JP6045802B2 - Secondary battery device - Google Patents

Description

  Embodiment described here is related with the secondary battery apparatus which has a some battery cell.

  A secondary battery device used in a vehicle such as a hybrid vehicle or an electric vehicle needs to have high output and cope with frequent output changes. Such a secondary battery device is generally configured as an assembled battery or battery module in which a plurality of battery cells are electrically connected in series or in parallel and mechanically integrated according to the required output and capacity. Has been. In a battery module, each battery cell has a positive electrode terminal and a negative electrode terminal, and among the plurality of battery cells, for example, electrode terminals of two adjacent battery cells are connected to each other by a conductive member such as a bus bar. . Further, the plurality of battery cells are accommodated in a case and adjacent to each other.

JP 2009-87721 A JP 2006-139919 A

  In such a battery module, it is required that it can be installed in a limited space such as in a vehicle, and further, it is required that an area other than the battery mounting portion is not affected even when an abnormality occurs. When an abnormal large current flows due to an external short circuit or the like, the battery cell generates heat and swells, and the entire battery module may be deformed to affect other areas. Therefore, a method of interrupting a large current by providing a separate fuse and a design method of configuring a sufficient blank space in the battery module have been implemented. For this reason, the battery cell filling rate in the battery module is lowered, and the volume energy efficiency of the battery module is lowered.

  The present invention has been made in view of the above circumstances, and its problem is that high-density mounting is possible, and even when an abnormal large current flows due to an external short circuit or the like, deformation is prevented and other areas are prevented. An object of the present invention is to provide a secondary battery device that does not have an influence.

According to the embodiment, the secondary battery device includes a rectangular box-shaped case body having an open top surface and a bottom, an upper case covering the upper surface opening of the case body, and a top cover covering the upper case. The upper case has an outer case having a ceiling wall and a peripheral wall, and each has an electrode terminal, and a plurality of battery cells arranged side by side in the case main body of the outer case , and can be fused. A plurality of connection bus bars each having a fusing portion and provided on the ceiling wall of the upper case to electrically connect the electrode terminals of the battery cells, and wiring connected to the plurality of connection bus bars for detecting a voltage and parts, are arranged superimposed on the fusion portion of the connection bus bar, located in a space facing the said wiring portion and the fusion portion, to prevent the scattering of fumes generated during the fusing of the connection bus bar We include a rim member.

FIG. 1 is a perspective view illustrating an appearance of a secondary battery device according to an embodiment. FIG. 2 is an exploded perspective view of the secondary battery device showing the top cover in an exploded manner. FIG. 3 is an exploded perspective view of the secondary battery device showing an outer case, an insulating sheet, and a control circuit board of the secondary battery device. FIG. 4 is a perspective view showing a battery cell group accommodated in the secondary battery device. FIG. 5 is a plan view showing an upper case and a connection bus bar of the secondary battery device. FIG. 6 is a cross-sectional view of the secondary battery device taken along line AA in FIG. FIG. 7 is a perspective view showing four types of connection bus bars. FIG. 8 is an exploded perspective view showing an enlarged output bus bar portion of the secondary battery device. FIG. 9 is a cross-sectional view of the secondary battery device taken along line BB in FIG. 1. FIG. 10 is a view showing a fusing characteristic of a fusing portion of the connection bus bar.

Hereinafter, the secondary battery device according to the embodiment will be described in detail with reference to the drawings.
1 is a perspective view showing an external appearance of a secondary battery device according to an embodiment, FIG. 2 is an exploded perspective view of a secondary battery device showing an exploded top cover, and FIG. 3 is an insulating sheet, a control circuit board, and FIG. 4 is a perspective view showing a battery cell group accommodated in the outer case of the secondary battery device. FIG.

  As shown in FIGS. 1 to 4, the secondary battery device 10 includes, for example, a rectangular box-shaped outer case 14 and a plurality of, for example, 18 battery cells (secondary batteries) housed side by side in the outer case. Battery cell) 12 and a control circuit board (voltage detection board, cell management unit) 17 that detects and controls the voltage of each battery cell, and is configured as a battery module (assembled battery). The electrode terminals of adjacent battery cells 12 are electrically connected by a connection bus bar as a conductive member.

  The outer case 14 includes a rectangular box-shaped case body 16 having an open top surface and a bottom, an upper case 18 that covers the upper surface opening of the case body 16, and a top cover 20 that covers the upper case. Have. The case main body 16 and the upper case 18 are manufactured by an injection molding method using a synthetic resin having insulation properties, for example, a thermoplastic resin such as polycarbonate (PC) or polyphenylene ether (PPE). The top cover 20 is made of a relatively flexible resin, for example, polypropylene so that it can be easily detached.

