet the automotive life requirements.

In addition to solving the above corrosion life problem from the perspective of the aluminum foil, it is also possible to improve the water corrosion resistance life of the aluminum plastic film from the outer plastic layer. For example, the outer plastic layer is a hydrolysis resistant plastic layer. Further, the outer plastic layer is a Teflon layer, or a PE layer, or a composite material of a PE layer and a PA layer, or a water resistant improvement layer of PA. Alternatively, if there is no plastic layer on the outer side, that is, the aluminum foil is an outer layer material, an anticorrosive coating such as chromizing treatment or rare earth oxide treatment may be applied on the outer surface of the aluminum foil layer. The above scheme may be employed, but is not preferred in the present invention.

Alternatively, from the perspective of vehicle application, it is preferred that the aluminum plastic film or its aluminum foil resistant to coolant (such as an antifreeze mainly composed of ethylene glycol and water) has a corrosion life of more than 5 years, preferably more than 10 years, more preferably more than 15 years.

Unless otherwise specified, the term "life" refers to the defect that the aluminum plastic film and the aluminum foil cannot be corroded and perforated during the life span. In order to obtain the above-mentioned resistance to coolant corrosion resistance, the aluminum foil in the aluminum plastic film needs to be selected from the above-mentioned suitable aluminum alloy material and has sufficient thickness. For example, preferably, the aluminum plastic film is composed of an aluminum foil layer and a thermoplastic resin film laminated on the aluminum foil, wherein the aluminum foil is a composite foil having a sacrificial anode function, and the thickness is preferably 100 to 300 μm. The existing aluminum plastic film product does not take into consideration the application of immersion in the antifreeze solution, nor does it have the function of immersing in the antifreeze solution for a long period of time without failing; and the aluminum plastic film product of the invention has the above special characteristics.

Further, the aluminum plastic film or the aluminum foil thereof also has deep drawability or moldability. In other words, the aluminum plastic film or its aluminum foil also has good deep drawability or moldability. Or the aluminum plastic film also has good deep drawability. Or the aluminum plastic film or its aluminum foil also has a good cupping value. Because of its deep drawability, it can be measured by the cupping value. For example, according to the standard test of GB/T4156-2007 "Metal material sheet and ribbon Eriksson cupping test", the stamping depth value or cupping value of the aluminum foil in the aluminum plastic film or aluminum plastic film is more than 5 mm, preferably Greater than 10 mm, more preferably greater than 12 mm. The so-called stamping depth value or cupping value means that the aluminum plastic film or its aluminum foil cannot be perforated after the stamping or cupping test within this value.

Further, the present invention further provides an aluminum plastic film comprising an aluminum foil layer and a plastic layer composited on the surface of the aluminum foil layer; the aluminum foil layer is a composite layer aluminum foil, the aluminum foil layer comprises a core material and is located outside the core material The corrosion potential of the leather material of the aluminum foil layer is lower than the corrosion potential of the core material; wherein the leather material located outside the core material is formed by two layers of leather material or more than two layers of multilayer leather material, and the corrosion potential is from inward direction. The outside is lowered in turn. This forms a surface corrosion gradient that is more conducive to preventing pitting corrosion. Or preferably, in the cross section of the aluminum foil layer, the potential on the outer side is gradually lower than or equal to the potential on the inner side (or the Zn content is gradually increased from the inside to the outside).

In order to form the potential gradient, the composite layer aluminum foil can be heated at a high temperature to gradually diffuse the zinc element in the leather material to the core material, so that the content of the zinc element continuously changes gradually from the outside to the inside of the aluminum foil layer, and the corrosion potential is also The continuous gradual change avoids the zinc content and the corrosion potential of the cliff type change or mutation, which is more conducive to the conversion of the corrosion form into uniform layered corrosion. The anti-corrosion mechanism of the composite aluminum foil is different from the traditional anti-corrosion coating treatment method such as chromization on the surface of the aluminum foil, and the composite aluminum foil itself is Aluminum material, which improves the corrosion state by adjusting the corrosion potential of different layers inside the aluminum foil, that is, it is guided by layer corrosion to form layer corrosion, preventing aluminum foil perforation and battery failure. If the outer surface of the aluminum foil is chromed and immersed in the cooling water, although the corrosion rate of the aluminum foil can be reduced, the corrosion state of the aluminum foil cannot be improved, and the pitting corrosion is not greatly inhibited.

It is worth noting that after the high-temperature diffusion process, the boundary between the layers of the above composite layer is not very clear, and the composition and potential between the layers are not stepwise mutations, but a gradual process. Therefore, the composite layer aluminum foil according to the present invention includes not only the composite between the plurality of different aluminum alloys before the high temperature treatment, but also the element content gradation or corrosion potential in the aluminum foil in the direction perpendicular to the surface of the aluminum foil after the high temperature treatment. Gradient composite layer. For example, the high temperature annealing process conditions can be selected as follows: an annealing temperature of 200 to 400 degrees Celsius, an annealing time of 1.5 to 3.5 hours, or multiple annealing to achieve an ideal state.

The soft pack battery thermal control device as described above includes a soft pack battery packaged by any of the above battery pack materials, and may further include a cooling liquid, the outer package of the soft pack battery being in direct contact with the coolant. Further, the battery thermal control device includes a coolant, which is water, or a mixture of ethanol and water, or a mixture of ethylene glycol and water, or a mixture containing propylene glycol and water, or other antifreeze. Coolant. These coolants are currently used in automotive and industrial coolants. They are not insulating cooling media, but conductive coolants with electrical conductivity (including weak electrical conductivity); however, compared to silicone oil or transformer oil. The insulating cooling medium has the advantages of high thermal conductivity, good fluidity, high heat conduction efficiency, and relatively low cost.

Based on the above, the present invention provides a soft pack battery thermal control device comprising a soft pack battery and a cooling liquid, the outer package of the soft pack battery being in direct contact with the coolant, and the soft pack battery is used. One or more of the soft pack batteries packaged in the packaging materials described above. Among them, the coolant is a conductive coolant. The soft pack battery of the present invention preferably employs a soft pack battery in which the electrolyte contains lithium hexafluorophosphate.

Further, the thermal control device further includes a partition; at least part of a surface of the partition is in direct contact with at least a portion of an outer surface of the soft pack battery, and a fluid passage is disposed in the partition; and a plurality of soft pack batteries form a battery The unit, the battery unit and the partition are spaced apart. The plurality of soft pack batteries may be one, or two, or a plurality of battery cells. When the soft pack battery thermal control device has a water-based coolant, the water-based coolant flows in the fluid passage, and the water-based coolant directly contacts the soft pack battery for heat exchange.

