KR20090003825A - Anode connecting member for secondary battery - Google Patents

Abstract

An anode connecting member is provided to connect at least two secondary battery cells electrically without a soldering and welding process. An anode connecting member(100) electrically connects at least two battery cells arranged in the side direction with the physical contact. The terminal connection units(100A,100B) are electrically connected corresponds to the number of battery cell arranged in the side direction, and comprise a terminal(152) for connecting cuicuits. The terminal connection unit comprises (a) a connection part(110) contacted to the battery cell terminal with the predetermined width in the circumference of the outside corresponding to the outside shape of the battery cell terminal; (b) an elastic protrusion part(130) tapered in the middle axis direction to the main connection part to provide the flexible contact force to the battery cell; and (c) a secondary connection part(140) tapered from the inner side of the main connection part downwardly to perform the flexible connection with the electrode terminal.

Description

Anode Connecting Member for Secondary Battery

The present invention relates to a connecting member used for electrical connection of batteries, and more particularly, when mounting a plurality of secondary battery cells in a battery pack, the two or more battery cells arranged in the lateral direction to the physical contact method A connecting member electrically connected to each other, the main connecting portion being in contact with the battery cell terminals with a predetermined width, an elastic protrusion providing elastic grounding force to the battery cell, and an electrode terminal corresponding to the outer surface shape of the battery cell terminal; A terminal connecting portion having a configuration including an auxiliary connecting portion to enable a flexible connection is electrically connected corresponding to the number of battery cells in the side array, and provides a connection member including a circuit connection terminal portion on one side.

As technology development and demand for mobile devices increase, the demand for secondary batteries as an energy source is rapidly increasing.

The secondary battery may be used in the form of a single battery, or in the form of a battery pack in which a plurality of unit cells are electrically connected, depending on the type of external device used therein. For example, a small device such as a mobile phone can operate for a predetermined period of time with the output and capacity of one battery, while a medium or large size such as a notebook computer, a portable DVD, a small PC, an electric vehicle, a hybrid electric vehicle, or the like. Large devices require the use of secondary battery packs due to power and capacity issues.

The secondary battery pack is manufactured by connecting a protection circuit or the like to a core pack in which a plurality of unit cells are arranged in series and / or in parallel. In the case of using a square or pouch type battery as a unit cell, the electrodes may be connected by connecting members such as bus bars after stacking the wide surfaces to face each other. Therefore, in the case of manufacturing a three-dimensional secondary battery pack having a hexahedral structure, a square or pouch type battery is advantageous as a unit cell.

On the other hand, the cylindrical battery generally has a larger capacitance than the square and pouch type batteries, but due to the external characteristics of the cylindrical battery is not easy to arrange in a laminated structure. However, when the shape of the secondary battery pack has a linear or plate-like structure as a whole, there is a structural advantage over the square or pouch type.

Therefore, in the case of a notebook computer, a portable DVD, a small PC, etc., a secondary battery pack in which a plurality of cylindrical batteries are connected in series or in parallel and in series is used. As the core pack structure used in such a secondary battery pack, for example, a linear structure of 2P (parallel) -3S (serial), a plate structure of 2P-3S, a linear structure of 2P-4S, a plate structure of 2P-4S, Linear structures of 1P-3S and plate-like structures of 1P-3S are used.

A parallel connection structure is achieved by arranging two or more cylindrical cells adjacent in their lateral direction with the electrode terminals oriented in the same direction, and welding them to the connecting member. Such parallel cylindrical cells are also referred to as "banks".

In series connection structure, two or more cylindrical cells are arranged in a lateral direction while two or more cylindrical cells are arranged in a long manner so that electrode terminals of opposite polarities are continuous or the electrode terminals are arranged in opposite directions. Arranged adjacent to each other, the welding is performed by the connecting member.

In the electrical connection of such cylindrical cells, spot welding is generally performed using a thin connecting member (for example, a metal plate) such as a nickel plate.

FIG. 1 is a schematic view showing a state in which a secondary battery pack having a plate-like structure of 2P-3S is completed in an electrical connection work by spot welding. Figure 1 shows the coupling relationship of the secondary battery pack of the plate-like structure of 2P-3S for convenience of understanding as an exploded view.

