Water cooling plate and method for improving thermal safety performance of battery by using elastic refrigeration material

Abstract

The invention relates to the technical field of batteries, in particular to a water cooling plate and a method for improving thermal safety performance of a battery by using an elastic refrigerating material. A water-cooling plate for a battery comprises a water-cooling substrate, a water inlet and a water outlet, the water-cooling substrate is made of an elastic refrigerating material, the water inlet and the water outlet are formed in the two ends of the water-cooling substrate in the length direction of the water-cooling substrate respectively, a cooling liquid channel is formed in the water-cooling substrate, and the water-cooling liquid channel is communicated with the water-cooling substrate. The cooling liquid channels extend from one end of the water-cooling substrate to the other end of the water-cooling substrate, the number of the cooling liquid channels is one or more, and the multiple cooling liquid channels are evenly distributed. And the water cooling plate has a wave structure. The water cooling plate prepared from the elastic refrigeration material can obtain a better cooling effect, and is beneficial to prolonging the service life of the lithium ion battery and improving the safety of the lithium ion battery.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a water cooling plate and a method for improving the thermal safety performance of a battery by using elastic refrigeration materials. Background Art

[0002] With the rapid popularization of electric vehicles, consumers and automakers are paying more and more attention to battery safety issues. Power batteries are not only the main power source and core components of electric vehicles, but also the main technical barrier to their rapid development. Lithium batteries are widely used in mobile phones, electric vehicles, mobile power supplies and other fields due to their high energy density, high cycle life and high environmental protection.

[0003] Elastic refrigeration is a new type of refrigeration technology with great application potential to solve most of the problems existing in the current traditional refrigerant refrigeration and vapor compression refrigeration technologies. It is considered to be one of the most promising refrigeration technologies. It has the advantages of environmental protection, high efficiency and energy saving, and has considerable advantages in terms of cost, cooling capacity, efficiency and feasibility. However, the elastic thermal devices that use elastic refrigeration occupy a large space during the deformation process and the material life is short. In practical applications, they still need to be continuously improved. Therefore, it is still a huge challenge to achieve more efficient and environmentally friendly solid-state refrigeration technology.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] An object of the present invention is to provide a water cooling plate for a battery, which is beneficial to ensuring the thermal safety performance of the battery.

[0006] Another object of the present invention is to provide a method for improving the thermal safety performance of a battery by using an elastic refrigeration material, which method can improve the safety performance of the battery.

[0007] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

[0008] A water-cooling plate for a battery comprises a water-cooling base plate, a water inlet and a water outlet, wherein the material of the water-cooling base plate comprises an elastic refrigeration material, the water inlet and the water outlet are located at two ends of the water-cooling base plate along its length direction, a cooling liquid channel is arranged inside the water-cooling base plate, the cooling liquid channel extends from one end of the water-cooling base plate to the other end, the cooling liquid channel has one or more cooling liquid channels, and the multiple cooling liquid channels are evenly distributed; the water-cooling plate has a wave configuration.

[0009] In some embodiments, the elastic refrigeration material includes at least one of a copper-zinc-aluminum composite material, a nickel-titanium composite material, a nickel-titanium-copper composite material, an iron-palladium composite material, an iron-indium-palladium composite material, an iron-rhodium composite material, and a nickel-manganese-indium-cobalt composite material.

[0010] In some embodiments, the material of the water-cooled substrate includes Cu 68.13 Zn 15.74 Al1 6.13 , Cu 68 Zn 16 Al1 16 、Ni 50 Ti 50 、Ni 32.5 Ti 50.4 Cu 12.6 , Fe 68.8 Pd 31.2 , Fe 49 R 51 、Ni 45 Mn3 6.4 In 13.6 One or more of Co5.

[0011] In some embodiments, a water circulation device is further included, wherein the water outlet of the water circulation device is connected to the water inlet of the water-cooled substrate, the water inlet of the water circulation device is connected to the water outlet of the water-cooled substrate, and the circulating liquid is cooled in the water circulation device to provide cooling liquid.

[0012] In some embodiments, the water-cooling substrate includes a middle layer, a first end layer, and a second end layer, and the first end layer and the second end layer are located on both sides of the middle layer.

[0013] In some embodiments, the intermediate layer is Cu 68.13 Zn 15.74 Al1 6.13 and / or Cu 68 Zn 16 Al1 16 The first end layer and the second end layer are each independently Ni 50 Ti 50 、Ni 32.5 Ti 50.4 Cu 12.6 , Fe 68.8 Pd 31.2 , Fe 49 R 51 and Ni 45 Mn3 6.4 In 13.6 Any one of Co5.

[0014] A method for improving the thermal safety performance of a battery by using an elastic refrigeration material comprises the following steps:

[0015] (a) By establishing a model and conducting theoretical analysis, the relationship (1) for the temperature change of elastic refrigeration materials under stress is determined;

[0016] Relation (1): Where, h is the thermal coefficient, Λ is the surface area, Text is the ambient temperature, T is the temperature of the elastic cooling material, l is the length of the elastic cooling material, and γ is the elastic thermal constant established according to equation (1);

[0017] Get the relationship (2): T0 is the temperature of the elastic refrigeration material in the initial state, l0 is the length of the elastic refrigeration material in the initial state, l f is the tensile length of the elastic refrigeration material; T f is the temperature generated when the elastic refrigeration material is deformed; c is the heat capacity of the elastic refrigeration material obtained according to equation (2);

[0018] Get the relationship (3): R c is the refrigeration capacity of the elastic refrigeration material, γ is the elastic thermal constant, T is the temperature of the elastic refrigeration material, c is the thermal melting of the elastic refrigeration material, and Δl is the deformation of the elastic refrigeration material;

