JP5481309B2 - Secondary battery device and manufacturing method thereof - Google Patents

Description

  Embodiment described here is related with the secondary battery apparatus which has a some secondary battery cell, and its manufacturing method.

  In recent years, secondary batteries have been widely used as power sources for electric vehicles, hybrid electric vehicles, electric bicycles, or electric devices. For example, a lithium ion secondary battery, which is a non-aqueous secondary battery, has attracted attention as a power source for electric vehicles and the like because of its high output and high energy density.

  Generally, a secondary battery is configured as a battery cell including an outer container, an electrode group housed in the outer container together with an electrolytic solution, and electrode terminals provided in the outer container. In order to increase capacity and output, a battery pack or a secondary battery device in which a plurality of battery cells are arranged in a case and these cells are connected in parallel or in series is used.

  Usually, in order to operate a lithium ion secondary battery safely and efficiently, it is necessary to monitor the voltage and temperature of the battery cell and control the charge / discharge state. Therefore, the secondary battery device includes a temperature monitoring sensor such as a thermistor for monitoring the temperature of the battery cell. When the secondary battery device is installed in a moving body such as an automobile, the temperature monitoring sensor receives vibration from the moving body and is exposed to a wide range of operating temperature environments. For this reason, the temperature monitoring sensor is required to have quick response and sufficient reliability even in an environment of vibration and a wide range of operating temperatures.

International Publication No. 2006/06973

  For example, in a thermistor for automobiles, from the viewpoint of maintaining mechanical strength against vibration and temperature environment, the detection element is covered with a thick protective film such as a glass coating, and is attached to the detection object with an adhesive. When such a thermistor is used for monitoring the temperature of the secondary battery device, the responsiveness to the temperature change of the battery cell is deteriorated and the installation in a limited space becomes difficult. On the other hand, if a film-like thin film thermistor laminated with a thin resin or the like in order to obtain high responsiveness is simply used with an adhesive tape stopper, there is a concern that reliability may deteriorate due to peeling or dropping of the tape.

  An object of the present invention is to provide a secondary battery device capable of ensuring high responsiveness and reliability of temperature monitoring and further reducing the size, and a method for manufacturing the same.

  A secondary battery device according to an embodiment includes a housing, a plurality of battery cells accommodated in the housing, and a temperature monitoring sensor that is provided in contact with the battery cell and detects a temperature of the battery cell. And the housing includes an inner surface facing the battery cell, a groove formed on the inner surface and facing the temperature monitoring sensor, and projecting in the groove, the temperature monitoring sensor being connected to the housing and the battery cell. And a pressing protrusion sandwiched between the two.

FIG. 1 is a perspective view showing a secondary battery device according to an embodiment. FIG. 2 is an exploded perspective view of the secondary battery device shown with a top cover removed. FIG. 3 is an exploded perspective view of the secondary battery device showing a case and battery cells in an exploded manner. FIG. 4 is a perspective view showing a battery cell. FIG. 5 is a perspective view showing an inner surface side of an upper case constituting the case. FIG. 6 is a cross-sectional view of the secondary battery device taken along line AA of FIG. FIG. 7 is a plan view schematically showing the arrangement and connection state of battery cells and bus bars in the secondary battery device. FIG. 8 is an exploded perspective view showing a cell unit, an upper case, and a common bus bar. FIG. 9 is a perspective view of an upper case upper portion showing a connection state between the bus bar and the FPC. FIG. 10 is a perspective view showing an upper portion of an upper case and a thermistor. FIG. 11 is an exploded perspective view showing a part of the upper case, the thermistor, the battery cell, and the center case. FIG. 12 is a plan view and a side view showing the thermistor. FIG. 13 is a perspective view showing a rib of the center case. FIG. 14 is a cross-sectional view of the secondary battery device taken along line BB in FIG. 10. FIG. 15 is a cross-sectional view of the secondary battery device taken along line CC in FIG. FIG. 16 is an exploded perspective view showing a front end portion of the case and a base terminal. FIG. 17 is an enlarged perspective view showing an engagement portion between the engagement protrusion of the base terminal and the case. FIG. 18 is a perspective view showing a state where battery cells are mounted on the upper case assembly in the assembly process of the secondary battery device. FIG. 19 is a perspective view showing a state in which a center case is mounted on the upper case assembly in the assembly process of the secondary battery device. FIG. 20 is a perspective view showing a state in which a center case is mounted on an upper case assembly in the assembly process of the secondary battery device. FIG. 21 is an exploded perspective view showing a lower case attachment process in the assembly process of the secondary battery device. FIG. 22 is an exploded perspective view showing a state in which the top cover is removed in the assembly process of the secondary battery device. FIG. 23 is a perspective view showing an attaching process of the upper case in the assembling process of the secondary battery device.

Hereinafter, the secondary battery device according to the embodiment will be described in detail with reference to the drawings.
FIG. 1 is a perspective view showing an external appearance of a secondary battery device according to the embodiment, FIG. 2 is a perspective view showing a bus bar mounting structure of the secondary battery device by removing a top cover of the secondary battery device, and FIG. It is a disassembled perspective view of the secondary battery device which disassembles and shows a case and a battery cell.
As shown in FIGS. 1, 2, and 3, the secondary battery device includes a substantially rectangular box-shaped case (housing) 10 and a plurality of, for example, 30 battery cells (secondary batteries) accommodated in the case. ) 12 and is configured as an assembled battery. The case 10 includes a rectangular frame-shaped center case 14 that is open at the top, a lower case 16 that is formed in a rectangular plate shape and forms a bottom wall, and an upper case 18 that is formed in a rectangular plate shape and forms a ceiling wall. It has a dividing member. The lower case 16, the center case 14, and the upper case 18 are joined together in this order to form a rectangular box-like case 10. The upper surface side of the upper case 18 is covered with a rectangular plate-like top cover 20. Each component of the case 10 and the top cover 20 are made of a synthetic resin having insulation properties, for example, polyphenylene ether (PPE).

