WO2024113976A1

WO2024113976A1 - Large cylindrical battery system having three liquid cooling surfaces

Info

Publication number: WO2024113976A1
Application number: PCT/CN2023/113802
Authority: WO
Inventors: 冯炎强; 欧阳效群
Original assignee: 湖北亿纬动力有限公司
Priority date: 2022-11-30
Filing date: 2023-08-18
Publication date: 2024-06-06

Abstract

The present application discloses a large cylindrical battery system having three liquid cooling surfaces, comprising: a power battery module, the power battery module comprising at least one battery module, and multiple rows of cells being uniformly distributed in the battery module; a liquid cooling system, the liquid cooling system comprising liquid cooling pipes located at two sides of the power battery module and a liquid cooling plate located at the top portion of the power battery module; multiple separating cooling plates arranged linearly are held between the liquid cooling pipes at the two sides of the power battery module, a separating cooling plate is arranged at either side of each row of cells, the separating cooling plates are connected with the cells by means of a thermally conductive adhesive, and the liquid cooling plates are connected with the cells by means of the thermally conductive adhesive.

Description

A large cylindrical battery system with three-sided liquid cooling

This application claims the priority of the Chinese patent application filed with the China Patent Office on November 30, 2022 with application number 2022115206637 and the Chinese patent application filed with the China Patent Office on November 30, 2022 with application number 2022232583761. The entire contents of the above applications are incorporated by reference into this application.

Technical Field

The present application relates to the field of power battery technology, and in particular to a large cylindrical battery system with three-sided liquid cooling.

Background technique

At present, the power battery monomers of electric vehicles and energy storage systems mainly include cylindrical batteries, square batteries and soft-pack batteries. Cylindrical wound battery monomers are the earliest, most mature and most stable lithium-ion batteries, with mature production processes, high standardization, consistency and safety of batteries, low overall costs, and high energy density of assembled battery modules. They are widely used in electric vehicles and energy storage systems of many companies.

Cylindrical batteries have small single-cell capacity and require a large number of single-cells. Temperature differences are prone to occur inside the battery, and heat dissipation management needs to be strengthened to improve the uniformity of temperature distribution. With the continuous improvement of the structural size and energy density of battery modules, the challenges faced by the temperature uniformity of battery modules are becoming increasingly greater due to the limitations of cost, structure and reliability. Too high or too low ambient temperature will affect the performance and life of lithium batteries. Therefore, the battery system must be cooled in high temperatures in summer and heated in low temperatures in winter to keep the battery in an appropriate temperature range to ensure its safety, efficiency and life.

The liquid cooling method used in the cylindrical battery system in the industry adopts a single-sided liquid cooling solution. The cooling efficiency of single-sided liquid cooling is low and cannot meet the requirements of ultra-high charging rates. When the demand for supercharging gradually increases, the heat generated by the system increases, and the cooling efficiency requirements are also higher. At the same time, in order to store more electricity in a smaller volume and provide longer battery life, the requirements for system integration efficiency are gradually increasing. When users use the product, the absolute safety of the product is the primary condition to ensure the application of the system.

technical problem

In order to overcome at least one defect described in the above-mentioned related art, the present application provides a large cylindrical battery system with three-sided liquid cooling. It can solve the current pain points of new energy vehicles and the concerns about battery life. In order to meet the increasing demand for fast charging from users, the innovative and efficient three-sided liquid cooling system design can ensure the temperature control of the battery system under ultra-high rate charging and meet the actual supercharging needs.

Technical Solutions

The present application provides a three-sided liquid-cooled large cylindrical battery system, comprising: a power battery module, wherein the power battery module comprises at least one battery module, wherein multiple rows of battery cells are evenly distributed in the battery module; a liquid cooling system, wherein the liquid cooling system comprises liquid cooling tubes located on both sides of the power battery module and a liquid cooling plate located on the top of the power battery module; wherein a plurality of linearly arranged spacer cooling plates are sandwiched between the liquid cooling tubes on both sides of the power battery module, wherein a spacer cooling plate is distributed on both sides of each row of battery cells, wherein the spacer cooling plates are connected to the battery cells by thermally conductive adhesive, and wherein the liquid cooling plates are connected to the battery cells by thermally conductive adhesive.

