A battery model and test system for battery thermal management experimental testing

Abstract

The present application provides a battery model and test system for battery thermal management experimental testing, the battery model includes: a battery frame; two battery covers, the battery covers are respectively covered on both sides of the battery frame; at least four first material plates, the thermal conductivity of the first material plates is greater than the thermal conductivity of the actual battery thickness direction; the first material plates are attached and assembled with the battery covers; at least two second material plates, the thermal conductivity of the second material plates is less than the thermal conductivity of the actual battery thickness direction; the second material plates are alternately assembled with the first material plates; an electric heating plate, both sides of the electric heating plate are attached and assembled with the first material plate. This scheme uses two different isotropic materials with thermal conductivities greater than and less than the thermal conductivity in the battery thickness direction, respectively, and then alternately assembles the two materials, and arranges the electric heating plate in the middle, so that the overall battery model is an anisotropic material, so as to achieve the effect of simulating the heat generation of a real battery.

Description

Technical Field

[0001] The present invention belongs to the technical field of batteries and battery thermal management, and in particular relates to a battery model and a test system for battery thermal management experimental testing. Background Art

[0002] In recent years, due to energy shortage and serious environmental pollution, the vigorous development of new energy vehicles has been promoted. With the successful advent of lithium-ion batteries, the development of electric vehicles has also ushered in glory. Lithium-ion batteries are widely used for their high energy density, long cycle life, and low self-discharge rate. However, in order to improve the endurance of the car, power performance and the development of fast charging, the power battery must often be in a high-rate charge and discharge state, resulting in a large amount of heat generated by the battery. If the heat cannot be effectively dissipated, it will damage the performance of the battery and reduce the service life of the battery. In severe cases, thermal runaway may occur, and there is a risk of spontaneous combustion and explosion. Therefore, there have been a lot of studies on the thermal management of power batteries.

[0003] At present, there are two experimental devices for battery thermal management testing. One is to use real batteries and supporting charging and discharging equipment to test the heat generation of batteries and the temperature rise and temperature difference of monomers and modules during the battery charging and discharging process; the other is to directly use aluminum blocks plus electric heating rods and electric heating plates to replace the heat generation process of batteries. Both have their own advantages and disadvantages. The use of real batteries for experiments has accurate experimental data, high precision, and simple experimental operation, but its disadvantages are also obvious. It requires corresponding equipment. Secondly, when large-capacity batteries are charged and discharged at high rates, the discharge current is too large, which may reach hundreds of amperes, so there are greater safety hazards. The use of aluminum blocks avoids expensive charging and discharging equipment, and only a small current is needed to obtain the same amount of heat, with high safety performance, but the power needs to be calibrated in advance; and the actual battery is anisotropic material, especially the thermal conductivity. The thermal conductivity in the thickness direction and the other two directions differs by an order of magnitude, while aluminum blocks, as isotropic materials, cannot do this. Summary of the invention

[0004] The purpose of the embodiments of this specification is to provide a battery model and test system for battery thermal management experimental testing, aiming to solve the problem of thermal management experiments when there are no real batteries and charging and discharging equipment, and the current use of aluminum blocks and electric heating rods cannot simulate the most realistic battery heat generation process.

[0005] To solve the above technical problems, the embodiments of the present application are implemented in the following ways:

[0006] In a first aspect, the present application provides a battery model for battery thermal management experimental testing, the battery model comprising:

[0007] Battery frame;

[0008] Two battery covers, which are respectively arranged on two sides of the battery frame;

[0009] At least four first material plates, the thermal conductivity of the first material plates being greater than the thermal conductivity of the actual battery in the thickness direction; the first material plates being attached and assembled to the battery cover plate;

[0010] At least two second material plates, the thermal conductivity of the second material plates is smaller than the thermal conductivity of the actual battery in the thickness direction; the second material plates are alternately assembled with the first material plates;

[0011] The electric heating plate has two sides which are attached and assembled with the first material plate.

[0012] In one embodiment, the material of the first material plate is a first isotropic material, and the material of the second material plate is a second isotropic material.

[0013] In one embodiment, the battery frame is an aluminum battery frame.

