Battery box and electric vehicle battery

Abstract

The invention discloses a battery box, the battery box is used for accommodating a battery, a ventilation pipeline is arranged on a bottom plate in the battery box, a fan is arranged in the ventilation pipeline, a plurality of ventilation holes are distributed in the battery box, and the diameter of the ventilation holes on the outer side of the battery box is larger than that on the inner side of the battery box. A thermoelectric power generation piece is embedded in at least one face of the battery box and electrically connected with the fan. The invention also discloses an electric vehicle battery. By adopting various heat dissipation and airflow adjusting mechanisms, the internal temperature of the battery box is ensured to be within a safe range, and the safety problem caused by overheating of the battery is prevented.

Description

Technical Field

[0001] The present invention relates to the field of electric vehicles, and in particular to a battery box and an electric vehicle battery. Background Art

[0002] With the popularity of electric vehicles and the rapid growth of the market share of new energy vehicles, the temperature control and safety issues of battery packs have become the focus of attention. In particular, lithium batteries are prone to thermal runaway or fire under high temperature conditions, and an efficient temperature control and fire extinguishing system is urgently needed to ensure the safety of batteries.

[0003] At present, battery temperature control technologies include air cooling system, liquid cooling system and phase change material (PCM). Air cooling system is a technology commonly used in existing battery boxes. By setting fans and heat dissipation channels inside the battery box, airflow is used to take away the heat generated by the battery, thereby adjusting the battery temperature. The airflow flows through the channels inside the battery box to reduce heat accumulation and keep the battery within a safe temperature range. The air cooling system usually relies on the air flow of the external environment and is suitable for temperature control requirements in ordinary environments or regular driving conditions. It has limited effect under high load or high temperature. At the same time, the air cooling system requires the battery itself to provide electricity to drive the fan, which adds an additional burden to a certain extent; the liquid cooling system achieves more effective heat dissipation through liquid cooling, but the system is complex and costly; phase change materials can absorb heat and alleviate temperature increases, but the reaction speed is slow. At the same time, some electric vehicle battery boxes have introduced automatic fire extinguishing systems. The fire extinguishing system adds an automatic fire extinguishing device to the battery box, such as embedding a fire extinguishing agent package or a temperature sensitive device in the battery box. When the battery temperature is too high or a fire occurs, the fire extinguishing agent is automatically released to extinguish the fire. Common fire extinguishing agents include powder fire extinguishing agents or gas fire extinguishing agents. Most fire extinguishing systems react slowly and rely on manual or delayed trigger mechanisms. They usually need to be manually started or activated after a fire occurs. They cannot prevent fires in time when the battery temperature is too high, and there are certain safety hazards.

[0004] In summary, existing battery boxes have defects such as insufficient heat dissipation effect, high cost, and slow response. Summary of the invention

[0005] The main purpose of the present invention is to solve the technical problems described in the background technology.

[0006] To achieve the above-mentioned purpose, the present invention provides a battery box, which is used to accommodate batteries. A ventilation duct is arranged on the bottom plate of the battery box, and a fan is arranged in the ventilation duct. A plurality of ventilation holes are distributed on the battery box, and the diameter of the ventilation holes on the outside of the battery box is larger than the diameter on the inside. A thermoelectric power generation sheet is embedded in at least one surface of the battery box, and the thermoelectric power generation sheet is electrically connected to the fan.

[0007] In one of the embodiments, the top plate of the battery box includes a first heat insulation layer and a first fire extinguishing layer from the outside to the inside, and the first fire extinguishing layer is inlaid with a plurality of capsules containing fire extinguishing agent and inert gas.

[0008] In one embodiment, the ventilation hole includes a contraction section, a throat and a diffusion section from the inside to the outside.

[0009] In one embodiment, the capsule is coated with a phase change material.

[0010] In one of the embodiments, the side panels of the battery box include a second heat insulation layer, a cooling layer and a second fire extinguishing layer from the outside to the inside, and the second fire extinguishing layer is inlaid with a plurality of capsules containing fire extinguishing agent and inert gas.

[0011] In one embodiment, the cooling layer is perfluorohexanone gas.

[0012] In one embodiment, the pressure inside the capsule is greater than the pressure outside the capsule.

[0013] In one embodiment, the second thermal insulation layer is made of chlorinated polyvinyl chloride resin material.

[0014] In one of the embodiments, a heat conductive sheet is provided at the bottom of the battery box, and the heat conductive sheet is tightly fitted with the hot end and the cold end of the thermoelectric power generation sheet.