As in FIG. 1, three cell pairs of cells 20, 21, each connected in parallel, are connected in series through a metal plate 30 to form a core pack 10.

2 shows a schematic diagram of the secondary battery pack 50 in a state where assembly is completed. For convenience of description, the pack case is omitted.

As shown in FIG. 2, each of the cells 20 and 21 is connected to the protection circuit module 90 through the positive lead 60 and the negative lead 70 and the FPCB 80 connected to the metal plate 30. It is determined. The electrical connection of the protection circuit module 90 to the metal plate 30 is mainly achieved by soldering.

In general, the secondary battery pack repeatedly performs a lot of charging and discharging during the use process, and lithium secondary batteries having a safety problem under conditions such as external shock, dropping, bed penetration, overcharge, overcurrent, etc. are used as unit cells. In order to solve this safety problem, a safety device such as a protection circuit module is added. The safety device secures the safety of the pack by acquiring information such as a voltage from a corresponding terminal connection portion of the secondary battery pack and performing a predetermined safety process. Therefore, when the connection state of the site is variable, for example, when the resistance value of the terminal connection portion is changed by vibration or the like, due to the inaccuracy of the detection information, the safety device cannot perform the desired process. Therefore, in general, the electrical connection between the battery cell and the protection circuit in the secondary battery pack is made by soldering or the like.

In addition, in order to construct a high output, high capacity secondary battery pack, it is necessary to connect a plurality of battery cells in series and / or in parallel. In order to maintain the performance of the secondary battery pack uniformly, to minimize the resistance change in the terminal connection region. Stable coupling method is required. The electrical connection between these battery cells is typically made through soldering or welding, preferably spot welding.

However, the welding or soldering process between the battery cells has the following problems. Specifically, the welding or soldering process requires a skilled skill and know-how of the operator, and must continuously manage the parameters for determining the strength of the welding, which leads to complicated production process and increased cost, thus increasing production efficiency. It acts as a factor to inhibit. In addition, in the process of directly welding or soldering to the battery cell, electrical or thermal damage is caused between the battery cell and the connection member, which threatens the safety of the battery and increases the defective rate of the product. Furthermore, when some battery cells fail during the manufacturing process or use, there is a problem that all battery cells constituting the battery pack should be discarded.

Therefore, it is possible to replace the connection method through welding, soldering, etc., which threatens the stability of the battery and requires a complicated work process, and at the same time, it is possible to reuse the remaining battery cells when some battery cells are defective while ensuring a stable connection structure between the battery cells. There is a high need for a technology that can be used.

Meanwhile, in battery packs using primary batteries, various attempts have been made to the electrical connection structure of the connection method. For example, Korean Patent No. 0413381 discloses a technology for forming conductive coils at both ends of left and right sides of a battery case for electrical connection of a battery, and US Patent No. 525037 describes elasticity at both ends of a battery pack. Disclosed is a technical content of making an electrical connection by installing a metal plate bent to have.

However, the above technologies have a problem in that the connection member must have sufficient elasticity to fix the battery cell and to make stable connection with the electrode terminal. In particular, the technique using the conductive coil has a high electric resistance because the cross-sectional area of the wire constituting the coil is small and the connection length is relatively long, and the increased resistance causes power loss and heat generation, resulting in stable connection of the battery. May inhibit. In addition, the technology using the metal plate bent to have elasticity, due to excessive force or repeated use in the process of inserting the battery cell into the pack case, the metal plate loses its elasticity or is destroyed, the external impact on the battery cell When applied, the phenomenon of detachment or disconnection of the electrical connection may occur.

In addition, the connection member as described above has a limitation in that it is applicable to the secondary battery pack as described above due to the variable connection state at the corresponding site.

Therefore, there is a need for a technology that can replace a connection method through welding and soldering, which threatens the safety of the battery and requires a complicated work process, and at the same time secures a stable connection structure between the battery cells.

The present invention aims to solve the problems of the prior art as described above and the technical problems that have been requested from the past.

