JP2004213937A - Battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery capable of reducing the variation in characteristics that occurs between terminal pairs even if there exists characteristic variations between power generation elements 2, by connecting two positive electrode terminals 3 and negative electrode terminals 4 to the electrodes of two power generation elements 2. <P>SOLUTION: Two power generation wire wound elements 2 are housed in a battery case 1a, with lid plates 1b-1d fitted to both-end opening parts. The positive electrode terminals 3 are fitted to terminal part lid plates 1b and 1c at the upper and lower end parts of these openings. The terminals 3 and 4 are internally connected to the electrodes corresponding to two power generation elements 2 through power-collecting connection bodies 5. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a battery that houses a plurality of power generating elements and has a plurality of positive and negative terminals.
[0002]
[Prior art]
As shown in FIG. 4, a battery may include a plurality of (two in the figure) wound power generating elements 2 that share an electrolytic solution in a battery container 1 formed of a battery can or the like. In such a battery, when one positive electrode terminal 3 and one negative electrode terminal 4 are attached to the battery case 1, respectively, as shown in FIG. Is collected at one place and connected to the terminals 3 and 4, so that the distance for routing these current collecting connectors 5 to the terminals 3 and 4 becomes longer, and the internal resistance of the battery becomes lower. It becomes large and battery characteristics deteriorate. In particular, in the case of a large-sized battery, if the internal resistance is increased as described above, the voltage drop becomes too large to take out a large current, and the current distribution becomes non-uniform due to branching of the current collector 5. This may further increase the voltage drop.
[0003]
Therefore, as shown in FIG. 4B, the positive electrode terminal 3 and the negative electrode terminal 4 are attached to the battery container 1 by the same number (two in the figure) as the power generating elements 2 and the positive and negative electrodes of each power generating element 2 are One connected to each of the positive electrode terminal 3 and the negative electrode terminal 4 corresponding to the above has been developed (for example, see Patent Document 1). When the terminals 3 and 4 are provided for each power generating element 2 as described above, the distance from the electrode of the power generating element 2 to the terminals 3 and 4 can be minimized, so that the internal resistance of the battery can be reduced. In particular, in the battery disclosed in Patent Document 1, since the positive and negative electrodes of each power generating element 2 are directly connected to the terminals 3 and 4, there is no voltage drop at the current collector 5 and a large current can be easily taken out. .
[0004]
[Patent Document 1]
JP-A-2000-331714 (FIGS. 1 and 3)
[0005]
[Problems to be solved by the invention]
However, when the terminals 3 and 4 are provided for each power generating element 2 in the common electrolyte, if there is a difference in the battery characteristics between the individual power generating elements 2, this characteristic difference is used as it is for each set of terminals 3 and 4. There was a problem that appeared in.
[0006]
The present invention has been made in order to cope with such a situation, by connecting a plurality of positive and negative terminals to the electrodes of all power generation elements, respectively, even when there is a characteristic difference between the power generation elements, It is an object of the present invention to provide a battery that can reduce a characteristic difference that appears for each terminal set.
[0007]
[Means for Solving the Problems]
According to the first aspect of the present invention, a plurality of wound power generating elements are housed in a battery container, and a plurality of positive terminals and a plurality of negative terminals are respectively attached to the battery container. Each of the plurality of power generating elements is connected to a corresponding electrode via a current collecting connector.
[0008]
According to the invention of claim 1, the plurality of positive terminals are connected to the positive electrodes of all the power generating elements, respectively, and the plurality of negative terminals are also connected to the negative electrodes of all the power generating elements. Are connected in parallel to the positive and negative terminals of each set, and even if there is a difference in battery characteristics for each power generation element, the battery characteristics for each set of positive and negative terminals The difference is reduced and appears.