  As shown in FIG. 4, each battery cell 12 is, for example, a nonaqueous electrolyte secondary battery such as a lithium ion battery, and is a flat, substantially rectangular parallelepiped outer container 21 formed of aluminum or an aluminum alloy, and an outer container. 21 and an electrode body 23 housed together with a non-aqueous electrolyte. The outer container 21 has a container main body 21a having an open upper end and a rectangular plate-shaped lid body 21b welded to the container main body to close the opening of the container main body, and the inside thereof is formed fluid-tight. The electrode body 23 is formed in a flat rectangular shape, for example, by 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 22a and a negative electrode terminal 22b are provided at both ends in the longitudinal direction of the lid body 21b and project from the lid body. The positive electrode terminal 22a and the negative electrode terminal 22b are connected to the positive electrode and the negative electrode of the electrode body 23, respectively. One terminal, for example, the positive electrode terminal 22 a is electrically connected to the lid body 21 b and has the same potential as the outer container 21. The negative terminal 22b extends through the lid 21b. Between the negative electrode terminal 22b and the lid 21b, a sealing material made of an insulating material such as synthetic resin or glass, for example, a gasket is provided.

For example, a rectangular safety valve 24 is formed at the center of the lid 21b. When gas is generated in the outer container 21 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 24 is opened and the internal pressure is lowered to rupture the outer container 21 or the like. Prevent malfunctions.
The battery cell 12 is not limited to the can cell in which the electrode body is accommodated in the metal can as described above, and a so-called laminate cell may be used.

  As shown in FIG. 4, the plurality of battery cells 12 are arranged in three rows of six. In each row, the six battery cells 12 are in a state where the main surfaces of the outer casing 21 face each other with a predetermined gap, and the upper end of the outer casing 21 provided with the electrode terminals 22a and 22b is They are arranged side by side in the same direction. Further, in each row, two battery cells 12 are divided into three groups, and the two battery cells 12 in each group are arranged in the same direction so that the positive terminals 22a and the negative terminals 22b are arranged side by side. Has been placed. Further, the two adjacent groups are arranged in opposite directions that are inverted by 180 degrees so that the positive electrode terminal 22a and the negative electrode terminal 22b are adjacent to each other. Two adjacent battery cells 12 are arranged such that the positive electrode terminal 22a of the battery cell 12 in one column and the negative electrode terminal 22b of the other column are adjacent to each other, and the negative electrode terminal 22b of the battery cell 12 in one column The battery cells in the other row are arranged side by side so as to be adjacent to the positive electrode terminal 22a.

  Next, the configuration of the outer case 14 will be described in detail. As shown in FIGS. 1 to 3, the case main body 16 is formed in a size corresponding to 18 battery cells 12 and has a rectangular bottom wall 30 facing the bottom of the battery cells 12, and the bottom wall 30. Two opposite side edges, here, a pair of first side walls 32a and 32b that are erected along the long side and face the main surface of the battery cell 12, and the other two side edges that face the bottom wall 30, here And a pair of second side walls 34a and 34b which are erected along the short side and face the side surface of the battery cell 12, and a plurality of partition walls (not shown) erected on the bottom wall in the case body. ing. The bottom wall 30, the first side walls 32a and 32b, and the second side walls 34a and 34b or the partition walls define a plurality, here, 18 battery accommodating portions. Each battery housing portion is formed in a cross-sectional shape slightly larger than the cross-sectional shape of the battery cell 12, and has an upper opening through which the battery cell can be inserted. The depth, that is, the height of each battery accommodating portion is formed to a size that can accommodate, for example, about 90% of the battery cell 12 excluding the electrode-side end portion. The 18 battery cells 12 are mounted in the corresponding battery accommodating portions, and are positioned by positioning means such as a pressing spring and an adhesive (not shown).

  As shown in FIG. 1 to FIG. 3, an upper case 18 is attached to the case main body 16 from above, and is attached to the case main body 16 in which the battery cells 12 are accommodated. As a result, a rectangular box-shaped outer case 14 is formed as a whole. The upper case 18 integrally includes a rectangular plate-like ceiling wall 36 having substantially the same size as the bottom wall 30 of the case body 16 and a rectangular frame-shaped peripheral wall 38 formed around the ceiling wall. ing. By engaging a plurality of engagement claws (not shown) formed in the lower part of the peripheral wall 38 with the engagement holes 37 formed in the upper part of each side wall of the case main body 16, the peripheral wall 38 is formed on the side wall of the case main body 16. It is attached continuously.

  The ceiling wall 36 is positioned facing the bottom wall 30 of the case body 16 in parallel and covers the upper portions of the plurality of battery cells 12. As shown in FIGS. 2, 3, 5, and 6, the ceiling wall 36 is formed with a plurality of openings 40 and a plurality of exhaust holes 42 for inserting the electrode terminals of the battery cells 12, respectively. . The openings 40 are provided in six rows along the width direction of the ceiling wall 36. The exhaust holes 42 are formed in three rows along the width direction of the ceiling wall 36, and each row is provided substantially at the center between the two rows of openings 40.

  The battery cell 12 accommodated in the case main body 16 is in contact with the inner surface of the ceiling wall 36 of the upper case 18 to determine the upper end position, particularly the height positions of the electrode terminals 22a and 22b. The positive electrode terminal 22a and the negative electrode terminal 22b of each battery cell 12 are inserted into the opening 40 of the corresponding ceiling wall 36 and exposed upward. The safety valve 24 of each battery cell 12 faces the exhaust hole 42 of the ceiling wall 36.

