WO2024061197A1

WO2024061197A1 - Battery and means of transport

Info

Publication number: WO2024061197A1
Application number: PCT/CN2023/119632
Authority: WO
Inventors: 王乾新
Original assignee: 舜传科技(深圳)有限公司
Priority date: 2022-09-23
Filing date: 2023-09-19
Publication date: 2024-03-28
Also published as: CN116207399A

Abstract

A battery and a means of transport, which relate to the technical field of lithium batteries. When the battery is in an operating condition of use, a battery casing includes two or more separate flat sealing cavities for phase-change heat transfer in the gravity direction and/or horizontal direction of a side surface casing wall and/or an upper bottom surface and/or a lower bottom surface; part or all of cavity walls of the sealing cavities are part of the casing; and a phase-change heat transfer working medium filled in the sealing cavities can be in direct contact with the battery casing to carry out heat transfer. A thermal management system based on the battery has a better capability to inhibit thermal runaway caused after stalling, and a space utilization rate of a battery system is increased.

Description

A kind of battery and transportation tool

Technical field

The present invention relates to the technical field of lithium batteries, specifically a battery and a transportation tool.

Background technique

Lithium batteries are widely used in new energy fields such as electric vehicles, electric ships, and power storage. Lithium battery thermal management is a key technology for lithium battery applications, involving the safety of lithium battery use and the working life of lithium batteries.

Liquid cooling is gradually becoming the mainstream technology for lithium battery thermal management. There are three main forms of lithium batteries, namely cylindrical batteries, soft pack batteries and prismatic batteries. The liquid cooling solution for cylindrical batteries is to use a snake-shaped liquid cooling plate to contact the cylindrical battery shell for heat exchange, and the heat generated by the battery is taken away by the refrigerant flowing in the liquid cooling plate; the liquid cooling solution for soft-pack batteries is to use soft-pack batteries It is sandwiched in the middle of the liquid-cooled plate for heat exchange, and the heat generated by the battery is taken away by the refrigerant flowing in the liquid-cooled plate; the liquid cooling solution for square batteries is to set up a liquid-cooled plate under the square battery for heat exchange, and through the liquid-cooled plate The flowing refrigerant takes away the heat generated by the battery. For these three battery forms and their liquid cooling solutions, each has its own advantages and disadvantages. For example, the heat exchange effect of liquid cooling solutions for columnar and soft-pack batteries is good, but the space utilization of the battery system is low. The heat exchange effect of liquid cooling solutions for prismatic batteries is poor. Poor, but the space utilization of the battery system is high. The liquid cooling solutions of the above three battery forms all have a common shortcoming. When the electric car is turned off, the liquid in the liquid cooling plate no longer flows. The heat emitted by the short circuit caused by the aging of the battery cannot be quickly dispersed, and the accumulation of heat will cause Thermal runaway occurs, that is, it is difficult to suppress thermal runaway when stalling. Statistics on thermal runaway accidents of Chinese trams in 2021 show that about 25% of trams occurred in a stalled state. Moreover, with the development of ultra-fast charging technology, the current liquid cooling solutions for prismatic batteries can no longer meet the heat dissipation needs of lithium batteries, and the liquid cooling solutions for cylindrical batteries and soft-pack batteries have low space utilization. In short, the current liquid cooling solutions used in cylindrical batteries, soft pack batteries, and prismatic batteries are not ideal.

Chinese invention patent CN201910078281.5 discloses a lithium battery and a lithium battery packaging case. The technical solution of the invention is to integrate a phase change heat transfer cavity on the battery case, and use phase change heat transfer to quickly transfer heat away. However, the phase change heat transfer technical solution disclosed in this invention cannot achieve reverse gravity heat transfer, that is, the phase change heat transfer working medium cannot overcome gravity and return, and the heat generated by the battery can only be transmitted upward. For this reason, the invention patent has a surface on the aluminum shell of the battery. , A water channel is arranged at the top of the phase change heat transfer cavity. Through phase change heat transfer, the heat is quickly collected into the top water channel and then taken away. This invention fails to solve the technical problems of lithium battery liquid cooling technology such as difficulty in suppressing flameout thermal runaway and low space utilization.