In a more preferred embodiment, the spacer comprises two flat plates, each of which is in contact with a battery unit, and a connecting plate connected to the at least one flat plate is disposed between the two flat plates, so that the two flat plates are A fluid passage is formed between them.

In another more preferred embodiment, the spacer is a fin structure, and preferably, the fins are sequentially connected, and the connection may be "V" shape, "U" shape, trapezoidal shape, curved shape, Zigzag or the like is connected, and adjacent fins may be parallel or at an angle to form the fluid passage between adjacent fins.

More preferably, the fin structure includes a riser and a flat plate at both ends of the riser, the flat plate being in direct contact with the battery.

More preferably, the fin structure comprises two sets of said flat plates, the two sets being respectively in contact with one of the adjacent two battery cells, each set comprising a plurality of flat plates. More preferably, each panel is connected to only two risers.

The riser is not necessarily perpendicular to the flat plate, but may also be obliquely connected to the flat plate.

In a more preferred embodiment, the fins may also be provided with holes.

In another more preferred embodiment, the fins may be any one or more of straight fins and wavy fins, wherein the wavy fins may be curved at the bends, It may be a sharp corner (such as an acute angle, a right angle or an obtuse angle), more preferably an arc.

Wherein, the partition between two adjacent battery cells may be a partition or a sub-separator group composed of a plurality of sub-separators, for example, a plurality of sub-separators are arranged at intervals between the two battery cells; The sub-separator structure is selected from any one or more of the above-described separator structures.

The separator is preferably made of a metal material (such as aluminum alloy, stainless steel, etc.); the corrosion potential of the separator is equal to or less than the corrosion potential of the aluminum foil in the aluminum plastic film. Further, the separator is made of a metal material; the corrosion potential of the separator is lower than the corrosion potential of the aluminum foil in the aluminum plastic film, or the corrosion potential of the separator is equal to or lower than the corrosion potential of the aluminum material of the aluminum foil in the aluminum plastic film. The baffle serves to support the function of the soft pack battery and the tissue flow field, and the baffle may be an extruded flat tube, or may be various types of fins such as flat fins and staggered serrated fins. In the present invention, the above fin is a type of separator, or a fin-shaped separator having a fluid passage. These fin separators function to separate adjacent battery cells and form a flow path, and support and fix the battery cells, so that the soft pack battery thermal control system has reliable vibration resistance and can be used for automobiles. In a vibrating environment. The fin spacer of the present invention does not include fins such as pin fins that cannot support the battery cells. In addition, the fin separator of the present invention has a fluid passage (or flow passage) inside, and the fluid passage is in direct contact with the soft pack battery. The battery cells are closely spaced from the fin spacers to form a unitary body, and the entire body can be fastened together by straps or through bolts. The fin separator of the present invention is not only simpler in structure than the flat tube or other forms of separators in the prior art, but also has higher heat transfer efficiency because there is no partition wall surface. The fins are not resistant to high temperatures or requirements, so the fin separators are not limited to metal materials, and plastic materials such as ABS and PP may be used.

Further, the aluminum plastic film seals the battery core, and only the battery electrode or the electrode connection port protrudes from the aluminum plastic film; the battery thermal control device further includes a main board, and the main board has a socket The portion of the battery that protrudes from the aluminum plastic film is inserted into the main board through the socket.

Further, the battery thermal control device further includes an outer casing, the outer casing is provided with a receiving chamber, and the battery unit and the partition are disposed in the receiving chamber of the outer casing, and the outer casing further includes Fluid inlet and fluid outlet.

Or, further, the thermal control device further comprises a main board and an outer casing, the main board and the outer casing form a sealed cavity, the electrode of the soft pack battery protrudes above the main board, and the body of the soft pack battery is placed in the sealed cavity. In addition to the device of the above type, the thermal control device may have a plurality of main plates forming a plurality of sealed cavities.

Further, the main board is located in the accommodating chamber of the outer casing, and divides the accommodating chamber into two parts, the first part accommodating the battery unit main body and the partition, and the second part is accommodated from the aluminum plastic film The extended electrode and/or electrode is connected to the port portion, the first portion and the second portion being physically isolated.

The battery thermal control device of the present invention may further include a cooling pump, a coolant heat exchanger and a corresponding water pipe; or the present invention provides a battery cooling system using the above battery thermal control device, further comprising a cooling pump (preferably Low voltage pumps below 24 volts), coolant heat exchangers and corresponding water pipes. The coolant heat exchanger is a gas-liquid heat exchanger that directly exchanges heat between the coolant and the ambient air.

The present invention also provides a method of cooling a battery unit using any of the above-described soft pack battery thermal control devices, the fluid passage of which contains a water-based coolant. The method includes conducting thermal energy from the battery unit into the aluminum plastic film. The method also includes directing thermal energy from the aluminum plastic film directly into the water-based coolant (and/or the fins) to cool the battery cells. It can be found that compared with the battery water cooling mode in the prior art, the heat energy generated by the battery in the present invention is very small from the battery cell to the cooling water, and there is no contact thermal resistance between the solids, so the heat transfer efficiency very high.

Due to the above battery thermal control device, the heat exchange efficiency of the battery is very high, the heat transfer resistance between the battery body and the coolant is very low, and the heat transfer temperature difference is very small; therefore, the material in the battery body (such as electrolyte, The separator and the solid electrolyte interface film SEI) can allow the coolant to have a higher temperature without over-temperature, that is, reduce the external requirements of the battery cooling, and reduce the cooling cost, so that the above-mentioned gas-liquid heat exchanger can be used. Further, the above cooling system may further include an electric heater for heating the battery.

In the above-mentioned aluminum-plastic film which is resistant to the corrosion of the coolant and the soft-packed battery wrapped by the aluminum-plastic film, the aluminum foil layer is initially contacted as a contact layer with the cooling liquid, or is peeled off from the outer protective layer (such as a nylon film). After that, it is in contact with the coolant as a water contact layer.

The present invention provides another battery packaging material which is formed by compounding a metal foil and a thermoplastic resin film located inside the metal foil; or a composite of a thermoplastic resin film and a metal foil and a heat resistant resin film, the metal foil being located in the thermoplastic resin Between the film and the heat resistant resin film; wherein the metal foil is a single layer metal having corrosion resistance, or the metal foil comprises a core material and a skin material located outside the core material, and the corrosion potential of the metal material of the metal foil is lower than The corrosion potential of the core material. The metal foil is preferably an aluminum foil and/or a copper foil and/or a stainless steel foil. The thickness of the metal foil is preferably 20 to 50 microns, or 50 to 80 microns, or 80 to 150 microns, or 150 to 200 microns, or 200 to 300 microns. Preferably, the outer side of the metal foil does not contain a plastic film, that is, the plastic film is only composited on the inner side of the metal foil.