  As shown in FIGS. 2, 3, 5, and 6, a plurality of, for example, three cylindrical bosses 44 for standingly screwing the control circuit board 17 are erected on the upper surface of the ceiling wall 36. Yes. These bosses 44 are provided at a distance from each other on a central axis extending in the longitudinal direction of the ceiling wall 36. A metal female screw is embedded in each boss 44. A plurality of, for example, eight support protrusions 46 are erected on the upper surface of the ceiling wall 36. Each support protrusion 46 is formed in, for example, an elongated cylindrical shape, and a cross-shaped reinforcing rib is formed on the base end side thereof. The eight support protrusions 46 are arranged in two rows of four along the longitudinal direction of the ceiling wall 36. The two rows of support protrusions 46 are disposed substantially at the center, here, on both sides of the boss 44 in the width direction of the ceiling wall 36. Each support protrusion 46 is inserted through a corresponding through hole of the control circuit board 17 described later, and is formed at a height capable of contacting the inner surface of the top cover 20.

  Further, on the upper surface of the ceiling wall 36, a plurality of positions for positioning the control circuit board 17, for example, two plate-like positioning projections 48, a plurality of abutting on the lower surface of the control circuit board 17 and supporting this control circuit board A plurality of linear positioning ribs 50 and plate-like positioning protrusions for positioning a support bar 53, a bus bar, which will be described later, are projected.

  In the upper case 18, a plurality of engagement holes 39 are formed in the peripheral wall 38 over the entire periphery. Engaging claws of the top cover 20 to be described later engage with the engaging holes 39, and the top cover 20 is attached to the upper case 18.

  As shown in FIGS. 2, 3, 5, and 6, the plurality of battery cells 12 are electrically connected, for example, two in parallel, by a plurality of connection bus bars as conductive members, Nine sets of battery cells connected in parallel are connected in series. In the present embodiment, four types of connection bus bars as the conductive member and the connection member are used. That is, as shown in FIGS. 5 and 7, a substantially H-shaped first connection bus bar 52 that connects the positive terminal 22 a and the negative terminal 22 b of two sets of battery cells 12 adjacent in the longitudinal direction of the outer case 14, one row. The second connecting bus bar 54 having a linear shape for connecting the two positive terminals and the two negative terminals of the two battery cells 12 arranged in parallel to each other, and the positive terminal or the negative terminal of one battery cell are electrically connected. In addition, a first output bus bar 56a and a second output bus bar 56b having an output terminal integrally are used.

  As shown in FIG. 7A, the first connection bus bar 52 includes a pair of flat connection portions 62a each having a connection opening 60 and a pair of connection portions 62b each having a connection opening 60. The connecting portion 62c that connects these two connecting portions, and the connecting piece 64 that extends from each connecting portion and has a screw hole 63 formed therein, are made of a conductive material such as aluminum, brass, etc. It is formed by bending a metal plate made of The connecting portion 62c constitutes a convex bent portion whose cross section is bent into an arc shape, a U shape, or a V shape. Further, the first connection bus bar 52 has a fusing part 62d provided between the connecting part 62c and the connecting part 62a and between the connecting part 62c and the connecting part 62b, that is, on both sides of the connecting part 62c. Yes. Each fusing part 62 d extends across the entire length in the width direction of the first connection bus bar 52. The melted part 62d is thinner than the other part of the first connection bus bar 52 or narrower than the other part so as to melt when an abnormally high current flows through the first connection bus bar 52. Is also formed to have a high electrical resistance.

  As shown in FIG. 7B, the second connection bus bar 54 includes four flat connection portions 68a each having a connection opening 60 and three connection portions 68b that connect these four connection portions 68a in a row. And a connecting piece 70 extending from one connecting portion 68a and having a screw hole 69 formed thereon, and formed by bending a metal plate made of a conductive material such as aluminum or brass. ing. Each connecting portion 68b constitutes a convex bent portion whose cross section is bent into an arc shape, a U shape, or a V shape. Further, the second connection bus bar 54 has a fusing part 68d provided on one side or both sides of the at least one connecting part 68b, here, on both sides of each connecting part 68b. Each fusing part 68d extends across the entire length of the second connection bus bar 54 in the width direction. The fusing part 68d is thinner than the other part of the second connection bus bar 54 or narrower than the other part so as to melt when an abnormally high current flows through the second connection bus bar 54. Is also formed to have a high electrical resistance.

