JP2013165067A - Secondary battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a secondary battery pack where operations for connecting a plurality of secondary batteries and detection and control systems and the like can be simplified, and prevention of wrong connection and improvement of safety can be achieved.SOLUTION: The secondary battery pack comprise: a plurality of unit cell batteries 10 which comprise a positive electrode terminal 21 and a negative electrode terminal 22 and are arranged side by side; a battery monitoring board 14 which is arranged on the plurality of unit cell batteries and monitors voltage and temperature of the unit cell batteries; and a plurality of bus-bars 18 which electrically connect electrode terminals of the respective adjacent unit cell batteries. The bus-bars comprise a connecting piece 36 for detection which is formed of the same material as the bus-bar and the connecting piece is directly soldered and connected to the battery monitoring board.

Description

  The present invention relates to a secondary battery pack including a plurality of unit cell batteries and a battery monitoring substrate.

  The secondary battery pack has a structure in which a plurality of secondary batteries (for example, prismatic secondary batteries) in which a positive electrode terminal and a negative electrode terminal are separated from each other in the same plane are stored in a container adjacent to each other. ing. Such a secondary battery pack needs to detect and manage the charging voltage of each secondary battery (unit cell).

  A conventional secondary battery pack includes, for example, a bus bar that connects a positive terminal of one secondary battery and a negative terminal of the other secondary battery among adjacent secondary batteries among a plurality of secondary batteries incorporated in a housing. Connecting, connecting a lead wire to the bus bar, and drawing the other end of the lead wire to connect to a detection circuit or the like disposed at a predetermined location of the housing is performed (for example, Patent Document 1).

JP 2006-139919 A

  However, in such a secondary battery pack, 1) work for bundling and aligning the lead wire routing portions is required, and 2) a plurality of lead wires need to be connected to the bus bar and the detection circuit. 3) If the number of lead wires increases along with the increase in the number of secondary batteries to be accommodated, there will be a problem in connecting the positive and negative terminals of the secondary battery. Since it is necessary to secure a sufficient space for avoiding bending of the lead wire, there is a problem that the case is enlarged.

  The present invention has been made in view of the above points, and its purpose is to simplify connection work between a plurality of secondary batteries and a detection / control system, to prevent erroneous connection and to improve safety. Is to provide a secondary battery pack.

  A secondary battery pack according to an aspect of the present invention includes a plurality of unit cell batteries each having a positive electrode terminal and a negative electrode terminal, arranged side by side, and disposed on the plurality of unit cell batteries. A battery monitoring substrate that monitors the voltage and temperature of the cell battery, and a plurality of bus bars that electrically connect the electrode terminals of the adjacent unit cell batteries. The bus bar has a detection connecting piece formed of the same material as the bus bar, and the battery monitoring substrate includes a plurality of cutouts formed on side edges thereof and a cutout including an inner surface of the cutout. A conductive layer formed around the notch, and the connection piece engages with the notch of the battery information monitoring substrate, is soldered to the conductive layer, and is directly connected to the battery monitoring substrate. Has been.

  According to the above configuration, it is possible to provide a secondary battery pack capable of simplifying connection work between a plurality of secondary batteries and a detection / control system, preventing misconnection, and improving safety. .

FIG. 1 is a perspective view showing a secondary battery pack according to a first embodiment of the present invention. FIG. 2 is an enlarged perspective view illustrating a connection portion between a substrate and a connection piece of the secondary battery pack. FIG. 3 is an exploded perspective view of the secondary battery pack. FIG. 4 is an exploded perspective view of the secondary battery pack. FIG. 5 is a cross-sectional view of the secondary battery pack taken along line AA of FIG. FIG. 6 is a perspective view showing a secondary battery pack according to a second embodiment of the present invention. FIG. 7 is an exploded perspective view of the secondary battery pack according to the second embodiment. FIG. 8 is an exploded perspective view showing an enlarged connection portion between a substrate and a connection piece of the secondary battery pack according to the second embodiment. FIG. 9 is a plan view showing the connecting portion. FIG. 10 is an exploded perspective view showing an enlarged connection portion between a substrate and a connection piece of a secondary battery pack according to a third embodiment.