Alternatively, the inner side of the metal foil layer may further have an anti-corrosion treatment layer formed by chromate treatment or by rare earth oxide treatment.

From another point of view, the present invention also provides a soft pack battery solution, that is, a soft pack battery, which is packaged in an aluminum plastic film having the following resistance to coolant corrosion:

The corrosion resistance test method is: OY aqueous solution corrosion test;

The body of the soft pack battery was immersed in a cooling liquid having a corrosion resistance life of more than 500 hours in the above test.

Further, the corrosion-resistant life of the flexible battery body is greater than 1000 hours. Further, the soft pack battery body has a corrosion resistance life of more than 2000 hours.

Alternatively, the above corrosion resistance test method is an internal corrosion resistance test in the ASTM D2570 standard, or an outer package aluminum foil is evaluated using a method similar to the "internal corrosion performance test" in Section 5.14 of the QC/T468-2010 standard.

The OY water solution corrosion test referred to in the present invention is a general OY aqueous solution corrosion test in the heat exchanger aluminum heat transfer industry.

The method for manufacturing an aluminum plastic film according to the present invention comprises: first selecting a corresponding aluminum foil by the following aqueous solution corrosion test: the corrosion resistance test adopts an OY aqueous solution corrosion test method, and the corrosion resistance life of the aluminum foil under the corrosion test method is greater than 500 Hours; then the aluminum foil and the plastic film are composited to form an aluminum plastic film.

The corrosion-resistant life is preferably greater than 1000 hours. More preferably, it is more than 2000 hours. The aluminum foil may be selected from the above pure aluminum or aluminum alloy.

Conventional aluminum plastic films basically have no long-term hydrolysis resistance requirements and characteristics, or, in order to improve the resistance of water vapor hydrolysis in the outer layer of the aluminum plastic film, it is usually to improve the hydrolysis resistance of the outer plastic film, such as a fluorine-containing outer layer. Plastic protective film, but its cost, process and thermal efficiency are poor. One of the more preferable solutions of the present invention provides that the aluminum foil of the aluminum plastic film is only composited with a thermoplastic film on the inner side, that is, the outer side of the aluminum foil does not contain a heat-resistant plastic film or a protective film, and the aluminum foil is directly in contact with the cooling water. Heat exchange. The aluminum foil in the aluminum plastic film of the invention not only has the function of blocking water vapor and the like, but also has the function of long-term hydrolysis and corrosion resistance, and also has the functions of molding and packaging. One of the main inventive aspects of the present invention is the improvement of the aluminum foil in the aluminum plastic film compared to the existing aluminum plastic film and omitting the outer plastic layer, which has improved corrosion resistance by adopting different structures and/or components. Sexual and mechanical strength, so the outer side of the aluminum plastic film after omitting the outer plastic film still has good resistance to chemical medium corrosion, pinhole resistance and scratch resistance, and the process is simpler and lower cost when the aluminum When the plastic film is in contact with the cooling water, the heat exchange efficiency is higher; more importantly, the aluminum plastic film of the invention has a new function, that is, it has the function of long-term resistance to cooling water corrosion, so it can be immersed in cooling for a long time. The water does not fail, so as to better meet the thermal management requirements of the immersed water-cooled soft pack battery cooling system, which provides a reliable guarantee for the performance improvement of the battery system.

Another more preferred solution of the various technical solutions provided by the present invention is that the aluminum foil in the aluminum plastic film is made to have a layered corrosion of the aluminum foil by adopting a composite layer aluminum foil with different corrosion potential matching between the inner layers. Compared with the single-layer aluminum foil, the above-mentioned composite aluminum foil can better avoid the pitting perforation failure of the aluminum foil in the aluminum plastic film.

Different from other composite layer aluminum foils, the aluminum foil used in the invention is used for the outer packaging of the soft-packed battery, and needs to take into consideration both the deformation property and the resistance to cooling water corrosion. One of the more preferable schemes is to use a pure aluminum core material and a pure aluminum base. The composite of zinc leather material not only has excellent resistance to cooling water pitting, but also has good formability and packageability.

The aluminum plastic film provided by the invention can also be a technical solution formed by the combination of the above technical features, and has a new function compared with the conventional aluminum plastic film, and can be used for the packaging of the soft pack battery which is in direct contact with the cooling water for a long time. It has the advantages of resistance to cooling water corrosion and long service life.

In addition, the immersion water cooling of the present invention has a very outstanding technical effect compared to the immersion insulating oil cooling in the prior art.

As shown in the table below, for the comparative analysis of several coolants, whether it is thermal conductivity or fluidity, the performance of insulating coolant such as transformer oil or silicone oil is much worse than antifreeze or water.

Compared with insulating oil, by using antifreeze or water as the immersion cooling medium, the heat dissipation capacity of the battery can be significantly improved. In the case of the same cooling system, the heat dissipation capacity can be increased by 15 to 20 times. The specific performance of the battery is further increased by 5 to 10 degrees Celsius, and the temperature difference between the battery cells is further reduced to 1.0 to 2.0 degrees Celsius. In the current situation where the battery thermal management bottleneck problem is still very prominent, this technical effect is very much expected in the field, and the above-mentioned heat dissipation effect cannot be achieved by indirect water cooling or immersion oil cooling.

Although the invention is based on the motivation of obtaining a more efficient soft pack battery cooling performance, the technical solution provided by the invention not only obtains excellent cooling performance, but also further solves the mechanical strength and resistance of the battery cooling system. Many technical problems such as corrosion durability, manufacturing process and cost have achieved good technical results.

DRAWINGS

Figure 1 is a schematic view showing the structure of a first aluminum plastic film;

2 is a schematic view showing the structure of a second aluminum plastic film;

3 is a schematic view showing the application of a battery using the aluminum plastic film of the present invention;

Figure 4 is a schematic diagram of a soft pack battery;

Figure 5 is a schematic diagram of a thermal control device for a soft pack battery;

Figure 6 is a schematic view showing the structure of a third type of aluminum plastic film;

Figure 7 is a comparison diagram of the corrosion resistance of a single-layer aluminum alloy (left) and a composite aluminum alloy (right);

The fin spacer shown in FIG. 8 is a staggered serrated fin, and includes a plurality of tooth-shaped units. The inner rows of the same-toothed unit are connected to form a fluid passage, and adjacent tooth-shaped units are alternately arranged in a front-back direction, and the tooth-shaped unit is The top and bottom planes are in direct contact with the battery.

