WO2012062185A1

WO2012062185A1 - Power battery pack

Info

Publication number: WO2012062185A1
Application number: PCT/CN2011/081796
Authority: WO
Inventors: 马洪沛; 王震坡; 马洪敏; 陆春
Original assignee: Ma Hongpei; Wang Zhenpo; Ma Hongmin; Lu Chun
Priority date: 2010-11-08
Filing date: 2011-11-04
Publication date: 2012-05-18
Also published as: CN102005603A; CN102005603B

Abstract

A power battery pack, comprising a plurality of individual storage batteries. A ridge is disposed on an outer surface of a terminal of each storage battery. Adjacent terminals of adjacent individual storage batteries are connected through the ridges on the respective outer surfaces thereof. The ridges are connected to form a three-dimensional grid structure. The three-dimensional grid structure is a heat conduction bridge of the individual storage batteries, and is capable of enhancing heat exchange. All or part of holes and gaps in the three-dimensional grid communicate with one another to form criss-crossed net shaped flow passages. A heat exchange medium passes the outer surface of the terminal through the net shaped flow passages, thereby implementing effective heat exchange of the power battery pack. Points and lines of the three-dimensional grid structure that cross and overlap one another form electrical connection points and electrical connection bands between adjacent individual storage batteries. Pretension enables the sharp tops of the ridges to deform and engage one another, so that the electrical connection points and the electrical connection bands form reliable contact. In the power battery pack of the present invention, heat flow lines and current lines do not converge, enhancing electrical connection, solving the heat exchange problem, and reducing the thermal resistance and electric resistance, thereby achieving a dual advantage.

Description

BACKGROUND OF THE INVENTION The present application claims priority to Chinese Patent Application No. 20101053587, the entire disclosure of which is incorporated herein by reference. Technical field

The invention belongs to the technical field of electric energy storage, and specifically belongs to the technical field of power batteries.

Background technique

The power battery generally refers to a battery that has a capacity of more than 2 Ah and is applied to a power traction and high-power energy storage system. The power battery pack is a battery pack that is connected by a single battery (single power battery).

The known power battery pack generally connects the individual cells by means of bolting, welding, cable, and row, and has a small effective contact area with the battery terminals, resulting in a large connection resistance, and is not easily consistent. Fast charge and discharge cannot be achieved.

Chinese Patent 201019060011.8 (a cylindrical lithium ion power battery and a preparation method thereof) discloses a technical solution of a high-power battery, and at the same time provides a group method using the battery.

The invention of the invention mentions that the outwardly projecting dots are punched out on the pole shell to enhance the contact between adjacent cells; however, the technical solution lacks practicality, because in actual production, the shell of the pie-shaped battery Due to the deviation of the plate rolling, the influence of the unevenness of the strips (rebound), and the accuracy of the production of the shell, it is difficult to maintain the plane of the contact position, which is easy to cause contact after assembly. Or the effective contact area is unevenly distributed.

The invention does not give a more reliable and practical technical solution for the method of temperature control and electrical connection of the battery pack.

The battery is an electrochemical system whose performance is greatly affected by temperature. To make the battery pack work properly, an appropriate and uniform temperature must be maintained. Summary of the invention

In order to solve the above problems, an object of the present invention is to provide a power battery pack in which the conductive structure and the heat transfer structure between the battery cells are improved, the electrical connection between the individual battery cells is enhanced, and the battery is effectively The heat exchange problem is solved, so that the heat flow line and the current line are not aggregated, the thermal resistance and the resistance are lowered, and the two advantages are obtained.