[0019] Get relation (4): ΔT adi is adiabatic temperature change, ΔS is isothermal entropy change, T is ambient temperature, and C is the specific heat capacity of the elastic refrigeration material under constant stress;

[0020] Get the relationship (8): C COP，mat is the solid-state elastic refrigeration performance of the elastic refrigeration material, Q is the refrigeration capacity during the cycle, and W is the input work during the cycle;

[0021] (b) testing the influence of elastic refrigeration material samples of different materials on refrigeration performance to obtain multiple performance parameters; making samples of elastic refrigeration materials of different materials and testing them to verify the accuracy of the model of step (a); through step (b), the relationship of step (a) can be verified and corrected;

[0022] (c) applying the corrected relationship of the elastic cooling material to the battery and verifying it through actual testing; the elastic cooling material is made into a water cooling plate and used in the battery to cool it.

[0023] In some embodiments, in the relation (4), ΔS is obtained through the relation (5):

[0024] Relation (5): T0 is obtained by equation (6);

[0025] Relation (6):

[0026] Among them, Q is the latent heat of the phase change process of the elastic refrigeration material, Ms is the temperature at which the martensite phase change starts; Af is the temperature at which the austenite phase change ends;

[0027] When the elasto-caloric effect presented by the phase change is of the first-order type, ΔS is obtained through equation (7);

[0028] Relation (7): Δε represents the deformation; σ represents the uniaxial stress; T is the experimental temperature.

[0029] In some embodiments, the water-cooled plate includes a water-cooled base plate, a water inlet and a water outlet, the material of the water-cooled base plate includes an elastic refrigeration material, the water inlet and the water outlet are separated at both ends of the water-cooled base plate along its length direction, a cooling liquid channel is arranged inside the water-cooled base plate, the cooling liquid channel extends from one end of the water-cooled base plate to the other end, the cooling liquid channel has one or more cooling liquid channels, and the multiple cooling liquid channels are evenly distributed; the water-cooled plate has a wave configuration.

[0030] In some embodiments, the elastic refrigeration material includes at least one of a copper-zinc-aluminum composite material, a nickel-titanium composite material, a nickel-titanium-copper composite material, an iron-palladium composite material, an iron-indium-palladium composite material, an iron-rhodium composite material, and a nickel-manganese-indium-cobalt composite material.

[0031] In some embodiments, the water-cooled plate further includes a water circulation device, a water outlet of the water circulation device is connected to a water inlet of the water-cooled base plate, a water inlet of the water circulation device is connected to a water outlet of the water-cooled base plate, and the circulating liquid is cooled in the water circulation device to provide a coolant.

[0032] In some embodiments, the copper-zinc-aluminum composite material comprises Cu 68.13 Zn 15.74 Al1 6.13 and Cu 68 Zn 16 Al1 16 The nickel-titanium composite material comprises Ni 50 Ti 50 The nickel-titanium-copper composite material comprises Ni 32.5 Ti 50.4 Cu 12.6 The iron-palladium composite material comprises Fe 68.8 Pd 31.2 The iron-rhodium composite material includes Fe 49 R 51 The nickel-manganese-indium-cobalt composite material comprises Ni 45 Mn3 6.4 In 13.6 Co5.

[0033] In some embodiments, the water-cooled substrate includes a middle layer, a first end layer and a second end layer, wherein the first end layer and the second end layer are located on both sides of the middle layer; the middle layer is Cu 68.13 Zn 15.74 Al1 6.13 and / or Cu 68 Zn 16 Al1 16 The first end layer and the second end layer are each independently Ni 50 Ti 50 、Ni 32.5 Ti 50.4 Cu 12.6 , Fe 68.8 Pd 31.2 , Fe 49 R 51 and Ni 45 Mn3 6.4 In 13.6 Any one of Co5.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] (1) The battery water cooling plate of the present invention is conducive to better cooling, which can ensure the safety performance of the battery and extend the service life.

[0036] (2) The present invention designs related devices based on the actual structure of the power battery and the principles and types of caloric elastic materials. Specifically, the present invention summarizes and concludes the basic principles of the caloric elastic effect through its material characterization method, and tests and characterizes it through relevant tests. The present invention uses nickel-titanium-based, copper-based, iron-based, ferromagnetic shape memory alloys and elastic polymers as caloric elastic materials to achieve the research purpose of solid-state refrigeration, thereby solving the problems related to thermal safety of power batteries, which can fundamentally guide the improvement of lithium-ion batteries.

[0037] (3) Components made of elastic refrigeration materials can achieve better cooling effects, which can directly guide the improvement of lithium-ion batteries from a mechanistic perspective, help improve the life and safety of lithium-ion batteries, and further promote their commercial application. Components using elastic refrigeration will not increase the weight and size of the equipment, and can extend its service life, which can then form an empirical analysis model that can be applied to the design and optimization of electric vehicles and power battery-related fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 A schematic diagram of a water cooling plate of the present invention;

[0040] Figure 2 Another schematic diagram of the water cooling plate of the present invention;

[0041] Figure 3 This is a temperature change principle diagram of the elastic refrigeration material of the present invention;

[0042] Figure 4 is the temperature change of Cu alloy during loading and unloading;

[0043] Figure 5 The temperature variation of NiTi alloy wire during loading and unloading;

[0044] Figure 6 The load stress and temperature of FePd alloy change with time.

[0045] Reference numerals:

[0046] 1- water cooling base plate, 2- water inlet, 3- water outlet, 4- water circulation device. DETAILED DESCRIPTION

[0047] The embodiments of the present invention will be described in detail below in conjunction with the examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present invention and should not be considered as limiting the scope of the present invention. If no specific conditions are specified in the examples, the conditions are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be obtained commercially.

