JP5244860B2 - Collective secondary battery - Google Patents

Description

The present invention also relates to the current case-type secondary batteries.

  As a conventional collective secondary battery in which a plurality of single cells are connected and integrally connected so as to obtain a required power capacity, a battery as shown in FIG. 10 is known (for example, Patent Document 1). 1). In this collective secondary battery, a plurality of unit cells 41 (41a to 41j) made of sealed alkaline secondary batteries as shown in FIG. The end plates 52 are brought into contact with the outside of the battery case 42 of the cells 41a and 41j at both ends, and the end plates 52 and 52 are bound together by a restraining band 53 so as to be integrally connected. Configured.

  The unit cell 41 accommodates an electrode plate group 47, which is a power generation element formed by laminating a positive electrode plate and a negative electrode plate with a separator, together with an electrolyte in the battery case 42, and opens an opening of each battery case 42 with a safety valve 45. Closed by the provided lid 46, the lead 49 is drawn upward from the upper end of one side of each positive electrode plate constituting the electrode plate group 47, and the positive terminal 43 is connected to the upper portion thereof. Similarly, the other side of each negative electrode plate A lead 49 is drawn upward from the upper end, a negative electrode terminal 44 is connected to the upper portion, and the positive electrode terminal 43 and the negative electrode terminal 44 are attached to a lid 46.

  And the positive electrode terminal 43 and the negative electrode terminal 44 between the connected unit cells 41 are connected by the connection plate 51, and each unit cell 41 is connected in series. Further, when the battery cases 42 are connected to each other, ribs 48 projecting in the vertical direction on the long side surfaces of the battery case 42 are abutted between adjacent ones, and in the space between the long side surfaces between the ribs 48, 48. A refrigerant flow path penetrating in the vertical direction of the battery case 42 is formed, and the unit cells 41a to 41j are cooled by blowing air to the refrigerant passage.

JP 09-115490 A

  By the way, in the configuration of the unit cell 41 of the above-described conventional collective secondary battery, the terminals 43 and 44 that protrude outside the lid 46 are connected by the connection plate 51. There is a problem that the installation space cannot be made compact because it is necessary to secure a connection space and the connection portion is exposed.

  Moreover, since the poles of the pole terminals 43 and 44 pass through the lid 46, the O-ring is generally arranged only on the inner surface side of the lid and is sealed only in a single layer. there were.

  In view of the above-described conventional problems, an object of the present invention is to provide a secondary battery in which the installation space can be made compact and there is no fear of liquid leakage.

The collective secondary battery of the present invention has a rectangular parallelepiped battery case having a narrow short side surface and a wide long side surface, and a large number of positive and negative electrode plates parallel to the long side surface through a separator. In a collective secondary battery in which unit cells containing a group of electrode plates stacked in the short side direction are connected , the unit cell has opposite side edges of the positive electrode plate and the negative electrode plate facing each other. Projecting outward from the projecting portion, using the projecting portion as a lead portion, fixing the side edge of each of the positive and negative lead portions of the electrode plate group to the current collector plate, holding the electrode plate group on the current collector plate, a plurality of battery cases By connecting the current collector plates on both sides with connecting metal fittings that penetrate the short side surface between the battery case, the battery unit is adjacent to the inside of the integrated battery case. The unit cells to be connected can be connected, and the installation space for the assembled secondary battery can be made compact.

  In addition, a pair of through holes formed in the short side surface between the battery cases, a connecting metal fitting having a protruding shaft portion that is inserted into the connection hole and welded at the distal ends thereof, and a current collector plate is fixed to the base end surface The current collector plate can be easily connected by welding using a pair of top metal fittings.

  In addition, a rectangular parallelepiped battery case having a narrow short side surface and a wide long side surface accommodates an electrode plate group having a positive electrode and a negative electrode current collector plate at both ends in the long side direction, and an electrolyte. A pair of top metal fittings that constitute the battery, have a connecting hole formed in the upper end of the short side surface of the battery case, have a protruding shaft portion that is inserted into the connecting hole, and has a current collector plate fixed to the base end surface, or the like If the connection terminal and the top piece of the protruding shaft part are arranged on both sides of the short side surface and the tips of the protruding shaft parts are welded together, the battery case and the outside are connected by welding using a pair of piece metal parts. Connection can be easily made with a compact configuration.