Hereinafter, a secondary battery pack according to a first embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a perspective view showing the entire secondary battery pack according to the first embodiment, FIG. 2 is an enlarged perspective view showing a connection portion between a substrate and a connection piece of the secondary battery pack, and FIG. 4 is an exploded perspective view showing the battery pack main body and the substrate of the secondary battery pack in an exploded state, FIG. 4 is an exploded perspective view showing the battery pack main body of the secondary battery pack in an exploded state, and FIG. 5 is a line A in FIG. It is sectional drawing of the secondary battery pack along -A.

  As shown in FIGS. 1, 3 to 5, the secondary battery pack is connected to the battery pack body 12 having a plurality of, for example, six secondary batteries (unit cell batteries) 10, and the secondary batteries. And a battery monitoring circuit board 14 for monitoring the voltage and temperature of the secondary battery. The battery pack body 12 includes a rectangular box-shaped housing 16 that houses six secondary batteries (unit cell batteries), a plurality of bus bars 18 that are electrically connected between electrode terminals of adjacent secondary batteries, It has.

  Each secondary battery 10 is a non-aqueous electrolyte secondary battery such as a lithium ion battery, for example, a flat rectangular box-shaped container 20 formed of aluminum or an aluminum alloy, and an electrode (not shown) accommodated in the container And a positive electrode terminal 21 and a negative electrode terminal 22 each having a stepped rectangular shape, for example, are provided on one end face of the container so as to be separated from each other. The positive terminal 21 and the negative terminal 22 are made of, for example, aluminum or an aluminum alloy.

  The housing 16 includes a rectangular plate-shaped bottom wall 24, a rectangular box-shaped cover body 26 having an open bottom, and a rectangular plate-shaped lid body 28, which is formed of an insulating material such as a synthetic resin. Has been. On the bottom wall 24, a number corresponding to the number of the secondary batteries 10, here, six engaging grooves 25 are formed. Each engagement groove 25 is formed in an elongated rectangular shape corresponding to the cross-sectional shape of the container 20 of the secondary battery 10 and extends along the width direction of the bottom plate. The plurality of engaging grooves 25 are provided side by side with a predetermined interval in the longitudinal direction of the bottom wall 24.

  Six engagement holes 27 corresponding to the number of the secondary batteries 10 are formed in the ceiling wall 26 a of the cover body 26. Each engagement hole 27 is formed in an elongated rectangular shape corresponding to the cross-sectional shape of the container 20 of the secondary battery 10, and extends along the width direction of the ceiling wall 26a. The plurality of engagement holes 27 are provided side by side with a predetermined interval in the longitudinal direction of the ceiling wall 26a. In a state where the cover body 26 is put on the bottom wall 24, the plurality of engagement holes 27 are positioned to face the plurality of engagement grooves 25 of the bottom wall 24. A plurality of partition ribs 30 are integrally formed on the inner surface of the ceiling wall 26 a, and these partition ribs are positioned in the adjacent engagement holes 27.

  Each secondary battery 10 is in a state where the lower end portion of the container 20 is fitted into the engagement groove 25 of the bottom wall 24 and the upper end portion of the container is inserted into the engagement hole 27 of the ceiling wall 26a. Housed in the body 16. Thus, the six secondary batteries 10 are held in a row with the main surfaces of the containers 20 facing each other with a predetermined gap. One end surface on which the positive electrode terminal 21 and the negative electrode terminal 22 are provided is exposed in the engagement hole 27.

