Patent Application
20240234980
Embodiments described herein relate to a bipolar storage battery.
In recent years, power generation facilities using natural energy such as sunlight and wind power have increased. In such power generation facilities, because the amount of power generation cannot be controlled, the power load is leveled by using a storage battery. In other words, when the amount of power generation is larger than consumption, a difference is charged into the storage battery, and when the amount of power generation is smaller than consumption, a difference is discharged from the storage battery. As the storage battery described above, a lead-acid storage battery is frequently used from a viewpoint of economic efficiency, safety, and the like. As such a conventional lead-acid storage battery, for example, a double-poled battery (bipolar storage battery) described in JP Patent Publication No. 6124894 B2 is known.
The bipolar storage battery has a resin substrate attached to the inside of a picture frame-like resin frame. Lead layers are arranged on two surfaces of the substrate. A positive active material layer is adjacent to the lead layer formed on one surface of the substrate, and a negative active material layer is adjacent to the lead layer formed on the other surface of the substrate. In addition, a picture frame-like resin spacer is provided, and a glass mat impregnated with an electrolytic solution is disposed inside the spacer. Then, a plurality of frames and spacers are alternately stacked, and the frames and the spacers are bonded to each other with an adhesive or the like. In addition, the lead layers formed on the two surfaces of the substrate are connected via a through-hole provided in the substrate.
In other words, the bipolar storage battery described in JP Patent Publication No. 6124894 B2 includes a plurality of cell members each including a positive electrode including a positive electrode current collector plate and a positive active material layer, a negative electrode including a negative electrode current collector plate and a negative active material layer, and a separator (glass mat) interposed between the positive electrode and the negative electrode. The cell members are arranged in a stacked manner with intervals, and a plurality of space forming members form a plurality of spaces for individually accommodating the plurality of cell members.
In addition, the space forming members each include a substrate covering at least one of a side of the positive electrode and a side of the negative electrode of the cell member, and a frame body (frame portions of a bipolar plate and an end plate and the spacer) surrounding all side surfaces of the cell member. The cell member and the substrate of the space forming member are alternately arranged in a stacked state, the cell members are electrically connected with each other in series, and adjacent frame bodies are joined to each other.
Furthermore, JP Patent Publication No. 6124894 B2 describes an example in which a protective case is provided, and in this example, a surrounding portion of the frame body surrounding one side surface of the cell member is covered with a lid (a member indicated by the reference numeral 202 in
In the example of the bipolar storage battery described in JP Patent Publication No. 6124894 B2 in which the protective case is provided, because the bent portion of the lug portion of the current collector plate constituting the cell member arranged at one end in the stacking direction, and the terminal protruding from the lid to the outside are connected in the electrode receiving space, there is a possibility that the connection portion of the terminal with the lug portion may be corroded. In such a situation, the battery performance may be deteriorated (for example, the life may be shortened, the internal resistance may be increased, or the battery capacity may be lowered) for a reason that, for example, the electrolytic solution reaches the electrode receiving space along the current collector plate due to the capillary phenomenon.
An object of the present invention is to provide a bipolar storage battery in which a connection portion of a terminal with a lug portion of a current collector plate is difficult to corrode.
To solve the problems described above, a first aspect of the present invention is a bipolar storage battery having the following configurations (1) to (4).
(1) A bipolar storage battery includes a plurality of cell members each including a positive electrode including a positive electrode current collector plate and a positive active material layer, a negative electrode including a negative electrode current collector plate and a negative active material layer, and a separator interposed between the positive electrode and the negative electrode. The plurality of cell members is arranged in a stacked manner with intervals, and a plurality of space forming members forms a plurality of spaces for individually accommodating the plurality of cell members. An electrolytic solution is present in the spaces.
(2) The space forming members each include a substrate covering both a side of the positive electrode and a side of the negative electrode of one of the cell members and also a frame body surrounding side surfaces of one of the cell members. The cell members and the substrates of the space forming members are alternately arranged in a stacked state. The adjacent frame bodies are joined.
(3) The bipolar storage battery includes a lid covering a surrounding portion of the frame body surrounding one of the side surfaces of each cell member and includes a positive electrode terminal component and a negative electrode terminal component, each including a connection surface exposed to an outer surface of the lid.
(4) The positive electrode current collector plate constituting one of the cell members includes a positive electrode lug portion, and the positive electrode lug portion is connected with the positive electrode terminal component at a point ahead of a location where the positive electrode lug portion penetrates the surrounding portion and the lid. The negative electrode current collector plate constituting one of the cell members includes a negative electrode lug portion, and the negative electrode lug portion is connected with the negative electrode terminal component at a point ahead of a location where the negative electrode lug portion penetrates the surrounding portion and the lid.
To solve the problems described above, a second aspect of the present invention is a bipolar storage battery having the following configurations (5) to (9).