[0048] According to one aspect of the present invention, the present invention relates to a water-cooled plate for a battery, comprising a water-cooled substrate, a water inlet and a water outlet, wherein the material of the water-cooled substrate comprises an elastic refrigeration material, the water inlet and the water outlet are located at both ends of the water-cooled substrate along its length direction, a coolant channel is arranged inside the water-cooled substrate, the coolant channel extends from one end of the water-cooled substrate to the other end, the coolant channel has one or more coolant channels, and the multiple coolant channels are evenly distributed; the water-cooled plate has a wave configuration.

[0049] The water cooling plate of the present invention can effectively cool the battery and ensure the thermal safety performance of the battery.

[0050] In some embodiments, the elastic refrigeration material includes at least one of a copper-zinc-aluminum composite material, a nickel-titanium composite material, a nickel-titanium-copper composite material, an iron-palladium composite material, an iron-indium-palladium composite material, an iron-rhodium composite material, and a nickel-manganese-indium-cobalt composite material. In some embodiments, copper-based shape memory alloy is the earliest and most diverse shape memory alloy, and has been widely studied due to its advantages such as excellent shape memory performance and low cost. Binary nickel-titanium alloy has excellent superelasticity, corrosion resistance, biocompatibility, and shape memory effect, which immediately attracted widespread attention and has a wide range of applications in the aviation industry, medical industry, construction industry, and other fields. Compared with application research in other fields, the huge elastic-caloric effect in NiTi alloy.

[0051] In some embodiments, the material of the water-cooled substrate includes Cu 68.13 Zn 15.74 Al1 6.13 , Cu 68 Zn 16 Al1 16 、Ni 50 Ti 50 、Ni 32.5 Ti 50.4 Cu 12.6 , Fe 68.8 Pd 31.2 , Fe 49 R 51 、Ni 45 Mn3 6.4 In 13.6 One or more of Co5.

[0052] In some embodiments, a water circulation device is further included, wherein the water outlet of the water circulation device is connected to the water inlet of the water-cooled substrate, the water inlet of the water circulation device is connected to the water outlet of the water-cooled substrate, and the circulating liquid is cooled in the water circulation device to provide cooling liquid. The water circulation device is connected to the water-cooled substrate through a pipeline.

[0053] In some embodiments, the aperture of the coolant channel, the thickness of the water cooling plate and other related parameters are specifically designed according to the specific battery structure. In some embodiments, the aperture of the water cooling plate is evenly distributed.

[0054] In some embodiments, the water-cooled substrate includes a middle layer, a first end layer and a second end layer, wherein the first end layer and the second end layer are located on both sides of the middle layer. 68.13 Zn 15.74 Al1 6.13 and / or Cu 68 Zn 16 Al116 The first end layer and the second end layer are each independently Ni 50 Ti 50 、Ni 32.5 Ti 50.4 Cu 12.6 , Fe 68.8 Pd 31.2 , Fe 49 R 51 and Ni 45 Mn3 6.4 In 13.6 Any one of Co5. The water-cooling plate with a specific structure is prepared by the elastic refrigeration material of the specific material mentioned above, which is more conducive to ensuring the cooling effect and the safety performance of the battery.

[0055] The water-cooled plate of the present invention has good cooling effect. It has been verified in practice that it can ensure that the temperature of the water outlet pipe is below 32°C, such as 22°C, 25°C, 28°C, 30°C, etc. during thermal runaway.

[0056] According to another aspect of the present invention, the present invention also relates to a method for improving the thermal safety performance of a battery by using an elastic refrigeration material, comprising the following steps:

[0057] (a) By establishing a model and conducting theoretical analysis, the relationship (1) for the temperature change of elastic refrigeration materials under stress is determined;

[0058] Relation (1): Where, h is the thermal coefficient, Λ is the surface area, Text is the ambient temperature, T is the temperature of the elastic cooling material, l is the length of the elastic cooling material, and γ is the elastic thermal constant established according to equation (1);

[0059] Get the relationship (2): T0 is the temperature of the elastic refrigeration material in the initial state, l0 is the length of the elastic refrigeration material in the initial state, l f is the tensile length of the elastic refrigeration material; T f is the temperature generated when the elastic refrigeration material is deformed; c is the heat capacity of the elastic refrigeration material obtained according to equation (2);

[0060] Get the relationship (3): R c is the refrigeration capacity of the elastic refrigeration material, γ is the elastic thermal constant, T is the temperature of the elastic refrigeration material, c is the thermal melting of the elastic refrigeration material, and Δl is the deformation of the elastic refrigeration material;

[0061] Get relation (4): ΔT adiis adiabatic temperature change, ΔS is isothermal entropy change, T is ambient temperature, and C is the specific heat capacity of the elastic refrigeration material under constant stress;

[0062] Get the relationship (8): C COP，mat is the solid-state elastic refrigeration performance of the elastic refrigeration material, Q is the refrigeration capacity during the cycle, and W is the input work during the cycle;

[0063] (b) testing the influence of elastic refrigeration material samples of different materials on refrigeration performance to obtain multiple performance parameters; making samples of elastic refrigeration materials of different materials and testing them to verify the accuracy of the model of step (a); through step (b), the relationship of step (a) can be verified and corrected;

[0064] (c) applying the corrected relationship of the elastic cooling material to the battery and verifying it through actual testing; the elastic cooling material is made into a water cooling plate and used in the battery to cool it.

[0065] Based on the basic principle of the elasto-caloric effect, the present invention summarizes and concludes through its material characterization method, and performs test characterization through relevant detection, so as to achieve the research purpose of solid-state refrigeration, and further solve the problems related to thermal safety of power batteries, which can fundamentally play a guiding role in the improvement of lithium-ion batteries.