  As shown in FIG. 7C, the first output bus bar 56a has a pair of flat connection portions 77 each having a connection opening 60 formed therein, and extends from these connection portions 77 by 180 degrees and extends upward. A turn part 78, a narrow band-shaped fusing part 79 extending from the turn part, a flat output terminal 74 a extending from the fusing part 79 in the same direction as the connection part 77, and extending from one connection part 77. And a connecting piece 81a in which a screw hole 81b is formed, and is formed by bending a metal plate made of a conductive material such as aluminum or brass. The fusing part 79 and the output terminal 74 a extend from the turn part 78 in the same direction as the connection part 77 and substantially parallel to the connection part 77, and are located at a predetermined interval from the connection part 77. Yes. The fusing part 79 is formed thinner or narrower than the other part of the first output bus bar 56a so as to melt when an abnormal high current flows through the first output bus bar 56a. Is also formed to have a small cross-sectional area and high electrical resistance. In addition, since the fusing part 79 extends from the connection part 77 in the same direction, the fusing part 79 can be lengthened in a relatively narrow installation space, and the electrical resistance of the fusing part correspondingly. Can be lowered.

  As shown in FIG. 7D, each of the second output bus bars 56b includes a pair of flat connection portions 72 each having a connection opening 60 formed therein, and extends from these connection portions 72 and is bent into a crank shape to form a step. A step bending portion 73a to be formed, a flat output terminal 74b extending from the step bending portion 73a in a direction opposite to the connection portion 72, substantially parallel to the connection portion 72 and having a step, A connecting piece 76 extending from the connecting portion 72 and having a screw hole 75 formed thereon, and is formed by bending a metal plate made of a conductive material such as aluminum or brass. The second output bus bar 56b has a fusing part 73b provided between the step bending part 73a and the output terminal 74b. The fusing part 73b extends over the entire length in the width direction of the second output bus bar 56b. The fusing part 73b is formed thinner or narrower than the other part of the second output bus bar 56b so as to melt when an abnormal high current flows through the second output bus bar 56b. Is also formed to have a small cross-sectional area and high electrical resistance.

  The fusing parts of the connection bus bar and the output bus bar described above are designed as follows, for example.

Regarding the fusing part, the relationship between the fusing time from the start of heating to fusing and the supply current was considered. As a fusing part for measurement, a fusing part 79 of the output bus bar 56a is used, and three types of output bus bars, A) a fusing part sectional area 100%, B) a fusing part sectional area 94%, and C) a fusing part sectional area 88%. The fusing time and the supply current were measured for each.
As shown in FIG. 10, the fusing time varies greatly on the side where the supply current is low, and there is no tendency of fusing time with respect to dimensional change (changing the resistance of the fusing part). The initial temperature of the bus bar varies from −30 to + 60 ° C. depending on the installation environment of the secondary battery device. Also, the fusing time varies due to variations in the electrical conductivity of the bus bar and variations due to dimensional tolerances of the bus bar fusing part. Therefore, in FIG. 10, the simulation center value of the fusing time; simulation, variation, −side value; and simulation, variation, + side value are shown. In order to control the fusing time, it is desirable to use one with small variation. From FIG. 10, it can be seen that if the simulation center value of the fusing time is set within about 10 seconds, the fusing part will blow out when a current of about 1500 A or more is input.

In addition, when using a Li ion battery cell, when a large current is applied, the movement of Li ions cannot keep up with electron conduction, and in general, the time to reach an equilibrium state is about 10 to 20 seconds or more. Become. The resistance of Li ion migration is one of the major causes of heat generation when the battery cell carries current, so gas generation due to heat generation and chemical reaction will open the battery cell valve until Li ion migration reaches a sufficient equilibrium. It seems that it has not happened enough. Accordingly, when the melted portion of the connection bus bar is blown within about 20 seconds when a large current is applied, the battery cell is reliably cut off without opening the valve. Therefore, it is desirable to set the fusing time within 10 seconds in consideration of the variation in fusing time on the low current side.
From the above, the melted portions of the connection bus bars 52 and 54 and the output bus bars 54a and 54b are formed to have a cross-sectional area or resistance value that melts within about 10 seconds with respect to an input current of about 1500 A or more. As a result, as shown in FIG. 10, when a current of about 1500 A is input, the melted portion of the output bus bar and the connection bus bar is melted in about 10 seconds, and the variation in the fusing time is reduced, and the stable target time It becomes possible to blow out.

  As shown in FIGS. 3, 5, and 6, six first connection bus bars 52, two second connection bus bars 54, and two first and second output bus bars 56 a configured as described above, 56b are mounted at predetermined positions on the upper surface of the ceiling wall 36, and are connected to the electrode terminals of the battery cell 12, respectively.

  The first output bus bar 56 a is disposed, for example, at the lower right corner (FIG. 5) of the ceiling wall 36, and the pair of connection portions 77 are connected to the positive terminal 22 a of the battery cell 12. The positive terminals 22a are respectively engaged with the two connection openings 60 of the connection part 77, and are welded to the first output bus bar 56a by laser welding, electron beam welding, resistance welding or the like. The output terminal 74a of the first output bus bar 56a forms a positive output terminal.