(5) A bipolar storage battery includes a plurality of cell members each including a positive electrode including a positive electrode current collector plate and a positive active material layer, a negative electrode including a negative electrode current collector plate and a negative active material layer, and a separator interposed between the positive electrode and the negative electrode. The plurality of cell members is arranged in a stacked manner with intervals, and a plurality of space forming members forms a plurality of spaces for individually accommodating the plurality of cell members. An electrolytic solution is present in the spaces.
(6) The space forming members each include a substrate covering both a side of the positive electrode and a side of the negative electrode of one of the cell members and a frame body surrounding side surfaces of one of the cell members. The cell members and the substrates of the space forming members are alternately arranged in a stacked state. The adjacent frame bodies are joined.
(7) The bipolar storage battery includes a lid covering a surrounding portion of the frame body surrounding one of the side surfaces of each cell member and includes a positive electrode terminal component and a negative electrode terminal component, each including a connection surface exposed to an outer surface of the lid.
(8) The positive electrode current collector plate constituting one of the cell members includes a positive electrode lug portion, the negative electrode current collector plate constituting one of the cell members includes a negative electrode lug portion, and each of the positive electrode lug portion and the negative electrode lug portion includes a bent portion at a point ahead of a location where the positive electrode lug portion or the negative electrode lug portion penetrates the surrounding portion and the lid.
(9) Each of the positive electrode terminal component and the negative electrode terminal component includes a terminal portion including the connection surface and a linking portion with which the bent portion is connected in different regions in a plan view. The bent portion of the positive electrode lug portion is connected with the linking portion of the positive electrode terminal component, and the bent portion of the negative electrode lug portion is connected with the linking portion of the negative electrode terminal component.
According to the bipolar storage battery of the present invention, it can be expected that the connection portions of the terminals (the positive electrode terminal component and the negative electrode terminal component) with the lug portions (the positive electrode lug portion and the negative electrode lug portion) of the current collectors become difficult to corrode.
Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the embodiments described below. In the embodiments described below, technically preferable limitations are made to implement the present invention, but these limitations are not essential requirements of the present invention.
As illustrated in
Here, a stacking direction of the cell members 110 is defined as an X direction (the left-right direction in
The lid 150 covers an upper end surface of the battery main body formed in a substantially rectangular parallelepiped shape and includes recesses 151 and 152 line-symmetric with respect to the center in the X direction on an upper surface. The positive electrode terminal component 160 is arranged in the recess 151, and the negative electrode terminal component 170 is arranged in the recess 152. Through-holes 151b and 152b are formed in bottom plates 151a and 152a of the recesses 151 and 152. The through-hole 151b is formed at a position in an upper part of the first end plate 130, and the through-hole 152b is formed at a position in an upper part of the second end plate 140.
The cell member 110 includes a positive electrode 111, a negative electrode 112, and a separator (electrolyte layer) 113. The separator 113 is impregnated with an electrolytic solution. The positive electrode 111 includes a positive electrode lead foil 111a or 111aa (positive electrode current collector plate) and a positive active material layer 111b. The negative electrode 112 includes a negative electrode lead foil 112a or 112aa (negative electrode current collector plate) and a negative active material layer 112b. The separator 113 is interposed between the positive electrode 111 and the negative electrode 112. In the cell member 110, the positive electrode lead foil 111a or 111aa, the positive active material layer 111b, the separator 113, the negative active material layer 112b, and the negative electrode lead foil 112a or 112aa are stacked in this order.
A dimension (thickness) in the X direction is larger (thicker) in the positive electrode lead foil 111a than in the negative electrode lead foil 112a and is larger (thicker) in the positive active material layer 111b than in the negative active material layer 112b.
The plurality of cell members 110 is arranged in a stacked manner with intervals in the X direction, and a substrate 121 of the biplate 120 is arranged in this interval portion. That is, the plurality of cell members 110 are stacked with the substrate 121 of the biplate 120 sandwiched between the cell members 110. In addition, the positive electrode lead foil 111aa constitutes the cell member 110 arranged at one end in the stacking direction, and the negative electrode lead foil 112aa constitutes the cell member 110 arranged at the other end in the stacking direction.
The plurality of biplates 120, the first end plate 130, and the second end plate 140 are members for forming a plurality of spaces (cells) C for individually accommodating the plurality of cell members 110.
The biplate 120 includes the substrate 121 having a rectangular planar shape, a frame body 122 arranged outside four end surfaces of the substrate 121 and surrounding four side surfaces of the cell member 110, and one or a plurality of column portions (not illustrated) vertically protruding from two surfaces of the substrate 121. The substrate 121, the frame body 122, and the column portions are integrally formed of a synthetic resin such as acrylonitrile-butadiene-styrene copolymer (ABS).
In the X direction, a dimension of the frame body 122 is larger than a dimension (thickness) of the substrate 121, and a dimension between protruding end surfaces of the column portion is the same as the dimension of the frame body 122. Then, the space C is formed between the substrate 121 and the substrate 121 by arranging the plurality of biplates 120 in a stacked manner with the frame bodies 122 and the column portions in contact with each other, and a dimension of the space C in the X direction is maintained by the column portions that are in contact with each other.