  In the present embodiment, the two adjacent secondary batteries 10 are arranged in a state where they are inverted by 180 degrees so that the positions of the positive electrode terminal 21 and the negative electrode terminal 22 are reversed. That is, the six secondary batteries 10 are arranged so that the positive electrode terminals 21 and the negative electrode terminals 22 are alternately arranged in two rows along the arrangement direction.

  The lid body 28 of the housing 16 has a plurality of openings 32 corresponding to the electrode terminals of the secondary battery 10 and a plurality of bosses 34 that support the circuit board 14 for battery monitoring. The plurality of openings 32 are provided in two rows at predetermined intervals. Each opening 32 is formed in a rectangular shape larger than the electrode terminal of the secondary battery 10. A plurality of, for example, three bosses 34 project from the upper surface of the lid 28 and are respectively provided at both ends and the center in the longitudinal direction of the lid.

  The lid body 28 overlaps the ceiling wall 26 a of the cover body 26 and is fixed to the cover body, and covers one end surface of the secondary battery 10. The positive electrode terminal 21 and the negative electrode terminal 22 of each secondary battery 10 are located in the opening 32 of the lid 28 and exposed upward through this opening.

  As shown in FIGS. 3 to 5, the plurality of secondary batteries 10 are connected in series by a plurality of bus bars 18. The bus bar 18 is formed by bending a metal plate made of a conductive material such as aluminum. The bus bar 18 includes a pair of rectangular connection portions 18a and a curved connection portion 18b extending between the connection portions 18a. Each connection portion 18a is formed with a terminal opening 18c with which the electrode terminal 21 or 22 of the secondary battery 10 is engaged. The bus bar 18 has a connection terminal 36 that extends from the coupling portion 18b in a direction perpendicular to the surface of the connection portion 18a. The connection terminal 36 is integrally formed with the bus bar 18 by the same conductive material as the bus bar 18, here, aluminum. The connection terminal 36 functions as a connection piece, and an extended end portion thereof is coated with a conductive film such as copper having high wettability with respect to solder.

  The bus bar 18 has one connecting portion 18 a connected to the positive terminal 21 of the secondary battery 10 and the other connecting portion 18 a connected to the negative terminal 22 of another adjacent secondary battery 10. Each connecting portion 18a is joined to the electrode terminal by welding, for example, laser welding, with the tip of the electrode terminal 21 or 22 engaged in the terminal opening 18c. For welding, electron beam welding or resistance welding may be used instead of laser welding. The six secondary batteries 10 are connected in series by five bus bars 18. The connection terminals 36 of the bus bars 18 extend substantially vertically upward with respect to the lid body 28 of the housing 16.

Among the plurality of secondary batteries 10, the negative terminal 22 of the secondary battery 10 positioned at one end of the array and the positive terminal 21 of the secondary battery 10 positioned at the other end of the array have output terminals 38 respectively. Is connected. Each output terminal 40 has a rectangular connection portion 40a, a terminal opening 40b formed in the connection portion, and a connection terminal 42 extending vertically upward from the connection portion, and is made of a metal plate such as aluminum. It is integrally formed. Each connecting portion 40a is joined to the electrode terminal by laser welding in a state where the tip of the electrode terminal 21 or 22 is engaged in the terminal opening 40b. The connection terminal 36 of the output terminal 40 extends substantially vertically upward with respect to the lid body 28 of the housing 16.
The connection terminal 36 of the bus bar 18 and the connection terminal 42 of the output terminal 40 are formed at substantially the same height, and are arranged in two rows.

  As shown in FIGS. 1 to 5, the battery monitoring circuit board 14 is formed in a rectangular shape having a size substantially equal to the lid body 28 of the housing 16. A desired wiring pattern is formed on the battery monitoring circuit board 14 with a copper foil or the like, and a plurality of control elements 44 are mounted almost at the center. These control elements 44 constitute a battery monitoring unit 47 that measures and monitors the voltage, temperature, and the like of each secondary battery 10.