  In addition, if a piece of metal fittings arranged on both sides of the short side surface or a sealing material for sealing between the short side surfaces around the protruding shaft portion of the connection terminal, double sealing is performed on both sides of the short side surface. It is possible to reliably prevent liquid leakage during use.

  According to the assembled secondary battery of the present invention, as is apparent from the above description, the opposite side edge portions of the positive electrode plate group and the negative electrode plate group are protruded outward from the opposing portions of the two electrode plates, and the protruding portion A lead part, and an integrated battery case in which a plurality of battery cases are integrally connected to each other at its short side surface, and current collector plates on both sides are connected by a connecting metal fitting that penetrates the short side surface between the battery cases. Accordingly, adjacent cells can be connected inside the integrated battery case, and the installation space of the assembled secondary battery can be made compact.

  In addition, a pair of through holes formed in the short side surface between the battery cases, a connecting metal fitting having a protruding shaft portion that is inserted into the connection hole and welded at the distal ends thereof, and a current collector plate is fixed to the base end surface The current collector plate can be easily connected by welding using a pair of top metal fittings.

  Also, a pair of top metal fittings or a similar projecting shaft that has a projecting shaft portion that is inserted into the connection hole and that has a projecting shaft portion inserted into the upper end portion of the short side surface of the battery case, and a current collector plate is fixed to the base end surface. If the connection terminal and the top metal fittings with parts are arranged on both sides of the short side and the tips of the protruding shafts are welded together, the connection between the battery case and the outside is compacted by welding using a pair of top metal fittings It can be performed easily with a simple configuration.

  In addition, if a piece of metal fittings arranged on both sides of the short side surface or a sealing material for sealing between the short side surfaces around the protruding shaft portion of the connection terminal, double sealing is performed on both sides of the short side surface. It is possible to reliably prevent liquid leakage during use.

1 is an external perspective view of a collective secondary battery according to an embodiment of the present invention. It is a partial vertical side view of the same embodiment. It is AA arrow sectional drawing of FIG. It is a front view of the electrode group of the same embodiment. It is a BB arrow sectional view of Drawing 4. The positive electrode plate in the embodiment is shown, (a) is a front view, (b) is a plan view and its partial detail view. The negative electrode plate in the same embodiment is shown, (a) is a front view, (b) is a plan view and its partial detail view. It is a longitudinal cross-sectional view which shows the structure of the connection part between the single cells in the same embodiment. It is a disassembled perspective view of the electrode group in other embodiment of this invention. It is an external appearance perspective view of the collection type secondary battery of a prior art example. It is a partially broken perspective view of the cell of the conventional example.

  Hereinafter, a collective secondary battery according to an embodiment of the present invention will be described with reference to FIGS.

  The collective secondary battery 1 of the present embodiment is a nickel-hydrogen secondary battery that can be suitably used as a drive power source for an electric vehicle. As shown in FIGS. A plurality of rectangular parallelepiped (six in the illustrated example) battery case 3 having an open top surface having a wide long side surface is constituted by an integral battery case 2 formed by integrally connecting the short side surfaces to each other. In addition, the upper surface opening of each battery case 3 is integrally closed by an integral lid body 4.

  In each battery case 3, as will be described in detail later, an electrode plate group 5 in which a number of positive and negative electrode plates parallel to the long side surface of the battery case 3 are stacked in the short side direction through a separator. Is stored together with the electrolytic solution, and the unit cell 6 is configured.

  A connection hole 7 is formed in the short side outside the battery case 3 at both ends of the integral battery case 2 and the upper end of the short side surface between the battery cases 3, 3, and the connection of the short side surface outside the battery case 3 at both ends is made. A positive or negative connection terminal 8 is attached to the hole 7, and a connection fitting 9 for connecting the cells 6, 6 on both sides in series is attached to the short side connection hole 7 between the middle battery case 3, 3. Yes. In addition, the lid 4 is provided with a safety valve 10 for releasing the pressure when the internal pressure exceeds a certain level for each battery case 3, and a temperature detection sensor for detecting the temperature of the unit cell 6 is mounted. A sensor mounting hole 11 is formed for each appropriate unit cell 6 or each unit cell 6.

