Immersed cooling energy storage battery pack

Abstract

The invention discloses an immersed cooling energy storage battery pack which comprises a box body, a flat heat pipe, a battery cell and a liquid cooling runner plate, a battery area and an electrical area are arranged in the box body; the battery area is filled with immersion liquid; the flat heat pipe is fixed on the inner wall of the battery area; a mounting groove is formed between every two adjacent flat heat pipes; the battery cell is embedded in the mounting groove, and the two side surfaces of the battery cell are bonded and fixed with the outer wall of the flat heat pipe; and the liquid cooling runner plate is fixed on the outer wall of the box body. The box body is divided into the electrical area and the battery area which are independent of each other, so that the leakage problem of the immersed battery pack is solved, and corrosion pollution of electrical elements is prevented; the liquid cooling runner plate can improve the structural strength of the box body, the flat heat pipe is introduced into the battery area, heat exchange of the battery pack is achieved through the flat heat pipe and the liquid cooling runner plate, the heat exchange performance of a product is improved, under the condition that the battery cell is in thermal runaway, the immersion liquid in the battery area can absorb heat generated by thermal runaway of the battery cell, meanwhile, the immersion liquid isolates the battery cell from air, and the battery cell is prevented from being damaged. The thermal safety performance of the battery pack is improved.

Description

Technical Field

[0001] This invention relates to the field of lithium-ion battery technology, and more specifically to an immersion-cooled energy storage battery pack. Background Technology

[0002] With the development of lithium battery technology and the industry, battery safety has become a major concern. To improve safety, energy storage products typically incorporate thermal insulation materials between cells or install sensors and active fire suppression systems within the battery pack. These measures play a role in suppressing thermal runaway in lithium-ion battery products.

[0003] In recent years, immersion cooling technology has attracted much attention in the energy storage industry due to its inherent safety. However, immersion cooling technology also has some problems, such as large coolant consumption, high energy consumption, and susceptibility to leakage.

[0004] Compared to traditional liquid cooling products, immersion cooling technology uses approximately 30 times more coolant. The coolant itself needs to be conditioned before cooling and heating, resulting in lower system heat exchange efficiency and higher energy consumption due to the significant energy required to conditioned a large volume of coolant. Existing immersion-cooled battery enclosures are mostly constructed using stamping and welding or extrusion and welding of profiles. The welding process easily creates micropores or weld seams. After the immersion fluid is injected into the enclosure, it can leak through these micropores or seams due to liquid siphoning. Micropores or gaps also exist in the seals of electrical connectors within the enclosure, leading to leakage problems after prolonged immersion in the fluid.

[0005] In existing technologies, immersion cooling systems consume a lot of energy during cooling and heating, and the sealing and structural strength of the enclosure are insufficient, making them prone to leakage and thermal runaway. These problems limit the widespread application of immersion cooling technology in the field of energy storage batteries.

[0006] Therefore, there is an urgent need to provide a battery pack that can solve the problems of leakage in the submerged energy storage battery box and the high energy consumption of the submerged cooling system during the heating and cooling process. Summary of the Invention

[0007] In view of this, the present invention provides an immersion-cooled energy storage battery pack, which increases the heat exchange area by adding a flat heat pipe to the large surface of the cell, while reducing the heat exchange between the immersion liquid and the thermal management system during the thermal management process, thereby reducing thermal management energy consumption, improving battery thermal safety performance, and reducing costs.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: An immersion-cooled energy storage battery pack includes: The housing is divided into a battery area and an electrical area from left to right by a partition; the battery area is filled with an immersion liquid. The device includes multiple flat heat pipes, with both ends of each heat pipe fixed to the inner walls of the housing corresponding to the battery area. Adjacent heat pipes and the inner walls of the housing together form an installation groove. A battery cell, wherein the battery cell is embedded in the mounting groove and its two side surfaces are bonded and fixed to the outer wall of the flat heat pipe; A liquid-cooled flow channel plate is fixed to the outer wall of the housing and its surface is arranged perpendicular to the axis of the flat heat pipe; the liquid-cooled flow channel plate corresponds to the battery area.