Chinese invention patent CN202111218813.4 discloses a square battery casing and batteries, battery packs and cars using the casing. The lithium battery casing disclosed in this invention contains a phase change heat transfer cavity, and a liquid-absorbing wick is set in the sealed cavity. It has the ability to transfer heat against gravity, and can adopt a liquid cooling solution of setting a liquid cooling plate under the battery. , this solution can simultaneously solve the technical problems of lithium battery liquid cooling technology such as difficulty in suppressing flameout thermal runaway and low space utilization. Due to the low density and cheap price of aluminum, square batteries usually use aluminum shells. The water phase change heat transfer fluid is not suitable for working in aluminum sealed cavities. The phase change heat transfer fluid is suitable for working in aluminum cavities and is against gravity. The reflow capacity is only one-third of that of water phase change heat transfer fluid, which limits the height of prismatic lithium batteries and makes them difficult to apply.

Integrating a phase change heat transfer cavity on the battery case and placing the liquid cooling plate at the bottom of the battery are the most promising methods of overcoming the two major shortcomings of the current liquid cooling solution for thermal management of lithium batteries (weak ability to suppress flameout thermal runaway and low battery system space utilization). (low) technical solution, the key to the problem is how to solve the technical problem of rapid reflow of phase change heat transfer fluid against gravity.

technical problem

The purpose of the present invention is to provide a battery and a transportation vehicle, aiming to overcome the two major shortcomings of the lithium battery liquid cooling and heat management solution, namely, the weak ability to suppress flameout thermal runaway and the low space utilization of the battery system.

Technical Solutions

In order to achieve the above object, the present invention adopts the following technical solution: a battery. Under use conditions, the battery casing contains more than two flat sealed cavities with independent phase change heat transfer in the direction of gravity of the side shell wall. , part or all of the cavity walls of the sealed cavity are part of the shell, and the phase change heat transfer fluid poured into the sealed cavity can directly contact the battery shell for heat exchange.

A further technical solution of the present invention is that, under operating conditions, the battery casing includes two or more flat sealed cavities with independent phase change heat transfer in the horizontal direction on the side and/or the upper bottom surface and/or the lower bottom surface. , part or all of the cavity walls of the sealed cavity are part of the shell, and the phase change heat transfer fluid poured into the sealed cavity can directly contact the battery shell for heat exchange.

A further technical solution of the present invention is that the distance between adjacent sealed cavities is ≤5cm.

A further technical solution of the present invention is that the two inner surfaces of the sealed cavity are partially welded together.

A further technical solution of the present invention is that wires, meshes or plates are provided in the sealed cavity to improve the heat transfer capability against gravity.

A further technical solution of the present invention is that the inner surface of the sealed cavity undergoes chemical etching or/and laser or/and ion beam surface treatment to improve the anti-gravity heat transfer capability.

A further technical solution of the present invention is that the battery casing includes a first shell and a second shell, and the first shell and/or the second shell have 1 or 2 openings. The bodies are nested together, and the two cavity walls of the phase change heat transfer sealed cavity provided in the battery casing include a first shell and a second shell.

A further technical solution of the present invention is that the outer surface of the battery casing is provided with heat dissipation fins.

A further technical solution of the present invention is that the inner surface of the sealed cavity is mechanically processed to form micro-grooves or/and rough surfaces to improve the anti-gravity heat transfer capability.

A transportation tool, including the battery described in any one of the above.

beneficial effects

The beneficial effects of the present invention are:

1. The side walls of the battery casing contain two or more flat sealed cavities with independent phase change heat transfer in the horizontal direction. Part or all of the walls of the sealed cavity are part of the battery casing. The phase change heat transfer fluid is infused into the sealed cavity. The phase change heat transfer fluid in the sealed cavity can directly contact the battery shell. This overall improves the ability of the battery to exchange heat with the external environment, especially in conjunction with the liquid cooling thermal management system. It enhances the ability to suppress thermal runaway when a tram stalls and improves the space utilization of the lithium battery system.