  As shown in FIGS. 3, 8, and 9, the first output bus bar 56 a is arranged so that the turn part 78 is positioned on the control circuit board 17 side with respect to the fusing part 79. The fusing part 79 and the output terminal 74a are opposed to the ceiling wall 36 substantially in parallel with a gap. The output terminal 74a is sandwiched from above and below by two elongated conductive plates 102a and 102b, and is fixedly supported on the ceiling wall 36 by fixing these conductive plates 102a and 102b to the ceiling wall 36 with fixing screws 104. ing. Further, the output bolt 106a is screwed into the lower conductive plate 102a through the conductive plate 102b and the output terminal 74a.

  As shown in FIGS. 3 and 5, the second output bus bar 56 b is disposed, for example, at the upper left corner (FIG. 5) of the ceiling wall 36, and the pair of connection portions 72 is the negative electrode of the battery cell 12 in one set. It is connected to the terminal 22b. The negative terminal 22b engages with the two connection openings 60 of the connection portion 72, and is welded to the second output bus bar 56b by laser welding, electron beam welding, resistance welding, or the like. The output terminal 74b of the second output bus bar 56b forms a negative output terminal. The fusing part 79 and the output terminal 74a of the second output bus bar 56b are opposed to the ceiling wall 36 substantially in parallel with a gap. The output terminal 74b is sandwiched from above and below by two elongated conductive plates, and is firmly supported on the ceiling wall 36 by fixing these conductive plates to the ceiling wall 36 with fixing screws. The output bolt 106b is screwed into the lower conductive plate through the upper conductive plate and the output terminal 74b.

  As shown in FIGS. 3, 5, and 6, one second connection bus bar 54 is a set of battery cells arranged in the same row as the positive electrode terminal 22 a of the battery cell 12 to which the positive output bus bar 56 a is connected. The four negative electrode terminals 22b and the positive electrode terminal 22a of the battery cell 12 are connected to four electrode terminals. Two negative terminals 22b and two positive terminals 22a engage with the four connection openings 60 of the four connection portions 68a, respectively, and are welded to the second connection bus bar 54 by laser welding, electron beam welding, resistance welding, or the like. .

  The other second connection bus bar 54 is connected to the negative electrode terminal 22b of the battery cell 12 to which the output bus bar 56b on the negative electrode side is connected. Are connected to four electrode terminals of the negative electrode terminal 22b. The two negative terminals 22b and the two positive terminals 22a engage with the four connection openings 60 of the four connection portions 68a, respectively, and are welded to the second connection bus bar 54.

  The six first connection bus bars 52 are arranged in two rows of three each, and are positioned substantially at the center of the ceiling wall 36. Of the connection bus bars arranged in four rows, the first connection bus bars 52 are arranged in two middle rows. Each first connection bus bar 52 is connected to two positive terminals 22a of one set of battery cells 12 and two negative terminals 22b of another set of battery cells 12 adjacent in the longitudinal direction of the outer case 14. Yes. Two negative terminals 22b or two positive terminals 22a engage with the two connection openings 60 of the two connection portions 62a, respectively, and are welded to the first connection bus bar 52 by laser welding, electron beam welding, resistance welding, or the like. . Two positive terminals 22a or two negative terminals 22b are engaged with the two connection openings 60 of the other two connection portions 62b, respectively, and are welded to the first connection bus bar 52.

  As a result, 18 battery cells 12 are connected in parallel by the bus bar two by two (one set at a time), and nine battery cells are connected from the first output bus bar 56a on the positive electrode side to the second one on the negative electrode side. The output bus bar 56b is connected in series.

  3 shows a state in which screws are screwed into the screw holes of the boss 44 and the bus bars. These screws are screwed through the through holes of the control circuit board 17 during assembly. Screw into the hole.

  As shown in FIGS. 2, 3, 6, and 9, the control circuit board 17 is formed in a rectangular shape and has a width and length slightly smaller than the ceiling wall 36 of the upper case 18. A plurality of electronic components 80 are mounted on the control circuit board 17. The control circuit board 17 has a circuit pattern (wiring pattern) (not shown) formed on the front and back surfaces thereof. This circuit pattern functions as a wiring connected to the connection bus bar. Further, the control circuit board 17 can be inserted with two slit-shaped through holes 82 through which the positioning projections 48 of the ceiling wall 36 are inserted, and screws for screwing the control circuit board 17 and the connection pieces of the plurality of bus bars. A plurality of through holes 83 are provided. The control circuit board 17 can be applied to both the secondary battery device according to the present embodiment and other different secondary battery devices, for example, a secondary battery device containing 24 battery cells. It is configured as a substrate. And the some through-hole 83 contains both the some through-hole suitable for the secondary battery apparatus which concerns on this embodiment, and the some through-hole suitable for another secondary battery apparatus.

  The control circuit board 17 is placed on the ceiling wall 68 with the insulating sheet 71 interposed therebetween, and covers most of the bus bars. As shown in FIGS. 3, 5, and 6, the insulating sheet 71 that functions as an insulating member is formed in a substantially rectangular shape by, for example, PPE or modified PPE. The insulating sheet 71 is arranged so as to cover the six second connection bus bars 52 positioned substantially at the center of the ceiling wall 36, that is, overlap each other. Note that the insulating member is not limited to the insulating sheet, and an insulating molding or an insulating adhesive may be used, or the second connection bus bar 52 may be embedded by an insulating mold or an insulating adhesive.