[0014] In one embodiment, the battery cover is an aluminum battery cover.

[0015] In one embodiment, the electric heating plate is mounted at the center of the battery frame.

[0016] In one embodiment, the thickness of the first material plate and the second material plate is 1-2 mm.

[0017] In one embodiment, the total thickness of all first material plates and / or second material plates is determined based on the thickness of the battery cover, the thickness of the actual battery, the thermal conductivity in the thickness direction of the actual battery, the thermal conductivity of the first material plates, and the thermal conductivity of the second material plates.

[0018] In one embodiment, the total thickness D1 of all first material sheets is:

[0019]

[0020] Wherein, D2 is the total thickness of the battery cover; D is the thickness of the real battery; z is the thermal conductivity of the real battery in the thickness direction; y is the thermal conductivity of the second material plate; x is the thermal conductivity of the first material plate;

[0021] The total thickness D3 of all second material plates is: D3 = D-D1-D2.

[0022] In one embodiment, thermal conductive silicone grease is applied between the first material plate and the second material plate, between the first material plate and the electric heating plate, and between the first material plate and the battery cover.

[0023] In a second aspect, the present application provides a test system for battery thermal management experimental testing, the system comprising: a battery model as in the first aspect, a programmable DC power supply, a data acquisition device, an acquisition computer, a data acquisition card, and a K-type thermocouple;

[0024] The temperature sensing end of the K-type thermocouple is attached to the four corners and the center of the battery model; the terminal of the K-type thermocouple is connected to the data acquisition card; the data acquisition card is inserted into the data acquisition device; the data acquisition device is connected to the acquisition computer;

[0025] The positive and negative electrodes of the programmable DC power supply are connected to the positive and negative electrodes of the electric heating plate of the battery model correspondingly to supply power to the electric heating plate; the programmable DC power supply is connected to the acquisition computer through a serial port line; the power supply of the programmable DC power supply, the acquisition computer, and the data acquisition device is connected to a 220V AC power supply.

[0026] It can be seen from the technical solution provided in the above embodiments of this specification that the solution: utilizes two different isotropic materials whose thermal conductivity is respectively greater than and less than the thermal conductivity in the thickness direction of the battery, and then alternately assembles the two materials and arranges an electric heating plate in the middle, so that the overall battery model is an anisotropic material, so as to achieve the effect of simulating the heat generation of a real battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0028] Figure 1 An isometric view of the battery model assembly provided for this application;

[0029] Figure 2 Provided for this application Figure 1 Middle AA section view;

[0030] Figure 3 An exploded view of a battery model provided for this application;

[0031] Figure 4 A schematic diagram of the battery cover structure and dimensions provided for this application;

[0032] Figure 5 A schematic diagram of the structure and dimensions of the first material plate provided for this application;

[0033] Figure 6 A schematic diagram of the structure and dimensions of the second material plate provided for this application;

[0034] Figure 7Axonometric drawing of the battery frame provided for this application;

[0035] Figure 8 A schematic diagram of the structure of the test system provided for this application;

[0036] Fig. 9 Schematic diagram of experimental testing using a battery model under vehicle driving conditions. DETAILED DESCRIPTION

[0037] In order to enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below in conjunction with the drawings in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this specification.

[0038] In the following description, specific details such as specific system structures and technologies are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, and circuits are omitted to prevent unnecessary details from obstructing the description of the present application.

[0039] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present application description without departing from the scope or spirit of the present application. Other embodiments derived from the present application description will be apparent to those skilled in the art. The present application description and examples are exemplary only.

[0040] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0041] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more. In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] The present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0043] Reference Figure 1 , which shows a structural schematic diagram of a battery model suitable for battery thermal management experimental testing provided in an embodiment of the present application.

[0044] like Figures 1 to 3 As shown, the battery model 1 used for battery thermal management experimental testing may include:

[0045] Battery frame 1-1;

[0046] Two battery cover plates 1-2, the battery cover plates 1-2 are respectively covered on both sides of the battery frame 1-1;

[0047] At least four first material plates 1-3, the thermal conductivity of the first material plates 1-3 is greater than the thermal conductivity of the actual battery in the thickness direction; the first material plates 1-3 are attached and assembled with the battery cover plate 1-2;

[0048] At least two second material plates 1-4, the thermal conductivity of the second material plates 1-4 is smaller than the thermal conductivity in the thickness direction of the real battery; the second material plates 1-4 are alternately assembled with the first material plates 1-3;

[0049] The electric heating plate 1-7, both sides of the electric heating plate 1-7 are attached and assembled to the first material plate 1-3.