2. The two inner surfaces of the sealed cavity wall are partially welded together through solder joints. The solder joints will not lead to the isolation of the liquid or vapor phase change heat transfer medium in the sealed cavity. The setting of the solder joints enhances the sealing cavity. Strength, to prevent the cavity from bulging and excessive deformation when the vapor phase change heat transfer medium expands due to heat.

Description of drawings

Figure 1 is a schematic diagram of the first embodiment of the present invention;

Figure 2 is a schematic diagram of a comparative solution according to the first embodiment of the present invention;

Figure 3 is a schematic diagram of tilting conditions according to the first embodiment of the present invention;

Figure 4 is a schematic diagram of the second embodiment of the present invention;

Figure 5 is a schematic diagram of the tilt working condition of the second embodiment of the present invention;

Figure 6 is a schematic diagram of the third embodiment of the present invention;

Figure 7 is a schematic diagram of the fourth embodiment of the present invention.

Best Mode of Carrying Out the Invention

Using phase change heat transfer technology to improve the heat exchange capacity between the lithium battery casing and the liquid cooling plate is a feasible method to suppress thermal runaway and improve the space utilization of the lithium battery system. However, it is necessary to solve the problem of the phase change heat transfer medium under anti-gravity conditions. The technical problem of being able to quickly reflow to the heat source is the problem to be solved by the present invention.

The specific embodiments of the present invention will be further described below with reference to the accompanying drawings.

Figure 1 shows a first embodiment of the present invention, a battery. Under use conditions, the side walls of the battery casing 20 include two or more flat sealed cavities for independent phase change heat transfer in the direction of gravity. Body 40, part or all of the cavity wall of the sealed cavity 40 is part of the battery shell, the sealed cavity 40 is filled with a phase change heat transfer medium, and the phase change heat transfer medium poured in the sealed cavity 40 can directly contact the battery The shell improves the heat exchange and heat transfer performance as a whole; in this embodiment, three flat sealed cavities 401, 402 and 403 for independent phase change heat transfer are provided. The area between is A1, the area between sealed cavity 402 and sealed cavity 403 is A2, the area between sealed cavity 403 and the contact surface of the battery shell and the liquid cooling plate is A3, the heights of A1, A2 and A3 ≤ 5cm. In this embodiment, the heights of A1 and A2 are 1mm, and the height of A3 is 5mm. Under normal charging and discharging conditions, the heat generated inside the battery will be transferred to the casing 20, causing the temperature of the casing 20 to rise; when the sealed cavity 403 is heated, the liquid phase change heat transfer medium in the 403 cavity will absorb heat It changes into a vapor state and fills the sealed cavity. Since the liquid cooling plate takes away the heat in the sealed cavity 403 area near the A3 area, the temperature will be low. The vapor phase change heat transfer medium releases heat here. becomes a liquid, and the released heat is conducted to the liquid cooling plate 50 through the A3 area, and the phase change heat transfer medium that becomes liquid overcomes gravity and flows back to everywhere in the sealed cavity 403, and starts the next round of phase change heat transfer. Thermal cycling. The heat transfer of the sealed cavity 402 is similar to that of the sealed cavity 403. The difference is that the vapor phase change heat transfer medium in the sealed cavity 402 releases heat at the bottom of the sealed cavity 402 and turns into liquid reflux. The released heat is conducted through the A2 area. to the sealed cavity 403, and then transferred to the liquid cooling plate 50 through the sealed cavity 403. The heat transfer process of the sealed cavity 401 is similar to that of the sealed cavity 402, and its heat transfer path is: 401 sealed cavity → A1 area → 402 sealed cavity → A2 area → 403 sealed cavity → A3 area → liquid cooling plate 50 .