Beneficial Effects

By adopting the above solution, each battery cell has three-sided cooling, forming a three-dimensional liquid cooling heat dissipation, which can quickly take away the heat energy generated by the system supercharging and effectively reduce the temperature of the system. The battery module can be bonded into a whole through thermal conductive glue to improve the overall strength, ensure the rigidity and strength requirements, and ensure the reliability of the system.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the three-dimensional structure of a system housing according to an embodiment of the present application;

FIG2 is a schematic diagram of an explosion structure of an embodiment of the present application;

FIG3 is a schematic diagram of the three-dimensional structure of a power battery module according to an embodiment of the present application;

FIG4 is a schematic diagram of the side structure of a power battery module according to an embodiment of the present application;

FIG5 is an enlarged view of area A in FIG4 ;

FIG6 is a schematic diagram of a partial explosion structure of an embodiment of the present application;

FIG7 is an enlarged view of area B in FIG6 ;

FIG8 is an enlarged view of area C in FIG6 ;

FIG. 9 is a schematic diagram of the structure of the interval cooling plate according to an embodiment of the present application.

The meanings of the reference numerals are as follows:

1. Power battery module; 11. Battery module; 111. Battery cell; 2. System housing; 21. Upper housing; 22. Lower housing; 23. Side panel; 231. Battery charging port; 232. Liquid cooling water inlet; 233. Liquid cooling water outlet; 3. Liquid cooling system; 31. Liquid cooling pipe; 311. Tubular liquid cooling section; 32. Liquid cooling plate; 321. Travel groove; 33. Interval cooling plate; 331. Connection part; 332. Liquid flow hole; 333. Quick pipe; 34. Liquid cooling main pipe; 35. Tee; 36. Curved pipe; 4. Support structure; 41. Support plate; 411. Pressure relief port; 42. Support part; 5. Independent pressure relief space; 6. Battery tray; 61. Slot; 62. Columnar groove.

Embodiments of the present invention

In the description of the present application, it should be noted that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application 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 a limitation on the present application.

In one embodiment, the liquid cooling tubes on both sides of the power battery module are spliced together by multiple tubular liquid cooling sections, and a spacer cooling plate is connected at the joint of every two tubular liquid cooling sections, and a spacer cooling plate is clamped between the two tubular liquid cooling sections at the same position on both sides, so that there is a spacer cooling plate on both sides of each row of battery cells in the power battery module, and the three sides of the battery cells are cooled by stacking the spacer cooling plates in combination with the liquid cooling plates.

By adopting the above solution, the liquid cooling tube structure is further restricted, the connection stability of the interval cooling plate is improved, and at the same time, a side cooling effect is provided for the battery cell.

In one embodiment, a system housing is further included, and the system housing is used to accommodate and fix the power battery module and the liquid cooling system.

By adopting the above solution, the system integrated design is realized, and the extremely simple process and structural design are adopted to simplify the product complexity and improve the system integration.

In one embodiment, the system housing includes an upper housing and a lower housing, and the upper housing is detachably connected to the lower housing.

By adopting the above solution, it is convenient for disassembly and maintenance.

In one embodiment, a support structure is provided between the lower shell and the power battery module, and the support structure separates the bottom surface of the battery cell from the lower shell to form an independent pressure relief space.

By adopting the above solution, the gas can be quickly depressurized through independent pressure relief, and extremely fast response to thermal runaway and rapid warning can be achieved.

In one embodiment, the support structure includes a support plate and at least two support parts, the support plate is erected by the support parts, and a plurality of pressure relief ports are provided on the support plate.

By adopting the above solution, an independent pressure relief channel is formed in the system, and the pressure relief is rapid.

In one embodiment, the battery module also includes a battery tray, which is provided with a plurality of slots in the same direction as the spacing cooling plate, and a plurality of cylindrical slots are provided in the center of the battery tray. The cylindrical slots are divided into multiple rows by the plurality of slots, and the rows are arranged alternately.