[0050] Specifically, the size of the battery model 1 is consistent with the size of the real battery. The length and width of the battery frame 1-1 and the battery cover 1-2 are the same. Figures 4 to 6 The structure and size diagram of the battery cover plate 1-2, the first material plate 1-3, and the second material plate 1-4 are shown as follows: Figure 4 As shown, the battery cover is H long and W wide, and the width of the battery frame 1-1 is △L. Figure 5 , 6 As shown, the lengths of the first material plate 1-3 and the second material plate 1-4 are both H-2×△L, and the widths of the first material plate 1-3 and the second material plate 1-4 are both W-2×△L.

[0051] like Figure 7 As shown, a plurality of bolt holes 1-1-1 are provided in the thick wall of the battery frame 1-1, and bolt holes 1-1-1 of the same size and number are provided on the battery cover 1-2 at positions corresponding to the battery frame 1-1. Bolts 1-5 pass through the bolt holes 1-1-1 of the battery cover 1-2 and the battery frame 1-1 in sequence, and cooperate with nuts 1-6 to tighten the battery cover 1-2 and the battery frame 1-1.

[0052] Continue to refer to Figure 7 In the vertical thickness direction of the battery frame 1-1, there is an electric heating plate outlet hole 1-1-2, and the outlet hole 1-1-2 supplies the wire 1-7-1 of the electric heating plate 1-7 (refer to Figure 1 ) out.

[0053] The battery frame 1-1 may be an aluminum battery frame, and the battery cover plate 1-2 may be an aluminum battery cover plate.

[0054] The material of the first material plate 1-3 is a first isotropic material, and the material of the second material plate 1-4 is a second isotropic material, wherein the thermal conductivity of the first material plate is greater than the thermal conductivity of the actual battery thickness direction, and the thermal conductivity of the second material plate is less than the thermal conductivity of the actual battery thickness direction, that is, the first isotropic material and the second isotropic material are different materials. Exemplarily, the first isotropic material is 304 stainless steel, and the second isotropic material is soda-lime glass.

[0055] Reference Figure 2 The first material plate 1-3 and the second material plate 1-4 are assembled alternately, and the first material plate 1-3 is also attached and assembled with the battery cover plate 1-2 and the electric heating plate 1-7 respectively.

[0056] The electric heating plate 1-7 can be a thin electric heating plate. From the thickness direction, the electric heating plate 1-7 can be installed at the center position of the battery frame 1-1, that is, the electric heating plate 1-7 is at an equal distance from the battery cover plate 1-2 on both sides. In this way, when the electric heating plate 1-7 transfers heat to both sides, the heat transfer rate is the same, and the heat generated on both sides of the battery model 1 is the same.

[0057] The thickness of each of the first material plate 1-3 and the second material plate 1-4 may be 1-2 mm.

[0058] The total thickness of all first material plates and / or second material plates is determined according to the thickness of the battery cover, the thickness of the actual battery, the thermal conductivity in the thickness direction of the actual battery, the thermal conductivity of the first material plates, and the thermal conductivity of the second material plates.

[0059] Optionally, the total thickness D1 of all first material plates is:

[0060]

[0061] Wherein, D2 is the total thickness of the battery cover; D is the thickness of the real battery; z is the thermal conductivity of the real battery in the thickness direction; y is the thermal conductivity of the second material plate; x is the thermal conductivity of the first material plate;

[0062] The total thickness D3 of all second material plates is: D3 = D-D1-D2.

[0063] It can be understood that the total thickness D3 of all the second material plates can be:

[0064]

[0065] The total thickness D1 of all first material plates is: D1 = D-D3-D2.

[0066] Among them, D, D2, x, y, and z are all known parameters.