[0009]
In addition, since the positive electrode and the negative electrode of each power generation element are connected to each positive electrode terminal and each negative electrode terminal, as in the case where there is only one positive electrode terminal and one negative electrode terminal, the current collector is connected to these terminals. The distance for routing may be long. However, in the present invention, since there are a plurality of positive electrode terminals and a plurality of negative electrode terminals, for example, even if the distance between the positive electrode of a specific power generation element and the current collection connector connected to the specific positive electrode terminal increases, The distance of the current collecting connector connected from the positive electrode to another positive electrode terminal can be shortened, and the imbalance that only a specific power generation element has a longer distance to any terminal than other terminals can be prevented. Can be. Moreover, even if the distance of the current collecting connector from the terminal side to the electrode of each power generating element is long or short, the magnitude of the current is distributed according to the length of this distance. The voltage drop and the amount of heat generated in the connection body are not particularly large.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0011]
1 to 3 show one embodiment of the present invention. FIG. 1 is a perspective view (a) showing a power generating element, a terminal, and a current collecting connector in a non-aqueous electrolyte secondary battery, and their connection. FIG. 2 is a perspective view showing a connection between an electrode of a power generating element and a terminal via a current collector in a non-aqueous electrolyte secondary battery, and FIG. 3 is a central portion at an opening of a battery case. It is a perspective view of a nonaqueous electrolyte secondary battery just before attaching a cover plate. Components having the same functions as those of the conventional example shown in FIG. 4 are denoted by the same reference numerals.
[0012]
In the present embodiment, two long cylindrical winding type power generating elements 2 as shown in FIG. 1A are housed side by side in a rectangular cylindrical battery case 1a as shown in FIG. A non-aqueous electrolyte secondary battery in which lid plates 1b to 1d are attached to openings at both ends of the battery case 1a as shown in FIG. The battery case 1a is formed by forming a stainless steel plate, an aluminum alloy plate or the like into a rectangular cylindrical shape having a rectangular cross section whose longer side (vertical direction in the drawing) is longer than shorter side (horizontal direction in the drawing). Yes, with openings at both ends. The power generating element 2 is configured such that a positive electrode and a negative electrode are shifted in the axial direction and wound around a separator, so that a positive electrode substrate (a conductive member for holding an active material, also referred to as a current collector) is provided from one end face. And a long cylindrical wound type in which a copper foil as a negative electrode base is projected from the other end face while projecting an aluminum foil. Then, the two power generating elements 2 are arranged such that the flat side surfaces of the long cylinder overlap each other, and inserted into the opening of the battery case 1a from one end face side, so that both end faces of these power generating elements 2 The case 1a is housed so as to face the openings at both ends. These two power generating elements 2 are housed in such a direction that an aluminum foil protrudes from one opening side and a copper foil protrudes from the other opening side.
[0013]
The cover plates 1b to 1d constitute the battery container 1 by being fitted into the opening of the battery case 1a. These lid plates 1b to 1d are made of a rectangular stainless steel plate or an aluminum alloy plate or the like. Before assembling, two substantially square terminal portion lid plates 1b and 1c constituting upper and lower ends in the longitudinal direction are formed. Are divided into a single central lid plate 1d constituting a central portion therebetween, and are joined and integrated after assembly. The lid plates 1b to 1d fit into the openings from which the aluminum foil, which is the positive electrode base, of the housed power generating element 2 protrudes, and the lid plates 1b to 1d fit into the openings from which the copper foil, which is the negative electrode base, protrudes. The thing becomes the negative electrode side. As shown in FIG. 1A, one positive electrode terminal 3 is attached to each of the positive terminal cover plates 1b and 1c, and each of the negative terminal cover plates 1b and 1c is attached to the negative terminal cover 1b. Negative electrode terminals 4 are attached one by one. The positive electrode terminal 3 is made of an aluminum alloy material, and the negative electrode terminal 4 is made of a copper alloy material or the like. However, since the positive electrode terminal 3 only needs to be made of an aluminum alloy material at the portion that comes into contact with the electrolytic solution inside the battery, bolts and the like for connection to the outside are made of a copper alloy or the like to increase strength. Preferably, such an aluminum alloy material and a copper alloy material that have been joined in advance can be used.