  A rectangular base terminal base 22 made of synthetic resin is screwed to a side wall located on one end side in the longitudinal direction of the case 10, for example, the front end wall 10a. The terminal base 22 is attached with a positive electrode output terminal 24, a negative electrode output terminal 26 of the secondary battery device, and a battery monitoring board 28 for monitoring the voltage, temperature and the like of the battery cell 12.

  As shown in FIG. 4, each battery cell 12 is a nonaqueous electrolyte secondary battery such as a lithium ion battery. For example, a flat, substantially rectangular parallelepiped outer container 30 formed of aluminum or an aluminum alloy, and an outer container 30 and an electrode body 31 housed together with a non-aqueous electrolyte. The outer container 30 includes a container body 30a having an open upper end and a rectangular plate-like lid body 30b welded to the container body and closing the opening of the container body, and is formed in a liquid-tight manner. The electrode body 31 is formed in a flat rectangular shape by, for example, winding a positive electrode plate and a negative electrode plate in a spiral shape with a separator interposed therebetween, and further compressing in a radial direction.

  A positive electrode terminal 32a and a negative electrode terminal 32b are provided at both ends in the longitudinal direction of the lid body 30b and project from the lid body 30b. The positive electrode terminal 32 a and the negative electrode terminal 32 b are connected to the positive electrode and the negative electrode of the electrode body 31, respectively. One terminal, for example, the positive electrode terminal 32 a is electrically connected to the lid body 30 b and has the same potential as the outer container 30. The negative terminal 32b extends through the lid 30b. Between the negative electrode terminal 32b and the lid 30b, a sealing material made of an insulating material such as synthetic resin or glass, for example, a gasket 34 is provided. The gasket 34 provides a liquid-tight seal between the negative electrode terminal 32 b and the outer container 30 and electrically insulates the short circuit between the negative electrode terminal 32 b and the outer container 30. Further, the gasket 34 extends outward from the entire circumference of the negative electrode terminal 32b on the upper surface side of the lid 30b.

  For example, a rectangular safety valve 36 is formed at the center of the lid 30b. The safety valve 36 is formed by a thin portion in which a part of the lid 30b is thinned to about half the thickness, and a plurality of inscriptions are formed at the center of the upper surface of the thin portion. When gas is generated in the outer container 30 due to an abnormal mode of the battery cell 12 and the internal pressure in the outer container rises to a predetermined value or more, the safety valve 36 is opened, and the internal pressure is lowered to rupture the outer container 30 or the like. Prevent malfunctions.

  An insulating film 37 is wound around the container body 30a except for the upper end and the lower end of the container. The film 37 regulates the expansion of the outer container 30 and prevents a short circuit between the outer container 30 and another battery cell 12 or a short circuit between the outer container 30 and another member.

  As shown in FIG. 3, the battery cell 12 is provided with a plurality of battery cells, for example, three battery cells 12 connected in parallel to form one cell unit C, and only 10 cell units C connected in series. It has been. The arrangement of the battery cells 12 and the electrical connection structure will be described in detail later.

  As shown in FIG. 3, on the inner surface of the lower case 16, a number corresponding to the number of battery cells 12, here, thirty engagement grooves 38 are formed. Each engagement groove 38 is formed in an elongated rectangular shape corresponding to the cross-sectional shape of the outer container 30 of the battery cell 12, and extends along the width direction of the lower case 16. The plurality of engaging grooves 38 are provided in two rows at a predetermined interval in the longitudinal direction of the lower case 16. Center ribs 39 are formed between the two rows and extend over the entire length of the lower case 16 in the longitudinal direction.

  The center case 14 is formed in a rectangular frame shape, and has a pair of side walls 14a and 14b extending in the longitudinal direction and facing each other, and another pair of side walls extending in the width direction and facing each other. Four partition walls 50 are integrally formed in the center case 14. Each of these partition walls 50 extends over the entire length of the center case 14 in the width direction, and is provided at equal intervals in the longitudinal direction of the center case 14. The center case 14 is divided into five spaces by these partition walls 50. Further, support posts 52 extending in the height direction of the center case 14 are formed at the center of each partition wall 50 and the center of both longitudinal end walls of the center case 14. Each space in the center case 14 is divided into two left and right accommodation chambers 53 by support posts 52. Thereby, in the center case 14, the ten storage chambers 53 which can each accommodate 1 cell unit C are formed in 2 rows.

  As shown in FIGS. 2 and 3, a plurality of vent holes 51 are formed in each of the two side walls 14 a and 14 b extending in the longitudinal direction of the center case 14. For example, four vent holes 51 are formed corresponding to one storage chamber 53, and communicate with the storage chamber 53. Through these ventilation holes 51, cooling air can be blown into the case 10.

  As shown in FIG. 5, on the inner surface side of the upper case 18, a number corresponding to the number of battery cells 12, here, thirty engagement grooves 54 are formed. Each engagement groove 54 is formed in an elongated rectangular shape corresponding to the cross-sectional shape of the outer container 30 of the battery cell 12, and extends along the width direction of the upper case 18. The plurality of engaging grooves 54 are provided in two rows at a predetermined interval in the longitudinal direction of the upper case 18. Center ribs 59 are formed between the two rows and extend over the entire length of the upper case 18 in the longitudinal direction.