A through-hole (not illustrated) for the column portion to penetrate through is formed in each of the positive electrode lead foil 111a or 111aa, the positive active material layer 111b, the negative electrode lead foil 112a or 112aa, the negative active material layer 112b, and the separator 113.
The substrate 121 of the biplate 120 has a plurality of through-holes 121a penetrating a plate surface. A first recess 121b is formed on one surface of the substrate 121, and a second recess 121c is formed on the other surface of the substrate 121. A depth of the first recess 121b is deeper than a depth of the second recess 121c. Dimensions of the first recess 121b and the second recess 121c in the X direction and a Y direction are made correspondent to the dimensions of the positive electrode lead foil 111a and the negative electrode lead foil 112a in the X direction and the Y direction.
The substrate 121 of the biplate 120 is arranged between the cell members 110 neighboring to each other in the X direction. The substrate 121 of the biplate 120 is a substrate that covers both a side of the positive electrode 111 of one cell member 110 and a side of the negative electrode 112 of another cell member 110 next to the one cell member 110. The positive electrode lead foil 111a of the cell member 110 is arranged in the first recess 121b of the substrate 121 of the biplate 120 via an adhesive layer 114.
In addition, the negative electrode lead foil 112a of the cell member 110 is arranged in the second recess 121c of the substrate 121 of the biplate 120 via the adhesive layer 114.
An electrical conductor 115 is arranged in the through-hole 121a of the substrate 121 of the biplate 120, and two end surfaces of the electrical conductor 115 are in contact with and coupled to the positive electrode lead foil 111a and the negative electrode lead foil 112a. That is, the positive electrode lead foil 111a and the negative electrode lead foil 112a are electrically connected by the electrical conductor 115. As a result, all of the plurality of cell members 110 are electrically connected in series.
In addition, the frame body 122 of the substrate 121 has surrounding portions surrounding the respective four side surfaces of the cell member 110. In a surrounding portion 122a surrounding a side surface (one of the side surfaces) on an upper side in the Z direction among the surrounding portions, a groove 128 stretching from an outer side surface to an inner side surface of the surrounding portion 122a is formed in one end surface in the X direction at a position different from the position of the cross section illustrated in
The first end plate 130 includes a substrate 131 covering a side of the positive electrode of the cell member 110, a frame body 132 surrounding the four side surfaces of the cell member 110, and one or a plurality of column portions (not illustrated) vertically protruding from one surface of the substrate 131 (a surface facing the substrate 121 of the biplate 120 arranged closest to the side of the positive electrode). A planar shape of the substrate 131 is rectangular, the frame body 132 is arranged outside four end surfaces of the substrate 131, and the substrate 131, the frame body 132, and the column portions are integrally formed of a synthetic resin such as ABS.
In the X direction, a dimension of the frame body 132 is larger than a dimension (thickness) of the substrate 131, and a dimension between protruding end surfaces of the column portion is the same as the dimension of the frame body 132. Then, the space C is formed between the substrate 121 of the biplate 120 and the substrate 131 of the first end plate 130 by arranging the frame body 132 and the column portions in a stacked manner in contact with the frame body 122 and the column portions of the biplate 120 arranged on an outermost side (positive electrode side). A dimension of the space C in the X direction is maintained by the column portion of the biplate 120 and the column portion of the first end plate 130 in contact with each other.
A through-hole (not illustrated) for the column portion to penetrate through is formed in each of the positive electrode lead foil 111aa, the positive active material layer 111b, and the separator 113 of the cell member 110 arranged at one end in the stacking direction.
A recess 131b is formed on one surface of the substrate 131 of the first end plate 130. A dimension of the recess 131b in the X direction is made correspondent to a dimension of the positive electrode lead foil 111aa in the X direction. The dimension of the positive electrode lead foil 111aa arranged on one surface of the substrate 131 of the first end plate 130 in the X direction is larger than a dimension of the positive electrode lead foil 111a arranged on one surface of the substrate 121 of the biplate 120 in the X direction. The positive electrode lead foil 111aa includes a positive electrode lug portion 11.
The frame body 132 has surrounding portions surrounding the respective four side surfaces of the cell member 110, and a through-hole 133 extending in the Z direction is formed in a surrounding portion 132a (a portion covered with the lid) surrounding a side surface (one of the side surfaces) on an upper side in the Z direction, among the surrounding portions. In addition, as indicated by the broken line in
A portion of the positive electrode lead foil 111aa other than the positive electrode lug portion 11 is arranged in the recess 131b of the substrate 131 via the adhesive layer 114, a base portion of the positive electrode lug portion 11 is arranged in the lug portion arrangement recess 131c of the substrate 131, and an intermediate portion of the positive electrode lug portion 11 penetrates through the through-hole 133 of the frame body 132 of the first end plate 130 and the through-hole 151b of the bottom plate 151a of the lid 150. Then, a tip portion of the positive electrode lug portion 11 is bent at a substantially right angle inside the recess 151 of the lid 150.