To achieve the above object, the present invention adopts the following technical solutions:

A power battery pack is composed of a plurality of single battery cells, each of which has a battery case, and two positive and negative terminals are arranged on both sides of the battery case, and positive and negative plates are arranged in the battery case, and the positive and negative plates are respectively The positive and negative terminals are connected, and the outer surface of the terminal of each of the battery cells is provided with a plurality of protrusions, the protrusions have sharp top ends, and the top ends of the protrusions are located in the same plane, and adjacent terminals of adjacent battery cells pass through The protrusions on the outer surfaces of the respective surfaces are connected to each other, and the protrusions are connected to form a three-dimensional grid structure, which is a heat conduction bridge of the single battery to enhance heat exchange, and all the holes and gaps in the three-dimensional grid Or partially communicating, forming a crisscrossed mesh flow passage through which the heat exchange medium flows through the outer surface of the terminal, thereby realizing effective heat exchange for the power battery pack, and each cross-over coincidence point of the three-dimensional grid structure The wire constitutes the electrical connection point and the electrical connection band between the adjacent battery terminals, and all the single cells are pressed by the pre-tightening force on both sides of the power battery pack, and the pre-tightening force Deformable projections sharpened tip, fitted to each other on the adjacent terminals of adjacent unit batteries, the electrical connection points and electrical connection is formed with a reliable contact.

The projections provided on the surface of the terminal are formed by tapered d, blocks and strip-shaped ribs.

The edge of the terminal protrudes from the battery case and is bent inwardly, and the inwardly bent portion is provided with fins.

The edge of the terminal protrudes from the battery case, and the portion of the protruding battery case is provided with teeth.

The terminal is annealed to have a lower hardness, and the projection is integrally formed with the terminal, so that the convex sharp tip is more easily deformed, thereby forming a reliable electrical connection.

The outer surface of the terminal is covered with a soft metal, and the protrusion is integrally formed with the terminal, so that the sharp tip of the protrusion is more easily deformed, thereby forming a reliable electrical connection.

The single battery is in the shape of a ring, and the positive and negative plates are in a spiral winding structure, the positive plate is perpendicular to the positive terminal, and the negative plate is perpendicular to the negative terminal.

Adjacent terminals of the adjacent battery cells are indirectly connected by protrusions on respective outer surfaces, The junction is provided with a metal foil.

The single battery is in the shape of a ring, and the battery cells are arranged in the axial direction to form a power battery pack. The outer side of the power battery pack is provided with an insulated and insulated sleeve, and the power battery pack and the sleeve are encapsulated in the outer shell through the bracket. The sleeve is fixed on the battery case of the single battery through the bracket, and the gap between the sleeve and the outer casing constitutes an outer flow passage, and the gap between the sleeve and the battery case of the single battery constitutes an intermediate flow passage, each ring The hollow portion in the middle of the single-cell battery constitutes an inner flow passage, the outer flow passage communicates with the intermediate flow passage, the intermediate flow passage communicates with the mesh flow passage, the mesh flow passage communicates with the inner flow passage, and the inner flow passage communicates with the outer flow passage, The heat exchange medium circulates between the above flow channels to make the internal temperature field of the power battery pack uniform.

The inner flow passage, the intermediate flow passage and the outer flow passage are connected to each other to constitute a main flow passage of the power battery pack, and the mesh flow passage constitutes a branch flow passage of the power battery pack, and a pump is arranged in the main flow passage. The surface of the outer casing is provided with heat dissipating fins, and the heat exchange medium is circulated between the pump along the pump-outer flow passage-intermediate flow passage-net flow passage-inner flow passage, and the heat radiating fins are arranged through the outer surface of the battery casing Strengthen heat dissipation.

The outer flow channel is provided with a valve; when the temperature is low, the valve is closed, so that the heat exchange medium cannot flow to the outer flow channel, and only the pump-intermediate flow channel-network flow channel-inner flow channel-pump cycle To keep the temperature of the battery pack balanced.

A valve is disposed in the outer flow passage; a heating element is disposed in the intermediate flow passage, and when the temperature is low, the valve in the outer flow passage is closed, and the heat exchange medium is circulated through the heating element to achieve the purpose of heating the battery pack.

The power battery of the invention has more uniform temperature field, high cooling and heating efficiency, easy to maintain proper and uniform temperature, uniform current distribution, low thermal resistance and low resistance, can improve charging and discharging rate, is favorable for rapid charging, and also makes A large-capacity fast charge and discharge battery composition is possible.

DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing the structure of a power battery pack of the present invention.

2 is a schematic structural view of a first embodiment of a single battery according to the present invention.

Figure 3 is a plan view of Figure 2.

4 is a partial cross-sectional view of a single battery. Fig. 5 is a schematic view showing the connection structure of a battery cell and a terminal of a single battery.

Figure 6 is a front elevational view of Figure 4.

Figure 7 is a cross-sectional view taken along line A-A of Figure 6;

Fig. 8 is a schematic structural view of a second embodiment of the unit battery of the present invention.

Figure 9 is a plan view of Figure 8.

An L0 is a schematic structural view of a third embodiment of the rechargeable battery of the present invention.

1 is a schematic structural view of a fourth embodiment of the unit battery of the present invention.

^ 2 is a schematic view of a state of use of the power battery pack of the present invention.

3 is a schematic view showing another state of use of the power battery pack of the present invention. L4 is a partial enlarged view of B of Fig. 13.

The structure of the single-cell battery forming the mesh flow channel of the first embodiment of the present invention is a schematic diagram of the structure of adding a metal foil between the battery cells.

L7 is a schematic structural view of the embodiment shown in Fig. 16 forming a mesh flow path.

^ is a schematic view of a cross section of the outer surface of the terminal.

L9 is a schematic view of a cross section of the outer surface of the terminal.

Figure 20 is a schematic illustration of a cross section of the outer surface of the terminal.

Figure 21 is a schematic illustration of a cross section of the outer surface of the terminal.

Mark in the figure

1 battery case 2 terminals 3 terminals 4 plates

Plate 6 protrusion 7 holes, gap 8 mesh flow path

Electrical connection point and electrical connection belt 10 single battery

11 fins 12 edges 13 edges

14 small pieces 15 ribs 16 teeth

17 teeth 18 sleeve 19 shell

0 hollow 21 outer flow 22 intermediate flow

3 inner flow channel 24 pump 25 valve

6 bracket 27 fin 28 metal foil

9-force thermal element 30 three-dimensional grid structure detailed description

Referring to FIG. 1, FIG. 2, FIG. 3, FIG. 4, FIG. 5, FIG. 6, and FIG. 7, the present invention is a power battery pack which is formed by eleven single battery cells 10, each of which has The battery case 1 is provided with positive and negative terminals 2 and 3 on both sides of the battery case 1. The positive and negative plates 4 and 5 are arranged in the battery case 1, and the positive and negative plates 4 and 5 are respectively connected to the positive and negative terminals 2 and 3. .

The outer surfaces of the terminals 2, 3 of each of the single cells are provided with protrusions 6, the protrusions 6 having sharp tips, the tips of the protrusions being in the same plane, and the adjacent terminals 2, 3 of the adjacent cells 10 pass The protrusions 6 on the outer surfaces of the respective surfaces are connected to each other, and the protrusions 6 are connected to form a three-dimensional grid structure 30. As shown in FIG. 14, the three-dimensional grid structure 30 is a heat conduction bridge of a single battery to enhance heat exchange. The holes and slits 7 in the three-dimensional grid are all or partially connected to each other to form a crisscrossed mesh flow path 8 through which the heat exchange medium flows through the outer surfaces of the terminals 2 and 3, thereby realizing effective for the power battery pack. Heat exchange,

Each cross-coincing point and line of the three-dimensional grid structure constitutes an electrical connection point and an electrical connection strip 9 between adjacent single-cell terminals, as shown in FIG. 14, all of the single-cell batteries 10 are powered by a power battery pack. The pre-tightening force F of the side is as shown in FIG. 1. The pre-tightening force F deforms the sharp tips of the projections 6 on the adjacent terminals of the adjacent battery cells 10, and fits each other, so that the electrical connection points and The electrical connection strip 9 forms a reliable contact.