[0009] The beneficial effects of the technical solution of this invention are as follows: by designing the enclosure in sections, the electrical components and the battery are isolated, which can prevent the immersion liquid from leaking into the electrical components and reduce the amount of immersion liquid used; in the event of thermal runaway of the battery cell, the immersion liquid in the battery area can absorb the heat of thermal runaway of the battery cell, and at the same time, the immersion liquid isolates the battery cell from the air, improving the thermal safety performance of the battery pack; the heat of the battery can be transferred to the liquid-cooled flow channel plate on the enclosure for heat dissipation through the flat heat pipe, and this heat exchange process does not require cooling the immersion liquid in the battery pack, reducing the energy consumption in the battery pack cooling process; during the heating process, the heat of the liquid-cooled flow channel plate is transferred to the battery cell through the flat heat pipe, and there is no need to heat the immersion liquid and then heat the battery cell, thereby reducing the energy consumption in the battery pack heating process.

[0010] Preferably, the liquid-cooled flow channel plate has multiple heat dissipation grooves on its panel. The heat dissipation grooves can improve the heat exchange effect between the liquid-cooled flow channel plate and the battery cell.

[0011] Preferably, fins are fixed inside the heat dissipation groove. The fins further improve the heat dissipation performance of the liquid-cooled flow channel plate.

[0012] Preferably, there are two liquid-cooled flow channel plates, symmetrically arranged on both sides of the housing. Multiple hot-cooling flow channel plates can reduce the temperature difference in the battery cell system.

[0013] Preferably, a tray is detachably connected to the lower end of the box.

[0014] Preferably, a cover plate is detachably connected to the upper end of the housing, and an explosion-proof valve is detachably connected to the cover plate corresponding to the battery area. When the internal pressure of the battery area is too high, the explosion-proof valve will be pushed out, preventing the battery pack from exploding due to excessive internal pressure.

[0015] Preferably, grooves are formed on both the opposite end faces of the housing and the tray, and on both end faces of the housing and the cover plate. A sealing strip is embedded in the groove on the housing; the grooves on the tray and the cover plate engage with the sealing strip. The cooperation of the grooves and the sealing strip ensures the sealing performance of the battery pack.

[0016] Preferably, the housing and the partition are integrally cast.

[0017] Preferably, the flat heat pipe is made of copper or aluminum.

[0018] As can be seen from the above technical solution, compared with the prior art, the present invention discloses an immersion-cooled energy storage battery pack, which effectively solves the leakage problem of immersion battery packs by dividing the inner cavity of the box into independent electrical and battery areas, prevents corrosion and contamination of electrical components, and improves the product's technological maturity and reliability. The liquid-cooled flow channel plate fixed on the outer wall of the box can improve the structural strength of the box, and the introduction of flat heat pipes in the battery area enables the heat exchange of the battery pack to be realized through the flat heat pipes and liquid-cooled flow channel plates. The energy consumption of the immersion liquid temperature control process is adjusted, the energy consumption of the thermal management system is reduced, the product efficiency is improved, and the safety performance of the product is guaranteed. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the battery pack structure provided by the present invention; Figure 2 This is a schematic diagram of a battery pack explosion provided by the present invention.