That is, an object of the present invention is to provide a connection member that can stably electrically connect two or more secondary battery cells without performing soldering, welding, or the like.

Still another object of the present invention is to provide a connection member having a specific structure that is easy to assemble and detachable as needed, and to provide a secondary battery pack manufactured using the connection member.

The connection member according to the present invention is a connection member for electrically connecting two or more battery cells arranged in a lateral direction by physical contact when mounting two or more secondary battery cells in a battery pack.

(a) a main connection part which contacts the battery cell terminal with a predetermined width at a portion near its outer circumferential surface corresponding to the outer surface shape of the battery cell terminal;

(b) an elastic protrusion having a structure that is tapered upward in a central axis direction with respect to the main connection part to provide a resilient grounding force to the battery cell; And

(c) an auxiliary connection portion tapered downward from the inside of the main connection portion to enable elastic connection to the electrode terminal;

Terminal connection parts having a configuration including a, is electrically connected corresponding to the number of battery cells of the side array, and is configured in a structure including a terminal for circuit connection on one side.

Therefore, the connection member according to the present invention does not require a soldering and welding process for the electrical connection of the battery cell electrode terminals in the battery pack manufacturing process, and maintains a stable connection structure only by the coupling of the prefabricated member, so that soldering and welding It prevents the possibility of battery short-circuit that may occur during the process, and the resistance change of the connection part does not deviate from the reliability level even by an external impact, and at the same time facilitates the assembly process of the battery pack, and provides a stable bonding force between the battery cell electrode terminals. can do.

In addition, when a failure occurs during the assembly or use of the battery pack, the battery cells can be easily separated, so that all the battery cells constituting the battery pack due to the failure of some of the battery cells or the connection member has to be discarded. I can eliminate it.

In one preferred example, the elastic protrusion of the cross-shaped bridge structure protrudes upward with respect to the main connection portion of the connection member so that the connection member can maintain a more elastic connection state with the battery cells while the connection member is mounted on the battery pack case. Can be formed. In such elastic protrusions, two or more bridges are connected to each other in a symmetrical structure, thereby providing a more elastic coupling force as a whole.

The auxiliary connecting portion is continuously formed in a tapered structure inside the main connecting portion to further reinforce the elastic force of the connecting member and prevent the short-circuit of the electrode terminal when an external force such as vibration or bending is applied to the battery pack. Can be. This auxiliary connecting portion has a height at which its end is higher than the main connecting portion, and is inclined in the direction of the central axis of the terminal connecting portion.

Therefore, the radially symmetric auxiliary connecting portions extending downwardly higher than the main connecting portion can elastically support the upward protrusion while the connecting member is in contact with the electrode terminal of the lower battery cell, and further, the electrode terminal of the upper battery cell. Since the connected state is stably maintained, it is possible to prevent a short circuit occurring due to an unstable connection state when the external force is applied as described above.

These auxiliary connections are preferably formed in two or more numbers radially symmetrical with respect to the central axis of the terminal connection portion to ensure balanced support for the upward protrusion and more stable connection to the electrode terminals.

In one preferred embodiment, the ends of the auxiliary connecting portions are bent upward in a direction opposite to the overall taper direction of the auxiliary connecting member so that the battery cell electrode terminal face is scratched or damaged by the sharp ends of the auxiliary connecting portions. Injury can be prevented during assembly of the battery pack.

One or more auxiliary connections may be located between the bridges of the connection member. For example, one or more auxiliary connections between the bridge and the bridge extending from the cross-shaped main connection may be formed in a structure extending from the main connection.

The connecting member according to the present invention can be manufactured integrally, for example, by punching and pressure-deforming one conductive plate. That is, one conductive plate is punched and rolled to suit the shape of the connecting member so that the main contact portion is in contact with the electrode terminal of the lower battery cell, an elastic protrusion providing elastic grounding force to the lower battery cell, and the inner side of the main connection portion. As a result, it is possible to easily manufacture the auxiliary connecting portions which are continuous in the downward tapered structure and the like.