[0015] In another aspect, the present invention provides an electric vehicle battery, comprising: a battery and a battery box as described in any one of the first aspects.

[0016] The present invention can improve temperature control efficiency and ensure battery safety. Through innovative airflow adjustment design (vent design) and temperature difference power generation design, the present invention can more efficiently reduce the temperature inside the battery box and ensure that the battery is always within a safe temperature range. Especially in high-load or high-temperature environments, traditional heat dissipation systems may not be able to fully cope with them. The airflow acceleration mechanism and self-adjusting fan speed design of the present invention can stably take away the heat generated by the battery, thereby effectively preventing battery overheating, thermal runaway and fire risks. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 This is a schematic diagram of the top plate structure of a battery box in one embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of the side plate structure of a battery box in one embodiment of the present invention;

[0020] Figure 3 Schematic diagram of the cross-sectional structure of a battery box in one embodiment of the present invention.

[0021] Figure 4 for Figure 3 Schematic diagram of the bottom plate structure of the battery box;

[0022] Figure 5 for Figure 3 Schematic diagram of the side panel structure of the middle battery box;

[0023] Component symbols in the figure:

[0024] 1. First thermal insulation layer; 2. First fire extinguishing layer; 21. Capsule; 3. Second thermal insulation layer; 4. Cooling layer; 5. Second fire extinguishing layer; 51. Capsule; 6. Ventilation hole; 7. Fan; 8. Temperature difference power generation sheet; 9. Heat conducting sheet. DETAILED DESCRIPTION

[0025] In order to better understand the above technical solution, exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0026] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0027] It should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the coordinate system shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0028] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0030] In a first aspect, the present invention provides a battery box, referring to Figure 1-5 In one embodiment, the battery box is used to accommodate batteries, a ventilation duct is provided on the bottom plate of the battery box, a fan 7 is provided in the ventilation duct, a plurality of ventilation holes 6 are distributed on the battery box, the diameter of the ventilation holes 6 on the outside of the battery box is larger than the diameter on the inside, a thermoelectric power generation sheet 8 is embedded in at least one surface of the battery box, and the thermoelectric power generation sheet 8 is electrically connected to the fan 7.

[0031] The fact that the diameter of the ventilation hole 6 on the outside of the battery box is larger than that on the inside utilizes the Bernoulli principle, which is an important principle in fluid mechanics. It means that in the stable flow of an ideal fluid (incompressible and inviscid), the sum of the pressure, kinetic energy and gravitational potential energy at a certain point in the fluid is a constant. Where P is the pressure at a point in the fluid, ρ is the fluid density, v is the flow velocity of the fluid at that point, and h is the height of the point relative to a certain reference surface. From the formula, it can be seen that when the flow velocity v of the fluid increases, When this term increases, in order to ensure that the constant on the right side of the equation remains unchanged, the pressure will decrease; conversely, when the flow velocity v decreases, the pressure P will increase; refer to Figure 3-5, 4 ventilation ducts are arranged on the bottom plate of the battery box, two ventilation ducts are arranged near the two ends of the bottom plate as a group, a fan 7 is arranged in each channel duct, and the fan 7 can accelerate the air flow inside and outside the battery box, and 3 evenly distributed temperature difference power generation sheets 8 are embedded between the two groups of ventilation ducts in the bottom plate, and the temperature difference power generation sheets 8 are connected in series with each other and electrically connected to the fan 7 to provide power for the fan 7. A plurality of ventilation holes 6 are arranged on the four side plates of the battery box. For the ventilation holes 6, please refer to Figure 5 : 24 ventilation holes 6 are evenly arranged on the side panels of the battery box.