By adopting the above solution, it is convenient to install the interval cooling plates, and the staggered interval cooling plates can maximize the use of space, increase the number of battery cells and achieve efficient cooling.

In one embodiment, the battery tray is filled with thermally conductive glue so that the cold plate in the battery tray is fixedly connected to the slot, and the cylindrical slot is fixedly connected to the battery cell.

By adopting the above solution, the battery tray is sealed as a whole, thereby improving the heat conduction effect and its own strength.

In one embodiment, connecting parts are provided at both ends of the spacer cooling plate, and the connecting parts are provided with liquid flow holes for communicating with the tubular liquid cooling section.

By adopting the above solution, the tubular liquid cooling section is connected through the connecting part, which can be used to communicate the cooling liquid.

In one embodiment, the spacer cooling plate and the connecting portion are hollow inside so as to allow the coolant to flow through the liquid flow holes.

By adopting the above solution, the coolant in the tubular liquid cooling section can be passed into the interior of the interval cooling plate to cool down both sides of the battery cell.

In one embodiment, the closer the connecting portion is to the liquid flow hole, the smaller the internal space thereof is, so as to gather the cooling liquid.

By adopting the above solution, the coolant can circulate and flow, efficiently cool down, and effectively improve the energy replenishment speed and user experience.

Embodiment 1 of the present application refers to Figures 3 to 6. The present application discloses a three-sided liquid-cooled large cylindrical battery system, including a power battery module 1 and a liquid cooling system 3. The power battery module 1 includes at least one battery module 11, and multiple rows of battery cells 111 are evenly distributed in the battery module; in the present embodiment 1, the battery modules 11 include three, and there is a spacing between them; the liquid cooling system 3 includes liquid cooling pipes 31 located on both sides of the power battery module 1 and a liquid cooling plate 32 located on the top of the power battery module 1, and the surface of the liquid cooling plate 32 is provided with a travel groove 321, and the travel groove 321 is a closed irregularly oriented type groove; the liquid cooling tubes 31 are all spliced together by multiple tubular liquid cooling sections 311, and a spacing cooling plate 33 is connected to the splicing place of every two tubular liquid cooling sections 311, and a spacing cooling plate 33 is clamped between the two tubular liquid cooling sections 311 at the same position on both sides, so that there is a spacing cooling plate 33 on both sides of each row of battery cells 111 in the power battery module 1, and the stacked spacing cooling plates 33 are combined with the liquid cooling plates 32 to achieve three-sided cooling of the battery cells 111, so that each battery cell 111 is cooled on three sides, forming a three-dimensional liquid cooling heat dissipation, which quickly takes away the heat energy generated by the system supercharging, and efficiently reduces the temperature of the system.

It should be noted that in this embodiment 1, the cross-section of the spacing cooling plate 33 is wavy and the whole is in the shape of a corrugated plate. In other embodiments, the cross-section of the spacing cooling plate 33 includes but is not limited to straight lines, curves, semicircular lines or serrated lines, so as to place the battery cells 111 in the gaps between the spacing cooling plates 33 in a multiple stacking manner.

Specifically, the liquid cooling pipes 31 on the same side of the three battery modules 11 converge on a liquid cooling main pipe 34, and there are two liquid cooling main pipes 34 on the left and right sides, which are used to serve as the water inlet pipe and the water outlet pipe of the liquid cooling system 3, so as to realize the coolant circulation of the liquid cooling system 3. In the present embodiment 1, the connection method of the convergence of the liquid cooling pipe 31 and the liquid cooling main pipe 34 is to use a tee 35 and a curved pipe 36, one end of the curved pipe 36 is connected to the liquid cooling main pipe 34 through a tee, and the other end is connected to the liquid cooling pipe 31 through a control joint; in other embodiments, the connection method of the convergence of the liquid cooling pipe 31 and the liquid cooling main pipe 34 includes but is not limited to welding, threaded connection or adhesive connection.