The projections 6 may be formed by tapered small pieces or strip-shaped ribs. The strip-shaped ribs can be distributed along straight lines, oblique lines and curves. Please refer to Fig. 2, Fig. 3, Fig. 4, Fig. 5, the protrusions 6 can be composed of strip-shaped ribs, which are distributed along the curve to make the heat exchange medium Produces turbulence and enhances heat transfer. Referring to FIG. 8 and FIG. 9, the protrusion 6 provided on the surface of the terminal is composed of a tapered small piece 14 and a strip-shaped rib 15 to cause turbulent flow of the heat exchange medium and enhance heat exchange, and the rib 15 is distributed along the oblique line.

Referring to FIG. 10, the edge 12 of the terminal 2 protrudes from the battery case 1 and is bent inward. The edge 13 of the terminal 3 protrudes from the battery case 1 and is bent inward, and the edges 12 and 13 are bent inwardly. There are fins 11 to form a larger heat exchange surface.

Referring to FIG. 11, the edge 12 of the terminal 2 protrudes from the battery case 1. The portion of the protruding battery case 1 is provided with teeth 16. The edge 13 of the terminal 3 protrudes from the battery case 1. The portion of the protruding battery case 1 is provided with The teeth 17, thereby disturbing the heat exchange medium, generating turbulence and enhancing heat exchange.

The terminals 2, 3 are annealed and have a lower hardness, and the protrusions 6 are integrally formed with the terminals, so that The sharp tips of the projections 6 are more susceptible to deformation, resulting in a reliable electrical connection.

The outer surfaces of the terminals 2, 3 are covered with a soft metal such as lead, tin, tantalum or the like, and the projections 6 are integrally formed with the terminals, so that the sharp tips of the projections 6 are more easily deformed, thereby forming a reliable electrical connection.

Referring to FIG. 12, the battery cells 10 are in the shape of a ring. The battery cells 10 are arranged in the axial direction to form a power battery pack. The outside of the power battery pack is provided with an insulating and heat-insulating sleeve 18, a power battery pack and a sleeve. The tube 18 is housed in the outer casing 19, and the sleeve 18 is fixed to the battery case of the unit battery 10 via the bracket 26. The gap between the sleeve 18 and the outer casing 19 constitutes the outer flow path 21, the sleeve 18 and the unit battery 10. The gap between the battery cans 1 constitutes the intermediate flow channel 22, and the hollow portion 20 in the middle of each of the annular battery cells 10 constitutes the inner flow channel 23, and the outer flow channel 21 communicates with the intermediate flow channel 22, and the intermediate flow channel 22 and the mesh The flow channel 8 is connected, the mesh flow channel 8 is in communication with the inner flow channel 23, and the inner flow channel 23 is in communication with the outer flow channel 21, and the heat exchange medium circulates between the flow channels to exchange heat and power for the power battery pack. The internal temperature field of the battery pack is the same.

The inner flow passage, the intermediate flow passage and the outer flow passage are connected to each other to constitute a main flow passage of the power battery pack, and the mesh flow passage constitutes a branch flow passage of the power battery pack, and a pump 24 is disposed in the main flow passage. The surface of the 19 is provided with heat dissipating fins 27, and the heat exchange medium is circulated between the pump 24, the outer flow passage 21, the intermediate flow passage 22, the mesh flow passage 8, the inner flow passage 23, and the pump 24, and is disposed through the outer surface of the battery casing. Sheet 27 enhances heat dissipation.

The outer flow passage 21 is provided with a valve 25; when the temperature is low, the valve 25 is closed, so that the heat exchange medium cannot flow to the outer flow passage 21, and only along the intermediate passage 22 of the pump 24 - the mesh flow passage 8 - the inner flow passage 23 - Intermediate flow path 22 - Circulates between pumps 24 to maintain a balanced temperature of the battery pack.