[0014]
Each of the terminal cover plates 1b and 1c has a positive electrode terminal 3 or a negative electrode 3 via an insulating sealing material at the center on the surface (the surface on the side that becomes the outside when attached to the opening of the battery case 1a). The terminal 4 is placed, and a projection protruding from the back side of the terminal 3, 4 penetrates the plate surfaces of the terminal portion cover plates 1 b, 1 c. On the back surface of each terminal cover plate 1b, 1c, a current collecting connector 5 is disposed via an insulating sealing material. It can be swaged through the surface. Therefore, the current collector 5 is crimped on the projections of the terminals 3 and 4 on the back side of the terminal portion cover plates 1b and 1c, so that the main body of the terminals 3 and 4 on the front surface side of the terminal portion cover plates 1b and 1c. To be fixed. The current collector 5 and the terminals 3 and 4 are insulated from the terminal cover plates 1b and 1c via an insulating sealing material, respectively, and the penetrating portions are sealed. . As shown in FIG. 3, the central lid plate 1d is a rectangular plate material that blocks the space between these terminal lid plates 1b and 1c fitted in the opening of the battery case 1a.
[0015]
The current collector 5 is made of an aluminum alloy plate on the positive electrode side, a copper alloy plate or a nickel alloy plate on the negative electrode side, and as shown in FIG. The four thin plate portions 5a are protruded in a comb-like shape from above to below or upward. In these current collectors 5, the center of the main body is crimped on the projections of the terminals 3 and 4 on the back surfaces of the terminal cover plates 1 b and 1 c, and the thin plate portion 5 a is connected to the terminal cover plates 1 b and 1 c. Project from the back side of the center part to the center part side where the center part cover plate 1d is joined.
[0016]
As shown in FIG. 3, the terminal cover plates 1b and 1c are fitted into upper and lower ends of openings at both ends of the battery case 1a. Then, each thin plate portion 5a of the current collector 5 protrudes toward the center side from the terminal cover plates 1b and 1c at the upper and lower ends, and as shown in FIG. Each of the power generating elements 2 is overlapped with a metal foil serving as a positive electrode substrate or a negative electrode substrate that protrudes from an end face of the power generation element 2. Therefore, the thin plate portion 5a is sandwiched between the holding plates (not shown) together with the metal foil and connected by ultrasonic welding. At this time, the ultrasonic welding operation can be performed by utilizing the empty space between the terminal cover plates 1b and 1c at the upper and lower ends of the opening of the battery case 1a. When each of the thin plate portions 5a is connected to the electrodes of the two power generating elements 2 in this manner, the terminals 3 and 4 collect current inside the battery container 1 as shown in FIG. It is connected to the electrodes of the two power generating elements 2 via the connection body 5. The sandwiching plate is obtained by folding a thin plate material such as an aluminum alloy in the case of the positive electrode side and a copper alloy in the case of the negative electrode side into two folds. Ultrasonic welding is performed from both sides of the two-folded plate material while being sandwiched.
[0017]
When the connection between the electrode of the power generation element 2 and the thin plate portion 5a of the current collecting connector 5 is completed as described above, the terminal portions at the upper and lower ends of the openings at both ends of the battery case 1a as shown in FIG. The center cover plate 1d is fitted between the cover plates 1b and 1c, and the terminal cover plates 1b and 1c and the center cover plate 1d are joined by welding to integrate the cover plates 1b to 1d. The non-aqueous electrolyte secondary battery is completed by integrating the battery container 1 by welding the lid plates 1b to 1d and the opening edge of the battery case 1a. The electrolyte is injected into the battery case 1a from a liquid inlet or the like (not shown) after the lid plates 1b to 1d are joined, or from an opening at the time of joining.