  In the upper case 18, rectangular through holes 56 a and 56 b corresponding to the positive electrode terminal 32 a and the negative electrode terminal 32 b of the battery cell 12 are formed at the bottom of each engagement groove 54, and facing the safety valve of the battery cell 12. An exhaust hole 57 is formed. The through holes 56a and 56b are located at both ends of the engaging groove 54, and the exhaust hole 57 is located in the middle between the through holes 56a and 56b. In the present embodiment, the positive electrode terminal 32a of the battery cell 12 is formed larger than the negative electrode terminal 32b. Correspondingly, the through hole 56a for inserting the positive terminal 32a is formed larger than the through hole 56b for inserting the negative terminal 32b.

  The lower case 16 configured as described above is screwed to the lower surface side of the center case 14 and fixed to the center case, and constitutes the bottom wall of the case 10. The upper case 18 is screwed to the upper surface side of the center case 14 and fixed to the center case, and constitutes the ceiling wall of the case 10. The center case 14 is joined between the lower case 16 and the upper case 18 facing each other with a gap.

  As shown in FIGS. 4 and 6, the battery cell 12 is housed in the housing chamber 53 of the case 10 for each cell unit C. The lower end portion of each battery cell 12 is fitted in the engaging groove 38 of the lower case 16 and is fixed to the lower case 16 with an adhesive or the like. The upper end portion of each battery cell 12, that is, the end portion on which the electrode terminal is provided is fitted into the engagement groove 54 of the upper case 18, and is fixed to the upper case 18 with an adhesive or the like. A partition wall 50 of the center case 14 is sandwiched between two cell units C adjacent in the column direction to prevent a short circuit between the cell units. In addition, a center rib 39 of the lower case 16, a center rib 59 of the upper case 18, and a support post 52 of the center case 14 are sandwiched between the cell units C in one row and the cell units C in the other row, and the cell A short circuit between the units C is prevented.

  When the positions of the battery cells are determined by fitting into the engagement grooves 38 and 54 in this way, the adjacent battery cells have a predetermined relationship between the main surfaces of the exterior container 30, that is, the wide surfaces of the exterior container. It arrange | positions in the state which faced in parallel with the clearance gap of. Adjacent cell units C are also arranged facing each other in parallel with a predetermined gap. And the row | line | column of the some battery cell 12 arranged in parallel with such a clearance gap is arrange | positioned in parallel with 2 rows.

  Both side walls 14a and 14b of the center case 14 are opposed to the side surfaces of the battery cells 12 arranged in two rows with a slight gap therebetween. In each battery cell row, the gaps between adjacent battery cells 12 are opposed to the vent holes 51 formed in the side walls 14a and 14b of the center case 14, respectively. Thereby, the vent hole 51 formed in the side wall 14a, the gap between the battery cells 12, and the vent hole 51 formed in the side wall 14b are aligned and arranged. The outside air or cooling air that has flowed into the center case 14 from one vent hole 51 passes through the gap between the battery cells 12, cools the battery cell, and then is exhausted from the other vent hole 51.

  The positive electrode terminal 32 a and the negative electrode terminal 32 b of the battery cell 12 are inserted through the through holes 56 a and 56 b, respectively, and protrude to the upper surface side of the upper case 18. The safety valve 36 of the battery cell 12 is positioned to face the exhaust hole 57 of the upper case 18.

  As shown in FIGS. 6, 7, and 8, in one cell unit C, the three battery cells 12 are in a state where the main surfaces face each other with a predetermined gap and the electrode terminals face the same direction. In line. In one cell unit C, the three battery cells 12 are arranged such that the positive terminals 32a are arranged in a row and the negative terminals 32b are arranged in a row. Ten cell units C are arranged in two rows of five cell units, and in each row, the positive electrode terminals 32a and the negative electrode terminals 32b of adjacent cell units are arranged alternately. And the cell unit of each row | line | column is connected by the bus bar mentioned later, and comprises the assembled battery.

  A plurality of bus bars are provided on the upper surface side of the upper case 18, and the plurality of battery cells 12 in each cell unit C are connected in parallel by these bus bars, and the plurality of cell units C are connected in series. Yes. Specifically, as shown in FIGS. 2, 6, and 8, the upper surface of the upper case 18 is formed one step lower, and a peripheral wall 18 a is erected along the periphery of the upper surface. A center rib 61 is formed on the upper surface of the upper case 18 at the center in the width direction, and extends in the longitudinal direction from one end in the longitudinal direction of the upper case 18 to the vicinity of the other end. On the upper surface of the upper case 18, a pair of partition walls 60 a and 60 b are erected on both sides of the center rib 61. The pair of partition walls 60 a are located on both sides of each exhaust hole 57 formed in the upper case 18, and extend parallel to each other along the longitudinal direction from one longitudinal end of the upper case 18 to the other end. Similarly, the pair of partition walls 60 b are located on both sides of each exhaust hole 57 formed in the upper case 18, and extend parallel to each other along the longitudinal direction from one longitudinal end of the upper case 18 to the other end. The center rib 59, the partition walls 60a and 60b, and the peripheral wall 18a are formed at substantially the same height.

  On the upper surface of the upper case 18, there are respectively between the peripheral wall 18a and the partition wall 60a, between the peripheral wall 18a and the partition wall 60b, between the center rib 61 and the partition wall 60a, and between the center rib 61 and the partition wall 60b. In addition, a plurality of partition walls 62 are erected. The partition wall 62 is formed at substantially the same height as the peripheral wall 18a. By the peripheral wall 18a, the center rib 61, the partition walls 60a and 60b, and the partition wall 62, a plurality of bus bar mounting chambers 64a, 64b and 64c, bus bar mounting chambers 68a, 68b and 70, and a bus bar mounting chamber 72a are formed on the upper case 18. 72b, bus bar mounting chambers 74a, 74b, and 74c.