  On the long side surface 12 of the integrated battery case 2 in which the long side surface of each battery case 3 forms a flat surface, ribs 13 extending in the vertical direction are projected at positions corresponding to both side ends of each battery case 3, and the ribs A large number of relatively small circular protrusions 14 are provided in a matrix between 13 and 13 at an appropriate pitch interval. The ribs 13 and the protrusions 14 have the same height. Further, the upper end portion of the battery case 3 and the side surface of the lid body 4 have the same height as the rib 13 and the projecting portion 14 so as to extend between the side surfaces corresponding to the extended position of the rib 13 and the position of the projecting portion 14. The connecting ribs 15a and 15b are formed. In addition, a plurality of positioning members that are fitted to each other when the integrated battery case 2 is stacked on the long side surface 12 on the upper and lower portions of the outer surfaces of the two ribs 13 near both ends of the long side surface 12 of the integrated battery case 2. A protrusion 16 and a recess 17 are provided. The ribs 13, the protrusions 14 and the connecting ribs 15a and 15b form a refrigerant passage for efficiently and uniformly cooling the battery cases 3 therebetween when the integrated battery cases 2 are arranged in parallel.

  The electrode plate group 5 will be described in detail with reference to FIGS. 4 and 5, by alternately arranging a large number of positive electrode plates 18 and a large number of negative electrode plates 19, and covering each positive electrode plate 18 with a bag-shaped separator 20 having an opening in the lateral direction, An electrode plate group 5 is configured in which a positive electrode plate 18 and a negative electrode plate 19 are stacked with a separator 20 interposed therebetween. In FIG. 4, the shaded area indicates the area where the positive electrode plate 18 and the negative electrode plate 19 are opposed to each other with the separator 20 therebetween and exert power generation action. In these positive electrode plate 18 group and negative electrode plate 19 group, opposite side edges protrude outward and the protruding side edges are configured as lead portions 18a and 19a, and current collecting plates 21 and 19a are formed on the side edges, respectively. 22 is welded. Each of the current collector plates 21 and 22 is bent inward on both side edges so that the positive electrode plates 18 and 18 and the negative electrode plates do not spread outward even if the plates 18 and 19 and the current collector plates 21 and 22 are welded. While holding the 19th group, the size is regulated. Reference numeral 23 denotes an outer peripheral separator disposed on the outer surface between the current collecting plates 21 and 22 of the electrode plate group 5.

  The positive electrode plate 18 is made of Ni foam metal, and as shown in FIG. 6, the lead portion 18a is formed by pressurizing and compressing the foam metal and ultrasonically welding or seam welding the lead plate 24 on one surface thereof. Yes. Further, as shown in FIG. 7, the negative electrode plate 19 is configured by applying an active material to a punching metal of Ni except for the lead portion 19a. In these positive electrode plate 18 and negative electrode plate 19, the length of the side on which the lead portions 18a and 19a are provided is L, and the length of the side in the direction orthogonal thereto is D. L is greater than D and 4D or less. Is set to

  29 is a pair of positioning holes formed in the lead portions 18a and 19a at appropriate intervals in the vertical direction. By inserting a positioning pin into the positioning holes and pressing the side edges of the lead portions 18a and 19a, The side edges of the lead portions 18a and 19a are aligned, and the side edges and the current collecting plates 21 and 22 can be reliably and evenly welded.

  Further, as shown in FIG. 8, the connection fitting 9 for connecting the single cells 6 and 6 in series has a pair of pieces in which the upper end portions of the current collector plates 21 and 22 of the adjacent single cells 6 are welded to the respective base end surfaces. A projecting shaft portion 26 formed by a metal fitting 25 and projecting from the shaft core portion of the piece metal fitting 25 is inserted into the connection hole 7 formed on the short side surface of the battery case 3 from both sides, and the tip surfaces thereof are brought into contact with each other. They are connected by welding in contact. In addition, the welding of the upper end part of the current collecting plates 21 and 22 and the base end surface of the top metal fitting 25 and the welding of the front end surfaces of the protruding shaft part 26 are collectively resistance-welded in a state in which they are assembled. Further, annular grooves 27 are formed around the protruding shaft portions 26 of the top metal fittings 25, and the connection holes 7 are double-sealed by O-rings 28 attached to these annular grooves 27.