[0066] In some embodiments, step (1): determine the effect of elastic refrigeration materials of different materials on refrigeration efficiency. By establishing an equivalent temperature change equation, a set of n equations about the electromotive force is established, and the advantages and disadvantages of the elastic refrigeration performance of different materials are obtained through analysis. Step (2) Experimental testing determines the effect of elastic refrigeration material samples of different materials on refrigeration efficiency. Physical parameters such as applied stress, entropy change and other parameters are obtained through testing. After that, a variety of samples are made and relevant tests are carried out to verify the accuracy of the model. Step (3) The corrected model is applied to the electric vehicle power battery device, and then the accuracy of the model is verified through actual testing. If any problems occur, continue to repeat step (1).

[0067] In some implementations, establishing Figure 1 The principle model of the elastic refrigeration material is established and analyzed theoretically to determine the differential equation of the temperature change of the elastic refrigeration material under stress, that is, equation (1). Under the assumption that the heat exchange between the material and the environment is completed by convection and radiation, equation (1) is obtained.

[0068] In some embodiments, in the relation (4), ΔS is obtained through the relation (5): T0 is obtained by equation (6); equation (6): Among them, Q is the latent heat of the phase change process of the elastic refrigeration material. The martensitic phase transition is a first-order phase transition. The latent heat Q of the phase transition process can be measured by differential scanning calorimetry (DSC) using a quasi-direct method. Ms is the temperature at which the martensitic phase transition begins; Af is the temperature at which the austenitic phase transition ends. Substituting the calculated ΔS into the Clapeyron-Clausius equation can obtain the adiabatic temperature change of the elastic caloric material. Indirect measurement method: First measure the stress-strain curve of the sample or the strain-temperature curve under a certain load, and then calculate using the Clapeyron-Clausius equation.

[0069] Equation (4) shows that isothermal entropy reduction will lead to temperature rise, and conversely, isothermal entropy increase will lead to temperature drop, which is consistent with the temperature change of the material during stress loading and release. When the elasto-caloric effect presented by the phase change is of the first-order type, ΔS is obtained through equation (7); equation (7): Δε represents the deformation; σ represents the uniaxial stress; T is the experimental temperature. dσ / dT is the relationship between the critical stress of martensitic transformation and the experimental temperature. At present, the ΔS of martensitic transformation of shape memory alloys is generally measured by quasi-direct or indirect methods.

[0070] In some embodiments, the performance parameters include: phase transition temperature T t、 Applied stress Δσ, adiabatic entropy change ΔS e , entropy change ΔS i , adiabatic temperature change ΔT d , the temperature change ΔT calculated using the entropy change generated during the phase change t .

[0071] In some embodiments, the performance parameter test results of the elastic refrigeration material include: Cu 68.13 Zn 15.74 Al1 6.13 : Phase transition temperature T t is 230K, the applied stress Δσ is 120MPa, and the entropy change ΔS i 21 J·kg -1 ·K -1 , adiabatic entropy change ΔS e 11 J·kg -1 ·K -1 , adiabatic temperature change ΔT d is 6K, temperature change ΔT t 11K. Cu 68 Zn 16 Al1 16 : Phase transition temperature T t is 200K, the applied stress Δσ is 250MPa, and the entropy change ΔS i 18 J·kg -1 ·K-1 , adiabatic entropy change ΔS e 13 J·kg -1 ·K -1 , adiabatic temperature change ΔT d is 6K, temperature change ΔT t 12K; Ni 50 Ti 50 : Phase transition temperature T t is 260K, the applied stress Δσ is 230MPa, and the adiabatic entropy change ΔS e 26 J·kg -1 ·K -1 , adiabatic temperature change ΔT d 26K. 32.5 Ti 50.4 Cu 12.6 : Phase transition temperature T t is 320K, the applied stress Δσ is 300MPa, and the adiabatic entropy change ΔS e 21 J·kg -1 ·K -1 , adiabatic temperature change ΔT d 6K. 68.8 Pd 31.2 : Phase transition temperature T t is 250K, the applied stress Δσ is 200MPa, and the entropy change ΔS i 5J·kg -1 ·K -1 , adiabatic temperature change ΔT d 3K. Fe 49 R 51 :Phase transition temperature T t is 315K, the applied stress Δσ is 530MPa, and the adiabatic entropy change ΔS e 7 J·kg -1 ·K -1 , adiabatic temperature change ΔT d 5K. 45 Mn3 6.4 In 13.6 Co5: Phase transition temperature T t is 250K, the applied stress Δσ is 150MPa, and the adiabatic entropy change ΔS e 5J·kg -1 ·K -1 , adiabatic temperature change ΔT d is 4K.

[0072] For equation (8), C COP，mat The larger the value is, the better the refrigeration performance of the material is. Further considering many factors such as heat transfer medium and cycle frequency, the refrigeration performance coefficient of the entire device is calculated.

[0073] In some embodiments, the water-cooled plate includes a water-cooled base plate, a water inlet and a water outlet. The material of the water-cooled base plate includes an elastic refrigeration material. The water inlet and the water outlet are located at both ends of the water-cooled base plate along its length. A coolant channel is provided inside the water-cooled base plate. The coolant channel extends from one end of the water-cooled base plate to the other end. The coolant channel has one or more coolant channels, and the multiple coolant channels are evenly distributed. The water-cooled plate has a wave configuration. This water-cooled plate structure can better cool the battery to improve the thermal safety performance of the battery.