  As shown in FIGS. 2, 6, 7, and 8, bus bars are mounted in the plurality of bus bar mounting chambers formed in the upper case 18, and are connected to the electrode terminals of the battery cells 12. In the present embodiment, four types of bus bars as connection fittings are used. That is, the positive electrode bus bar 76 that connects the positive terminals 32a of the three battery cells 12 and has a positive output end at one end, and connects the negative terminals 32b of the three battery cells 12 and has a negative output end at one end. A negative electrode bus bar 77, eight common bus bars 78 for connecting the electrode terminals of six battery cells 12 to each other, and a bus bar unit 80 in which three bus bars are connected are provided. The bus bars 76, 77, 78 and the bus bar unit 80 are formed by bending a metal plate made of a conductive material such as aluminum. Each bus bar has a rectangular positive opening 82a with which the positive terminal 32a of the battery cell 12 is engaged, or a rectangular negative opening 82b with which the negative terminal 32b is engaged. These openings are provided side by side in the longitudinal direction of the bus bar at a predetermined interval.

  One end of the positive electrode bus bar 76 in the longitudinal direction is bent in a crank shape to form a positive output end 76b. One end of the negative electrode bus bar 77 in the longitudinal direction is bent in a crank shape to form a negative output end 77b.

  The positive electrode bus bar 76, the negative electrode bus bar 77, and the common bus bar 78 configured as described above are mounted in the corresponding bus bar mounting chambers and connected to the electrode terminals of the battery cell 12. As shown in FIGS. 2, 6, 7, and 8, the positive bus bar 76 is mounted in the bus bar mounting chamber 64 a adjacent to the positive output terminal 24. The positive electrode openings 82a of the positive electrode bus bar 76 are positioned in alignment with the corresponding through holes 56a on the upper case 18 side. The positive terminals 32a of the battery cells 12 are engaged with the three positive openings 82a of the positive bus bar 76, respectively, and are welded to the positive bus bar 76 by laser welding or the like. For welding, electron beam welding or resistance welding may be used instead of laser welding. Accordingly, the positive terminals 32 a of the three battery cells 12 in the one cell unit C are electrically connected to each other by the positive bus bar 76. A positive output end 76 b of the positive bus bar 76 is engaged with the upper part of the peripheral wall 18 a of the upper case 18 and is exposed to the front end wall 10 a side of the case 10.

  The negative bus bar 77 is mounted in the bus bar mounting chamber 74 a adjacent to the negative output terminal 26. The negative electrode opening of the negative electrode bus bar 77 is positioned in alignment with the corresponding through hole 56b on the upper case 18 side. The negative electrode terminals 32b of the battery cells 12 are engaged with the three negative electrode openings of the negative electrode bus bar 77, and are welded to the negative electrode bus bar 77 by laser welding or the like. Accordingly, the negative electrode terminals 32 b of the three battery cells 12 in one cell unit C are electrically connected to each other by the negative electrode bus bar 77. The negative electrode side output end 77 b of the negative electrode bus bar 77 is engaged with the upper part of the peripheral wall 18 a of the upper case 18 and is exposed to the front end wall 10 a side of the case 10.

  The eight common bus bars 78 include bus bar mounting chambers 64b and 64c aligned with the positive electrode bus bar 76, bus bar mounting chambers 68a and 68b in the adjacent row, bus bar mounting chambers 72a and 72b in the adjacent row, and negative electrode bus bar 77. They are mounted in the bus bar mounting chambers 74b and 74c arranged in a row.

  The negative opening 82b and the positive opening 82a of the common bus bar 78 are positioned in alignment with the corresponding through holes 56b and 56a on the upper case 18 side. The negative terminal is welded to the common bus bar 78 with the negative terminal 32 b of the battery cell 12 engaged with the three negative openings 82 b of the common bus bar 78. As a result, the negative terminals 32 b of the three battery cells 12 in one cell unit C are electrically connected to each other by the common bus bar 78. In addition, each positive terminal is welded to the common bus bar 78 in a state where the positive terminals 32 a of the battery cells 12 of the adjacent cell unit C are engaged with the three positive openings 82 a of the common bus bar 78. Thereby, the positive terminals 32a of the three battery cells 12 in one cell unit C are electrically connected to each other by the common bus bar 78, and further electrically connected to the negative terminals 32b of the battery cells 12 of the adjacent cell unit C. Has been.

  The bus bar unit 80 is mounted in the bus bar mounting chamber 70 of the upper case 18. The positive electrode openings of the bus bar unit are aligned with the corresponding through holes 56a on the upper case 18 side, and the negative electrode openings are aligned with the corresponding through holes 56b on the upper case 18 side. The positive terminals 32a of the battery cells 12 are respectively engaged with the three positive openings, and are welded to the bus bar by laser welding or the like. The negative electrode terminal 32b of the battery cell 12 of the adjacent cell unit C is engaged with the three negative electrode openings, and is welded to the bus bar. Thereby, the negative terminals 32b of the three battery cells 12 in one cell unit C are electrically connected to each other by the bus bar unit 80, and further electrically connected to the positive terminals 32a of the battery cells 12 of the adjacent cell unit C. Has been.

  As schematically shown in FIG. 7, the plurality of bus bars and bus bar units described above connect the three battery cells 12 of each cell unit C in parallel, and the ten cell units C are connected in series with each other. ing. The positive electrode output terminal 24 and the negative electrode output terminal 26 are provided on the same wall surface of the case 10, that is, on the front end wall 10 a side, and the ten cell units C are U-shaped from the positive electrode output terminal 24 to the negative electrode output terminal 26. Connected side by side.