[0032] In this embodiment, a plurality of ventilation holes 6 are distributed on the battery box, and are designed as an aperture structure with a large outside and a small inside according to the Bernoulli principle. When the external airflow enters the battery box through these holes, the flow rate is accelerated and the airflow temperature is reduced, thereby reducing the temperature inside the box. This design utilizes the change in air flow rate and pressure to optimize the orifice design of the ventilation holes 6, increases the flow rate of the airflow, and enables the airflow to effectively take away the heat generated by the battery, thereby achieving the purpose of cooling. At the same time, the battery box will generate heat energy when working. By arranging a thermoelectric power generation sheet 8 to utilize the temperature difference between the inside and outside of the battery box and drive the fan 7 in the battery box, the burden on the battery in the battery box can be reduced, and the heat generated by the battery box when working can be fully utilized. The thermoelectric power generation sheets 8 are connected in series, and the temperature difference is converted into electrical energy through the thermoelectric effect, thereby providing power for the fan 7 and driving the airflow circulation. The thermoelectric power generation effect formula is: V TE =α·ΔT·n, where α is the thermoelectric coefficient of the thermoelectric material, ΔT is the temperature difference between the inside and outside of the battery box, and n is the number of thermoelectric sheets 8 connected in series. By optimizing the configuration of the thermoelectric sheet 8, the power generation efficiency can be improved to ensure that the fan 7 can work stably under high temperature conditions; the fan 7 in the battery box is powered by the thermoelectric sheet 8, and the fan 7 sucks the hot air in the battery box and discharges it to the outside. This design eliminates the dependence on additional battery power, allowing the fan 7 to operate autonomously. This self-powered design not only improves the energy efficiency, but also reduces the impact on the battery burden, helps to extend the battery life, and reduces the system energy consumption. When the fan 7 is working, it drives the airflow through the ventilation holes 6 of the four panels, so that the air flows through the inside of the battery box, taking away excess heat, thereby adjusting the internal temperature; when the battery box burns, the temperature difference reaches the maximum, and the speed of the fan 7 is also the maximum, which maximizes the heat dissipation inside the battery box.

[0033] In one embodiment, referring to Figure 1-5 The top plate of the battery box includes a first heat insulation layer 1 and a first fire extinguishing layer 2 from the outside to the inside, and the first fire extinguishing layer 2 is inlaid with a plurality of capsules 21 with fire extinguishing agent and inert gas inside.

[0034] Among them, the first insulation layer 1 and the first fire extinguishing layer 2 of the top cover fire extinguishing structure of the present design in this application can be made of CPVC (chlorinated polyvinyl chloride resin) material, which has good thermal insulation performance, and the capsule 21 is embedded in the first fire extinguishing layer 2; the fire extinguishing agent in the capsule 21 is a powder fire extinguishing agent. It is worth noting that part of the capsule 21 is exposed outside the first fire extinguishing layer 2 and is in contact with the air inside the battery box, so that it is convenient to break in time to exert its fire extinguishing effect when an emergency occurs.

[0035] In this embodiment, by designing a fire extinguishing structure on the top plate of the battery box, the first heat insulation layer 1 can effectively block the external heat from entering the battery box, reduce the impact of the ambient temperature on the battery, help maintain the battery operating in an appropriate temperature range, and improve the battery performance and life. When the temperature in the battery box is too high and a fire is caused, the capsule 21 embedded in the first fire extinguishing layer 2 ruptures to release the fire extinguishing agent and inert gas, which can quickly suppress the fire, reduce the damage to the battery and the vehicle, and ensure the safety of personnel and vehicles.

[0036] In one embodiment, referring to Figure 1-5 The ventilation hole 6 includes a contraction section, a throat and a diffusion section from the inside to the outside.

[0037] The size design of the contraction section, throat and diffusion section of the ventilation hole 6 needs to be accurately calculated and optimized according to factors such as the heat generated in the battery box, the power of the fan 7 and external environmental conditions.

[0038] In this embodiment, when air flows through the ventilation holes 6, the flow velocity is accelerated and the pressure is reduced at the throat, thereby generating a suction effect, which can enhance the exchange efficiency of air inside and outside the battery box. Compared with ordinary ventilation holes 6, it can more effectively discharge the hot air in the battery box and introduce cold air from the outside, thereby improving the heat dissipation capacity of the battery box, ensuring that the battery works under good heat dissipation conditions, and preventing the battery performance from being reduced or even causing safety problems due to overheating.

[0039] In one embodiment, referring to Figure 1-5 , the capsule 21 is wrapped by a phase change material.

[0040] Among them, the phase change material remains solid at room temperature. When the temperature of the battery box rises to the set threshold, the material undergoes a phase change, releasing heat. Under the action of internal pressure, the fire extinguishing agent and gas in the capsule 21 are pushed out. The fire extinguishing agent covers the surface of the battery, and the inert gas reduces the oxidation reaction, thereby achieving the fire extinguishing and flame retardant function.

[0041] In this embodiment, by providing a phase change material to wrap the capsule 21, the capsule 21 is ruptured within a suitable temperature range to release the fire extinguishing agent and the inert gas, thereby improving the response accuracy and reliability of the fire extinguishing system. At the same time, the phase change material can also regulate the temperature in the battery box to a certain extent, assisting the heat insulation and heat dissipation functions of the battery box.