The connection member according to the invention can be preferably used in particular in a cylindrical battery cell. In this case, the main connecting portion and the auxiliary connecting portion of the connecting member are formed in a concentric structure as a whole, and therefore, they correspond to the shape of the electrode terminal surface of the cylindrical battery cell, it is possible to maximize the mutual contact surface.

In general, a cylindrical battery cell has a positive electrode terminal protruding from one end thereof, and the battery case is configured to form a negative electrode terminal in an insulated state. In the present specification, the concentric circle structure as a whole means that each of the portions is formed to have an approximately concentric shape in the outward direction from the central axis of the connecting member.

For example, the size of the concentric circles corresponding to the inner diameter or the outer diameter of the main connecting portion and the auxiliary connecting portion may be formed in an outer direction from the central axis of the connecting member.

The contact width of the main connection portion with respect to the battery cell is preferably made of a size of 5 to 20% based on the radius of the terminal connection portion. When the contact width of the main connection portion is less than 5%, the resistance of the contact portion increases due to the narrow contact area, and the electrical connection of the battery cell can be easily disconnected while the electrode terminal of the battery cell is slightly out of position due to external impact. . On the contrary, if the width of the main connection portion exceeds 20%, the size of the remaining portions such as the elastic protrusions may become small, so that it may be difficult to exert a predetermined elastic force, which is not preferable.

The upward taper width of the elastic protrusion may be 10 to 30% of the width based on the radius of the terminal connection portion. If the upward taper width is too small or too large, it is not preferable because it is difficult to provide a desired elastic force between the terminals of the battery cell and the main connection portion.

As another example, the elastic protrusion may have a structure in which the elastic protrusion is tapered at an inclination of 10 to 60 degrees with respect to one surface of the terminal connection part in order to provide stable elastic force when contacting the electrode terminal of the battery cell. If the inclination is too large, a strong pressure needs to be applied to the connection member when the battery cell is mounted on the pack case, so that the mounting operation is not easy, and the connection member may be damaged during the mounting process or the use of the battery pack, and the inverse slope Is too small to provide the desired elastic force, which is undesirable.

The elastic protrusion formed to protrude in the direction of the center axis of the connecting member has a predetermined height so that a desired elastic force can be induced from the elastic protrusion in a state where it is mounted on the pack case. In the non-applied state, it may be determined at a size of 40 to 90% based on the total height of the connection member.

In addition, since the auxiliary connection portion is formed to a depth of 10 to 50% based on the entire height of the connection member in the state that no external force is applied, the auxiliary connection portion can maintain the contact force with the battery cell more elastically.

If the depth of the elastic protrusion or auxiliary connection is too low, it may be difficult to maintain the desired elasticity of the electrode terminal, on the contrary too high may break during the assembly or use of the battery pack, in the case of the auxiliary connection It is not preferable because it may cause scratches on the electrode terminals.

In some cases, at least one side of the connection member may have a structure in which a side extension part in which the circuit connection terminal part is located is formed, and thus can be simply connected to a protection circuit. The structure of the terminal portion formed in the side extension portion is not particularly limited and the structure thereof varies depending on the type of member for connecting to the protective circuit.

The present invention also provides a battery pack for a notebook computer comprising the above connection member.

That is, the battery pack according to the present invention is a battery pack for a notebook computer having a structure in which a plurality of battery cells are arranged in an electrical connection and a row of batteries is arranged in a pack case, and battery cells are arranged in a lateral direction. Provided is a battery pack having a structure in which the connection member is used for electrical connection of a field (bank).

Specifically, a battery pack having a structure in which battery cells are mounted after mounting the connection member in a battery pack case for a notebook including at least one storage unit in which two or more secondary battery cells can be mounted adjacent to each other in a lateral direction. As a battery pack, the battery pack may be manufactured in a structure in which the connection member is coupled in an assembly manner such that the contact portion faces the electrode terminal on the sidewall of the sidewalls constituting the pack case.

In the battery pack, the connection member may be preferably used to connect the negative terminals of the bank to the negative electrode circuit of the pack case. This structure is a structure in which the connection member is positioned between the negative terminal of the bank and the side wall of the pack case, so that the negative terminal of the side wall and the bank is stably fixed and electrically connected by the elastic force of the elastic part.