  As shown in FIG. 2, an elongated rectangular blocking plate 90 a is fixed on a pair of partition walls 60 a erected on the upper surface of the upper case 18, and extends over the entire length of the upper case 18 in the longitudinal direction. The space between the partition walls 60a is closed by the closing plate 90a, and an exhaust flow path 92a extending over the entire length of the upper case 18 in the longitudinal direction is formed by this space. The exhaust holes 57 formed in the upper case 18 and arranged in a row communicate with the exhaust passage 92a.

  Similarly, on the pair of partition walls 60 b erected on the upper surface of the upper case 18, an elongated rectangular closing plate 90 b is fixed and extends over the entire length of the upper case 18 in the longitudinal direction. The space between the partition walls 60b is closed by the closing plate 90b, and an exhaust flow path extending over the entire length of the upper case 18 in the longitudinal direction is formed by this space.

  As shown in FIGS. 2, 3, and 9, a flexible wiring board (FPC) 98 for measuring the voltage and temperature of the battery cell 12 is affixed to the upper surfaces of the blocking plates 90 a and 90 b. Each FPC 98 is formed in a band shape having a width substantially equal to that of the closing plates 90a and 90b, and extends over substantially the entire length of the upper case 18 in the longitudinal direction. A connector 85 is mounted on the end of the FPC 98 on the front end wall 10a side.

  The FPC 98 has a plurality of wirings extending in the longitudinal direction. One end of these wires is connected to the connector 85. Further, the other end portions of the plurality of wirings extend outward from the side edges of the FPC 98, respectively. For example, three wirings 99a are drawn out from one side edge of the FPC 98, and two wirings 99b are drawn out from the other side edge of the FPC. In the other FPC 98, three wirings 99a are drawn out from one side edge, respectively, and three wirings 99b are drawn out from the other side edge, respectively. The FPC 98 further includes a wiring 99c extending in the longitudinal direction, and thermistors 102a and 102b described later are electrically connected to the wiring 99c.

  The extending ends of the wirings 99a and 99b drawn from the FPC 98 are electrically and mechanically connected to one corresponding bus bar. As shown in FIG. 9, end ends of the wires 99 a and 99 b, for example, extended ends of the wires 99 b are soldered to the common bus bar 78. For the other bus bars and bus bar unit 80, the extended ends of the wires 99a and 99b are soldered. Thereby, each bus bar is connected to the connector 85 via the wirings 99a and 99b.

  As shown in FIGS. 1 and 2, a plurality of harnesses 86 are extended from the connector 85 of each FPC 98, and a connector 87 is connected to the extended ends of these harnesses. The two connectors 87 are connected to a battery monitoring board 28 described later. The battery monitoring board 28 measures and monitors the voltage of each cell unit C via the harness 86 and the FPC 98. As shown in FIG. 9, a resistor 100 is mounted in the middle of each wiring 99a, 99b of the FPC 98. Each resistor 100 is formed to have several Ω to several hundred Ω, for example, and restricts overdischarge from the battery cell 12 to protect the battery monitoring board 28.

  By connecting each bus bar and the battery monitoring board 28 using the FPC 98 as described above, the wiring can be easily routed and the assemblability of the battery device can be improved as compared with the case where all the harnesses are used. The wiring installation space can be reduced.

  The secondary battery device includes a plurality of, for example, two temperature monitoring sensors that monitor the temperature of the battery cell 12, and these temperature monitoring sensors output the detected temperature to the battery monitoring board 28 via the FPC 98. In the present embodiment, a film-like thin film thermistor laminated with a thin resin or the like is used as a temperature monitoring sensor in order to provide high responsiveness necessary for control of the battery cell 12.

  FIGS. 10 and 11 show the thermistor mounting structure and the wiring state, and FIG. 12 is a plan view and a side view showing the thermistor itself. FIG. 13 is a perspective view showing a pressing portion formed in the center case for sandwiching and fixing the thermistor, and FIGS. 14 and 15 are cross-sectional views showing the attached state of the thermistor.

  As shown in FIG. 2, two thermistors 102 a and 102 b that detect the temperature of the battery cell 12 are provided in the case 10. One thermistor 102a will be described as a representative. As shown in FIG. 12, the thermistor 102 a is made of, for example, a semiconductor whose resistance changes in response to a temperature change, and includes a detection element 88 that detects the temperature of the battery cell, and two lead wires extending from the detection element 88. 93 and wirings 95 respectively connected to the lead wires. The detection element 88 and the lead wire 93 are covered with a resin laminate film 94. The detection element 88, the lead wire 93, and the resin laminate film 94 are formed in an elongated rectangular shape as a whole, and the width thereof is smaller than the thickness of the battery cell 12. The solder joint between each lead wire 93 and the wiring 95 is covered and protected by an insulating tube, for example, a heat shrinkable tube 96. That is, the heat-shrinkable tube 96 prevents the short circuit due to the maintenance of the mechanical strength of the joint and the ingress of water or the like. The other thermistor 102b is configured similarly to the thermistor 102a.

  The thermistors 102a and 102b make contact with the battery cell 12 provided at the highest temperature position and the battery cell 12 provided at the lowest temperature position among the many battery cells 12 of the secondary battery device. The temperature of these two battery cells 12 is representatively detected. In the present embodiment, it is assumed that the secondary battery device is installed so that the direction of arrow F faces upward in FIG. In this case, the battery cell 12 located in the middle of the right column is most likely to reach the highest temperature, and the thermistor 102a is in contact with the battery cell 12. Also, the battery cell at the rear end or front end of the left row is most likely to be at the lowest temperature, and the thermistor 102b is in contact with the battery cell 12 at the rear end, for example.