  The battery monitoring circuit board 14 is formed with a plurality of slit-like engagement holes 46 along both side edges of the circuit board. These engagement holes 46 are provided in two rows corresponding to the connection terminals 36 and 42 on the battery pack body 12 side. A conductive layer 50 is formed of a copper foil or a plating layer around the inner surface of each engagement hole 46 and around the engagement hole. These conductive layers 50 are electrically connected to the wiring pattern of the circuit board.

  A plurality of resistors 52 are mounted on the battery monitoring circuit board 14. Each resistor 52 is formed, for example, to several Ω to several hundred Ω, and is connected between each conductive layer 50 and the battery monitoring unit 47. These resistors 52 restrict overdischarge from the secondary battery 10 and protect the battery monitoring circuit board 14.

  The battery monitoring circuit board 14 is disposed above the battery pack body 12 and is screwed to the boss 34 of the lid 28 by a plurality of screws 62. Thus, the battery monitoring circuit board 14 is supported on the boss 34 and is supported so as to face the lid 28 with a gap. The connection terminal 36 of each bus bar 18 and the connection terminal 42 of each output terminal 40 are respectively inserted into the corresponding engagement holes 46 of the battery monitoring circuit board 14 and soldered to the conductive layer 50 of the battery monitoring circuit board 14 by the solder 54. Has been. Thereby, the connection terminal 36 and the connection terminal 42 of each output terminal 40 are directly and mechanically connected to the battery monitoring circuit board 14, and each is electrically connected to the battery monitoring unit 47 via the resistor 52. It is connected to the. The battery monitoring circuit board 14 is supported by the bus bar 18 and the output terminal 40 in addition to the boss 34, and is firmly supported and connected to the battery pack body 12. The battery monitoring circuit board 14 is electrically connected to each secondary battery 10 via the bus bar 18 having the connection terminals 36.

  The battery monitoring unit 47 of the battery monitoring circuit board 14 measures and monitors the voltage and temperature of each secondary battery 10 to prevent overcharge and overdischarge of the secondary battery 10.

  According to the battery pack configured as described above, the plurality of bus bars 18 that electrically connect the electrode terminals of the adjacent secondary batteries include the detection connection terminals 36 formed of the same material as the bus bar. This connection terminal is directly soldered to the battery monitoring circuit board 14. Accordingly, each secondary battery 10 is electrically connected to the battery monitoring circuit board 14 by the bus bar 18. Therefore, it is possible to easily connect the battery pack body 12 and the battery monitoring circuit board 14 as compared with the case where a plurality of lead wires are routed between the secondary battery and the circuit board as in the prior art. Connection can be prevented. Further, the lead wire short-circuit phenomenon does not occur, and safety can be improved. Furthermore, the support structure of the circuit board 14 can be made robust, and the reliability of the secondary battery pack can be improved.

Next, the secondary battery pack according to the second embodiment will be described.
6 is a perspective view showing the entire secondary battery pack according to the second embodiment, FIG. 7 is an exploded perspective view showing the battery pack body and the circuit board of the secondary battery pack in an exploded manner, and FIG. FIG. 9 is an enlarged perspective view showing an enlarged connection portion between the circuit board and the connection piece of the secondary battery pack, and FIG. 9 is an enlarged plan view showing the connection portion between the circuit board and the connection piece of the secondary battery pack. is there.
In the second embodiment, the same parts as those in the first embodiment described above will be denoted by the same reference numerals, detailed description thereof will be omitted, and different parts will be mainly described.

  As shown in FIGS. 6 to 9, according to the second embodiment, the battery monitoring circuit board 14 has a plurality of notches (engagement recesses) 60 formed on two opposing side edges, respectively. doing. These notches 60 are provided in two rows corresponding to the connection terminals 36 and 42 on the battery pack body 12 side. Each notch 60 is formed in a rectangular shape corresponding to the connection terminals 36 and 42, and has a width and depth slightly larger than the width and thickness of the connection terminal. In each notch 60 and around the notch, a conductive layer 50 is formed of a copper foil or a plated layer. These conductive layers 50 are electrically connected to the wiring pattern of the circuit board 14.