[0018]
According to the nonaqueous electrolyte secondary battery having the above configuration, as shown in FIG. 1B, two positive terminals 3 are connected to the positive electrodes of the two power generating elements 2 and two negative terminals. 4 are connected to the negative electrodes of the two power generating elements 2, respectively. Therefore, even when there is a difference in the battery characteristics of the two power generating elements 2, the pair of the positive electrode terminal 3 and the negative electrode terminal 4 is viewed. The difference in the characteristics of the power generation element 2 appears between the battery characteristics and the battery characteristics as viewed from the pair of the positive electrode terminal 3 and the negative electrode terminal 4. In particular, in the case of the present embodiment, since each current collecting connector 5 connects the two power generating elements 2 and the terminals 3 and 4 at the same distance, it is possible to completely balance the difference in battery characteristics. it can.
[0019]
In addition, in the said embodiment, although the case where the cover plates 1b-1d were divided | segmented for the connection work of the thin plate part 5a of the collector connection body 5 and the electrode of the electric power generation element 2 was shown, this connection work was inconvenient. If not, there is no need to divide the cover plate. Further, in the above-described embodiment, the battery case 1 in which the lid plates are respectively attached to the opening portions at both ends of the battery case 1a is shown. For example, the present invention can be similarly applied to a battery container 1 in which a cover plate is attached to an opening on only one side of a container-shaped battery case 1a. The positive electrode terminal 3 and the negative electrode terminal 4 only need to be mounted in plural at any place of such a battery container 1.
[0020]
Further, in the above embodiment, the case where the current collecting connector 5 is connected to the electrode of the power generating element 2 by the four thin plate portions 5a has been described, but the connection structure and the connection method between the current collecting connector 5 and the electrode are described. Is not limited. For example, a corrugated U-shaped portion may be formed in the current collector 5 and connected to the U-shaped portion with an electrode interposed therebetween. Furthermore, instead of sandwiching the electrode, the electrode and the current collector 5 can be brought into contact with each other and connected by resistance welding or the like.
[0021]
Further, in the above-described embodiment, the case where the long cylindrical wound type power generating element 2 is used has been described. However, if the power generating element is configured by winding one positive electrode and one negative electrode one by one, the winding shape may be used. Is arbitrary, and those having a cylindrical shape, an elliptical shape, or the like can also be used. Further, in the above embodiment, the non-aqueous electrolyte secondary battery has been described, but the present invention can be similarly applied to other batteries.
[0022]
【The invention's effect】
As is clear from the above description, according to the battery of the present invention, each of the positive and negative terminals is connected in parallel to the electrodes of the plurality of power generating elements, respectively. , It is possible to alleviate this characteristic difference as viewed from each set of positive and negative terminals.
[Brief description of the drawings]
FIG. 1 shows an embodiment of the present invention, and is a perspective view (a) showing a power generating element, a terminal, and a current collecting connector in a nonaqueous electrolyte secondary battery, and a circuit diagram showing these connections (FIG. b).
FIG. 2, showing an embodiment of the present invention, is a perspective view illustrating connection between an electrode of a power generating element and a terminal via a current collector in a nonaqueous electrolyte secondary battery.
FIG. 3 illustrates one embodiment of the present invention, and is a perspective view of a nonaqueous electrolyte secondary battery immediately before attaching a center cover plate to an opening of a battery case.
FIG. 4 shows a conventional example, in which a circuit diagram (a) of a battery having two power generating elements and having one positive and negative terminal is provided, and two batteries having positive and negative terminals are provided. FIG. 4B is a circuit diagram (b) of the battery.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Battery container 1a Battery case 1b Terminal cover plate 1c Terminal cover plate 1d Central cover plate 2 Power generation element 3 Positive terminal 4 Negative terminal 5 Current collecting connector 5a Thin plate portion

Claims (1)

A plurality of winding-type power generating elements are housed in the battery container, and a plurality of positive terminals and a plurality of negative terminals are respectively attached to the battery container, and each of these terminals is connected to the inside of the battery container through a current collector. A battery connected to the corresponding electrodes of all of the plurality of power generating elements.

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