  As shown in FIGS. 2, 8, and 10, the insertion groove extending through the bus bar mounting chamber to the middle in the height direction of the center case is formed on the inner surface of the peripheral wall 18 a of the upper case 18 and the inner surface of the side wall of the center case 14. 104a and 104b are formed. These insertion grooves 104a and 10b are respectively formed at a position penetrating the middle bus bar mounting chamber 64b in the right row and a position penetrating the bus bar mounting chamber 74c at the rear end of the left row.

  In the upper case 18, a guide groove 97 having a V-shaped cross section is formed in the peripheral wall 18 a and the partition wall 62. One guide groove 97 extends from the insertion groove 104 a to the position of the FPC 98 through the peripheral wall 18 a and the partition wall 62. The other guide groove 97 extends from the insertion groove 104b through the peripheral wall 18a and the partition wall 62 to the position of the FPC 98.

  As shown in FIGS. 11 and 13, in the side wall 14 b of the center case 14, elongated strip-like grooves 107 are formed on the inner surfaces of the side walls facing the battery cells 12 to which the thermistors 102 a and 102 b are attached. The groove 107 is formed to be narrower than the thickness of the battery cell 12 and larger than the width of the thermistors 102a and 102b. The groove 107 extends along the height direction of the center case 14 from the center thereof to the side edge on the upper case 18 side. That is, the groove 107 extends along the side surface of the battery cell 12. The groove 107 opens to the side edge of the center case 14 on the upper case 18 side, and communicates with one of the insertion grooves 104a and 104b of the upper case 18 described above.

  In each groove 107, elongated wedge-shaped ribs 106 functioning as pressing protrusions are formed integrally with the center case 14, respectively. The rib 106 extends in the groove 107 along the height direction of the center case 14 from the central portion thereof toward the side edge on the upper case 18 side. That is, the rib 106 extends along the side surface of the battery cell 12. The upper end of the rib 106 extends to a position slightly away from the side edge of the center case 14 on the upper case 18 side. The rib 106 is formed narrower than the width of the groove 107, and the groove 107 is formed on both sides of the rib 106.

  The rib 106 is formed to be slightly tapered from the center portion of the center case 14 toward the upper case 18 side. Further, the rib 106 is formed to have substantially the same height as the inner surface of the center case 14, and the tapered tip end portion 106 a of the rib 106 is formed in a wedge shape whose height gradually decreases toward the upper case 18 side. Yes.

  As shown in FIGS. 10, 11, 14, and 15, the thermistor 102 a is arranged such that the detection element 88 is in contact with the side surface of the battery cell 12, and is attached to the battery cell 12 with a tape 104. . In order to provide durability against vibration and temperature changes, the tape 104 is made of a polyimide-based material having excellent heat resistance and mechanical strength, and a pressure-sensitive adhesive having thermosetting properties.

  The rib 106 formed on the inner surface of the side wall 14b of the center case 14 faces the side surface of the battery cell 12 with a slight gap therebetween, and the detection element 88, the film 94, and the tape 104 of the thermistor 102a are opposed to the battery cell 12 and the rib 106. Between them. Thereby, the detection element 88, the film 94, and the tape 104 of the thermistor 102a are pressed against the side surface of the battery cell by the rib 106, and are held in contact with the battery cell. Even if the tape 104 is peeled off, the thermistor 102a can be prevented from falling off, and the battery cell 12 and the thermistor can be kept in contact with each other. Thereby, even when the secondary battery device receives vibration or the like, the temperature of the battery cell can be stably measured by the thermistor 102a, and long-term reliability can be ensured. When the thermistor 102 a is pressed by the rib 106, when the film 94 or the tape 104 swells on both sides of the rib, these extra width portions can be stored in the grooves 107 located on both sides of the rib 106.

  As shown in FIGS. 10, 11, and 14, the heat shrinkable tube 96 and the wiring 95 of the thermistor 102 a are drawn out to the upper case 18 side through the insertion groove 104 a, and the wiring 95 is further guided to the guide groove 97 of the upper case 18. And is routed to the FPC 98 along the guide groove 97. The wiring 95 is soldered to a pad on the FPC 98 and electrically connected to the wiring 99c.

The guide groove 97 is formed in a V-shaped cross-sectional shape having a width that allows the wiring 95 to be sufficiently fitted, and excluding a gap with the wiring. By installing the wiring 95 in the guide groove 97 without a gap, the wiring 95 rubs against the guide groove 97 due to vibration, and the coating of the wiring is damaged, so that a failure such as a short circuit can be prevented. In addition, the displacement of the wiring 95 due to vibration can be prevented. By using the partition wall 62, the peripheral wall 18a, and the like of the upper case 18 as a path of the guide groove 97, it becomes possible to increase the space efficiency and reduce the size of the entire secondary battery device.
Similarly to the thermistor 102a described above, the other thermistor 102b is affixed to the side surface of the battery cell 12 on the low temperature side with tape, and is further sandwiched between the battery cell and the rib by the rib 106 of the center case 14, so that the battery It is pressed against the cell. The wiring of the thermistor 102b passes through the insertion groove 104b, is fitted into the guide groove 97 of the upper case 18, and is routed to the FPC 98 along this guide groove.

  The thermistors 102a and 102b are electrically connected to the battery monitoring board 28 via the FPC 98. The thermistors 102a and 102b are, in the secondary battery device, the temperature of the battery cell 12 provided at a relatively high temperature position and the temperature of the battery cell 12 provided at a relatively low temperature position. Are detected and output to the battery monitoring board 28.

  According to the thermistor and the installation configuration of the thermistor configured as described above, the responsiveness is excellent, and the mechanical strength against vibration and temperature change is enhanced, and the reliability of the temperature measurement in the use environment of the mobile object such as an automobile Can be improved.