  In the collective secondary battery 1 having the above configuration, a plurality of rectangular parallelepiped battery cases 3 are integrally connected to each other at their short side surfaces, and the upper surface of each battery case 3 is formed. Current collector plates 21 of the electrode plate group 5 on both sides are connected with a fitting 9 that closes the opening integrally with a lid 4 and penetrates a connection hole 7 formed at the upper end of the short side surface between the battery cases 3 and 3. 22 are connected, the adjacent unit cells 6 can be connected inside the integrated battery case 2, and the connection configuration is not exposed to the outside, so the installation space of the assembled secondary battery 1 is made compact. be able to.

  Further, the connection fitting 9 is inserted into the connection hole 7 from both sides thereof, and has a protruding shaft portion 26 whose tips are welded to each other, and a pair of top fittings 25 to which the current collector plates 21 and 22 are fixed on the base end face. Therefore, the electrode plate group 5 of the adjacent battery case 3, that is, the single cells 6 can be easily connected in series by welding the top metal fitting 25. In addition, on the short side surfaces outside the battery case 3 at both ends, the connection terminals 8 having the same protruding shaft portions 26 and the piece metal fittings 25 are arranged on both sides of the short side surfaces, and the tips of the protruding shaft portions 26 and 26 are arranged. By welding, the battery case 3 can be easily connected to the outside with a compact configuration.

  Further, since the O-ring 28 for sealing between the short side surface is provided around the top metal fitting 25 and the protruding shaft portion 26 of the connection terminal 8, double sealing can be performed on both sides of the short side surface. , Liquid leakage during use can be surely prevented.

  Further, in the electrode plate group 5 of each unit cell 6, the opposite side edge portions of the positive electrode plate 18 group and the negative electrode plate 19 group are protruded outward from the opposing portions, and the protruding portions are lead portions 18a, 19a, Since the current collector plates 21 and 22 are fixed to the lead portions 18a and 19a over the entire length, the average distance from the entire surface of the electrode plates 18 and 19 to the current collector plates 21 and 22 can be shortened, and as a result. The resistance value in the battery can be reduced, and the utilization factor of the electrode active material can be increased to improve the battery output. In FIG. 4, the current collector plates 21 and 22 are fixed to the lead portions 18 a and 19 a over the entire length, but the current collector plates 21 and 22 are spread over ½ or more of the length of the lead portions 18 a and 19 a. If fixed, the same effect can be obtained.

  Moreover, since the electrode plates 18 and 19 are held by fixing the side edges of the lead portions 18 a and 19 a of the electrode plates 18 and 19 to the current collector plates 21 and 22, the electrode plate 18 has a compact configuration. 19 groups can be held, the area of the power generation region can be increased, and the battery capacity can be increased.

  In addition, each of the plates 18 and 19 is such that the length L of the side on which the lead portions 18a and 19a are provided and the length D of the side orthogonal to the lead are L> D and L ≦ 4D. The average distance from the entire surface to the current collecting plates 21 and 22 can be further shortened with respect to the total area, and the above effect can be further enhanced. When D ≧ L, the volume of the electrode plate group 5 in a space (dead space) for connecting the cells 6 between the upper end of the electrode plate group 5 and the upper wall of the lid 4 is determined. There is a problem that the ratio to the (power generating space) becomes large and the ratio of dead space becomes large and the volumetric efficiency of the battery deteriorates. However, such a problem can be solved.

  On the other hand, when L> 4D, the aspect ratio becomes too large, causing problems in other structural requirements such as maintaining the strength of the current collector plates 21 and 22 and manufacturing the battery case 3, and the outer surface of the integrated battery case 2 Between the lower end and the upper end of the electrode plate group 5 when the cooling medium is circulated in the vertical direction perpendicular to the arrangement direction of the battery cases 3, that is, in the longitudinal direction of the lead portions of the electrode plate group 5. However, setting L and D as described above does not cause such a problem.