In the present invention, the connecting members are not particularly limited as long as they have a material having electrical conductivity and elastic force, and it is preferable to use a metal plate in consideration of ease of processing. Among them, it may be preferably made of a material selected from the group consisting of nickel, brass, aluminum, copper and optional alloys thereof.

The battery pack according to the present invention can be used as a power source for household electronic devices such as portable DVDs, small PCs, etc., which require high output and large capacity, and can be preferably used as a power source for notebook computers.

Accordingly, the present invention also provides a notebook computer including the battery pack as a power source.

Since the general structure of the notebook computer and its manufacturing method and the like are known in the art, further description thereof will be omitted herein.

Since the connection member according to the present invention does not require a welding or soldering process for the electrical connection of the battery cell electrode terminals, it is possible to prevent a short circuit of the battery that may occur during the welding process and to significantly reduce the defective rate, and the secondary battery cell The stable coupling structure between the electrode terminals can minimize the resistance change in the connection area, and greatly improve the production efficiency.

Hereinafter, although described with reference to the drawings according to an embodiment of the present invention, this is for easier understanding of the present invention, the scope of the present invention is not limited thereto.

3 is a perspective view of a connecting member according to an embodiment of the present invention, and FIG. 4 is a front view of the connecting member of FIG.

Referring to these drawings, the connection member 100 according to the present invention has two terminal connection portions 100A and 100B connected to each other, and one side of the connection member has a circuit connection terminal portion 152 for connecting to an external circuit. Consists of a structure in which the side extension portion 150 is located.

Each of the terminal connecting portions 100A and 100B has a predetermined width w and a terminal connecting portion for the main connecting portion 110 and the main connecting portion 110 that are electrically connected to electrode terminals of a lower battery cell (not shown). An elastic protrusion 130 of the structure tapered upward in the direction of the central axis 180 of the bridge connected to the bridge, and the auxiliary connection portion 140 continuous in a downward tapered structure of the main connection portion 110.

The contact width w contacting the electrode terminal of the lower battery cell in the main connection part 110 is approximately 10% based on the radius W of the terminal connection part, and corresponds to the outer surface of the battery cell electrode terminal located below. It consists of concentric shapes.

The height h of the elastic protrusion 130 is approximately 60% based on the total height H of the connection member 100, and the four bridges of the elastic protrusion 130 form a symmetrical cross shape. It consists of shapes.

In addition, in the space between the elastic protrusion 130 and the main connector 110, four auxiliary connectors 140, which are radially symmetrical with respect to the central axis 180 of the terminal connector, are directed downward from the main connector 110. Tapered. The ends of the auxiliary connectors 140 are bent upwards 144 with respect to the downward taper direction of the auxiliary connectors. Therefore, in the process of mounting the connection member 100 to the negative terminal of the lower battery cell (not shown), the auxiliary connection portion 140 is elastically pressed while the electrode of the battery cell located below the connection member 100 It is connected to the terminal.

These auxiliary connections 140 show a somewhat low modulus of elasticity, but since the four parts are independently connected to the electrode terminals of the lower battery cells, the short circuit of the battery cells is prevented from being caused by external factors such as vibrations. Keep the electrical connections on.

In addition, the main connecting portion 110 of the terminal connecting portion is a circular shape as a whole, and if the four elastic protrusions 130 and the auxiliary connecting portion 140 are each connected to form a virtual concentric shape, so as to form a concentric circular structure as a whole The contact area between the terminal connecting portion and the outer circumferential surface of the cylindrical battery cell electrode terminals is improved.

FIG. 5 is a partial plan view schematically illustrating a state in which battery cells are mounted in a pack case using the connection member of the present invention.

Referring to FIG. 5, the connecting member 100 is arranged on the battery cell 200 such that the elastic protrusion 130 faces the side wall of the case, thereby connecting the main connecting portion 110 and the auxiliary connecting portion (FIG. 1: 140). It is electrically connected to the battery cell 200 through.