The fin spacer shown in FIG. 9 is a flat fin, and includes upper and lower flat plates connected to the parallel vertical plate and the both ends of the vertical plate. The flat plate is in direct contact with the battery, and a fluid passage is formed between the vertical plates.

detailed description

The invention is further described below in conjunction with specific examples, including but not limited to the scope of the invention.

Example 1

1 shows an aluminum plastic film comprising an aluminum foil layer 1 and

plastic layers

2, 3 laminated on both sides of the aluminum foil layer, wherein the aluminum foil layer 1 is composed of a 3 series aluminum alloy aluminum foil layer 7 (core The material is combined with a 7-series aluminum alloy aluminum foil layer 6 (skin material). If the 3003 aluminum alloy is combined with the 7072 aluminum alloy, the 7072 aluminum alloy layer 6 is composited on the outer side of the 3003 aluminum alloy layer 7. Alternatively, the aluminum plastic film is formed by laminating a heat seal layer, a 3003 aluminum foil layer, a 7072 aluminum foil layer, and a nylon layer, wherein the aluminum foil layer and the plastic layer are bonded by a conventional adhesive. In other words, the aluminum plastic film from the inside to the outside is: heat seal layer, adhesive layer, 3003 aluminum foil core layer, 7072 aluminum foil skin layer, adhesive layer, nylon protective layer.

The corrosion potential of 3003 aluminum alloy is about -0.72V, and the corrosion potential of 7072 aluminum alloy is about -0.88V. Since the corrosion potential of the 7072 aluminum alloy is lower than the corrosion potential of the 3003 aluminum alloy, when contacted with the coolant, the 7072 aluminum alloy acts as a sacrificial anode, protecting the core material from corrosion. The thickness of the heat seal layer is preferably 80-100 micrometers, the thickness of the nylon protective layer is preferably 20-30 micrometers, and the thickness of the composite aluminum foil layer is preferably 200-300 micrometers; wherein the thickness of the 7-series aluminum alloy layer 6 preferably accounts for the entire aluminum foil layer. 10% of 1%. Similarly, the inner and outer

plastic layers

2, 3 and the aluminum foil layer 1 are bonded and bonded by the

adhesives

4, 5, respectively.

Further, the heat treatment state of the aluminum foil layer may be an O state, an H14 state, or an H16 state, and among them, an O state is preferable.

The aluminum foil layer of the embodiment is thicker than the aluminum foil layer in the conventional aluminum plastic film, which is beneficial to the long-term anti-freezing liquid corrosion resistance and the water vapor barrier property of the aluminum plastic film, thereby ensuring the long-term reliability of the soft-pack battery packaging. .

Example 2

This embodiment is substantially similar to the structure of Embodiment 1, and the aluminum alloy layer 1 is also formed by the composite of the core material 7 and the skin material 6, and the leather material 6 It is an anode protective layer. The difference was that the 7072 aluminum alloy was replaced with zinc Zn-added 3003 aluminum alloy (3003 + 1% Zn or 3003 + 1.5% Zn as shown below) as the sacrificial anode layer. The potential of 3003+1% Zn is approximately -0.83V to -0.89V, and its potential is lower than the potential of the 3003 core material.

Table 1 alloy chemical composition

Example 3

2 is a second aluminum plastic film comprising an aluminum foil layer 1 and a thermoplastic resin film layer 3 laminated on the inner side of the aluminum foil layer, wherein the aluminum foil layer is a composite layer aluminum foil, the aluminum foil layer comprises a core material and The skin material located on the outer side of the core material has a corrosion potential lower than that of the core material. Further, the core material of the aluminum foil layer is formed of a corrosion-resistant aluminum alloy or pure aluminum. For example, the composite aluminum foil layer 1 is formed by a composite of a 3 series aluminum foil layer 7 (such as 3003) and a 7 series aluminum foil layer 6 (such as 7072). The aluminum foil layer 1 is only internally laminated with a thermoplastic resin film layer 3 (also referred to as a heat seal layer 3, such as CPP), without the need for an outer nylon protective layer. Compared with the aluminum plastic film with the outer plastic protective film in the prior art, the aluminum plastic film of the invention has the characteristics of good mechanical strength, moisture barrier property and electrolyte resistance after boldly omitting the outer plastic protective film. Moreover, it also has long-term external hydrolysis resistance, and also simplifies the composite process of aluminum plastic film and saves production process cost and raw material cost.

The thickness of the heat seal layer 3 (CPP) is preferably 30 to 50 μm, and the thickness of the entire composite aluminum foil layer 1 is preferably 200 μm. Among them, the 7-series aluminum alloy layer 6 is composited on the outer side as a sacrificial anode; the thickness of the 7-series aluminum alloy preferably accounts for 10% of the entire aluminum foil layer 1. When used as a soft pack battery pack and the battery is immersed in cooling water, the 7-series aluminum alloy acts as a water-repellent layer. Similarly, the inner thermoplastic resin film layer 3 and the aluminum foil layer 1 are bonded and bonded by an adhesive 5 which is commonly used for an aluminum plastic film. The soft pack battery made of the aluminum plastic film provided above can be immersed in the coolant for a long time, and has long-term resistance to coolant corrosion.

Example 4

This embodiment is substantially similar to the structure of Embodiment 3. The core material layer is also made of 3003 aluminum alloy, except that the skin material 6 is replaced by a metal zinc (Zn) layer instead of the 7-type aluminum foil layer, and the thickness of the metal zinc layer may preferably be 10 -20 microns can be formed by a zinc spray process. The potential of the metal zinc is lower than the potential of the aluminum alloy core material, so that the core material can be used as a sacrificial anode to prevent corrosion. And metal zinc can effectively prevent pitting of aluminum alloy core material.

Example 5

This embodiment describes a battery using the above aluminum plastic film and an application form of the battery. Providing a soft pack battery comprising an electrode material and a polymer electrolyte and an aluminum plastic film for outer wrapping, wherein the soft pack battery is wrapped with an aluminum plastic film comprising a composite layer aluminum foil having a sacrificial anode function, as in the embodiment 1 or The composite layer aluminum alloy aluminum foil in 3, that is, the aluminum foil is made of 3003 aluminum alloy core material and is externally compounded with 7072 aluminum alloy leather material. After the soft pack battery is packaged with the above-mentioned anti-freeze coolant immersed and etched aluminum plastic film, the soft pack battery can be immersed in the antifreeze coolant, so that the heat can be directly exchanged with the antifreeze coolant. As shown in FIG. 3, after the soft pack battery 11 is sealed to the main board 13 by the top edge 112, the body of the soft pack battery 11 is immersed in the antifreeze coolant. In this way, the heat exchange effect of the battery is better, and the temperature of the battery is more uniform around the upper and lower sides.