It should be noted that when the liquid cooling pipe 31 is connected to the end of the liquid cooling main pipe 34, one end of the tee needs to be blocked to achieve the closure of the pipeline.

As shown in Figures 1 and 2, the system of the present application may further include a system housing 2, which is used to accommodate and fix the power battery module 1 and the liquid cooling system 3, realize the system integrated design, adopt a minimalist process and structural design, simplify the product complexity, and improve the system integration. Specifically, the system housing 2 includes an upper housing 21, a lower housing 22 and a side plate 23, the upper housing 21 and the lower housing 22 are detachably connected, convenient for disassembly and maintenance, the side plate 23 is located on one side of the upper housing 21 and the lower housing 22, and the side plate 23 is provided with a battery charging port 231, a liquid cooling water inlet 232 and a liquid cooling water outlet 233, the battery charging port 231 is used to charge the power battery module 1, and the liquid cooling water inlet 232 and the liquid cooling water outlet 233 are used to circulate the coolant in the liquid cooling system 3.

In this embodiment 1, the upper shell 21 and the lower shell 22 are fixedly connected by screws and screw holes. In other embodiments, there is no specific restriction on the fixing method of the upper shell 21 and the lower shell 22, including but not limited to glue filling, welding, clamping or integrated connection.

As an embodiment of the present application, the spacer cooling plate 33 in the battery module 11 is connected to the battery cell 111 via thermal conductive adhesive, and the liquid cooling plate 32 is connected to the battery cell 111 via thermal conductive adhesive, so that the battery module 11 can be bonded into a whole, thereby improving the overall strength, ensuring the rigidity and strength requirements, and ensuring the reliability of the system.

As an embodiment of the present application, the battery module 11 uses a glue injection process to adhere and fix the spacer cooling plate 33 to the battery cell 111, which can improve the overall strength while conducting heat, ensure the rigidity and strength requirements, and ensure system reliability.

2, 3 and 5, a support structure 4 is provided between the lower shell 22 and the power battery module 1, and the support structure 4 separates the bottom surface of the battery cell 111 from the lower shell 22 to form an independent pressure relief space 5. Through the independent pressure relief, the gas can be quickly depressurized, and a rapid response to thermal runaway and a rapid warning can be achieved. The support structure 4 includes a support plate 41 and at least two support parts 42, and the support plate 41 is erected by the support parts 42. A plurality of pressure relief ports 411 are provided on the support plate 41. In the present embodiment 1, three battery modules 11 are provided on the support plate 41, and both ends of the support plate 41 are respectively fixed on the side walls of the two support parts 42. The fixing method is not specifically limited, including but not limited to welding, gluing or plugging. The pressure relief ports 411 on the support plate 41 correspond to the number of battery cells 111 one by one to realize an independent pressure relief space 5. The support part 42 is in the shape of a quadrangular prism and is provided below the two bottom edges of the bottom surface of the electric power battery module 1, with good supporting effect. A pad is also provided on the inner wall of the lower shell 22 corresponding to the bottom of the battery module 11, which can be used to buffer the pressure during pressure relief.

In other embodiments, the position and number of the support portions 42 are not limited, and they are only used to separate the bottom surface of the battery cell 111 from the lower housing 22 .

2 and 6 , the battery module 11 also includes a battery tray 6, which is rectangular and has a plurality of slots 61 arranged in the same direction as the spacing cooling plate 33. A plurality of cylindrical slots 62 are arranged in the center of the battery tray 6, and a large cylindrical battery cell 111 is arranged in each of the cylindrical slots 62. The cylindrical slots 62 are divided into multiple rows of structures by the plurality of slots 61. In order to increase the number of battery cells 111 while improving the cooling effect, every two adjacent spacing cooling plates 33 are symmetrically placed so that a battery cell 111 can be accommodated between the corrugated recess of the spacing cooling plate 33 and the corrugated recess of another spacing cooling plate 33. Through the symmetrically arranged spacing cooling plates 33, each row of battery cells 111 can be staggered, so that rows are staggered, the space is maximized, and the number of battery cells 111 accommodated is increased.