That is, the positive electrode lug portion 11 includes a bent portion 11a at a point ahead of a location where the positive electrode lug portion 11 penetrates the surrounding portion 132a of the frame body 132 constituting the first end plate 130 and the bottom plate 151a of the recess 151 of the lid 150. Then, the bent portion 11a of the positive electrode lug portion 11 is connected with the positive electrode terminal component 160. In addition, a gap between the positive electrode lug portion 11 and each of the through-hole 133 of the frame body 132 and the through-hole 151b of the lid 150 is sealed with a synthetic resin 135 made of an epoxy resin. Furthermore, the inside of the recess 151 of the lid 150 is sealed with a synthetic resin 155 made of an epoxy resin.
The second end plate 140 includes a substrate 141 covering a side of the negative electrode of the cell member 110, a frame body 142 surrounding the four side surfaces of the cell member 110, and one or a plurality of column portions (not illustrated) vertically protruding from one surface of the substrate 141 (a surface facing the substrate 121 of the biplate 120 arranged closest to the side of the negative electrode). A planar shape of the substrate 141 is rectangular, the frame body 142 is arranged outside four end surfaces of the substrate 141, and the substrate 141, the frame body 142, and the column portions are integrally formed of a synthetic resin such as ABS.
In the X direction, a dimension of the frame body 142 is larger than a dimension (thickness) of the substrate 141, and a dimension between two protruding end surfaces of a column portion 143 is the same as the dimension of the frame body 142. Then, the space C is formed between the substrate 121 of the biplate 120 and the substrate 141 of the second end plate 140 by arranging the frame body 142 and the column portions in a stacked manner in contact with the frame body 122 and the column portions of the biplate 120 arranged on an outermost side (negative electrode side). A dimension of the space C in the X direction is maintained by the column portion of the biplate 120 and the column portion of the second end plate 140 in contact with each other.
A through-hole (not illustrated) for the column portion 143 to penetrate through is formed in each of the negative electrode lead foil 112aa, the negative active material layer 112b, and the separator 113 of the cell member 110 arranged at the other end in the stacking direction.
A recess 141b is formed on one surface of the substrate 141 of the second end plate 140. A dimension of the recess 141b in the X direction is made correspondent to a dimension of the negative electrode lead foil 112aa in the X direction. The dimension of the negative electrode lead foil 112aa arranged on one surface of the substrate 141 of the second end plate 140 in the X direction is larger than a dimension of the negative electrode lead foil 112a arranged on the other surface of the substrate 121 of the biplate 120 in the X direction. The negative electrode lead foil 112aa includes a negative electrode lug portion 12.
The frame body 142 has surrounding portions surrounding the respective four side surfaces of the cell member 110, and a through-hole 143 extending in the Z direction is formed in a surrounding portion 142a surrounding a side surface (one of the side surfaces) on an upper side in the Z direction, among the surrounding portions. In addition, as indicated by the broken line in
A portion of the negative electrode lead foil 112aa other than the negative electrode lug portion 12 is arranged in the recess 141b of the substrate 141 via the adhesive layer 114, a base portion of the negative electrode lug portion 12 is arranged in the lug portion arrangement recess 141c of the substrate 141, and an intermediate portion of the negative electrode lug portion 12 penetrates through the through-hole 143 of the frame body 142 of the second end plate 140 and the through-hole 152b of the bottom plate 152a of the lid 150. Then, a tip portion of the negative electrode lug portion 12 is bent at a substantially right angle inside the recess 152 of the lid 150.
That is, the negative electrode lug portion 12 includes a bent portion 12a at a point ahead of a location where the negative electrode lug portion 12 penetrates the surrounding portion 142a of the frame body 142 constituting the second end plate 140 and the bottom plate 152a of the recess 152 of the lid 150. Then, the bent portion 12a of the negative electrode lug portion 12 is connected with the negative electrode terminal component 170. In addition, a gap between the negative electrode lug portion 12 and each of the through-hole 143 of the frame body 142 and the through-hole 152b of the lid 150 is sealed with a synthetic resin 145 made of an epoxy resin. Furthermore, the inside of the recess 152 of the lid 150 is sealed with the synthetic resin 155 made of an epoxy resin.
The positive electrode lead foils 111a and 111aa (positive electrode current collector plates) are formed of, for example, a lead alloy in which a content of tin (Sn) is 1.0% by mass or more but less than 2.0% by mass, a content of calcium (Ca) is 0.005% by mass or more but less than 0.030% by mass, and the rest is lead (Pb) and unavoidable impurities.
The negative electrode lead foils 112a and 112aa (negative electrode current collector plates) are formed of, for example, a lead alloy in which a content of tin (Sn) is 0.5% by mass or more but equal to or less than 2% by mass.