When the heat exchange medium passes through the mesh flow channel 8, the temperature of the heat exchange medium gradually increases. As the cross section of the mesh flow passage between the terminals is gradually narrowed, the flow rate of the heat exchange medium is gradually increased, and the heat exchange capacity is gradually strengthened, which offsets the heat exchange. The heat exchange capacity caused by the increase of the medium temperature is reduced; the difference in the radial heat exchange capacity of the battery terminals is small.

A heating element 29, such as a PTC heating element, may be disposed in the intermediate flow passage 22. When the temperature is low, the valve 25 is closed to heat the heat exchange medium through the heating element 29 to achieve the purpose of heating the entire power battery pack. The heat exchange medium may be clean, dry air, or an insulating heat transfer liquid.

If the temperature of the power battery pack is too high, the cooling medium can be introduced into the power battery pack and The cooling medium can pass through the mesh flow path 8 between adjacent terminals in a uniform, parallel manner. It can efficiently dissipate heat from the battery.

Referring to FIG. 6 and FIG. 7, in a preferred embodiment, the battery cells 10 are in the shape of a ring, and the positive and negative plates 4 and 5 are in a spiral winding structure, compared with the laminated structure of most large-capacity power batteries. It can make the plates closer together, which helps to improve the energy density of the battery, improve the consistency of the battery, and is more efficient and easier to automate.

Another advantage of this structure is that the positive and negative terminals 2, 3 are perpendicular and tightly connected to the positive and negative plates 4, 5, forming an effective electrical connection, and can be subjected to preload from both sides of the power battery pack. The sharp tips of the projections 6 are more susceptible to deformation, resulting in a reliable electrical connection. This structure also has an advantage in that it is possible to avoid problems such as powder drop and cracking which are caused by a small radius of the plate at the start of winding. In order to better dissipate the heat of the center of the single battery, it is necessary to control the width of the positive and negative plates 4, 5 between 20 and 80 mm to control the length of the heat transfer path;

In the above embodiment, the adjacent terminals of the adjacent unit cells 10 are directly joined by the projections 6 on the respective outer surfaces.

Referring to FIG. 16, FIG. 17, the adjacent terminals of the adjacent single cells are indirectly connected by the protrusions on the outer surfaces of the respective cells, and the metal foil 28 or the metal piece is disposed at the joint. Under pressure, the sharp tips of the projections 6 on adjacent terminals are embedded in the metal foil 28 to form a reliable electrical connection.

In FIGS. 15 and 17, the positive and negative terminals 2, 3 are subjected to imaginary processing to better understand the mesh contact condition of the adjacent terminals 2, 3 of the adjacent battery cells 10; in practical applications, The sharp tips of the positive and negative terminals 2, 3 of the surface protrusions 6 lie in the same plane.

The unit battery 10 may not be annular, for example, may have a solid core shape as shown in Fig. 17, and there is no hollow portion, and the power battery pack composed thereof is as shown in Fig. 13:

The heat transfer path is: Pump 24 - Outer flow path 21 - Intermediate flow path 22 - Mesh flow path 8 - Intermediate flow path 22 - Circulation between pumps 24, which also maintains the temperature balance of the battery pack.

The cross section of the protrusion 6 may be trapezoidal as shown in FIG. 18, or a pointed shape as shown in FIG. 19, or a triangular shape as shown in FIG. 20, or a sheet shape as shown in FIG. 21, and may be any other sharp. The shape of the top.

Claims

Rights request

1. A power battery pack comprising a plurality of single cells, each of which has a battery case, and positive and negative terminals are disposed on both sides of the battery case, and positive and negative plates, positive and negative plates are disposed in the battery case Connected to the positive and negative terminals respectively.