[0042] In one embodiment, referring to Figure 1-5 The side panels of the battery box include a second heat-insulating layer 3, a cooling layer 4 and a second fire-extinguishing layer 5 from outside to inside, and the second fire-extinguishing layer 5 is inlaid with a plurality of capsules 51 containing fire-extinguishing agent and inert gas.

[0043] Among them, the present design is the side automatic fire extinguishing mechanism of the present application. The second heat insulation layer 3 and the second fire extinguishing layer 5 can be made of CPVC (chlorinated polyvinyl chloride resin) material, which has good heat insulation performance. The cooling layer 4 of the middle layer adopts perfluorohexanone gas. The capsule 51 is embedded in the second fire extinguishing layer 5. It is worth noting that part of the capsule 51 is exposed outside the second fire extinguishing layer 5 and contacts with the air inside the battery box, so that it is convenient to break in time to play its fire extinguishing role when an emergency occurs; the cooling layer 4 adopts perfluorohexanone gas; refer to Figure 3 Since the battery box is provided with a plurality of ventilation holes 6 , the capsules 51 are not completely distributed on the side panels, and the distribution of the capsules can be specifically adjusted according to the positions of the ventilation holes 6 .

[0044] Specifically, when the temperature inside the battery box is too high and exceeds the set threshold, the phase change material undergoes a phase change, causing the capsule 51 to rupture, releasing the powdered fire extinguishing agent and inert gas for preliminary fire extinguishing. After the capsule 51 ruptures, the perfluorohexanone gas is ejected under the action of the internal pressure and fills the battery box again for secondary fire extinguishing; in this embodiment, a cooling layer 4 is provided between the second fire extinguishing layer 5 and the second heat insulation layer 3, providing secondary protection for the fire extinguishing of the battery box.

[0045] In this embodiment, the second heat insulation layer 3 further blocks the external heat from being transmitted from the side panels into the battery box, and works together with the first heat insulation layer 1 of the top plate to reduce the impact of the ambient temperature on the battery in all directions. The perfluorohexanone gas in the cooling layer 4 has good cooling performance, can absorb the heat generated by the battery, reduce the temperature in the battery box, and improve the heat dissipation efficiency of the battery. The capsules 51 on the second fire extinguishing layer 5 release fire extinguishing agents and inert gases when a fire occurs, and work together with the fire extinguishing layer of the top plate to enhance the fire extinguishing ability and effectively protect the safety of the battery and the vehicle.

[0046] In one embodiment, referring to Figure 1-5 , the cooling layer 4 is perfluorohexanone gas.

[0047] In this embodiment, the perfluorohexanone gas has excellent cooling performance. It can quickly absorb the heat generated by the battery and volatilize it away, achieving an efficient cooling effect. At the same time, perfluorohexanone is a clean coolant that will not pollute the battery and the environment, and has stable chemical properties under normal use conditions. It can reliably provide long-term and stable cooling function for the battery box, which helps to maintain the good working condition of the battery and extend the battery life.

[0048] In one embodiment, referring to Figure 1-5 , the pressure inside the capsule 51 is greater than the pressure outside the capsule 51.

[0049] In this embodiment, when a fire occurs in the battery box and the temperature rises sharply, since the pressure inside the capsule 51 is greater than the external pressure, the capsule 51 is more likely to rupture, and can quickly release the internal fire extinguishing agent and inert gas to extinguish the flames in time and prevent the fire from spreading, thereby providing more timely and effective fire protection for the battery and the vehicle and reducing the losses caused by the fire.

[0050] In one embodiment, referring to Figure 1-5 The second heat insulation layer 3 is made of chlorinated polyvinyl chloride resin material.

[0051] In this embodiment, the chlorinated polyvinyl chloride resin material has good thermal insulation properties, can effectively block external heat from entering the battery box, reduce the impact of ambient temperature on the battery, maintain the battery working in a suitable temperature range, and improve the performance and stability of the battery. At the same time, the material also has certain flame retardant properties, which enhances the fire safety of the battery box to a certain extent.

[0052] In one embodiment, referring to Figure 1-5 The second fire extinguishing layer 5 is made of chlorinated polyvinyl chloride resin material.