[0067] Optionally, thermal conductive silicone grease is applied between the first material plate and the second material plate, between the first material plate and the electric heating plate, and between the first material plate and the battery cover plate to reduce contact thermal resistance.

[0068] The battery model provided in the present application for battery thermal management experimental testing utilizes two different isotropic materials whose thermal conductivities are respectively greater than and less than the thermal conductivities in the battery thickness direction. The two materials are then assembled alternately and an electric heating plate is arranged in the middle, so that the overall battery model is an anisotropic material, thereby simulating the heat generation of a real battery.

[0069] The battery model provided in the present application for battery thermal management experimental testing calculates the thickness and quantity of the required first material plate and the second material plate through the equivalent thermal conductivity calculation formula to simulate the most realistic battery heat generation process, avoiding the expensive cost of using real batteries and charging and discharging equipment and the safety hazards caused by excessive current during high-rate charging and discharging.

[0070] Reference Figure 8 , which shows a structural schematic diagram of a test system for battery thermal management experimental testing provided in an embodiment of the present application.

[0071] like Figure 8 As shown, the test system for battery thermal management experimental test may include:

[0072] A battery model 1, a programmable DC power supply 2, a data acquisition device 3, a data acquisition computer 4, a data acquisition card 5, and a K-type thermocouple 6 for battery thermal management experimental testing as provided in the above embodiment;

[0073] The temperature sensing ends of the K-type thermocouple 6 are attached to the four corners and the center of the battery model 1; the terminals of the K-type thermocouple 6 are connected to the data acquisition card 5; the data acquisition card 5 is inserted into the data acquisition device 3; the data acquisition device 3 is connected to the acquisition computer 4 via a serial port line;

[0074] The positive pole of the programmable DC power supply 2 is connected to the positive pole of the electric heating plate 1-7 of the battery model 1, and the negative pole of the programmable DC power supply 2 is connected to the negative pole of the electric heating plate of the battery model 1, and the programmable DC power supply 2 uses this to power the electric heating plate 1-7; the programmable DC power supply 2 is connected to the acquisition computer 4 through a serial port line; the power supply of the programmable DC power supply 2, the power supply of the acquisition computer 4, and the power supply of the data acquisition device 3 are all connected to a 220V AC power supply.

[0075] Specifically, the programmable DC power supply 2 has a programming function, and the programmable DC power supply 2 can achieve transient changes in output current or voltage.

[0076] Working process of the test system:

[0077] Connect the positive and negative electrodes of the electric heating plates 1-7 in the assembled battery model 1 through the wires (corresponding to Figure 11-7-1) is connected to the positive and negative ends of the programmable DC power supply 2, wherein the positive electrode is connected to the positive electrode and the negative electrode is connected to the negative electrode. The programmable DC power supply 2 is connected to the acquisition computer 4 through a serial port line, and the output current / voltage of the programmable DC power supply 2 is controlled by the control software on the acquisition computer 4. The data acquisition device 3 is connected to the acquisition computer 4 through a serial port line, and then the power supply of the programmable DC power supply 2, the data acquisition device 3, and the acquisition computer 4 is connected to 220V AC. After all devices are powered, the acquisition computer 4 is turned on, and the acquisition software is turned on, and the acquisition signal is set to temperature, and the test begins. When the test is completed, the acquisition software is closed, and the power supply of the data acquisition device 3 and the programmable DC power supply 2 is disconnected.

[0078] The following is an explanation with reference to a specific example, taking the following real battery data as an example.

[0079]

[0080] The following takes the case where the first material plate is made of 304 stainless steel and the second material plate is made of soda-lime glass as an example.

[0081]

[0082] Select two aluminum battery cover plates, each 0.75mm thick, 6 first material plates (304 stainless steel), each 2mm thick; 5 second material plates (soda-lime glass), each 2mm thick; 1 second material (soda-lime glass), 3mm thick; the remaining 0.5mm and the gaps are coated with thermal grease to reduce the contact thermal resistance.