Example 6

This embodiment employs an aluminum plastic film structure similar to that of Embodiment 1, except that the adhesive for bonding the nylon protective layer is a release agent which is easy to separate. That is, the nylon protective layer is similar to the release film. Thus, in the deep drawing process of the aluminum plastic film, the nylon layer can protect the aluminum foil layer; after the deep drawing is completed, the nylon layer can be easily separated from the aluminum foil layer to form an aluminum plastic film similar to that in the embodiment 3.

Example 7

The aluminum plastic film described in this embodiment is formed by a composite of a thermoplastic resin film (i.e., a heat seal layer such as polypropylene) and a composite layer aluminum alloy aluminum foil. The core layer 7 of the aluminum foil layer is made of pure aluminum having a grade of 1050, and the skin material 6 is formed of an aluminum alloy containing 4% to 7% of zinc element based on pure aluminum 1050 (simplified as AA1050 + 4-7% Zn). The corrosion potential of the leather material is negative to the core material, and the leather material is used as the sacrificial anode protection core material, and the skin material recombination ratio is preferably 10±2%. The heat-treated state of the composite aluminum alloy aluminum foil layer is an annealed state (O state), and the thickness is preferably from 100 to 300 μm, more preferably from 100 to 200 μm. Compared with the conventional composite layer aluminum alloy, the above composite aluminum foil layer with pure aluminum as the core material has excellent resistance to coolant corrosion and good ductility and deep drawing performance.

The aluminum plastic film or the aluminum foil thereof is required to have good ductility and deep drawing properties, for example, the GB/T 4156-2007 "metal material sheet and thin strip Eriksson cupping test" standard test, the aluminum plastic film or The cup diameter of the aluminum foil is preferably greater than 5 mm, more preferably greater than 10 mm.

The aluminum plastic film or its aluminum foil is required to have good resistance to coolant corrosion. The corrosion resistance test method uses an OY water solution (Oyama Water Solution) corrosion test. The OY aqueous solution corrosion test is as follows:

OY aqueous solution components: chloride ion (Cl ^- ): 195 ± 1 mg / liter, sulfate ion (SO ₄ ^2- ): 60 ± 0.2 mg / liter, iron ion (Fe ^{3 +} ): 30 ± 0.1 mg / liter , copper ion (Cu ²⁺ ): 1 ± 0.01 mg / liter. The pH of the aqueous OY solution was about 3 (the pH of the aqueous solution in the OY test described in the present invention was about 3) unless otherwise specified.

OY aqueous solution temperature: 88 ° C, stirred at a rate of 0.6-0.9 m / s (200 rpm) for 8 hours, and then allowed to stand for 16 hours; the above cycle was repeated.

In the above OY aqueous solution corrosion test, any perforations of 5 mm near the edge of the aluminum foil were ignored. When corrosion perforation occurs at any point other than the edge of 5 mm in the aluminum foil, the accumulated corrosion test time is the corrosion-resistant life of the aluminum-plastic film aluminum foil in the OY aqueous solution. Experiments have shown that the corrosion resistance life of the aluminum foil of the embodiment of the invention is greater than 1000 hours.

Above, the corrosion-resistant life of the aluminum plastic film or its aluminum foil can also be evaluated by the corrosion-resistant service life of the aluminum plastic film or the aluminum foil immersed in the antifreeze on the actual vehicle, for example, the aluminum plastic film having a service life of more than 5 years on the actual vehicle is selected. It is preferably greater than 10 years, more preferably greater than 15 years.

Example 8

As shown in FIG. 4 and FIG. 5, the battery thermal control device introduced in this embodiment adopts the above soft pack battery which can be directly immersed in a coolant (such as a coolant mainly composed of ethylene glycol and water). The soft pack battery thermal control device comprises a soft pack battery 11 and a water-based coolant, and the outer package of the soft pack battery 11 is in direct contact with the cooling liquid, and the soft pack battery 11 is made of any one of the above-mentioned anti-cooling liquids. Corroded packaging materials (such as aluminum-plastic films that are resistant to water-based coolants) are formed. The thermal control device further includes a spacer 12, which is preferably a staggered serrated fin spacer as shown in FIG. 8 or a straight fin spacer as shown in FIG. 9; at least part of the surface of the spacer 12 At least part of the outer surface of the soft pack battery 11 is in direct contact, and a fluid passage 121 is disposed in the partition 12, and the fluid passage 121 is in direct contact with the battery 11, and the cooling water in the fluid passage 121 is in direct contact with the battery 11 to exchange heat; The soft pack battery 11 constitutes a battery unit (of course, two soft pack batteries can also be used to form one battery unit), and the battery unit is spaced apart from the partition plate 12. The baffle serves to support the soft pack battery on the one hand and to organize the flow field of the coolant on the other hand.

The aluminum plastic film seals the battery core, and only the battery electrode or the electrode connection port protrudes from the aluminum plastic film; the battery thermal control device further includes a main board 13, and the main board 13 is provided with a socket. The portion of the battery that protrudes from the aluminum plastic film (i.e., the positive and negative electrode tabs 111) is inserted into the main board 13 through the socket. Preferably, a portion of the top edge 112 of the battery is also inserted into the main board 13 through the socket.

The battery thermal control device further includes an outer casing 14 having a receiving chamber therein, and a plurality of the battery cells and the partition 12 are tightly integrated into the receiving chamber of the outer casing 14, the outer casing Body 14 also includes a fluid inlet and a fluid outlet (not shown).

The main board 13 is located in the accommodating chamber of the outer casing 14, and divides the accommodating chamber into two parts, the first part accommodating the battery unit main body and the partition 12, and the second part is accommodated from the aluminum plastic film The extended electrode and/or electrode is connected to the port portion, the first portion and the second portion being physically isolated.

The battery thermal control device further includes a coolant, which is water, or a mixture containing ethylene glycol and water, or a mixture containing propylene glycol and water, or an antifreeze coolant.

Preferably, the separator 12 is made of a metal material; more preferably, the corrosion potential of the separator 12 is lower than the corrosion potential of the aluminum foil in the aluminum plastic film, for example, the metal foil of the packaging material is selected from AA1050 aluminum alloy, and the separator 12 is selected from AA1050+5%. Zn. Alternatively, the corrosion potential of the separator 12 is negative to the corrosion potential of the aluminum foil of the aluminum plastic film. For example, the metal foil of the packaging material is selected from the composite material AA1050/AA1050+5% Zn aluminum alloy, and the separator 12 is selected from AA1050+7% Zn. Such a separator can also serve as an anodic protection to further prevent battery corrosion failure.