As such, when the battery cell 200 is mounted in the pack case 300 or the battery cell 200 is mounted in the pack case 300, the connection member 100 is additionally mounted. The structure in which the connection member 100 is positioned between the sidewall 310 of the pack case 300 and the negative electrode terminal of the battery cell 200 is made.

The overall height of the connection member 100 in the non-mounted state is greater than the width of the portion where the connection member 100 is inserted in the state in which the battery cell 200 is mounted in the pack case 300, and thus the connection member 100. The elastic protrusion 130 of) is pressed by the side wall 130 to cause an elastic force. Therefore, a close mechanical contact state is maintained between the battery cell 200 and the connection member 100, thereby making stable electrical connection.

Although described with reference to the drawings according to an embodiment of the present invention, those of ordinary skill in the art will be able to perform various applications and modifications within the scope of the present invention based on the above contents.

1 is an exploded view showing a coupling manner of batteries electrically connected by a metal plate which is a conventional connecting member;

2 is a schematic view of a battery pack with a metal plate and a protection circuit connected;

3 is a perspective view of a connecting member according to one embodiment of the present invention;

4 is a schematic front view of the connecting member of FIG. 3;

5 is a schematic partial plan view of the battery cells mounted on the pack case using the connection member of the present invention.

Claims (16)

When mounting two or more secondary battery cells in the battery pack, a connecting member for electrically connecting two or more battery cells arranged in the lateral direction by a physical contact method, (a) a main connection part which contacts the battery cell terminal with a predetermined width at a portion near its outer circumferential surface corresponding to the outer surface shape of the battery cell terminal; (b) an elastic protrusion having a structure that is tapered upward in a central axis direction with respect to the main connection part to provide a resilient grounding force to the battery cell; And (c) an auxiliary connection portion tapered downward from the inside of the main connection portion to enable elastic connection to the electrode terminal; The terminal connecting portion having a configuration including a, is electrically connected corresponding to the number of battery cells of the side array, the connection member comprising a terminal for connecting the circuit on one side. The connecting member according to claim 1, wherein the elastic protrusion protrudes in a planar cross-shaped bridge structure. The connecting member according to claim 1, wherein the auxiliary connecting portion is formed in two or more numbers radially symmetric with respect to the central axis. The connecting member according to claim 1, wherein the downward tapered end of the auxiliary connecting portion is bent upward. 3. A connecting member according to claim 2, wherein one or more auxiliary connections are located between the bridges. The connecting member according to claim 5, wherein the connecting member is manufactured as a single body by punching and pressing and deforming one conductive plate. The connecting member according to claim 1, wherein the battery cell is a cylindrical battery cell, and the main connection part and the auxiliary connection part have a concentric circular structure as a whole. The connecting member according to claim 1, wherein the contact width of the main connecting portion with respect to the battery cell is 5 to 20% in size based on the radius of the terminal connecting portion. The connecting member according to claim 1, wherein an upward taper width of the elastic protrusion is formed in a size of 10 to 30% based on a radius of the terminal connecting portion. The connecting member according to claim 1, wherein the elastic protrusion is tapered at an inclination of 10 to 60 degrees with respect to the main connecting portion. The connecting member according to claim 1, wherein the height of the elastic protrusion is 40 to 90% based on the total height of the connecting member in a state where no external force is applied. The connecting member according to claim 1, wherein the depth of the auxiliary connecting portion is 10 to 50% based on the total height of the connecting member without an external force applied. The connecting member according to claim 1, wherein at least one side of the connecting member is formed with a side extension part in which the terminal for circuit connection is located. A battery pack for a notebook computer having a structure in which a plurality of cylindrical battery cells are arranged to form an electrical connection and embedded in a pack case. The battery pack is provided to prevent electrical connection of battery cells (banks) arranged in a lateral direction. Battery pack, characterized in that the connection member according to claim 1 is used. 15. The battery pack according to claim 14, wherein the connection member is used to connect the negative terminals of the bank to the negative circuit of the pack case. A notebook computer comprising the battery pack according to claim 14 as a power source.

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