[0083] According to the parameters and number of the above selected materials, the thermal conductivity, density and specific heat of the battery model of this application and their corresponding errors are obtained as follows:

[0084]

[0085] Among them, the calculation formulas for equivalent thermal conductivity, equivalent density, and equivalent specific heat are:

[0086] Thickness direction: Height direction: Width direction: Equivalent density: Equivalent specific heat:

[0087] ∑L i is the thickness of the battery cell; Li is the thickness of the layer in the battery cell; λi is the thermal conductivity of the layer; ρ i is the density of the layer to which it belongs; c p,i is the specific heat of the layer.

[0088] It can be seen that the maximum error between the thermal conductivity of the physical model and the real battery is only 5.3%, the specific heat error is 21.4%, and the density error is 140%. The density error is relatively large, but the thermal conductivity is the most important in the heat transfer process, so the battery model is more realistic, and more appropriate materials can be selected to correct the density and specific heat.

[0089] The battery model can not only realize constant rate charge and discharge experiments, but also conduct experimental tests under the condition of automobile driving conditions, such as Fig. 9 As shown, the speed change over time under the driving condition of the car is obtained, and then the output power of the battery is calculated or simulated to obtain the change process of the discharge current of the battery over time during driving, and the change of the heat generation power over time is calculated. Then, the input current of the thin electric heating plate is inverted using the heat generation power. By inputting the corresponding current curve into the programmable DC power supply, the actual automobile driving conditions can be simulated.

[0090] It should be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of further restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0091] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

Claims

1. A battery model for battery thermal management experimental testing, characterized in that: The battery model includes: Battery frame; Two battery cover plates, the battery cover plates are respectively covered on two sides of the battery frame; At least four first material plates, the thermal conductivity of the first material plates is greater than the thermal conductivity of the actual battery in the thickness direction, and the first material plates are attached and assembled to the battery cover plate; At least two second material plates, the thermal conductivity of the second material plates is smaller than the thermal conductivity of the real battery in the thickness direction, and the second material plates are alternately assembled with the first material plates; Wherein, the material of the first material plate is a first isotropic material, the material of the second material plate is a second isotropic material, the first isotropic material is 304 stainless steel, and the second isotropic material is soda-lime glass; An electric heating plate, both sides of which are attached to and assembled with the first material plate, and the electric heating plate is assembled at the center of the battery frame.

2. The battery model according to claim 1, characterized in that: The battery frame is an aluminum battery frame.

3. The battery model according to claim 1, characterized in that: The battery cover plate is an aluminum battery cover plate.

4. The battery model according to claim 1, characterized in that: The thickness of the first material plate and the second material plate is 1-2 mm.

5. The battery model according to any one of claims 1 to 4, characterized in that: The total thickness of the first material plate and / or the second material plate is determined according to the thickness of the battery cover plate, the thickness of the actual battery, the thermal conductivity of the actual battery in the thickness direction, the thermal conductivity of the first material plate, and the thermal conductivity of the second material plate.

6. The battery model according to claim 5, characterized in that: The total thickness D1 of the first material plate is: Among them, D2 is the total thickness of the battery cover, D is the thickness of the actual battery, z is the thermal conductivity of the actual battery in the thickness direction, y is the thermal conductivity of the second material plate, x is the thermal conductivity of the first material plate, and the total thickness D3 of the second material plate is: D3=D-D1-D2.

7. The battery model according to any one of claims 1 to 4, characterized in that: Thermal conductive silicone grease is applied between the first material plate and the second material plate, between the first material plate and the electric heating plate, and between the first material plate and the battery cover plate.

8. A test system for battery thermal management experimental testing, characterized in that: The test system comprises: a battery model as described in any one of claims 1 to 7, a programmable DC power supply, a data acquisition device, an acquisition computer, a data acquisition card, and a K-type thermocouple; The temperature sensing ends of the K-type thermocouple are attached to the four corners and the center of the battery model, the terminals of the K-type thermocouple are connected to the data acquisition card, the data acquisition card is inserted into the data collector, and the data collector is connected to the acquisition computer; The positive and negative poles of the programmable DC power supply are connected to the positive and negative poles of the electric heating plate of the battery model correspondingly to supply power to the electric heating plate. The programmable DC power supply is connected to the acquisition computer via a serial port line. The power supplies of the programmable DC power supply, the acquisition computer, and the data acquisition device are connected to a 220V AC power supply.

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