Example 9

The core material and the skin material of the composite layer aluminum alloy may be selected from the following items 1 to 4 of Table 2:

Table 2

With the method of Example 7, the corrosion resistance life of the aluminum foil of this embodiment is greater than 1000 hours, even greater than 1500 or 2000 hours.

Example 10

The embodiment provides an aluminum plastic film comprising an aluminum foil layer and a plastic layer composited on the surface of the aluminum foil layer; the aluminum foil layer is a composite layer aluminum foil, and the aluminum foil layer comprises a core material and a leather material located outside the core material. The corrosion potential of the aluminum foil layer is lower than the corrosion potential of the core material; wherein the leather material located outside the core material is formed by two layers of leather material or more than two layers of multilayer leather material, and the corrosion potential is sequentially decreased from the inside to the outside. .

For example, the aluminum foil layer in the aluminum plastic film is the core material, the first layer of the skin material, and the second layer of the skin material from the inside to the outside, the core material is AA1050 aluminum alloy, and the first layer of the skin material is AA1050 plus 2% Zn. Aluminum alloy, the second layer of leather is AA1050 based on 4% Zn aluminum alloy. Therefore, the corrosion potential is: core material > first layer of skin material > second layer of skin material. This can further ensure that the corrosion is layered corrosion of layer-by-layer corrosion, thereby further avoiding spot corrosion and ensuring battery safety.

Example 11

This embodiment provides a corrosion resistance test of another soft-package battery outer package aluminum-plastic film aluminum foil, that is, a test method for anti-freeze liquid corrosion of a soft-pack battery. This test method is used to evaluate and determine the anti-freeze corrosion life of the product.

Soak a plurality of bodies of the same soft pack battery in the following mixed solution. The positive and negative electrodes of the soft pack battery are vertically upward, and the immersion height of the mixed solution is flush with the lower edge of the top edge of the soft pack battery.

Mixing solution components: consisting of a 40% by volume antifreeze solution and a 60% ASTM solution. The antifreeze model is 45% ethylene glycol antifreeze, the freezing temperature is minus 30 degrees Celsius; the ASTM solution is configured by 1 liter of distilled water and 148 mg of sodium sulfate, 165 mg of sodium chloride and 138 mg of sodium hydrogencarbonate.

Mixed solution temperature: 90 ± 2 degrees Celsius. The mixed solution flowed in a horizontal direction parallel to the largest surface of the battery body, and the flow rate through the surface of the battery body was 0.5 m/s.

The test was run for 76 hours at the above temperature and flow rate, and was stopped for 8 hours for one cycle. The pH value of the solution was checked and replenished during the shutdown. The solution was divided into pH value and visual inspection. No pH above ±1 was allowed during the test. The value changes, the appearance of the solution does not allow turbidity and precipitation.

The corrosion depth of the aluminum foil of the battery pack can be checked at any time during the test. If the maximum value of the corrosion depth values of all corrosion points is greater than 10% of the original thickness value of the aluminum foil, the test time accumulated at the time when the maximum corrosion depth value reaches 10% of the original thickness value of the aluminum foil is defined as the battery outer packaging aluminum plastic. The corrosion-resistant life of the film aluminum foil is also the anti-freeze corrosion life of the soft-pack battery. Therefore, the so-called life in the test method of this embodiment is the test time accumulated to achieve the above corrosion depth value.

In the above tests, the above descriptions of the present invention shall prevail in different places, and other places may refer to the Chinese automobile industry standard QC/T468-2010. It should be noted that the aluminum-plastic film of the soft pack battery outer packaging of the present invention is preferably an aluminum plastic film formed by laminating an aluminum foil and a thermoplastic resin film located inside the aluminum foil, and the outer side of the aluminum foil has no other plastic layer, so the aluminum foil starts with the antifreeze liquid. direct contact. However, the soft plastic battery outer packaging aluminum plastic film of the present invention may be (not preferred) an aluminum plastic film formed by laminating an aluminum foil and a thermoplastic resin film laminated on the inner side of the aluminum foil and a heat resistant resin film laminated on the outer side of the aluminum foil. Since a usual heat resistant resin film (such as PA or PET) is easily swelled and peeled off by the antifreeze solution, the heat resistant resin film outside the aluminum plastic film is peeled off before the above corrosion resistance life test is performed in order to unify the test standard. Then, the above corrosion test is performed.

In order to facilitate the brief description, the present invention defines the corrosion resistance test of the above-mentioned soft-package battery outer packaging aluminum-plastic film aluminum foil as "specific anti-freeze corrosion life test of soft-package battery" or "anti-freeze corrosion of ZPC soft-package battery" Life test".

In order to meet the automotive requirements for the durability of the parts, soft pack batteries having a lifetime value greater than 336 hours in the antifreeze corrosion life test of the particular soft pack battery were selected. Since the power battery is very demanding for safety, it is preferably a soft pack battery of more than 500 hours, more preferably a soft pack battery of more than 1000 hours; further preferably a soft pack battery of preferably more than 2000 hours; further preferably a soft pack of preferably more than 5000 hours Pack the battery.

Another assessment method is provided as follows. In the above-mentioned "specific anti-freeze corrosion life test of soft-package batteries", the test time is fixed at 14 days (ie, 336 hours), and the pitting depth is examined everywhere, and the maximum pitting depth is included. Requires less than the original thickness of aluminum foil 50% of the degree; preferably less than 20%, more preferably less than 10%; further preferably less than 8%; still more preferably less than 5%. In other words, the maximum pitting depth is 20% to 50% of the original thickness value of the aluminum foil, or is greater than 10% and less than 20%, or greater than 0% and less than 10%.

If it is desired to have the above corrosion resistance, the aluminum foil in the aluminum plastic film needs to have a suitable structure and/or a suitable material composition and/or a suitable thickness.

The aluminum foil material satisfying the above requirements for resistance to coolant corrosion can be selected from a single layer of a 1 series aluminum alloy (pure aluminum) or a composite layer aluminum alloy having a sacrificial anode protection function.

The thickness of the aluminum foil that satisfies the above requirements for resistance to coolant corrosion can be selected from the following thicknesses: 120-300 microns.

For example, pure aluminum AA1050 with a thickness greater than 150 microns, or a composite aluminum alloy formed by a combination of AA1050 with a thickness of 100 microns and AA7072 with a thickness of 20 microns (ie, a total thickness of the composite aluminum alloy of 120 microns), the above two aluminum foils are used to manufacture aluminum. Plastic film and soft pack batteries can meet the above-mentioned anti-freeze corrosion life requirements, thus meeting the automotive life requirements.