  As shown in FIGS. 1, 16, and 17, a rectangular plate-like terminal base 22 is attached to the outer surface side of the front end wall 10 a of the case 10. On the outer surface of the terminal base 22, a battery monitoring board 28 is fixed by screwing. The harness 86 extending from each FPC 98 described above is electrically connected to the battery monitoring board 28 via the connector 87. The battery monitoring board 28 detects and monitors the voltage between the cell units C via the FPC 98, and also monitors the cell temperature detected by the thermistors 102a and 102b. In addition, the battery monitoring board 28 has a balance adjustment circuit, and adjusts the voltage balance between the battery cells.

  A positive output terminal 24 and a negative output terminal 26 are attached to the terminal base 22. Engaging protrusions 107 are formed at the edge of the terminal base 22, for example, at the center of the upper edge. A cup-shaped positioning convex portion 108 projects from the center of the front end wall of the upper case 18.

  The terminal base 22 is positioned at a predetermined position with respect to the front end wall 10a of the case 10 by engaging the engaging protrusion 107 with the positioning projection 108 on the case side, and further, the front end of the case 10 is secured by a plurality of screws. It is fixed to the wall 10a with screws and is in close contact with the front surface of the case 10. The upper end of the positive output terminal 24 is inserted between the positive output end 76b of the positive bus bar 76 and the front surface of the case 10, and is fixed to the positive output end 76b with screws. Thus, the positive electrode output terminal 24 is electrically and mechanically connected to the positive electrode bus bar 76. The upper end portion of the negative electrode output terminal 26 is inserted between the negative electrode side output end portion 77b of the negative electrode bus bar 77 and the front surface of the case 10, and is fixed to the negative electrode side output end portion 77b with screws. Thereby, the negative output terminal 26 is electrically and mechanically connected to the negative bus bar 77.

  As shown in FIG. 1, the top cover 20 is formed in a rectangular plate shape having a size substantially equal to the planar shape of the case 10, and is provided to cover the plurality of bus bar mounting chambers of the upper case 18. The top cover 20 is screwed to the peripheral wall and the center rib of the upper case 18 at the periphery and the center thereof, and is closely joined to the upper case 18.

  Next, a method for assembling the secondary battery device configured as described above will be described.

  First, three components constituting the case 10, that is, a center case 14, an upper case 18, and a lower case 16 are prepared. Next, a bus bar and a bus bar unit corresponding to each bus bar mounting chamber of the upper case 18 are mounted in advance. An FPC 98 is stuck on each closing plate 90a, 90b of the upper case 18, and the wiring 99a, 99b of each FPC is connected to the corresponding bus bar by soldering or the like. Further, after the wiring 95 of the thermistors 102a and 102b is joined to each FPC 98, the thermistors are inserted into the insertion grooves 104a and 104b of the upper case 18 and pulled out from the inner surface side of the upper case. Further, the wiring 95 is fitted into a guide groove 97 formed in the upper case 18 and is routed along the guide groove.

After a pressing member such as a sponge is placed on each bus bar, the top cover 20 is put on the upper case 18 from above and temporarily fixed to the upper case. Further, an adhesive for fixing the battery cell 12 is applied to the peripheral edge of each engagement groove 54 formed on the inner surface side of the upper case 18. Thereby, an upper case assembly is constituted.
On the other hand, an adhesive for fixing the battery cell 12 is applied to the periphery of each engagement groove 38 formed on the inner surface side of the lower case 16.

  Subsequently, as shown in FIG. 18, the upper case assembly 150 is disposed with its inner surface facing upward. Next, 10 cell units C are loaded into the upper case 18 from above. The upper case portion of each battery cell 12, that is, the end portion on the side where the electrode terminal is provided, is fitted into the engagement groove 54 of the upper case 18, and the upper case is applied with an adhesive applied in advance. 18 is fixed. The mark M which shows the positive electrode side is attached | subjected to the bottom face of the exterior container 30 of each battery cell 12 so that the direction of a positive electrode and a negative electrode may be known. In each cell unit C, the battery cells are arranged so that the marks M of the three battery cells 12 are aligned, and the plurality of cell units C are arranged so that the positive electrode side and the negative electrode side are alternately arranged.

  By loading each cell unit C, the positive electrode terminal 32a and the negative electrode terminal 32b of each battery cell 12 pass through the through hole 56a and the through hole 56b of the upper case 18 to the positive electrode opening 82a and the negative electrode opening 82b of the corresponding bus bar, respectively. Engage. At this time, as described above, each battery cell 12 is mounted on the upper case 18 with the electrode terminal facing downward, so that even when there are variations in the height direction of the plurality of battery cells 12, the electrodes The terminal sides can be aligned and mounted in the engaging groove 54 of the upper case 18, and each electrode terminal can be reliably engaged with the bus bar.

  Next, the detection element portions and films of the thermistors 102 a and 102 b are attached to the side surface of the predetermined battery cell 12 with the tape 105, and are directly brought into contact with the battery cell 12. Subsequently, as shown in FIGS. 19 and 20, the upper case 18 is covered with the center case 14 from above, and the ten cell units C are loaded into the corresponding storage chambers 53 of the center case 14, respectively. Further, the thermistors 102a and 102b are sandwiched between the battery cells 12 by wedge-shaped ribs 106 formed on the inner surface of the center case 14, and the thermistors are pressed against the battery cells and fixed in a contact state. In this state, the center case 14 is temporarily fixed to the upper case 18.