  As shown in FIGS. 2, 3, 5, and 6, the control circuit board 17 is positioned at a predetermined position by inserting the two positioning protrusions 48 into the slit-like through holes 82 of the control circuit board 17. Is done. The control circuit board 17 is fixed to the ceiling wall 36 by screwing the fixing screws 84a into the bosses 44 of the ceiling wall 36 through the three through holes 83a formed side by side on the central axis of the control circuit board 17. . Further, the back surface (lower surface) of the control circuit board 17 abuts on the plurality of support ribs 53 and is supported by these support ribs 53. As a result, the control circuit board 17 is disposed substantially parallel to the ceiling wall 36 with a gap from the plurality of bus bars.

  A distal end portion of a connection piece 64 extending from the first connection bus bar 52; a distal end portion of a connection piece 70 extending from the second connection bus bar 54; a distal end portion of a connection piece 81a extending from the first output bus bar 56a; The distal end portions of the connection pieces 76 extending from the two-output bus bar 56b are in contact with the back surface of the control circuit board 17, respectively.

  A plurality of fixing screws 85 are inserted through the plurality of through holes 83 of the control circuit board 17 and screwed into the screw holes 63, 69, 75 formed in the connecting pieces of the corresponding bus bars, respectively. Thereby, each of the connection pieces 64, 70, 76, 81a is screwed to the back surface side of the control circuit board 17, and is electrically connected to the corresponding circuit pattern (wiring pattern).

  As shown in FIGS. 2, 3, 5, and 7, the plurality of support protrusions 46 erected on the ceiling wall 36 are inserted into the plurality of through holes 83 b formed in the control circuit board 17, respectively. Projecting upward from the circuit board 17. As described above, the through holes 83b and the support protrusions 46 are provided in two rows along the longitudinal direction of the ceiling wall 36, and are arranged from substantially the center in the width direction of the ceiling wall. The through-hole 83b uses a through-hole provided exclusively for the secondary battery device 10 or an empty through-hole (remaining through-hole) provided for another type of secondary battery device.

  As shown in FIGS. 1, 2, and 7, the top cover 20 of the outer case 14 is formed in a rectangular plate shape having a size substantially equal to the ceiling wall 36 of the upper case 18, and its peripheral portion is folded at a right angle. The peripheral wall 20b is formed by bending. A plurality of engaging claws 86 project from the peripheral wall 20b and are located at intervals over the entire circumference. The top cover 20 is attached to the upper case 18 by fitting the peripheral wall 20b inside the peripheral wall 38 of the upper case 18 and engaging the engaging claws 86 with the engaging holes 39 of the peripheral wall 38. The opening is closed and the control circuit board 17 and the bus bar are covered.

  As described above, the top cover 20 is relatively thin and flexible, and can be easily attached to and detached from the upper case 18 by an insulating resin such as polypropylene or PPE. The top cover 20 is formed at a position corresponding to the plurality of support protrusions 46, and has a plurality of boss portions 88 protruding to the inner surface side, that is, the ceiling wall 36 side of the upper case 18. In a state where the top cover 20 is mounted on the upper case 18, the plurality of support protrusions 46 abut against the inner surface of the top cover 20, here the boss portion 88, or face each other with a slight gap. Accordingly, the plurality of support protrusions 46 support the top cover 20 from the inner surface side. For this reason, even when the top cover 20 is formed flexibly, the top cover is supported by the support protrusions to prevent deformation or distortion to the control circuit board side. Therefore, for example, even when the top cover 20 is pushed from above, the top cover 20 can be prevented from coming into contact with the control circuit board, and damage to electronic components and the like can be prevented and protected.

  As shown in FIGS. 1, 2, 8, and 9, the top cover 20 has a recess 110 that is recessed toward the ceiling wall 36 at a position facing the first output bus bar 56 a and the second output bus bar 56 b. 112 is formed. The bottom wall of the recess 110 constitutes a shield wall 92a that functions as an insulating member. The shield wall 92a is adjacent to and directly above the fusing part 79 of the first output bus bar 56a, and covers the fusing part 79. The gap between the shield wall 92a and the fusing part 79 is set to 0.35 mm or less, for example. An opening 92b is formed at the bottom of the recess 110, and the conductive plate 102b and the output bolt 106 attached to the output terminal 74a of the first output bus bar 56a are exposed in the recess 110 through the opening 92b. . In addition, a detachable terminal cover 95 is mounted in the recess 110 to cover the conductive plate 102b and the output bolt 106a.