Note that, as can be seen from the above description, the biplate 120 is a space forming member including the substrate 121 covering both a side of the positive electrode and a side of the negative electrode of the cell member 110 and the frame body 122 surrounding all side surfaces of the cell member 110. The first end plate 130 is a space forming member including the substrate 131 covering only a side of the positive electrode (one of a side of the positive electrode and a side of the negative electrode) of the cell member 110 and the frame body 132 surrounding all side surfaces of the cell member 110.
The second end plate 140 is a space forming member including the substrate 141 covering only a side of the negative electrode (one of a side of the positive electrode and a side of the negative electrode) of the cell member 110 and the frame body 142 surrounding all side surfaces of the cell member 110. That is, each of the substrates 121, 131, and 141 is a substrate covering at least one of a side of the positive electrode and a side of the negative electrode of the cell member 110, and the substrate 121 is a substrate covering both the side of the positive electrode and the side of the negative electrode of the cell member 110.
In addition, at a position different from the position of the cross section illustrated in
As illustrated in
A width W2 of the linking portion 162 in a plan view is the same as or larger than a width of the bent portion 11a of the positive electrode lug portion 11. A width W1 of the terminal portion 161 in a plan view and a width W3 of the intermediate portion 163 in a plan view are the same, and the width W2 of the linking portion 162 in a plan view is larger than the width W1 of the terminal portion 161 in a plan view. That is, a portion between the terminal portion 161 and the linking portion 162 is formed to have a width narrower than the width of the linking portion 162 in a plan view.
As illustrated in
The positive electrode terminal component 160 other than the screw shaft 166 is, for example, a cast product made of lead or a lead alloy, and the screw shaft 166 made of brass is integrated (insert-molded) at the time of casting.
The negative electrode terminal component 170 is the same as the positive electrode terminal component 160 and has a terminal portion 171 including a connection surface 171a, a linking portion 172, and an intermediate portion 173, and a V-shaped groove 173a is formed on an upper surface of the intermediate portion 173. The terminal portion 171 includes a protrusion portion 174 protruding from a plane including an outer surface of the linking portion 172 (a surface on an opposite side of the battery main body), and the protrusion portion 174 includes a narrowed portion 175. An upper surface of the protrusion portion 174 serves as the connection surface 171a, and a screw shaft 176 protrudes from a center of the connection surface 171a.
When the bipolar lead-acid storage battery 100 is used, for example, respective round terminals connected to a positive electrode wiring line and a negative electrode wiring line are fitted to the screw shafts 166 and 176 of the positive electrode terminal component 160 and the negative electrode terminal component 170. Nuts are screwed and fastened to the screw shafts 166 and 176, whereby the bipolar lead-acid storage battery 100 is connected with the positive electrode wiring line and the negative electrode wiring line.
When the bipolar lead-acid storage battery 100 is manufactured, first, the battery main body is assembled in a state in which tips of the positive electrode lug portion 11 and the negative electrode lug portion 12 extend upward in the Z direction.
The battery main body is assembled by, for example, the following method.
First, the positive electrode lead foil 111a is fixed to the first recess 121b and the negative electrode lead foil 112a is fixed to the second recess 121c of the biplate 120 with an adhesive. The positive electrode lead foil 111a and the negative electrode lead foil 112a are connected by the electrical conductor 115 by a resistance welding method.
Next, in a state in which the tip portion of the positive electrode lug portion 11 of the positive electrode lead foil 111aa appears outside after passing through the through-hole 133 of the frame body 132 of the first end plate 130, the base portion of the positive electrode lug portion 11 is fixed to the lug portion arrangement recess 131c of the substrate 131, and the portion other than the positive electrode lug portion 11 is fixed to the recess 131b of the substrate 131, each with an adhesive.
In addition, in a state in which the tip portion of the negative electrode lug portion 12 of the negative electrode lead foil 112aa appears outside after passing through the through-hole 143 of the frame body 142 of the second end plate 140, the base portion of the negative electrode lug portion 12 is fixed to the lug portion arrangement recess 141c of the substrate 141, and the portion other than the negative electrode lug portion 12 is fixed to the recess 141b of the substrate 141, each with an adhesive.
In this manner, each plate to which each lead foil is fixed is obtained.
Next, repeatedly in the order of the first end plate 130 and all the biplates 120, the positive active material layer, the separator, and the negative active material layer are placed on the positive electrode lead foil fixed to each plate, and the plates are stacked and joined to each other by a vibration welding method. Finally, the negative electrode lead foil of the second end plate 140 is placed on the negative active material layer of the biplate 120, and the second end plate 140 is joined to the biplate 120 by a vibration welding method. Specifically, the facing surfaces of the frame bodies and the column portions of the substrates serve as joining surfaces to form each of the spaces (cells) C, and a state in which one cell member 110 is arranged in one cell C is achieved. In addition, the liquid injection holes 18 are formed by vibration welding on edge portions of the grooves 128, 138, and 148.