[0053] In this embodiment, the chlorinated polyvinyl chloride resin material has certain flame retardant properties. As the second fire extinguishing layer 5, it can delay the spread of fire when a fire occurs, buy time for the capsule 51 to rupture and release the fire extinguishing agent and inert gas, and enhance the fire extinguishing effect. At the same time, the fire extinguishing structure formed by it and the capsule 51 can more effectively suppress the fire, protect the battery and other components in the battery box, and improve the fire safety performance of the vehicle.

[0054] In one of the embodiments, a heat conducting sheet 9 is provided at the bottom of the battery box, and the heat conducting sheet 9 is tightly fitted with the hot end and the cold end of the temperature difference power generation sheet 8 .

[0055] When the heat conducting sheet 9 is installed at the bottom of the battery box, a material such as a heat conducting glue may be used to fill the middle to reduce thermal resistance.

[0056] In this embodiment, the heat conducting sheet 9 can quickly transfer the heat at the bottom of the battery box to the hot end of the thermoelectric power generation sheet 8, and dissipate the heat at the cold end, thereby maintaining the temperature difference at both ends of the thermoelectric power generation sheet 8 and improving the power generation efficiency of the thermoelectric power generation sheet 8. The electric energy generated by the thermoelectric power generation sheet 8 powers the fan 7, which accelerates the air flow and takes away the heat in the battery box, realizing the energy conversion using the temperature difference at the bottom of the battery box to provide power for the heat dissipation system, thereby achieving the dual effects of energy saving and optimized heat dissipation.

[0057] In a second aspect, the present invention provides an electric vehicle battery, comprising: a battery and a battery box as described in any one of the first aspects.

[0058] In the present application, the temperature inside the battery box can be effectively adjusted through the temperature control design (power is provided to the fan 7 according to the temperature difference between the inside and outside) and the automatic fire extinguishing mechanism, and the fire can be automatically extinguished when the battery is overheated or a fire occurs; the temperature control system combines airflow regulation and temperature difference power generation technology to ensure the stability of the temperature inside the box and avoid overheating of the battery; the fire extinguishing system combines the phase change material with the capsule 21 / 51 filled with powder fire extinguishing agent and cooperates with the gas fire extinguishing agent to achieve rapid fire extinguishing in the early stage of the fire and ensure the safety of the battery box. The battery box has an efficient and reliable temperature control and safety design; compared with the traditional manual or delayed start fire extinguishing system, the automatic fire extinguishing mechanism of the present application can be activated immediately when the initial overheating or fire occurs, ensuring that the battery box can be promptly and effectively handled in the event of danger, thereby greatly improving the safety of the electric vehicle.

[0059] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A battery box, characterized in that: The battery box is used to accommodate batteries. A ventilation duct is arranged on the bottom plate of the battery box. A fan is arranged in the ventilation duct. A plurality of ventilation holes are distributed on the battery box. The diameter of the ventilation holes on the outside of the battery box is larger than the diameter on the inside. A thermoelectric power generation sheet is embedded in at least one surface of the battery box, and the thermoelectric power generation sheet is electrically connected to the fan.

2. The battery box according to claim 1, characterized in that: The top plate of the battery box includes a first heat insulation layer and a first fire extinguishing layer from outside to inside, and the first fire extinguishing layer is inlaid with a plurality of capsules containing fire extinguishing agent and inert gas.

3. The battery box according to claim 2, characterized in that: The capsule is surrounded by a phase change material.

4. The battery box according to claim 1, characterized in that: The ventilation hole comprises a contraction section, a throat pipe and a diffusion section from the inside to the outside.

5. The battery box according to claim 1, characterized in that: The side plate of the battery box includes a second heat insulation layer, a cooling layer and a second fire extinguishing layer from the outside to the inside, and the second fire extinguishing layer is inlaid with a plurality of capsules containing fire extinguishing agent and inert gas.

6. The battery box according to claim 5, characterized in that: The cooling layer is perfluorohexanone gas.

7. The battery box according to claim 5, characterized in that: The pressure inside the capsule is greater than the pressure outside the capsule.

8. The battery box according to claim 6, characterized in that: The second heat insulation layer is made of chlorinated polyvinyl chloride resin material.

9. The battery box according to claim 1, characterized in that: A heat conducting sheet is arranged at the bottom of the battery box, and the heat conducting sheet is closely fitted with the hot end and the cold end of the temperature difference power generation sheet.

10. An electric vehicle battery, comprising: A battery and a battery box as claimed in any one of claims 1 to 9.

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