Example 12

This embodiment describes an aluminum plastic film whose aluminum foil is formed by compounding a core material and an outer skin material, wherein the core material is formed of an 8-series aluminum alloy (such as 8079 or 8021) of 100 micrometers to 300 micrometers, and the outer skin material is made of 8 series aluminum. The alloy is formed by adding 2% to 6% by mass of zinc element (as described in Table 3 below), and the compounding ratio is preferably 10% to 20%. The aluminum plastic film containing such a composite aluminum alloy has good corrosion resistance and deep drawability, and is tested according to the method of Example 7, and has a corrosion resistance life of more than 1300 hours.

table 3

Example 13

This embodiment describes an aluminum plastic film in which an aluminum foil is formed by compounding a core material and an outer skin material, wherein the core material is formed of a 1 series aluminum alloy (such as 1050) of 100 micrometers to 300 micrometers, and the outer skin material is composed of a 1 series aluminum alloy foundation. The addition of 2% to 6% by mass of zinc element was formed (as described in Table 4), and the recombination rate was 10% to 20%.

Example 14

The core material is formed by a 1 series aluminum alloy (such as 1050) of 100 micrometers to 300 micrometers, and the outer skin material is formed by adding 2% to 6% by mass of zinc element on the basis of the 1 series aluminum alloy (as shown in Table 4). ). The aluminum plastic film containing the composite aluminum alloy has good electrolyte corrosion resistance and good resistance to cooling water corrosion; and the corrosion resistance life is more than 1800 hours according to the method of Example 7.

Table 4

Example 15

An aluminum plastic film is provided, the aluminum plastic film comprising an aluminum foil layer and a plastic layer composited on the surface of the aluminum foil layer, wherein the aluminum foil layer material is a 3003 aluminum alloy.

Referring to FIG. 6, the aluminum plastic film is composed of an outer layer protective layer 2, an aluminum foil layer 1, and an inner layer heat sealing layer 3 from the outside to the inside, and the outer layer protective layer 2 is made of nylon (ON) and the inner layer heat sealing layer 3 is used for flow. The polypropylene film (CPP), which also acts as an insulating layer, also maintains electrical insulation between the aluminum foil layer 1 and the internal electrolyte. The outer protective layer 2, the inner layer heat seal layer 3 and the aluminum foil layer 1 are bonded and bonded by an adhesive (or an adhesive) 4, 5, respectively. The outer protective layer 2 serves to protect the aluminum foil layer 1 during the deep drawing process. The adhesive layer is composed of any one of the following resins: a polyester-urethane resin, a polyether-urethane resin, an isocyanate resin, and an unsaturated carboxylic acid graft polyolefin resin.

Above, the aluminum foil layer 1 can also be replaced by other rust-proof aluminum, such as 5 series rust-proof aluminum or other 3 series rust-proof aluminum, more specifically, such as: 3004, 3005, 3105, 5052, 5086, etc.; aluminum foil layer 1 can also Replace with 6 series aluminum alloy, such as 6063. Of course, the aluminum foil layer may also be pure aluminum, pure aluminum is 1050 aluminum alloy, or 1060 aluminum alloy, or 1100 aluminum alloy, or a modified type based on the above pure aluminum basic type. These pure aluminum also have good corrosion resistance.

The soft pack battery formed by the aluminum plastic film can be directly immersed in the cooling liquid and has a long-term resistance to coolant corrosion, wherein the coolant is preferably a water-based coolant containing ethylene glycol or/and propylene glycol. In the process of forming the soft pack battery, a deep drawing process is required, and the outer protective layer 2 provides protection for the aluminum foil layer 1 in this deep drawing process. After the soft pack battery is immersed in the coolant for a period of time, the nylon layer 2 may swell and dissolve, but this does not affect the insulation, sealing properties and long-term resistance to coolant corrosion of the aluminum plastic film. Since the aluminum-plastic film of the soft pack battery has long-term resistance to coolant corrosion, the soft pack battery can be directly immersed in the coolant for cooling. The beneficial effect of this is that the heat exchange efficiency of the soft pack battery is high, and it does not overheat even when working at a high current, which can improve the power density and reliability of the entire battery system.

Compared with the 8 series aluminum alloy, the 3 or 5 series rust-proof aluminum has better anti-freeze corrosion resistance, and its corrosion resistance life is longer and more reliable.

Example 16

This embodiment describes a soft-package polymer lithium ion battery coated with the aluminum plastic film described in Embodiment 15, which is substantially the same as Embodiment 5 except that the aluminum plastic used for packaging the soft pack battery is used. The aluminum foil in the film is formed of a single-layer aluminum alloy which is formed of a rust-proof aluminum foil, such as a 3003 aluminum foil.

Example 17

This embodiment describes a soft-package polymer lithium ion battery coated with the aluminum plastic film described in Embodiment 15, which is substantially the same as Embodiment 5 except that the aluminum plastic used for packaging the soft pack battery is used. The aluminum foil in the film is formed from a single layer of aluminum alloy formed of a 1 series aluminum alloy foil, such as an O-state 1050 aluminum alloy aluminum foil or other pure aluminum.

Example 18

This embodiment describes an aluminum plastic film in which an aluminum foil is formed by a composite of a core material and an outer skin material, wherein the core material is formed of an 8-series aluminum alloy (such as 8079 or 8021) of 150 micrometers to 300 micrometers, and the outer skin material is a 7-series aluminum. Alloy (such as 7072) or aluminum-zinc alloy, the compounding rate is 2%-20% or 20%-50%. Further, after the 8 series and the 7 series are combined, heating or annealing treatment is performed to form a step potential change by appropriate diffusion of the Zn element. The aluminum plastic film containing such a composite aluminum alloy has good corrosion resistance and deep drawability, and is tested according to the method of Example 7, and has a corrosion resistance life of more than 1500 hours.

Example 19

This embodiment describes an aluminum plastic film which is bonded from the inside to the outside by a thermoplastic film (e.g., CPP), an aluminum foil layer, and a Teflon film. Since the Teflon film has good water and corrosion resistance, the soft pack battery made of the aluminum plastic film can be immersed in water or antifreeze for a long time.

Example 20

Reference can be made to Example 7, but the pH of the aqueous OY solution selected in this example is about 11. This example is the same as Example 7 except that the pH of the OY aqueous solution is different from that of Example 7. In this embodiment, an aluminum foil having a corrosion resistance of more than 1000 hours is used for the aluminum plastic film for the battery packaging material.