[0021] Among them, 1-box body; 2-partition; 3-flat heat pipe; 4-battery cell; 5-liquid cooling flow channel plate; 6-cover plate; 7-tray; 8-explosion-proof valve. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] See appendix Figure 1 and 2This invention discloses an immersion-cooled energy storage battery pack, comprising a housing 1, flat heat pipes 3, battery cells 4, and a liquid-cooled flow channel plate 5. The housing 1 is divided into a battery area and an electrical area from left to right by a partition 2. The battery area is filled with immersion liquid. There are multiple flat heat pipes 3, with both ends of each pipe fixed to the two inner walls of the housing 1 corresponding to the battery area. Adjacent flat heat pipes 3 and the inner walls of the housing 1 form mounting grooves. The battery cells 4 are embedded in the mounting grooves, and their two side surfaces are bonded and fixed to the outer walls of the flat heat pipes 3. The liquid-cooled flow channel plate 5 is fixed to the outer wall of the housing 1, and its surface is arranged perpendicular to the axis of the flat heat pipes 3. The liquid-cooled flow channel plate 5 corresponds to the battery area. There are two liquid-cooled flow channel plates 5, symmetrically arranged on both sides of the housing 1. A tray 7 is detachably connected to the lower end of the housing 1. The tray 7 is a stainless steel tray used as the bottom plate of the housing 1, and is fastened to the lower end face of the housing 1 by structural adhesive and bolts. A cover plate 6 is detachably connected to the upper end of the housing 1. The cover plate 6 serves as the top plate of the housing 1. The cover plate 6, stainless steel support plate 7, and four side plates together form the inner cavity of the housing 1. An explosion-proof valve 8 is detachably connected to the surface of the cover plate 6 corresponding to the battery area. The cover plate 6 is fastened to the upper surface of the housing 1 by structural adhesive and bolts or by snap-fit. When the pressure inside the battery area is too high, it will push up the explosion-proof valve 8, thus ensuring the explosion-proof performance of the battery pack.

[0024] like Figure 2 As shown, the housing has a rectangular structure. A partition along the left-right direction divides its interior into an electrical zone and a battery zone. The volume of the electrical zone is smaller than that of the battery zone. The partition and housing are integrally cast as the main structure of the battery pack. This integral casting method ensures a good seal between the partition and the inner wall of the housing, preventing the immersion liquid in the battery zone from leaking into the electrical zone and corroding the electrical components. The area of ​​the sidewall facing the battery cell is at least twice the area of ​​the sidewall perpendicular to the partition. The flat heat pipe is bonded and fixed to the side of the battery cell facing the partition, ensuring sufficient heat exchange area between the flat heat pipe and the battery cell. Two liquid-cooled flow channel plates are fixed to the two outer walls along the long axis of the housing. During the cooling process of the battery pack, the heat from the battery cells is transferred to the liquid-cooled flow channel plate through flat heat pipes. The cooling of the battery cells is achieved through heat exchange between the flat heat pipes and the liquid-cooled flow channel plate. In this process, there is no need to cool the immersion liquid in the battery area. By introducing flat heat pipes into the battery area and adding liquid-cooled flow channel plates to the outer wall of the casing, the heat exchange area is increased while the energy consumption during the cooling process is reduced. During the heating process of the battery cells, the heat in the liquid-cooled flow channel plate is directly transferred to the battery cells through flat heat pipes. Compared with the existing battery pack technology that first heats the immersion liquid and then heats the battery cells, it can directly heat the battery cells, reducing the energy consumption during the heating process.

[0025] In this embodiment, an immersion liquid is added to the battery area. During thermal runaway, the immersion liquid can absorb a large amount of heat generated during the thermal runaway of the battery cell and isolate the battery cell from contact with the air. At the same time, the liquid cooling channel plate is separate from the immersion liquid and does not have direct contact. The flat heat pipe can continue to remove a large amount of heat generated by the thermal runaway of the battery cell through the liquid cooling channel plate, further accelerating heat dissipation, better suppressing battery thermal diffusion, and improving the thermal safety performance of the battery pack.

[0026] To further optimize the above technical solution and improve the heat dissipation effect of the liquid cooling channel plate, multiple heat dissipation slots are provided on the panel of the liquid cooling channel plate 5.

[0027] In some other specific embodiments, grooves are provided on both the opposite end faces of the box body 1 and the tray 7, and on the box body 1 and the cover plate 6. A sealing strip is embedded in the groove on the box body 1; the grooves on the tray 7 and the cover plate 6 are fitted with the sealing strip.

[0028] The battery pack has corresponding grooves on the casing, tray, and cover. Half of the sealing strip is embedded in the groove of the casing, and the other half of the sealing strip is engaged by the grooves on the tray and cover. The sealing performance of the battery pack is ensured by the cooperation of the grooves and the sealing strip.