[0074] In some embodiments, the water-cooled plate further comprises a water circulation device, the water outlet of the water circulation device is connected to the water inlet of the water-cooled base plate, the water inlet of the water circulation device is connected to the water outlet of the water-cooled base plate, and the circulating liquid is cooled in the water circulation device to provide cooling liquid.

[0075] In some embodiments, the elastic refrigeration material includes one or more of a copper-zinc-aluminum composite material, a nickel-titanium composite material, a nickel-titanium-copper composite material, an iron-palladium composite material, an iron-indium-palladium composite material, an iron-rhodium composite material, and a nickel-manganese-indium-cobalt composite material. 68.13 Zn 15.74 Al1 6.13 and Cu 68 Zn 16 Al1 16 The nickel-titanium composite material comprises Ni 50 Ti 50 The nickel-titanium-copper composite material comprises Ni 32.5 Ti 50.4 Cu 12.6 The iron-palladium composite material comprises Fe 68.8 Pd 31.2 The iron-rhodium composite material includes Fe 49 R 51 The nickel-manganese-indium-cobalt composite material comprises Ni 45 Mn3 6.4 In 13.6 Co5.

[0076] In some embodiments, the water-cooled substrate includes a middle layer, a first end layer and a second end layer, wherein the first end layer and the second end layer are located on both sides of the middle layer; the middle layer is Cu 68.13 Zn 15.74 Al1 6.13 and / or Cu 68 Zn 16 Al1 16 The first end layer and the second end layer are each independently Ni 50 Ti 50、Ni 32.5 Ti 50.4 Cu 12.6 , Fe 68.8 Pd 31.2 , Fe 49 R 51 and Ni 45 Mn3 6.4 In 13.6 Any one of Co5. The water-cooled plate with a specific structure prepared by the elastic refrigeration material of the above-mentioned specific material is conducive to ensuring the cooling effect and better ensuring the safety performance of the battery. It has been verified that the outlet pipe temperature can be kept below 32°C during thermal runaway, such as 22°C, 25°C, 28°C, 30°C, etc.

[0077] The following is further explained in conjunction with specific embodiments.

[0078] Example 1

[0079] (a) Determine the influence of elastic cooling materials of different materials on cooling performance. By establishing an equivalent temperature change equation, we can establish n sets of equations about electromotive force, and through analysis, we can find out the advantages and disadvantages of elastic cooling performance of different materials. Figure 3 The principle model of the elastic refrigeration material is established and analyzed theoretically to determine the differential equation of the temperature change of the elastic refrigeration material under stress, that is, the relationship (1). Under the assumption that the heat exchange between the material and the environment is completed by convection and radiation.

[0080] Relation (1): Where h is the thermal coefficient, Λ is the surface area, Text is the ambient temperature, T is the temperature of the elastic cooling material, l is the length of the elastic cooling material, and γ is the elastic thermal constant established according to equation (1).

[0081] Get the relationship (2): T0 is the temperature of the elastic refrigeration material in the initial state, l0 is the length of the elastic refrigeration material in the initial state, l f is the tensile length of the elastic refrigeration material; T f is the temperature generated when the elastic refrigeration material is deformed; c is the heat capacity of the elastic refrigeration material obtained according to equation (2).

[0082] Get the relationship (3): R c is the refrigeration capacity of the elastic refrigeration material, γ is the elasto-thermal constant, T is the temperature of the elastic refrigeration material, c is the thermal melting point of the elastic refrigeration material, and Δl is the deformation of the elastic refrigeration material.

[0083] Get the relationship (4): ΔT adiis adiabatic temperature change, ΔS is isothermal entropy change, T is ambient temperature, and C is the specific heat capacity of the elastic refrigeration material under constant stress.

[0084] ΔS is obtained through equation (5): T0 is obtained by equation (6); equation (6): Where Q is the latent heat of the phase change process of the elastic refrigeration material, Ms is the temperature at which the martensitic phase change begins, and Af is the temperature at which the austenitic phase change ends. When the elastocaloric effect of the phase change is of the first-order type, ΔS is obtained through equation (7);

[0085] Relation (7): Δε represents the deformation; σ represents the uniaxial stress; T is the experimental temperature.

[0086] Get the relationship (8): C COP，mat is the solid-state elastic refrigeration performance of the elastic refrigeration material, Q is the cooling capacity during the cycle, and W is the input work during the cycle.

[0087] (b) Testing the effects of elastic refrigeration material samples made of different materials on refrigeration efficiency to obtain multiple performance parameters; making samples of elastic refrigeration materials made of different materials and testing them to verify the accuracy of the model in step (a).

[0088] Different types of elastic refrigeration materials were selected for testing. The performance parameters are shown in Table 1. The phase transition temperature T t、 Applied stress Δσ, adiabatic entropy change ΔS e , entropy change ΔS i , adiabatic temperature change ΔT d , the temperature change ΔT calculated using the entropy change generated during the phase change t .

[0089] Table 1 Performance parameters of elastic refrigeration materials

[0090]