  Subsequently, as shown in FIG. 21, the lower case 16 is placed on the center case 14 from above and fixed to the center case 14 with a plurality of screws. As a result, the end portions on the bottom side of the plurality of battery cells 12 are fitted into the engagement grooves 38 formed on the inner surface side of the lower case 16 and fixed to the lower case 16 with an adhesive applied in advance. The

  Next, as shown in FIG. 29, after the entire case 10 is reversed, the top cover 20 that has been temporarily fixed is removed. Subsequently, the holding member 152 holding the bus bar is removed. Thereafter, as shown in FIG. 23, the upper case 18 is fixed to the center case 14 with a plurality of screws. Subsequently, the positive electrode terminal 32a and the negative electrode terminal 32b of the battery cell 12 are welded to each bus bar.

  On the other hand, as shown in FIG. 16, the positive output terminal 24 and the negative output terminal 26 are fixed to the terminal base 22 in advance, and the battery monitoring board 28 is fixed to the terminal base 22 with screws. Next, after positioning and fixing the terminal base 22 on the front surface of the case 10, the positive output terminal 24 and the negative output terminal 26 are connected to the positive output end 76 b of the positive bus bar 76 and the negative output end of the negative bus bar 77. Screwed to the portion 77b. Further, a harness 86 extending from the FPC 98 is connected to the battery monitoring board 28. Finally, the top cover 20 is put on the upper case 18 and fixed to the upper case with screws. Thereby, the secondary battery device is completed.

  According to the secondary battery device configured as described above, it is possible to perform temperature detection with high responsiveness by using a film-like thin film temperature sensor, and to connect the temperature sensor to the battery cell by the pressing portion on the housing. And the temperature sensor can be securely fixed and held in contact with the battery cell. Thereby, even when installed in a vibration environment, it is possible to ensure high responsiveness and reliability in battery cell control, and to provide a secondary battery device that can be miniaturized and a method for manufacturing the same. Can do.

  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, the number of thermistors installed is not limited to two, but may be one or three or more. The installation position of the thermistor is not limited to the above-described embodiment, and can be changed as necessary. Although the thermistor is configured to contact the side surface of the battery cell, the thermistor is not limited to the side surface, and may be configured to contact the main surface of the battery cell. The temperature sensor is not limited to the thermistor, and a thermocouple or the like may be applied. The number of battery cells constituting the cell unit is not limited to three, and may be two or four or more. Further, the number of cell units is not limited to 10 and can be increased or decreased as necessary.

DESCRIPTION OF SYMBOLS 10 ... Case (casing), 12 ... Battery cell, 14 ... Center case, 14a ... Side wall 16 ... Lower case, 18 ... Upper case, 20 ... Top cover,
22 ... Terminal base, 24 ... Positive output terminal, 26 ... Negative output terminal,
28 ... Battery monitoring board, 30 ... Exterior container, 32a ... Positive electrode terminal, 32b ... Negative electrode terminal,
62 ... partition wall, 88 ... detection element, 93 ... seed wire, 94 ... film, 95 ... wiring,
97 ... Guide groove, 96 ... Heat shrinkable tube, 102a, 102b ... Thermistor,
106 ... ribs

Claims (5)

The body,
A plurality of battery cells housed in the housing;
A temperature monitoring sensor that is provided in contact with the battery cell and detects the temperature of the battery cell;
The housing includes an inner surface facing the battery cell, a groove formed on the inner surface and facing the temperature monitoring sensor, and projecting in the groove between the housing and the battery cell. A secondary battery device comprising: a pressing protrusion sandwiched between the two. Each of the battery cells has an outer container and both electrodes protruding from one end of the outer container, the outer containers are parallel to each other, and the one end from which the two electrodes are drawn is arranged in the same direction,
The casing has a pair of side walls facing both sides of the outer casing of the battery cell, and the groove is formed on the inner surface of the side wall and extends along the battery cell with which the temperature monitoring sensor contacts, and the pressing protrusion Is formed by elongated ribs protruding in the groove and extending along the battery cell,
2. The secondary according to claim 1, wherein the rib is tapered from one end side to the other end side of the battery cell, and is formed in a wedge shape whose height gradually decreases toward the tapered end. Battery device. The temperature monitoring sensor includes a detection element that detects the temperature of the battery cell, a lead wire extending from the detection element, a wiring connected to the lead wire, and a film that covers the detection element and the lead wire. Have
The secondary battery device according to claim 1, wherein the temperature monitoring sensor includes the detection element and a film that are sandwiched between the battery cell and a pressing protrusion. The housing includes a ceiling wall that covers both sides of the battery cell, a plurality of partition walls and a peripheral wall that are formed on the ceiling wall and each define a plurality of bus bar chambers in which bus bars are installed, and the partition wall and the peripheral wall. A guide groove formed on at least one side,
4. The secondary battery device according to claim 1, wherein the wiring of the temperature monitoring sensor passes through the ceiling wall, is disposed in the guide groove, and is routed along the guide groove. 5. . A housing, a plurality of battery cells housed in the housing, and a temperature monitoring sensor that is provided in contact with the battery cell and detects the temperature of the battery cell, and the housing includes the battery An inner surface that faces the cell, a groove that is formed on the inner surface and faces the temperature monitoring sensor, and a pressing protrusion that protrudes into the groove and sandwiches the temperature monitoring sensor between the housing and the battery cell. A method for manufacturing a secondary battery device comprising:
A temperature monitoring sensor is mounted on the ceiling wall of the housing,
A plurality of battery cells are attached to the ceiling wall,
Affixing the temperature monitoring sensor to one of the attached battery cells,
A frame-like side wall of the housing is mounted on the plurality of battery cells and the temperature monitoring sensor, fixed to the ceiling wall, and the temperature monitoring sensor is pressed against the battery cell by a pressing protrusion formed on the side wall. ,
A method of manufacturing a secondary battery device, wherein the plurality of battery cells are covered with a bottom wall of the housing and fixed to the side wall.

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