Figure 2 is a schematic diagram of only one sealed cavity 40 being provided in the gravity direction of the side wall of the battery casing 20. In Figure 2, the area at point B generates heat, and the liquid phase change heat transfer medium in the bottom area of point A needs to flow back to B. , and in Figure 1, the area of point B generates heat, and only the liquid phase change heat transfer medium in the bottom area of the sealed cavity 401 where point A' is located needs to flow back to point B. The strokes between the two are very different, resulting in phase change. The return speed of the variable heat transfer working fluid is very different, that is, the heat transfer capacity is very different. It is even difficult for the phase change heat transfer fluid to flow back from the bottom area where point A is in Figure 2 to point B, and phase change heat transfer cannot be achieved. Although it seems that the heat transfer path in Figure 1 is complicated, the heat transfer effect is far better than that in Figure 2. For the aluminum shell commonly used in lithium batteries, the matching phase change heat transfer medium is restricted by factors such as anti-gravity capability, environmental protection, cost, etc. The solution in Figure 2 cannot meet application needs under most operating conditions.

As shown in FIG. 3 , it is a schematic diagram of the first embodiment under the climbing condition of the electric transportation vehicle. Taking the sealed cavity 401 as an example, under the action of gravity, the liquid phase change heat transfer medium gathers in the area near point A'. If the heat at B suddenly increases, the liquid phase change heat transfer medium at point A' needs to overcome gravity. Reflow to point B to complete the phase change heat transfer, but still faces the problem of slow reflow speed.

In order to meet the heat transfer requirements of multiple working conditions at the same time, Figure 4 shows a second embodiment of the present invention. The sealed cavity 40 includes more than two flat sealed cavities with independent phase change heat transfer in the horizontal direction, as shown in Figure The sealing chambers shown in 4 are arranged in three rows in the horizontal direction. The first row is four independent sealing chambers 4011, 4012, 4013, and 4014, and the second row is four independent sealing chambers 4021, 4022, 4023, and 4024. The third row of cavities is four sealed cavities 4031, 4032, 4033, and 4034. Some or all of the walls of the sealed cavities are part of the battery casing. In the second embodiment of the present invention, under the uphill working condition of an electric vehicle, as shown in Figure 5, the liquid phase change heat transfer medium only needs to flow back from point A" to point B, instead of from point A' as shown in Figure 3. When point B flows back to point B, the stroke of the phase change heat transfer medium is greatly reduced, the return speed is faster, and the heat transfer effect is better. The present invention does not limit the shape of each independent sealed cavity, which can be a regular polygon or a regular polygon. It is an irregular shape.

As shown in Figure 6, it is the third embodiment of the present invention. The difference from the second embodiment is that multiple welding spots 60 are provided in each sealed cavity, and the two inner surfaces of the sealed cavity wall are connected through the welding spots. Partially welded together, the solder joints will not lead to the isolation of the liquid or vapor phase change heat transfer medium in the sealed cavity. The setting of the welding joints enhances the strength of the sealed cavity and avoids the thermal expansion of the vapor phase change heat transfer medium. time, causing the cavity to expand and bulge, resulting in excessive deformation.

As shown in Figure 7, it is a fourth embodiment of the present invention, a battery. The battery housing includes a first housing 10 and a second housing 20. The first housing 10 and the second housing 20 each have one or two Each opening can be made by extrusion or stretching. The cross-sections of the first housing 10 and the second housing 20 can be polygonal shapes such as quadrilateral or pentagonal shapes, or curved shapes such as circles or ellipses. The external dimensions of the first housing 10 are slightly smaller than the internal dimensions of the second housing 20 , and the first housing 10 is inserted into the second housing 20 . Weld the edges of the first housing 10 and the second housing 20 to leave a vacuum port and a liquid filling port. After vacuuming and filling the liquid, weld and seal the vacuum port and the liquid filling port, and then seal the vacuum port and the liquid filling port on the second housing. Part or all of the surface of 20 is pressure welded and/or laser welded to form multiple sealed cavities with independent phase change heat transfer as shown in Figure 4 . In this fourth embodiment, a laser is used to form vertical groove morphology and microstructure on the surface 30 of the first shell to enhance the anti-gravity heat transfer capability of the phase change heat transfer medium.