The utility model is characterized in that: the outer surface of the terminal of each of the single battery cells is provided with a plurality of protrusions, the protrusions have sharp tips, the top ends of the protrusions are located in the same plane, and the adjacent terminals of the adjacent battery cells pass through the respective The protrusions on the surface are connected, and the protrusions are connected to form a three-dimensional grid structure, which is a heat conduction bridge of a single battery to enhance heat exchange, and all or part of the holes and gaps in the three-dimensional grid In the same manner, a crisscrossed mesh flow path is formed, and the heat exchange medium flows through the outer surface of the terminal through the mesh flow path, thereby realizing effective heat exchange for the power battery pack, and each cross point and line of the three-dimensional grid structure overlap. The electrical connection points and the electrical connection bands between the adjacent battery terminals are formed, and all the single cells are pressed by the pre-tightening force on both sides of the power battery pack, and the pre-tightening force makes the adjacent terminals of the adjacent battery cells The raised sharp tips on the upper surface are deformed and fitted to each other to form a reliable contact between the electrical connection points and the electrical connection strips.

A power battery pack according to claim 1, wherein: the projection provided on the surface of the terminal is formed by a tapered small piece and a strip-shaped rib.

3. A power battery pack according to claim 1, wherein: the edge of the terminal protrudes from the battery case and is bent inwardly, and the inwardly bent portion is provided with fins.

4. A power battery pack according to claim 1, wherein: the edge of the terminal protrudes from the battery case, and the portion of the protruding battery case is provided with teeth.

The power battery pack according to claim 1, wherein: the terminal is annealed to have a lower hardness, and the protrusion is integrally formed with the terminal, so that the sharp tip of the protrusion is more easily deformed, thereby Form a reliable electrical connection.

6. The power battery pack according to claim 1, wherein: the outer surface of the terminal is covered with a soft metal, and the protrusion is integrally formed with the terminal, so that the sharp tip of the protrusion is more easily deformed, thereby forming a reliable Electrical connection.

The power battery pack according to claim 1, wherein: the single battery is in the shape of a ring, the positive and negative plates are in a spiral winding structure, and the positive plate is perpendicular to the positive terminal, and the negative plate Vertical to the negative terminal.

8. A power battery according to claim 1, wherein: adjacent terminals of said adjacent single cells are indirectly connected by projections on respective outer surfaces, and metal foil is disposed at the junction.

The power battery pack according to claim 1, wherein the battery cells are in the shape of a ring, and the battery cells are arranged in the axial direction to form a power battery pack, and the power battery pack is disposed outside the power battery pack. The insulated and insulated sleeve, the power battery pack and the sleeve are all enclosed in the outer casing, and the sleeve is fixed on the battery case of the single battery through the bracket, and the gap between the sleeve and the outer casing constitutes the outer flow passage, the sleeve and the sleeve The gap between the battery shells of the single battery constitutes an intermediate flow passage, and the hollow portion in the middle of each annular battery constitutes an inner flow passage, the outer flow passage communicates with the intermediate flow passage, and the intermediate flow passage communicates with the mesh flow passage. The mesh flow channel is in communication with the inner flow channel, and the inner flow channel is in communication with the intermediate flow channel, and the heat exchange medium circulates between the flow channels to make the internal temperature field of the power battery pack uniform.

10. The power battery pack according to claim 9, wherein: the inner flow passage, the intermediate flow passage, and the outer flow passage are connected to each other to constitute a main flow passage of the power battery pack, and the mesh flow passage The utility model constitutes a branch flow channel of the power battery pack, and a pump is arranged in the main flow channel, and heat dissipating fins are arranged on the surface of the outer casing, and the heat exchange medium is arranged along the pump-external flow channel-intermediate flow channel-net flow channel Flow path - circulates between the pumps and heats the fins through the heat sink fins on the outside of the battery case.

11. The power battery pack according to claim 9, wherein: the outer flow passage is provided with a valve; when the temperature is low, the valve is closed, so that the heat exchange medium cannot flow to the outer flow passage, and only along the middle of the pump The flow path in the flow path of the flow channel is pumped to keep the temperature of the battery pack balanced.

12. The power battery pack according to claim 9, wherein: the outer flow passage is provided with a valve; the intermediate flow passage is provided with a heating element, and when the temperature is low, the valve in the outer flow passage is closed to make the heat exchange medium The heating element is circulated and heated to achieve the purpose of heating the battery pack.