In other embodiments, the battery tray 6 is filled with thermal conductive glue, or thermal conductive glue is simultaneously filled in the cylindrical groove 62. By filling the thermal conductive glue, the spacer cooling plate 33 inside the battery tray 6 is fixed to the slot 61, and the battery cell 111 is fixed to the cylindrical groove 62, thereby improving the overall thermal conductivity and self-strength.

In other embodiments, the same polarity poles of the battery cell 111 are all on the same surface, such as the positive poles of the battery cell 111 are all located at the top, the positive poles are connected to the copper bars, and the top liquid cooling plate 32 is located above the copper bars for cooling the copper bars connected to the top of the system, so that the copper bars can pass a larger current and meet the requirements of ultra-fast charging at a lower cost. It is worth mentioning that the installation of the battery cell 111 may not be limited to the same polarity poles on the same surface, and the top liquid cooling plate may not be in contact with the copper bars.

As shown in Figs. 7-9, the two ends of the spacer cooling plate 33 are provided with connecting parts 331, and the connecting parts 331 are provided with flow holes 332 for communicating with the tubular liquid cooling section 311. The tubular liquid cooling section 311 is connected through the connecting parts 331, which can be used to communicate the cooling liquid. The spacer cooling plate 33 and the connecting parts 331 are hollow inside, so that the cooling liquid can flow from the flow holes 332, and the cooling liquid in the tubular liquid cooling section 311 can be passed into the spacer cooling plate 33 to cool down the two sides of the battery cell 111. The closer the connecting part 331 is to the flow hole 332, the smaller its internal space is, so as to gather the cooling liquid, so that the cooling liquid can circulate, efficiently cool down, and effectively improve the energy replenishment speed and user experience.

It should be noted that the connection portion 331 of the spacer cooling plate 33 located at both ends of the battery module 11 is provided with a liquid flow hole 332 on only one side to avoid liquid leakage.

In this embodiment 1, the connection parts 331 at both ends of the interval cooling plate 33 are plate-shaped, and the thickness of the connection parts 331 is greater than the thickness of the interval cooling plate 33. The surface of the connection parts 331 remains horizontal, and the two sides of the connection parts 331 gradually shrink and transition toward the liquid flow hole 332. Quick-connect pipes 333 are provided on both sides of the liquid flow hole 332 of the connection part 331. The quick-connect pipes 333 are connected to the tubular liquid cooling section 311. The connection method is not specifically limited in this application, including but not limited to welding, screwing, clamping or gluing.

During installation of the present application, the battery module is inserted with a plurality of spacer cooling plates 33, and then the two connection parts 331 and the quick-connect pipes 333 are respectively connected through the tubular liquid cooling section 311 to realize the arrangement of the liquid cooling pipes 31 on both sides of the battery module, and then the liquid cooling pipes 31 on both sides of the plurality of battery modules are connected to the liquid cooling main pipe 34 through the three-way head 35 to realize the circulation of the coolant, and finally each battery module is poured with thermal conductive structural adhesive or fixed with thermal conductive double-sided adhesive, and finally the liquid cooling plate 32 is fixed to the top surface of the plurality of battery modules as a whole with thermal conductive structural adhesive, thereby realizing the integrated design of the power battery module 1, and the system housing 2 can also be added for packaging and fixing to further enhance the overall strength of the battery system.

In summary, the three-sided liquid-cooled large cylindrical battery system provided by the present application has the following technical effects:

1. By designing a three-sided liquid cooling structure, ultra-high rate fast charging is achieved, effectively improving the charging speed and user experience;

2. The overall integrated structural design of the system effectively improves the volume utilization efficiency and mass utilization efficiency, achieves high specific energy in a small space, and effectively improves the endurance level;

3. By designing an independent pressure relief space 5, the gas can be quickly depressurized, and a rapid response to thermal runaway can be achieved, with rapid warning;

4. By designing the interval cooling plate 33, the heat accumulation between each row of battery cells 111 is effectively avoided, thereby reducing the difficulty of heat dissipation;

5. Liquid cooling on three sides can reduce the internal temperature of the battery system, thereby increasing the current passing through, and can meet the needs of ultra-fast charging at a lower cost.