Next, the lid 150 is arranged in an upper part of the battery main body in the Z direction, and the lid 150 is put on an upper surface of the battery main body in the Z direction and thermally welded while tips of the positive electrode lug portion 11 and the negative electrode lug portion 12 are passed through the through-holes 151b and 152b of the lid 150. Next, a sealing agent is injected from the through-holes 151b and 152b toward the through-hole 133 to seal between the through-holes 151b and 152b and the positive electrode lug portion 11 and the negative electrode lug portion 12 and between the intermediate portion of the positive electrode lug portion 11 and the through-hole 133 of the frame body 132 with the synthetic resin 135.
Next, the positive electrode terminal component 160 and the negative electrode terminal component 170 are installed in the recesses 151 and 152 of the lid 150, respectively, and are fixed to upper surfaces of the bottom plates 151a and 152a with an adhesive. Next, the tip portions of the positive electrode lug portion 11 and the negative electrode lug portion 12 are bent at predetermined positions and arranged on top of the linking portions 162 and 172 of the positive electrode terminal component 160 and the negative electrode terminal component 170, respectively. At this time, the truncated cone-shaped projections 162a and 172a are made to pass through the through-holes in the tip portions of the positive electrode lug portion 11 and the negative electrode lug portion 12. Next, the truncated cone-shaped projections 162a and 172a are melted by a burner or the like, whereby the positive electrode lug portion 11 and the negative electrode lug portion 12 are connected with the linking portions 162 and 172, respectively.
Next, an electrolytic solution is injected to the inside of each cell C from each liquid inlet of the lid 150 via each liquid injection hole 18 of the battery main body, and then each liquid inlet of the lid 150 is closed.
As described above, in the bipolar lead-acid storage battery 100 of the first embodiment, the tips of the positive electrode lug portion 11 and the negative electrode lug portion 12 are connected with the linking portion 162 and 172 of the positive electrode terminal component 160 and the negative electrode terminal component 170 at points ahead of locations where the tips of the positive electrode lug portion 11 and the negative electrode lug portion 12 penetrate the surrounding portions 132a and 142a of the first end plate 130 and the second end plate 140 and the bottom plates 151a and 152a of the lid 150. That is, in the bipolar lead-acid storage battery 100 of the first embodiment, the current collector plate and the terminal are connected at a position different from a position where there is a high risk of coming into contact with the electrolytic solution that has been raised along the current collector plate due to the capillary phenomenon, such as a space between the battery main body and the lid (electrode receiving space of JP Patent Publication No. 6124894 B2), which is a position away from the position where there is a high risk.
As a consequence of this, in the bipolar lead-acid storage battery 100 of the first embodiment, the connection portions (the linking portions 162 and 172 of the positive electrode terminal component 160 and the negative electrode terminal component 170) of the terminals with the lug portions of the current collectors (the bent portions 11a and 12a of the positive electrode lug portion 11 and the negative electrode lug portion 12) are difficult to corrode because of the electrolytic solution raised along the current collector plate due to the capillary phenomenon.
In addition, because the through-holes (the through-holes 133 and 143 of the surrounding portions 132a and 142a and the through-holes 151b and 152b of the lid 150) for the positive electrode lug portion 11 and the negative electrode lug portion 12 to pass through are sealed with the synthetic resins 135 and 145, the resulting structure makes it difficult for the electrolytic solution that has been raised along the current collector plate due to the capillary phenomenon to enter the inside of the recess of the lid 150.
In addition, because the lid 150 includes the recesses 151 and 152, the positive electrode lug portion 11 and the negative electrode lug portion 12 include the bent portions 11aand 12a, and the bent portions 11a and 12a of the positive electrode lug portion 11 and the negative electrode lug portion 12 and the linking portions 162 and 172 of the positive electrode terminal component 160 and the negative electrode terminal component 170 are connected inside the recesses 151 and 152 of the lid 150, the thickness (the dimension in the Z direction) of the lid 150 can be reduced while the lengths of the positive electrode lug portion 11 and the negative electrode lug portion 12 are increased.
Furthermore, because the bent portions 11a and 12a of the positive electrode lug portion 11 and the negative electrode lug portion 12 and the linking portions 162 and 172 of the positive electrode terminal component 160 and the negative electrode terminal component 170 are arranged inside the recesses 151 and 152 of the lid 150, and the inside of the recesses 151 and 152 is sealed with the synthetic resin 155, the linking portions 162 and 172 (connection portions with the bent portions 11a and 12a) have a structure that makes it difficult to corrode from the outside.
In addition, because the positive electrode terminal component 160 and the negative electrode terminal component 170 include the intermediate portions 163 and 173 including the V-shaped grooves 163a and 173a (surfaces lower than the upper surfaces of the linking portions) between the terminal portions 161 and 171 and the linking portions 162 and 172, a structure is achieved that makes it difficult for the electrolytic solution that has reached the bent portions 11aand 12a of the positive electrode lug portion 11 and the negative electrode lug portion 12 to arrive at the terminal portions 161 and 171.