The present invention does not limit the shape and arrangement of the sealed cavities. As long as multiple independent sealed cavities are provided in the vertical or/and horizontal direction to overcome the technical problem of heat transfer against gravity, they all fall within the scope of the present invention. The present invention does not limit the material of the battery casing, which can be aluminum-based alloy, stainless steel or other alloys. The present invention does not limit the phase change heat transfer working fluid, which can be water, ethanol, acetone, ammonia, etc. In all embodiments of the present invention, the phase change heat transfer working fluid used is acetone. The present invention does not limit the shape and material of the wires, meshes, and plates provided in the phase change heat transfer sealed cavity. They can be metallic aluminum-based, nickel-based, copper-based, or non-metallic. In the embodiments of the present invention, no This method is used to improve the ability of the phase change heat transfer medium to overcome gravity. The present invention does not limit the surface treatment method of the inner surface of the sealed cavity. It can be laser, chemical corrosion, ion beam sputtering coating or ion beam bombardment. In all embodiments of the present invention, laser surface modification is used. Way. The welding method used to form the sealed cavity is not limited in the present invention. It can be laser, mechanical friction welding, pressure welding, etc. In this embodiment, a combination of laser and pressure welding is used. In an embodiment of the present invention, the distance between two adjacent sealed cavities is less than or equal to 5cm, preferably 5mm, and the distance between the inner surfaces of the sealed cavities is less than or equal to 5mm, preferably 2mm.

In the description of the present invention, unless otherwise expressly stipulated and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection. 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 an internal connection between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood on a case-by-case basis. In the description of the present invention, the meaning of "more than two" includes two.

It is obvious to those skilled in the art that the present invention is not limited to the details of the above-described exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be regarded as illustrative and non-restrictive from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is therefore intended that all claims falling within the claims All changes within the meaning and scope of equivalent elements are included in the present invention. Any reference signs in the claims shall not be construed as limiting the claim in question.

In addition, it should be understood that although this specification is described in terms of implementations, not each implementation only contains an independent technical solution. This description of the specification is only for the sake of clarity, and those skilled in the art should take the specification as a whole. , the technical solutions in each embodiment can also be appropriately combined to form other implementations that can be understood by those skilled in the art.

Claims

A battery, characterized in that: under operating conditions, the battery casing contains more than two flat sealed cavities for independent phase change heat transfer in the direction of gravity of the side shell walls, and the sealed cavities Part or all of the cavity wall is part of the shell, and the phase change heat transfer fluid poured into the sealed cavity can directly contact the battery shell for heat exchange.
The battery according to claim 1, characterized in that: under operating conditions, the battery casing side and/or upper bottom surface and/or lower bottom surface include two or more independent phase-change heat-transmitting flat elements in the horizontal direction. A sealed cavity is formed in the shape of a sealed cavity. Part or all of the cavity walls of the sealed cavity are part of the shell. The phase change heat transfer fluid poured into the sealed cavity can directly contact the battery shell for heat exchange.
The battery according to claim 1 or 2, characterized in that the distance between adjacent sealed cavities is ≤5cm.
The battery according to claim 1 or 2, characterized in that: the two inner surfaces of the sealed cavity are partially welded together.
The battery according to claim 1 or 2, characterized in that: wires, meshes or plates are provided in the sealed cavity to improve the anti-gravity heat transfer capability.
The battery according to claim 1 or 2, characterized in that: the inner surface of the sealed cavity undergoes chemical etching or/and laser or/and ion beam surface treatment to improve the anti-gravity heat transfer capability.
The battery according to claim 1 or 2, characterized in that: the battery casing includes a first shell and a second shell, the first shell and/or the second shell have 1 or 2 openings, the first The casing and the second casing are nested together, and the two cavity walls of the phase change heat transfer sealed cavity provided in the battery casing contain the first casing and the second casing.
The battery according to claim 1 or 2, characterized in that: the outer surface of the battery casing is provided with heat dissipation fins.
The battery according to claim 1 or 2, characterized in that the inner surface of the sealed cavity is machined to form micro grooves and/or a rough surface to improve the heat transfer capacity against gravity.
A means of transportation, characterized by: including the battery described in any one of claims 1 to 9.