Claims

A three-sided liquid-cooled large cylindrical battery system, comprising:

A power battery module (1), wherein the power battery module (1) comprises at least one battery module (11), wherein a plurality of rows of battery cells (111) are evenly distributed in the battery module (11);

A liquid cooling system (3), the liquid cooling system (3) comprising liquid cooling pipes (31) located on both sides of the power battery module (1) and a liquid cooling plate (32) located on the top of the power battery module (1);

A plurality of linearly arranged spacing cooling plates (33) are sandwiched between the liquid cooling tubes (31) on both sides of the power battery module (1), a spacing cooling plate (33) is distributed on both sides of each row of battery cells (111), the spacing cooling plates (33) and the battery cells (111) are connected via thermal conductive adhesive, and the liquid cooling plates (32) and the battery cells (111) are connected via thermal conductive adhesive.
According to a three-sided liquid-cooled large cylindrical battery system according to claim 1, the liquid cooling tubes (31) on both sides of the power battery module (1) are formed by splicing a plurality of tubular liquid cooling sections (311), a spacing cooling plate (33) is connected at the splicing point of every two tubular liquid cooling sections (311), and a spacing cooling plate (33) is clamped between two tubular liquid cooling sections (311) at the same position on both sides, so that there is a spacing cooling plate (33) on both sides of each row of battery cells (111) in the power battery module (1), and the stacked spacing cooling plates (33) are combined with the liquid cooling plates (32) to achieve cooling of the three sides of the battery cells (111).
A three-sided liquid-cooled large cylindrical battery system according to claim 1, further comprising a system housing (2), wherein the system housing (2) is used to accommodate and fix the power battery module (1) and the liquid cooling system (3).
According to a three-sided liquid-cooled large cylindrical battery system as claimed in claim 3, wherein the system housing (2) comprises an upper housing (21) and a lower housing (22), and the upper housing (21) and the lower housing (22) are detachably connected.
A three-sided liquid-cooled large cylindrical battery system according to claim 4, wherein a support structure (4) is provided between the lower shell (22) and the power battery module (1), and the support structure (4) separates the bottom surface of the battery cell (111) from the lower shell (22) to form an independent pressure relief space (5).
According to a three-sided liquid-cooled large cylindrical battery system according to claim 5, wherein the support structure (4) comprises a support plate (41) and at least two support parts (42), the support plate (41) is supported by the support parts (42), and a plurality of pressure relief ports (411) are provided on the support plate (41).
A three-sided liquid-cooled large cylindrical battery system according to any one of claims 1 to 6, wherein the battery module (11) further comprises a battery tray (6), the battery tray (6) being provided with a plurality of slots (61) in the same direction as the spacing cooling plate (33), a plurality of columnar slots (62) being provided in the center of the battery tray (6), the columnar slots (62) being divided into a plurality of rows by the plurality of slots (61), and the rows being arranged in an alternating manner.
According to a three-sided liquid-cooled large cylindrical battery system as described in claim 7, thermal conductive glue is filled in the battery tray (6) so that the spacer cooling plate (33) in the battery tray (6) is fixedly connected to the slot (61), and the cylindrical slot (62) is fixedly connected to the battery cell (111).
According to a three-sided liquid-cooled large cylindrical battery system according to claim 7, wherein the spacer cooling plate (33) is provided with connecting parts (331) at both ends, and the connecting parts (331) are provided with liquid flow holes (332) for communicating with the tubular liquid cooling section (311).
According to the three-sided liquid-cooled large cylindrical battery system of claim 9, the spacer cooling plate (33) and the connecting portion (331) are hollow inside so as to allow the cooling liquid to flow through the liquid flow hole (332).
According to the three-sided liquid-cooled large cylindrical battery system of claim 9, the closer the connecting portion (331) is to the liquid flow hole (332), the smaller the internal space thereof is, so as to be used for gathering the cooling liquid.