In addition, because the width W2 of the linking portions 162 and 172 of the positive electrode terminal component 160 and the negative electrode terminal component 170 in a plan view is the same as or larger than the widths of the bent portions 11a and 12a of the positive electrode lug portion 11 and the negative electrode lug portion 12, a structure is achieved that makes it difficult for the electrolytic solution that has reached the bent portions 11a and 12a of the positive electrode lug portion 11 and the negative electrode lug portion 12 to arrive at the terminal portions 161 and 171, as compared with a case where the width W2 is smaller.
In addition, because the terminal portions 161 and 171 of the positive electrode terminal component 160 and the negative electrode terminal component 170 include the protrusion portions 164 and 174 that protrude from a plane including outer surfaces (surfaces on an opposite side of the surrounding portions) of the linking portions 162 and 172, and the protrusion portions 164 and 174 include the narrowed portions 165 and 175, a structure is achieved that makes it difficult for the electrolytic solution that has reached lower portions of the terminal portions 161 and 171 to arrive at the connection surfaces 161a and 171a, as compared with a case where the terminal portions do not include the narrowed portions 165 and 175.
In addition, because the width W3 of the intermediate portions 163 and 173 of the positive electrode terminal component 160 and the negative electrode terminal component 170 in a plan view is formed narrower than the width W2 of the linking portions 162 and 172 in a plan view (W3<W2), a structure is achieved that makes it difficult for the electrolytic solution that has reached the bent portions 11a and 12a of the positive electrode lug portion 11 and the negative electrode lug portion 12 to arrive at the terminal portions 161 and 171, as compared with the case of W3≥W2.
From the above, the bipolar lead-acid storage battery 100 of the first embodiment has a structure that not only makes it difficult for the linking portions 162 and 172 (the connection portions with the bent portions 11a and 12a of the positive electrode lug portion 11 and negative electrode lug portion 12) of the positive electrode terminal component 160 and the negative electrode terminal component 170 to corrode, but also makes it difficult for the terminal portions 161 and 171 of the positive electrode terminal component 160 and the negative electrode terminal component 170 to corrode.
As illustrated in
A lid 150A constituting the bipolar lead-acid storage battery 100A of the second embodiment includes a plurality of projections 156 at positions on upper surfaces of bottom plates 151a and 152a of recesses 151 and 152 where a positive electrode terminal component 160 and a negative electrode terminal component 170 are arranged. A dimension in the Z direction of the lid 150A is larger than the dimension in the Z direction of the lid 150 of the first embodiment by an amount equal to the height of the projection 156.
Then, the positive electrode terminal component 160 and the negative electrode terminal component 170 are arranged on top of the plurality of projections 156. The plurality of projections 156 are members forming a space between the positive electrode terminal component 160 and the negative electrode terminal component 170 and the bottom plates 151a and 152a. A synthetic resin 155 is present in this space. Note that, when the positive electrode terminal component 160 and the negative electrode terminal component 170 are fixed to the inside of the recesses 151 and 152 of the lid 150A with an adhesive at the time of manufacturing, the adhesive runs around into this space.
The bipolar lead-acid storage battery 100A of the second embodiment has the following effects in addition to the actions and effects that the bipolar lead-acid storage battery 100 of the first embodiment has.
In the bipolar lead-acid storage battery 100A of the second embodiment, because the positive electrode terminal component 160 and the negative electrode terminal component 170 are installed on top of the plurality of projections 156 provided on the bottom plates 151a and 152a of the recesses 151 and 152 of the lid 150A, as compared with the bipolar lead-acid storage battery 100 of the first embodiment in which the positive electrode terminal component 160 and the negative electrode terminal component 170 are installed directly on the upper surfaces of the bottom plates 151a and 152a, the amount of the electrolytic solution that arrives at the positive electrode terminal component 160 and the negative electrode terminal component 170 along the upper surfaces of the bottom plates 151a and 152a can be decreased.
In addition, because lower portions of the positive electrode terminal component 160 and the negative electrode terminal component 170 are in a bonded state to the bottom plates 151a and 152a by the synthetic resin 155 present between the plurality of projections 156, the positive electrode terminal component 160 and the negative electrode terminal component 170 are more firmly fixed to the lid than in the bipolar lead-acid storage battery 100 of the first embodiment. Therefore, when external terminals are fastened to the positive electrode terminal component 160 and the negative electrode terminal component 170 by screwing screw shafts 166 and 176 and nuts, the positive electrode terminal component 160 and the negative electrode terminal component 170 can withstand larger fastening stress and torque.