[0091] In Table 1, Cu 68.13 Zn 15.74 Al1 6.13 : Phase transition temperature T t is 230K, the applied stress Δσ is 120MPa, and the entropy change ΔS i 21 J·kg -1 ·K -1 , adiabatic entropy change ΔS e 11 J·kg -11 ·K -1 , adiabatic temperature change ΔT d is 6K, temperature change ΔT t11K. Cu 68 Zn 16 Al1 16 : Phase transition temperature T t is 200K, the applied stress Δσ is 250MPa, and the entropy change ΔS i 18 J·kg -1 ·K -1 , adiabatic entropy change ΔS e 13 J·kg -1 ·K -1 , adiabatic temperature change ΔT d is 6K, temperature change ΔT t 12K; Ni 50 Ti 50 : Phase transition temperature T t is 260K, the applied stress Δσ is 230MPa, and the adiabatic entropy change ΔS e 26 J·kg -1 ·K -1 , adiabatic temperature change ΔT d 26K. 32.5 Ti 50.4 Cu 12.6 : Phase transition temperature T t is 320K, the applied stress Δσ is 300MPa, and the adiabatic entropy change ΔS e 21 J·kg -1 ·K -1 , adiabatic temperature change ΔT d 6K. 68.8 Pd 31.2 : Phase transition temperature T t is 250K, the applied stress Δσ is 200MPa, and the entropy change ΔS i 5J·kg -1 ·K -1 , adiabatic temperature change ΔT d 3K. Fe 49 R 51 :Phase transition temperature T t is 315K, the applied stress Δσ is 530MPa, and the adiabatic entropy change ΔS e 7 J·kg -1 ·K -1 , adiabatic temperature change ΔT d 5K. 45 Mn3 6.4 In 13.6 Co5: Phase transition temperature T t is 250K, the applied stress Δσ is 150MPa, and the adiabatic entropy change ΔS e 5J·kg -1 ·K -1 , adiabatic temperature change ΔTd is 4K.

[0092] (c) Through step (b), the relationship of step (a) can be verified and corrected, and the corrected relationship of the elastic refrigeration material is applied to the battery and verified through actual testing.

[0093] Example 2

[0094] The cooling performance of Cu-Zn-Al single crystal alloy (the specific lattice parameters of the above metals are in the range of 0-1) at different temperatures was evaluated by theoretical calculation. The corresponding theoretical ΔT adi It can reach -15K, and the maximum martensite ΔS is about 20J·kg -1 ·K -1 , and cooling can be achieved by applying very low stress, such as Figure 4 As shown. The water cooling plate made of this copper-based shape memory alloy is as follows Figure 1 , Figure 2 As shown, the experiment found that in addition to water cooling, the cooling effect caused by the phase change thermal effect of the Cu-based memory alloy is more obvious, indicating that this water cooling plate is more conducive to cooling the power battery module.

[0095] A water cooling plate, such as Figure 2 As shown, it includes a water-cooling base plate 1, a water inlet 2 and a water outlet 3. The material of the water-cooling base plate 1 is Cu 68.13 Zn 15.74 Al1 6.13 The water inlet 2 and the water outlet 3 are located at both ends of the water-cooled substrate 1 along its length direction. A cooling liquid channel is provided inside the water-cooled substrate 1. The cooling liquid channel extends from one end of the water-cooled substrate 1 to the other end. There are multiple cooling liquid channels, and the multiple cooling liquid channels are evenly distributed. The water-cooled plate has a wave configuration. It also includes a water circulation device 4, the water outlet end of the water circulation device 4 is connected to the water inlet 2 of the water-cooled substrate 1, and the water inlet end of the water circulation device 4 is connected to the water outlet 3 of the water-cooled substrate 1. The circulating liquid is cooled in the water circulation device 4 to provide a cooling liquid.

[0096] Example 3

[0097] The huge elastic-caloric effect in NiTi alloy (the specific lattice parameters of the above metals are all in the range of 0-1) has a adiabatic temperature change of -14K. COP，matThe maximum temperature drop of NiTi alloy sheet under 500MPa is about -16K. NiTi alloy wire can produce adiabatic cooling of -17K under 600MPa tensile stress. NiTi alloy wire is stretched / released at different temperatures, and the maximum temperature drop of NiTi alloy wire under 500MPa is about -16K. Figure 5 The NiTi alloy was prepared into a ribbon structure and stretched into a cooling plate. The temperature was detected using an infrared camera, and it was found that the NiTi alloy ribbon could produce a temperature drop of about -15K.

[0098] A water cooling plate, such as Figure 2 As shown, it includes a water-cooling base plate 1, a water inlet 2 and a water outlet 3. The material of the water-cooling base plate 1 is Ni 50 Ti 50 The water inlet 2 and the water outlet 3 are located at both ends of the water-cooled substrate 1 along its length direction. A cooling liquid channel is provided inside the water-cooled substrate 1. The cooling liquid channel extends from one end of the water-cooled substrate 1 to the other end. There are multiple cooling liquid channels, and the multiple cooling liquid channels are evenly distributed. The water-cooled plate has a wave configuration. It also includes a water circulation device 4, the water outlet end of the water circulation device 4 is connected to the water inlet 2 of the water-cooled substrate 1, and the water inlet end of the water circulation device 4 is connected to the water outlet 3 of the water-cooled substrate 1. The circulating liquid is cooled in the water circulation device 4 to provide a cooling liquid.

[0099] Example 4

[0100] The adiabatic cooling of -5.17 K was detected for the first time in the stress-induced ferromagnetic-antiferromagnetic transition of Fe-Rh alloy, and the isothermal entropy change of the material reached 13 J·kg under the stress of 529 MPa. -1 ·K -1 .

[0101] Fe-Pd based memory alloys are also the main Fe-based alloys with elastic and thermal effects, such as Figure 6 As shown, under the stress of 100MPa, the alloy exhibits an adiabatic temperature change of -2K. By adding a certain amount of In element, the Pd-In-Fe alloy exhibits an adiabatic temperature change of -5.4K and has good superelasticity and ductility.

[0102] A water-cooled plate includes a water-cooled substrate 1, a water inlet 2 and a water outlet 3. The material of the water-cooled substrate 1 is Pd-In-Fe. The water inlet 2 and the water outlet 3 are located at both ends of the water-cooled substrate 1 along its length. A cooling liquid channel is provided inside the water-cooled substrate 1. The cooling liquid channel extends from one end of the water-cooled substrate 1 to the other end. There are multiple cooling liquid channels, and the multiple cooling liquid channels are evenly distributed. The water-cooled plate has a wave configuration. It also includes a water circulation device 4, the water outlet end of the water circulation device 4 is connected to the water inlet 2 of the water-cooled substrate 1, and the water inlet end of the water circulation device 4 is connected to the water outlet 3 of the water-cooled substrate 1. The circulating liquid is cooled in the water circulation device 4 to provide cooling liquid.