  Further, as shown in FIG. 2, the battery case 3 in which the electrode plate group 5 composed of the electrode plates 18 and 19 having the relationship of L> D and L ≦ 4D is accommodated as shown in FIG. , 19a, the long side length in the direction parallel to 19 and the long side length perpendicular to it as d, where l> d and l ≦ 4d, the ratio of dead space becomes suitable, and the volumetric efficiency of the battery Will improve. Furthermore, when the cooling medium is circulated in the vertical direction of the long side surface of the battery case 3 for cooling, the temperature variation between the lower end portion and the upper end portion can be reduced.

  Next, another embodiment of the secondary battery of the present invention will be described with reference to FIG. In the above embodiment, the separator 20 is interposed between the positive electrode plate 18 and the negative electrode plate 19 by covering the positive electrode plate 18 with the bag-shaped separator 20, but the positive electrode plate group 18 and the negative electrode plate group 19 are opposite to each other. Since the side edge portion protrudes outward and the side edge portions serve as lead portions 18a and 19a, a separator can be interposed between the positive electrode plate 18 and the negative electrode plate 19 in a zigzag manner. A separator 30 is provided. According to this embodiment, a separator can be easily interposed as compared with the case where each electrode plate 18, 19 is covered with a bag-like separator 20.

  The present invention is useful for an assembled secondary battery.

DESCRIPTION OF SYMBOLS 1 Collective type secondary battery 2 Integrated battery case 3 Battery case 4 Cover body 5 Electrode plate group 6 Single battery 7 Connection hole 8 Connection terminal 9 Connection metal fitting 18 Positive electrode plate 18a Lead part 19 Negative electrode plate 19a Lead part 20 Separator 21 Current collector plate 22 Current collector plate 25 Top bracket 26 Projection shaft 28 O-ring (seal material)
30 zigzag folded separator

Claims (5)

In a rectangular battery case having a narrow short side surface and a wide long side surface, an electrode plate group in which a large number of positive electrode plates and negative electrode plates parallel to the long side surface are stacked in the short side direction through a separator. In the collective secondary battery in which the unit cells that are housed are connected ,
The unit cell is
The opposite side edge portions of the positive electrode plate and the negative electrode plate are protruded outward from the opposing portions of both electrode plates, and the protruding portion is a lead portion,
The side edge of each lead part positive and negative of the electrode plate group is fixed to the current collector plate, and the electrode plate group is held by the current collector plate,
The collective secondary battery is provided with an integrated battery case in which a plurality of battery cases are integrally connected to each other at its short side surfaces, and current collector plates on both sides are connected by connecting fittings that penetrate the short side surfaces between the battery cases. A collective secondary battery characterized by being connected. The assembled secondary battery according to claim 1, wherein the upper end of the current collector plate is connected to another electrode plate group or an external terminal. A pair of comers having a connecting hole penetratingly formed on the short side surface between the battery cases, the connecting metal fitting having a protruding shaft portion that is inserted into the connecting hole and welded at the distal ends thereof, and the current collector plate is fixed to the base end surface 3. The assembled secondary battery according to claim 1, wherein the assembled secondary battery is constituted by a metal fitting. In an assembled secondary battery in which cells are connected,
A unit cell containing an electrode plate group having positive and negative current collectors at both ends in a rectangular parallelepiped battery case having a narrow short side surface and a wide long side surface, and an electrolyte solution. A pair of top metal fittings or similar protrusions that have a connecting hole formed in the upper end portion of the short side surface of the battery case and that have a protruding shaft portion that is inserted into the connecting hole and the current collector plate is fixed to the base end surface. A collective secondary battery comprising: a connecting terminal having a shaft portion and a top metal fitting arranged on both sides of a short side surface, and the tips of the protruding shaft portions welded together. 5. The assembly according to claim 3 or 4, wherein a seal member for sealing between the short side surfaces is disposed around the protruding metal parts of the top metal fittings or connection terminals disposed on both sides of the short side surfaces. Type secondary battery.

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