As illustrated in
A lid 150B constituting the bipolar lead-acid storage battery 100B of the third embodiment includes ribs 158 at positions on upper surfaces of bottom plates 151a and 152a of recesses 151 and 152 where base portions of bent portions 11a and 12a of a positive electrode lug portion 11 and a negative electrode lug portion 12 (portions behind connection portions with a positive electrode terminal component 160 and a negative electrode terminal component 170) are arranged. The ribs 158 support the bent portions 11a and 12a from a lower side. In addition, the bipolar lead-acid storage battery 100B of the third embodiment includes a pressing member or pressing members 180 configured to press the bent portions 11a and 12a against a side of the ribs 158.
The bipolar lead-acid storage battery 100B of the third embodiment has the following effects in addition to the actions and effects that the bipolar lead-acid storage battery 100A of the second embodiment has.
Because the ribs 158 supporting base portions of the bent portions 11a and 12a from the lower side are installed, the electrolytic solution that has arrived at the base portions of the bent portions 11a and 12a can be restrained from arriving at tip portions of the bent portions 11aand 12a (connection portions with the positive electrode terminal component 160 and the negative electrode terminal component 170), as compared with the bipolar lead-acid storage battery 100 of the first embodiment without such ribs.
In addition, because the bent portions 11a and 12a are supported from the lower side by the ribs 158 and also are pushed from an upper side with the pressing members 180, bent states of the bent portions 11a and 12a are favorably maintained. As a result, deformation of the positive electrode lug portion 11 and the negative electrode lug portion 11 when pressure is applied from the outside is restrained. In addition, because the pressing members 180 are present on the upper side of the bent portions 11a and 12a, cracking can be prevented in a synthetic resin 155 when pressure is applied from the outside to the synthetic resin 155 sealing the recesses 151 and 152.
Note that the lids 150, 150A, and 150B are made of, for example, ABS. In the third embodiment, after the lid 150B made of ABS is joined to the battery main body to seal between the positive electrode lug portion 11 and the negative electrode lug portion 12 and the through-holes 151b and 152b, the recesses 151 and 152 may be sealed with the synthetic resin 155 after peripheral edge portions of the through-holes 151b and 152b of the bottom plates 151a and 152aare closed. The seal may be achieved by melting portions of the ribs 158 on sides of the positive electrode lug portion 12 and the negative electrode lug portion 12, using a sealing agent for melting ABS, before bending tip portions of the positive electrode lug portion 11 and the negative electrode lug portion 12.
As the positive electrode terminal component and the negative electrode terminal component, as in a terminal component 160A illustrated in
The terminal component 160A has a structure that makes it difficult for the electrolytic solution that has arrived at the terminal portions 161 and 171 to arrive at the connection surface 161a, as compared with a terminal component having a dimensional relationship of W1=W3<W2. Therefore, by using the terminal component 160A as the positive electrode terminal component 160 and the negative electrode terminal component 170, even when the electrolytic solution has arrived at the terminal portion 161, the connection surface 161a can avoid corrosion.
In addition, as the positive electrode terminal component and the negative electrode terminal component, the positive electrode terminal component 160 having a recess instead of the V-shaped groove 163a, or the positive electrode terminal component 160 formed with a groove having an inclined surface (a surface lower than an upper surface of the linking portion) lowering or rising from the linking portion 162 toward the terminal portion 161 (a groove having a right triangular cross section) may be used.
In the bipolar lead-acid storage battery of each of the above embodiments, the lid 150 having the recesses 151 and 152 is used. However, a lid without a recess may be used, the positive electrode terminal component and the negative electrode terminal component may be installed on an upper surface of the lid (a surface on an opposite side of the battery main body), and the positive electrode lug portion and the negative electrode lug portion penetrating through the lid may be connected with the positive electrode terminal component and the negative electrode terminal component. In these circumstances, it is preferable to seal the connection portions present on an upper surface of the lid with a synthetic resin.
In each of the above embodiments, the bipolar lead-acid storage battery in which the positive electrode current collector plate and the negative electrode current collector plate are made of a lead foil (formed of lead or a lead alloy) has been described, but one aspect of the present invention can also be applied to a bipolar storage battery in which the positive electrode current collector plate and the negative electrode current collector plate are formed of a metal (such as aluminum, copper, or nickel) or an alloy other than lead or a lead alloy, or a conductive resin.
In each of the above embodiments, the respective bent portions of the positive electrode lug portion and the negative electrode lug portion are connected with the positive electrode terminal component and the negative electrode terminal component by thermal welding, but the bent portions may be connected with the positive electrode terminal component and the negative electrode terminal component by any of welding, caulking, bolt fastening, pressure bonding, and spring fixing. Because these connection types (thermal welding, welding, caulking, bolt fastening, pressure bonding, spring fixing) are vulnerable to corrosion, the effects obtained by the present invention are higher.
The following is a list of reference signs used in this specification and in the drawings.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2021-161020 | Sep 2021 | JP | national |
| 2021-161021 | Sep 2021 | JP | national |
This application is a continuation of PCT Application No. PCT/JP2022/036287, filed Sep. 30, 2021, the disclosure of which is incorporated herein in its entirety by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP2022/036287 | Sep 2022 | WO |
| Child | 18613685 | US |