[0103] Example 5

[0104] A water cooling plate, such as Figure 2 As shown, it includes a water-cooled substrate 1, a water inlet 2 and a water outlet 3. The water-cooled substrate 1 includes an intermediate layer, a first end layer and a second end layer. The intermediate layer is Cu 68.13 Zn 15.74 Al1 6.13 The first end layer and the second end layer are located on both sides of the middle layer, and the first end layer and the second end layer are Ni 32.5 Ti 50.4 Cu 12.6 . The water inlet 2 and the water outlet 3 are located at both ends of the water-cooled substrate 1 along its length direction. A coolant channel is provided inside the water-cooled substrate 1. The coolant channel extends from one end of the water-cooled substrate 1 to the other end. There are multiple coolant channels, and the multiple coolant channels are evenly distributed. The water-cooled plate has a wave configuration. It also includes a water circulation device 4, the water outlet end of the water circulation device 4 is connected to the water inlet 2 of the water-cooled substrate 1, and the water inlet end of the water circulation device 4 is connected to the water outlet 3 of the water-cooled substrate 1. The circulating liquid is cooled in the water circulation device 4 to provide a coolant.

[0105] Example 6

[0106] A water cooling plate, such as Figure 2 As shown, it includes a water-cooled substrate 1, a water inlet 2 and a water outlet 3. The water-cooled substrate 1 includes an intermediate layer, a first end layer and a second end layer. The intermediate layer is Cu 68.13 Zn 15.74 Al1 6.13 The first end layer and the second end layer are located on both sides of the middle layer, and the first end layer and the second end layer are Ni 45 Mn3 6.4 In 13.6 Co 5。The water inlet 2 and the water outlet 3 are located at both ends of the water-cooled substrate 1 along its length direction. A cooling liquid channel is provided inside the water-cooled substrate 1. The cooling liquid channel extends from one end of the water-cooled substrate 1 to the other end. There are multiple cooling liquid channels, and the multiple cooling liquid channels are evenly distributed. The water-cooled plate has a wave configuration. It also includes a water circulation device 4, the water outlet end of the water circulation device 4 is connected to the water inlet 2 of the water-cooled substrate 1, and the water inlet end of the water circulation device 4 is connected to the water outlet 3 of the water-cooled substrate 1. The circulating liquid is cooled in the water circulation device 4 to provide cooling liquid.

[0107] Example 7

[0108] A water cooling plate, such as Figure 2 As shown, it includes a water-cooled substrate 1, a water inlet 2 and a water outlet 3. The water-cooled substrate 1 includes an intermediate layer, a first end layer and a second end layer. The intermediate layer is Cu 68 Zn 16 Al1 16 The first end layer and the second end layer are located on both sides of the middle layer, and the first end layer and the second end layer are Ni 45 Mn3 6.4 In 13.6 Co 5。 The water inlet 2 and the water outlet 3 are located at both ends of the water-cooled substrate 1 along its length direction. A cooling liquid channel is provided inside the water-cooled substrate 1. The cooling liquid channel extends from one end of the water-cooled substrate 1 to the other end. There are multiple cooling liquid channels, and the multiple cooling liquid channels are evenly distributed. The water-cooled plate has a wave configuration. It also includes a water circulation device 4, the water outlet end of the water circulation device 4 is connected to the water inlet 2 of the water-cooled substrate 1, and the water inlet end of the water circulation device 4 is connected to the water outlet 3 of the water-cooled substrate 1. The circulating liquid is cooled in the water circulation device 4 to provide cooling liquid.

[0109] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A battery water cooling plate, characterized in that: It includes a water-cooled base plate, a water inlet and a water outlet. The material of the water-cooled base plate includes an elastic refrigeration material. The water inlet and the water outlet are separated at the two ends of the water-cooled base plate along its length direction. A cooling liquid channel is arranged inside the water-cooled base plate. The cooling liquid channel extends from one end of the water-cooled base plate to the other end. There are one or more cooling liquid channels, and the multiple cooling liquid channels are evenly distributed. The water-cooled plate has a wave configuration.

2. The battery water cooling plate according to claim 1, characterized in that: The elastic refrigeration material includes at least one of a copper-zinc-aluminum composite material, a nickel-titanium composite material, a nickel-titanium-copper composite material, an iron-palladium composite material, an iron-indium-palladium composite material, an iron-rhodium composite material and a nickel-manganese-indium-cobalt composite material.

3. The battery water cooling plate according to claim 2, characterized in that: The material of the water-cooling substrate includes Cu 68.13 Zn 15.74 Al1 6.13 , Cu 68 Zn 16 Al1 16 、Ni 50 Ti 50 、Ni 32.5 Ti 50.4 Cu 12.6 , Fe 68.8 Pd 31.2 , Fe 49 R 51 、Ni 45 Mn3 6.4 In 13.6 One or more of Co5.

4. The battery water cooling plate according to claim 1, characterized in that: It also includes a water circulation device, the water outlet of the water circulation device is connected to the water inlet of the water-cooled base plate, the water inlet of the water circulation device is connected to the water outlet of the water-cooled base plate, and the circulating liquid is cooled in the water circulation device to provide cooling liquid.

5. The battery water cooling plate according to claim 1, characterized in that: The water-cooling substrate comprises a middle layer, a first end layer and a second end layer, wherein the first end layer and the second end layer are located at two sides of the middle layer.