Similarly, the bottom wall of the recess 112 constitutes a shield wall 90a that functions as an insulating member. The shield wall 90a is adjacent to and directly above the fusing part 73b of the second output terminal 56b, and covers the fusing part 73b. ing. The gap between the shield wall 90a and the fusing part 37b is set to 0.35 mm or less, for example. An opening 90b is formed at the bottom of the recess 112, and the conductive plate and the output bolt 106b attached to the output terminal 74b of the second output bus bar 56b are exposed in the recess 112 through the opening 90b. Further, a removable terminal cover 94 is mounted in the recess 112 and covers the conductive plate and the output bolt 106b.
Further, the top cover 20 is formed with an exhaust groove 94 for exhausting gas generated in the outer case 14. The exhaust groove 94 is covered with a removable terminal cover 94.

  According to the secondary battery device configured as described above, when an abnormal large current flows due to an external short circuit or the like, the connection bus bar that constitutes the cell main circuit has a bent portion, a turn portion, or a step portion. By providing the fusing part adjacent to this, the heat generated by the large current energization can be intentionally concentrated on the fusing part and fusing, and the large current can be cut off. As a result, even when an abnormal large current flows, the secondary battery device can be protected with minimal damage such as fusing of the connection bus bar without causing abnormal expansion of each battery cell and opening of the safety valve. Become. By preventing abnormal expansion of the battery cell, the blank space in the outer case can be reduced, and high-density mounting of the battery cell is possible.

  On the other hand, in the battery module of the present embodiment, the connection bus bar is hardly heated at a current of several hundreds A in the normal operation range, and the resistance is sufficiently low in the normal operation range. Therefore, it is possible to make the resistance lower than that of the fuse while sufficiently securing current interruption at the time of abnormality without using a fuse or the like. Furthermore, since a fuse is not required, a battery module configuration with a high volume energy density is possible.

  By disposing a plurality of second connection bus bars 52 having the same cross-sectional area at the place where the temperature rises most in the secondary battery device, that is, in the central portion of the device, the temperature difference in the secondary battery device during overcurrent energization The melted portion of the second connection bus bar 52 can be selectively melted using this. Further, by covering these second connection bus bars 52 with the insulating sheet 71, the insulating sheet can provide a heat retaining effect of the second connection bus bars, increase the temperature difference of the second connection bus bars, and promote fusing of the fusing part. can do.

  In addition, as described above, when a current of about 1500 A is input, the melted portion of the output bus bar is melted in about 10 seconds, and the variation in the melt time is reduced, so that it can be melted in a stable target time. It becomes. Therefore, the bus bar can be blown when the abnormal current is input / output without deteriorating the input / output characteristics of the secondary battery device 10 by the bus bar.

  By disposing the insulating sheet between the connection bus bar and the circuit pattern of the control circuit board 17, fumes generated at the time of fusing are captured by the insulating sheet, and scattered to the circuit pattern and the control circuit board, and to the outside of the apparatus. Can be prevented. Furthermore, in the horizontal direction, the distance between the fume generating portion and the outer surface of the device can be set to the maximum by fusing the connecting bus bar at the central portion of the device, so that scattering to the outside can be prevented. .

  By providing the shield walls 92a and 90a of the top cover directly above the fusing parts 79 and 73b of the first and second output bus bars 56a and 56b, the fumes generated at the fusing are caught by the shielding walls, and the circuit pattern and the control circuit board are obtained. Can be prevented. Further, in the first output bus bar, since the turn part is located between the fusing part and the control circuit board, the fumes generated at the time of fusing are stopped at the turn part and scattered to the control circuit board side and the outside of the apparatus. It is possible to prevent scattering. Thereby, even when fume is generated during fusing, adverse effects on the surroundings can be prevented and reliability can be improved.

  From the above, it is possible to obtain a secondary battery device that enables high-density mounting and prevents deformation and does not affect other areas even when an abnormal large current flows due to an external short circuit or the like.

Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiments. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.
The wiring portion connected to the connection bus bar is not limited to the wiring pattern of the control circuit board described above, and a flexible cable or the like may be used. The number of battery cells constituting the battery cell group, the shape of the outer case, the structure, and the like are not limited to the above-described embodiments, and can be appropriately changed as necessary. The turn portion of the first output bus bar is not limited to the U shape, but may be a U shape, a wave shape, a dogleg shape, or the like.
Hereinafter, the invention described in the scope of claims of the present application will be appended.
[1] An outer case, a plurality of battery cells each having an electrode terminal, arranged side by side in the outer case, and a fusing part capable of fusing, each provided on the outer case. A plurality of connection busbars for electrically connecting the electrode terminals; a wiring portion connected to the plurality of connection busbars for detecting voltage; and being placed over the fusing portion of the connection busbar, the fusing portion and the wiring A secondary battery device comprising: an insulating member positioned between the two.
[2] A control circuit board that includes the wiring, is disposed on the outer case so as to overlap the plurality of connection bus bars, and is electrically connected to the connection bus bars, and the insulating member includes the control circuit board The secondary battery device according to [1], further including an insulating sheet disposed between the plurality of connection bus bars and the melted portions of the plurality of connection bus bars.
[3] The secondary battery device according to [1], wherein the insulating member includes an insulating mold or an insulating adhesive that covers the connection bus bar.
[4] The connection bus bars are arranged in a plurality of rows, and the insulating member is arranged on the connection bus bar located at the center of the plurality of connection bus bars [2] or [3]. The secondary battery device described in 1.
[5] At least one of the connection bus bars is formed by bending a metal plate, and a plurality of connection portions connected to the electrode terminals, and a convex bent portion positioned between the connection portions and bent in a convex shape. And [1] thru | or [4] the secondary battery apparatus which has the said fusing part provided between the said connection part and the convex bending part.
[6] At least one of the connection bus bars constitutes an output bus bar, and the output bus bar is formed by bending a metal plate and connected to the electrode terminal, and a flat output terminal portion. And a turn part extending from the connection part to the output terminal part side, and a fusing part extending from the turn part to the output terminal part and having a width narrower than other parts. [1] The secondary battery device according to any one of [5].
[7] At least one of the connection bus bars constitutes an output bus bar, and the output bus bar is formed by bending a metal plate and connected to the electrode terminal, and a flat output terminal portion. A step bending portion that forms a step extending from the connection portion toward the output terminal portion, and a fusing portion that extends from the step bending portion to the output terminal portion and is narrower than other portions. The secondary battery device according to any one of [1] to [6].
[8] A top cover made of an insulating resin that covers the plurality of connection bus bars and is attached to the outer case, the top cover being adjacent to and directly above the fusing portion of the connection bus bar, The secondary battery device according to [6] or [7], which includes a shield wall to be configured.
[9] The secondary battery device according to [6], wherein the turn portion of the connection bus bar is disposed between the fusing portion and the wiring.

DESCRIPTION OF SYMBOLS 10 ... Secondary battery apparatus, 12 ... Battery cell, 14 ... Outer case, 16 ... Case main body,
17 ... Control circuit board, 18 ... Upper case, 20 ... Top cover, 22a ... Positive electrode terminal,
22b ... negative electrode terminal, 36 ... ceiling wall, 38 ... peripheral wall, 52 ... first connection bus bar,
54 ... 2nd connection bus bar, 56a ... 1st output bus bar, 56b ... 2nd output bus bar,
62d, 68d, 73b, 79 ... fusing part, 71 ... insulating sheet,
90a, 92a ... Shield wall

Claims (9)

A rectangular box-shaped case main body having an upper surface opened and a bottom, an upper case covering the upper surface opening of the case main body, and a top cover covering the upper case, the upper case including a ceiling wall An outer case having a peripheral wall ;
Each having an electrode terminal, a plurality of battery cells arranged side by side in the case body of the outer case , and
A plurality of connecting bus bars each having a fusing part capable of fusing and electrically connecting between electrode terminals of the battery cells provided on the ceiling wall of the upper case ;
A wiring portion connected to the plurality of connection bus bars for detecting a voltage;
Which are disposed so as to overlap the fusion portion of the connecting bus bars, an insulating member located in the space facing the said wiring portion and the fusion portion, to prevent the scattering of fumes generated during the fusing of the connection bus bar,
A secondary battery device comprising: Wherein a wiring portion is disposed to overlap the plurality of connection bus bar on said ceiling wall of the upper case includes an electrically connected control circuit board to said connection bus bar,
2. The secondary battery device according to claim 1, wherein the insulating member includes an insulating sheet that is disposed between the control circuit board and the plurality of connection bus bars so as to overlap the fusing portions of the plurality of connection bus bars. .   The secondary battery device according to claim 1, wherein the insulating member includes an insulating mold or an insulating adhesive that covers the connection bus bar.   The secondary bus according to claim 2 or 3, wherein the connection bus bars are arranged side by side in a plurality of rows, and the insulating member is arranged so as to overlap the connection bus bar located at the center of the plurality of connection bus bars. Battery device.   At least one of the connection bus bars is formed by bending a metal plate, each of which is connected to the electrode terminal, a convex bent portion located between the connection portions and bent in a convex shape, The secondary battery device according to any one of claims 1 to 4, further comprising: the fusing part provided between the connection part and the convex bending part. At least one of the connection bus bars constitutes a first output bus bar, and the first output bus bar is formed by bending a metal plate and connected to the electrode terminal, and a flat output terminal portion And a turn part extending from the connection part to the output terminal part side, and a fusing part extending from the turn part to the output terminal part and having a width narrower than other parts. The secondary battery device according to any one of claims 1 to 5. At least one of the connection bus bars constitutes a second output bus bar, and the second output bus bar is formed by bending a metal plate and connected to the electrode terminal, and a flat output terminal portion. A step bending portion that forms a step extending from the connection portion toward the output terminal portion, and a fusing portion that extends from the step bending portion to the output terminal portion and is narrower than other portions. The secondary battery device according to any one of claims 1 to 6. The top cover is formed of an insulating resin material,
It said top cover, the secondary battery according to claim 6 or 7 having a shield wall you pair toward and adjacent directly above the fusion portion of the output bus bar. The secondary battery device according to claim 6, wherein a turn portion of the first output bus bar is disposed between the fusing portion and the wiring portion .

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