  A plurality of resistors 52 are mounted on the battery monitoring circuit board 14. Each resistor 52 is formed, for example, to several Ω to several hundred Ω, and is connected between each conductive layer 50 and the battery monitoring unit 47. These resistors 52 restrict overdischarge from the secondary battery 10 and protect the battery monitoring circuit board 14.

The battery monitoring circuit board 14 is disposed above the battery pack body 12 and is screwed to the boss 34 of the lid 28 by a plurality of screws 62. Thus, the battery monitoring circuit board 14 is supported on the boss 34 and is supported so as to face the lid 28 with a gap. The connection terminal 36 of each bus bar 18 and the connection terminal 42 of each output terminal 40 are respectively engaged with the corresponding notches 60 of the battery monitoring circuit board 14, and soldered to the conductive layer 50 of the battery monitoring circuit board 14 by the solder 54. Has been. Thereby, the connection terminal 36 and the connection terminal 42 of each output terminal 40 are directly and mechanically connected to the battery monitoring circuit board 14, and each is electrically connected to the battery monitoring unit 47 via the resistor 52. It is connected to the. The battery monitoring circuit board 14 is supported by the bus bar 18 and the output terminal 40 in addition to the boss 34, and is firmly supported and connected to the battery pack body 12. The battery monitoring circuit board 14 is electrically connected to each secondary battery 10 via the bus bar 18 having the connection terminals 36.
Other configurations of the battery pack body 12 and the battery monitoring circuit board 14 are the same as those of the first embodiment described above.

  According to the secondary battery pack according to the second embodiment configured as described above, the plurality of bus bars 18 that electrically connect the electrode terminals of adjacent secondary batteries are formed of the same material as the bus bar. The detection connection terminal 36 is connected to the battery monitoring circuit board 14 by soldering. Accordingly, each secondary battery 10 is electrically connected to the battery monitoring circuit board 14 by the bus bar 18. Therefore, it is possible to easily connect the battery pack body 12 and the battery monitoring circuit board 14 as compared with the case where a plurality of lead wires are routed between the secondary battery and the circuit board as in the prior art. Connection can be prevented. Further, the lead wire short-circuit phenomenon does not occur, and safety can be improved. The support structure of the circuit board 14 can be made robust, and the reliability of the secondary battery pack can be improved.

  Furthermore, according to the second embodiment, the connection part of the battery monitoring circuit board 14 is made into the notch 60, so that the connection terminal of the bus bar and the connection terminal of the output terminal can be easily aligned with the notch 60. Connection work becomes easier. Further, when any of the secondary batteries is removed from the battery pack for the purpose of replacement or repair, the connection between the connection terminals 36 and 42 and the battery monitoring circuit board 14 can be easily removed, and maintenance is improved.

  In addition, this invention is not limited to embodiment mentioned above, In an implementation stage, it can embody by deform | transforming a component in the range which does not deviate from the summary. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. Some constituent elements may be deleted from all the constituent elements shown in the embodiments, or constituent elements over different embodiments may be appropriately combined.

  For example, as shown in FIG. 10, the connection part of the connection terminal in the battery monitoring circuit board 14 may be provided on the side edge of the circuit board. In other words, the conductive layer 50 is formed at and around the side edge of the battery monitoring circuit board 14, and the connection terminal 36 of the bus bar 18 is directly connected to the side edge of the battery monitoring circuit board 14.

  Even if it is set as such a structure, while being able to obtain the effect similar to embodiment mentioned above, it becomes possible to perform the connection operation | work of a connection terminal still more easily.