[0029] In some other specific embodiments, in order to ensure the heat transfer effect of the flat plate heat pipe, the flat plate heat pipe 3 is made of copper or aluminum.

[0030] In the manufacturing process of the battery pack provided in this embodiment, the sealed body formed by the casing and partitions is first produced through a casting process. The sealed body is divided into a battery area and an electrical area, which are separated by the cast partitions. The liquid cooling flow channel plates on both sides are brazed to the outer wall of the casing along the long axis, with the positions of the liquid cooling flow channel plates corresponding to the battery area. Then, the stainless steel reinforcing tray is assembled with the casing using structural adhesive and bolts. After the structural adhesive has cured, the battery cells and flat heat pipes are installed in the casing. First, a flat heat pipe is placed in, and its two sides are fixed to the inner wall of the casing with thermally conductive structural adhesive. The outer wall of the partition corresponding to the battery cell is coated with thermally conductive adhesive and pasted to the corresponding position of the flat heat pipe. All battery cells and flat heat pipes are installed in sequence, and then the adhesive is cured. After the adhesive has cured, the electrical components are installed in the electrical area. Immersion liquid is injected into the battery area. After the immersion liquid reaches the designated position, the top cover and explosion-proof valve are installed.

[0031] In other specific embodiments, the casting process of the housing and partition can be replaced by stamping, the connection between the flat heat pipe and the housing can be replaced by welding instead of gluing, and the liquid cooling flow channel plates on both sides can be replaced by profile cold plates. In order to further increase the heat dissipation capacity of the battery pack, heat pipes / brazed cold plates can also be added to the bottom of the cells. The entire battery pack is not limited to two rows of cells and multiple rows can be added according to actual needs.

[0032] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0033] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An immersion-cooled energy storage battery pack, characterized in that, include: The housing (1) is divided into a battery area and an electrical area from left to right by a partition (2); the battery area is filled with an immersion liquid. The flat heat pipe (3) is a multi-plate heat pipe, and the two ends of the multi-plate heat pipe (3) are respectively fixed on the two inner walls of the box (1) corresponding to the battery area; the two adjacent flat heat pipes (3) and the inner wall of the box (1) form an installation groove. The battery cell (4) is embedded in the mounting groove and its two side surfaces are bonded and fixed to the outer wall of the flat heat pipe (3); Liquid cooling channel plate (5) is fixed to the outer wall of the housing (1) and its surface is arranged perpendicular to the axis of the flat heat pipe (3); the liquid cooling channel plate (5) corresponds to the battery area.

2. The immersion-cooled energy storage battery pack according to claim 1, characterized in that, The liquid cooling channel plate (5) has multiple heat dissipation slots on its panel.

3. The immersion-cooled energy storage battery pack according to claim 2, characterized in that, Fins are fixed inside the heat dissipation groove.

4. The immersion-cooled energy storage battery pack according to claim 1, characterized in that, The liquid-cooled flow channel plates (5) are two in number and are symmetrical on both sides of the housing (1).

5. The immersion-cooled energy storage battery pack according to claim 1, characterized in that, The lower end of the box (1) is detachably connected to a tray (7).

6. The immersion-cooled energy storage battery pack according to claim 5, characterized in that, The upper end of the housing (1) is detachably connected to a cover plate (6), and an explosion-proof valve (8) is detachably connected to the cover plate (6) corresponding to the battery area.

7. The immersion-cooled energy storage battery pack according to claim 6, characterized in that, Grooves are provided on both ends of the box (1) and the tray (7), and on both ends of the box (1) and the cover plate (6). A sealing strip is embedded in the groove on the box (1); the groove on the tray (7) and the cover plate (6) engages with the sealing strip.

8. The immersion-cooled energy storage battery pack according to claim 1, characterized in that, The box body (1) and the partition (2) are integrally cast.

9. The immersion-cooled energy storage battery pack according to claim 1, characterized in that, The flat heat pipe (3) is made of copper or aluminum.

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