6. The battery water cooling plate according to claim 5, characterized in that ,, the intermediate layer is Cu 68.13 Zn 15.74 Al1 6.13 and / or Cu 68 Zn 16 Al1 16 The first end layer and the second end layer are each independently Ni 50 Ti 50 、Ni 32.5 Ti 50.4 Cu 12.6 , Fe 68.8 Pd 31.2 , Fe 49 R 51 and Ni 45 Mn3 6.4 In 13.6 Any one of Co5.

7. A method for improving the thermal safety performance of a battery by using an elastic refrigeration material, characterized in that: The following steps are involved: (a) By establishing a model and conducting theoretical analysis, the relationship (1) for the temperature change of elastic refrigeration materials under stress is determined; Relation (1): Where, h is the thermal coefficient, Λ is the surface area, Text is the ambient temperature, T is the temperature of the elastic cooling material, l is the length of the elastic cooling material, and γ is the elastic thermal constant established according to equation (1); Get the relationship (2): T0 is the temperature of the elastic refrigeration material in the initial state, l0 is the length of the elastic refrigeration material in the initial state, l f is the tensile length of the elastic refrigeration material; T f is the temperature generated when the elastic refrigeration material is deformed; c is the heat capacity of the elastic refrigeration material obtained according to equation (2); Get the relationship (3): R c is the refrigeration capacity of the elastic refrigeration material, γ is the elastic thermal constant, T is the temperature of the elastic refrigeration material, c is the thermal melting of the elastic refrigeration material, and Δl is the deformation of the elastic refrigeration material; Get the relationship (4): ΔT adi is adiabatic temperature change, ΔS is isothermal entropy change, T is ambient temperature, and C is the specific heat capacity of the elastic refrigeration material under constant stress; Get the relationship (8): C COP，mat is the solid-state elastic refrigeration performance of the elastic refrigeration material, Q is the refrigeration capacity during the cycle, and W is the input work during the cycle; (b) testing the influence of elastic refrigeration material samples of different materials on refrigeration performance to obtain multiple performance parameters; making samples of elastic refrigeration materials of different materials and testing them to verify the accuracy of the model of step (a); through step (b), the relationship of step (a) can be verified and corrected; (c) applying the corrected relationship of the elastic cooling material to the battery and verifying it through actual testing; the elastic cooling material is made into a water cooling plate and used in the battery to cool it.

8. The method for improving the thermal safety performance of batteries by using elastic refrigeration materials according to claim 7, characterized in that: In the relation (4), ΔS is obtained through the relation (5): Relation (5): T0 is obtained by equation (6); Relation (6): Among them, Q is the latent heat of the phase change process of the elastic refrigeration material, Ms is the temperature at which the martensite phase change starts; Af is the temperature at which the austenite phase change ends; When the elasto-caloric effect presented by the phase change is of the first-order type, ΔS is obtained through equation (7); Relation (7): Δε represents the deformation; σ represents the uniaxial stress; T is the experimental temperature.

9. The method for improving the thermal safety performance of batteries by using elastic refrigeration materials according to claim 7, characterized in that: The water-cooling plate comprises a water-cooling base plate, a water inlet and a water outlet. The material of the water-cooling base plate comprises an elastic refrigeration material. The water inlet and the water outlet are located at both ends of the water-cooling base plate along its length direction. A cooling liquid channel is arranged inside the water-cooling base plate. The cooling liquid channel extends from one end of the water-cooling base plate to the other end. The cooling liquid channel has one or more cooling liquid channels, and the multiple cooling liquid channels are evenly distributed. The water-cooling plate has a wave configuration.

10. The method for improving battery thermal safety performance by using elastic refrigeration materials according to claim 9, characterized in that: The elastic refrigeration material comprises at least one of a copper-zinc-aluminum composite material, a nickel-titanium composite material, a nickel-titanium-copper composite material, an iron-palladium composite material, an iron-indium-palladium composite material, an iron-rhodium composite material, and a nickel-manganese-indium-cobalt composite material; And / or, the water-cooled plate further comprises a water circulation device, a water outlet of the water circulation device is connected to a water inlet of the water-cooled base plate, a water inlet of the water circulation device is connected to a water outlet of the water-cooled base plate, and the circulating liquid is cooled in the water circulation device to provide a coolant.

11. The method for improving battery thermal safety performance by using elastic refrigeration materials according to claim 10, characterized in that: The copper-zinc-aluminum composite material comprises Cu 68.13 Zn 15.74 Al1 6.13 and Cu 68 Zn 16 Al1 16 The nickel-titanium composite material comprises Ni 50 Ti 50 The nickel-titanium-copper composite material comprises Ni 32.5 Ti 50.4 Cu 12.6 The iron-palladium composite material comprises Fe 68.8 Pd 31.2 The iron-rhodium composite material includes Fe 49 R 51 The nickel-manganese-indium-cobalt composite material comprises Ni 45 Mn3 6.4 In 13.6 Co5.

12. The method for improving battery thermal safety performance by using elastic refrigeration materials according to claim 11, characterized in that: The water-cooling substrate comprises a middle layer, a first end layer and a second end layer, wherein the first end layer and the second end layer are located on both sides of the middle layer; The intermediate layer is Cu 68.13 Zn 15.74 Al1 6.13 and / or Cu 68 Zn 16 Al1 16 The first end layer and the second end layer are each independently Ni 50 Ti 50 、Ni 32.5 Ti 50.4 Cu 12.6 , Fe 68.8 Pd 31.2 , Fe 49 R 51 and Ni 45 Mn3 6.4 In 13.6 Any one of Co5.

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