Example 21

In this embodiment, a single layer of 1050 aluminum alloy and a composite layer of aluminum alloy (the core material is 1050 aluminum alloy, and the skin material is a sacrificial layer with a negative potential) is subjected to a corrosion resistance comparison test in the OY experiment.

The antifreeze system was selected for the OY experiment. The experiment time was 4 weeks. After the experiment, the surface of the material was immersed in nitric acid to remove the corrosion products. The details are as follows:

As shown in Fig. 7, after 4 weeks of the OY test of the antifreeze system, the left figure shows that the AA1050 single-layer aluminum alloy has obvious pitting corrosion, and the pitting corrosion is more serious; while the right figure shows the aluminum of the composite sacrificial layer. No significant pitting occurred on the alloy surface. From this, it is understood that the occurrence of pitting corrosion can be effectively suppressed by compounding a skin material having a relatively negative corrosion potential on the surface of the aluminum alloy core material. After the heat sealing of the inner surface of the aluminum plastic film formed by the above-mentioned composite aluminum foil, the time of corrosion resistance of the aluminum foil against the cooling water can meet the requirements of the automobile; and since the inner core of the aluminum foil is pure aluminum, the electrolyte corrosion resistance is superior to the conventional one. The aluminum-iron alloy ensures the battery's longevity and safe use.

Example 22

The embodiment provides a soft pack battery thermal control device, which comprises a soft pack battery, fins of a metal material (such as serrated fins), and a water-based coolant. At least a portion of the surface of the fin is in direct contact with at least a portion of the outer surface of the soft pack battery. A plurality of soft pack batteries form a battery unit, the battery unit is spaced apart from the fins, the fins support the soft pack battery and the tissue flow field and form a fluid passage; the water-based coolant flows in the fluid passage, the water-based coolant and The soft pack battery is in direct contact with heat transfer. The soft pack battery is packaged by an aluminum plastic film formed by a composite of a thermoplastic resin film located on the inner side and an aluminum foil layer on the outer side, and the composite method may be a thermal composite or a dry composite by an adhesive. The aluminum foil layer is in direct contact with the water-based coolant for heat exchange. Wherein, the aluminum foil layer comprises a core material and a skin material located outside the core material, and the core material of the aluminum foil layer is a 1 series aluminum alloy (such as AA1050 or AA1060) or an 8 series aluminum alloy (such as AA8021 or AA8079), and an aluminum foil layer. The leather material is aluminum-zinc-aluminum alloy (such as AA7072), or the aluminum foil layer is formed by adding 1%-10% by mass of zinc element on the basis of 1 series aluminum alloy or 3 series aluminum alloy or 8 series aluminum alloy, or aluminum foil. The skin material of the layer is an aluminum alloy containing 1% to 10% by mass of zinc. The aluminum foil in the above aluminum plastic film not only has the function of blocking water vapor, but also has long-term hydrolysis and corrosion resistance, and has higher mechanical strength without the protection of the outer nylon layer, and also has good moldability and packaging effect.

Compared with the insulating oil immersion cooling as described in CN202550023U, the heat dissipation capability of the battery cooling system using antifreeze or water as the immersion cooling medium can be significantly improved. In the case of the same cooling system, the heat dissipation capacity can be increased by 15 to 20 times. The specific performance of the battery is further increased by 5 to 10 degrees Celsius, and the temperature difference between the battery cells is further reduced to 1.0 to 2.0 degrees Celsius. In the current situation where the battery thermal management bottleneck problem is still very prominent, this technical effect is very much expected in the field, and the above-mentioned heat dissipation effect cannot be achieved by indirect water cooling or immersion oil cooling.

The specific embodiments of the present invention have been described in detail above, but are merely exemplary, and the invention is not limited to the specific embodiments described above. Any equivalent modifications and substitutions to the invention are also within the scope of the invention. Accordingly, equivalents and modifications may be made without departing from the spirit and scope of the invention.

Claims

A soft pack battery thermal control device comprising a soft pack battery and a fin of a metal material;

At least part of the surface of the fin is in direct contact with at least part of the outer surface of the soft pack battery, and a fluid passage is disposed in the fin; a plurality of soft pack batteries form a battery unit, and the battery unit is spaced apart from the fin, The fin supports the soft pack battery and the tissue flow field; when the soft pack battery thermal control device has a water-based coolant, the water-based coolant flows in the fluid passage, and the water-based coolant directly contacts the soft pack battery to exchange heat;

The soft pack battery is packaged by an aluminum plastic film formed by a composite of a thermoplastic resin film located inside and an aluminum foil layer located outside; when the soft pack battery thermal control device has a water-based coolant, the aluminum foil The layer is in direct contact with the water-based coolant for heat exchange;

Wherein, the aluminum foil layer comprises a core material and a skin material located outside the core material, the core material of the aluminum foil layer is a 1 series aluminum alloy or an 8 series aluminum alloy, and the aluminum foil layer has a skin material of 1%-10% by mass. Aluminum alloy with zinc.
A soft pack battery thermal control device according to claim 1 wherein:

The core material is an aluminum alloy containing the following components (mass percentage): Si ≤ 0.25 wt%; Cu ≤ 0.05 wt%; Mg ≤ 0.05 wt%; Zn ≤ 0.05 wt%; Mn ≤ 0.05 wt%; Ti ≤ 0.03 Wt%; V ≤ 0.05 wt%; Fe ≤ 0.4 wt%; the balance is aluminum;

Or; the core material is an aluminum alloy containing the following components (mass percentage): Si ≤ 0.25 wt%; Cu ≤ 0.05 wt%; Mg ≤ 0.05 wt%; Zn ≤ 0.05 wt%; Mn ≤ 0.05 wt%; Ti ≤0.03wt%; V≤0.05wt%; Fe≤0.4wt%; Sm 0.1-0.3wt%; the balance is aluminum;

The skin material is an aluminum zinc aluminum alloy containing the following components (mass percentage): Zn 4-7 wt%; Si 0.5-1.0 wt%; Ti 0.1-0.2 wt%; Fe 0.5-1.5 wt%;

Alternatively, the skin material is an aluminum zinc aluminum alloy containing the following components (mass percentage): Zn 4-7 wt%; Si 0.5-1.0 wt%; Ti 0.1-0.2 wt%; Fe 0.5-1.5 wt%; Sm 0.1-0.3 wt%.
A method of cooling a battery unit using the soft pack battery thermal control device of claim 1, wherein the fluid passage of the thermal control device contains a water-based coolant, the method comprising:

Conducting thermal energy from the battery unit into the aluminum plastic film;

Thermal energy is conducted directly from the aluminum plastic film into a water-based coolant to cool the battery cells.