In the secondary battery pack, the number of secondary batteries is not limited to six, and can be increased or decreased as necessary. The positive electrode terminal and the negative electrode terminal of each secondary battery are not limited to a prismatic shape, and may have other shapes such as a cylindrical shape. A bus bar without a pair of terminal openings may be used as the bus bar. The connection terminal of the bus bar is not limited to the connection part of the bus bar, and may be configured to extend from the connection part.
The shape and material of the bus bar, and the shape, material, and structure of the housing are not limited to the above-described embodiment, and can be changed as appropriate.

The present invention has been described in detail with particular reference to preferred embodiments thereof. For easy understanding of the present invention, specific embodiments of the present invention will be described below.
(Appendix 1)
A plurality of unit cell batteries each having a positive electrode terminal and a negative electrode terminal and arranged side by side;
A battery monitoring substrate disposed on the plurality of unit cell batteries and monitoring the voltage and temperature of the unit cell batteries;
A plurality of bus bars that electrically connect the electrode terminals of the adjacent unit cell batteries,
The bus bar has a connection piece for detection formed of the same material as the bus bar, and the connection piece is directly connected to the battery monitoring board by soldering.

(Appendix 2)
The battery monitoring board has a plurality of engagement holes through which the connection pieces are inserted, and a conductive layer formed around the engagement holes, and the connection pieces are inserted into the engagement holes. The secondary battery pack according to appendix 1, wherein the battery pack is soldered to the conductive layer.

(Appendix 3)
The battery monitoring substrate has a plurality of notches formed on the side edges thereof, and a conductive layer formed around the notches including the inner surface of the notches,
The secondary battery pack according to appendix 1, wherein the connection piece engages with a notch of the battery information monitoring substrate and is soldered to the conductive layer.

(Appendix 4)
The battery monitoring board has a rectangular shape corresponding to the plurality of unit cell batteries, and the plurality of notches are respectively formed on two opposing side edges of the battery monitoring board. The secondary battery pack according to 3.

(Appendix 5)
The secondary battery pack according to any one of appendices 1 to 4, wherein the bus bar and the connecting piece are formed by bending a metal plate.
(Appendix 6)
The secondary battery pack according to claim 5, wherein each of the bus bars has a pair of terminal openings with which electrode terminals of unit cell batteries are engaged, and the connection piece extends from the bus bar between the terminal openings. .

10 ... secondary battery, 12 ... battery pack body, 14 ... circuit board for battery monitoring, 16 ... casing,
18 ... Bus bar, 18a ... Connector, 18b ... Connector, 18c ... Terminal opening,
21 ... Positive terminal, 22 ... Negative terminal, 36 ... Connection terminal, 40 ... Output terminal,
42 ... Connection terminal, 46 ... engagement hole, 47 ... battery monitoring part, 50 ... conductive layer, 60 ... notch

Claims (4)

A plurality of unit cell batteries each having a positive electrode terminal and a negative electrode terminal and arranged side by side;
A battery monitoring substrate disposed on the plurality of unit cell batteries and monitoring the voltage and temperature of the unit cell batteries;
A plurality of bus bars that electrically connect the electrode terminals of the adjacent unit cell batteries,
The bus bar has a connection piece for detection formed of the same material as the bus bar,
The battery monitoring substrate has a plurality of notches formed on the side edges thereof, and a conductive layer formed around the notches including the inner surface of the notches,
The connection piece engages with a notch of the battery information monitoring substrate, is soldered to the conductive layer, and is directly connected to the battery monitoring substrate.   The battery monitoring substrate has a rectangular shape with a size corresponding to the plurality of unit cell batteries, and the plurality of notches are respectively formed on two opposing side edges of the battery monitoring substrate. Item 11. The secondary battery pack according to Item 1.   The secondary battery pack according to claim 1, wherein the bus bar and the connection piece are formed by bending a metal plate.   The bus bar has a pair of terminal openings each engaging with an electrode terminal of a unit cell battery, and the connection piece extends from the bus bar between the terminal openings. The secondary battery pack according to item.

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