JP5227894B2 - Battery electrode unit and battery - Google Patents

Description

The present invention relates to a battery electrode plate unit and a battery using the same.

  In recent years, the use of secondary batteries has been diversified. In particular, demand for future use as an electric vehicle driving power source is greatly expected as demands for protecting the global environment and effectively using energy resources increase. With such diversification of applications, further improvements in battery characteristics and reliability are required for secondary batteries.

  As shown in FIG. 14, the conventional secondary battery has a structure in which a battery case 51 containing an electrode plate group 52 and an electrolytic solution is closed with a lid 57 having a safety valve 56. As shown in FIG. 15, the electrode plate group 52 has a structure in which a plurality of positive electrode plates 61 and a plurality of negative electrode plates 62 are alternately stacked via separators 63. The positive plate 61 and the negative plate 62 have a structure in which a substrate is filled with an active material. As shown in FIG. 14, the lead 53 is drawn from the positive electrode plate and connected to the positive electrode terminal 54 provided on the lid 57. Similarly, a lead is drawn out from the negative electrode plate and connected to a negative electrode terminal 55 provided on the lid body 57.

  The board | substrate which comprises each electrode plate is produced by cut | disconnecting a metal plate. Since punching metal is used for the substrate of the negative electrode plate, there are few burrs generated by the cutting. On the other hand, since foam metal is used for the substrate of the positive electrode plate, fibrous burrs are easily generated by the cutting. Therefore, as shown in FIG. 15, in the electrode plate group 52 constituting the conventional secondary battery, the burr 61a generated at the end of the positive electrode plate 61 penetrates the separator 63 and contacts the negative electrode plate 62, As a result, there is a problem that an internal short circuit occurs between the positive and negative electrode plates.

  Further, in the conventional secondary battery, since the side surface of the electrode plate group is exposed, the electrode plate contacts the wall surface of the battery case when the electrode plate group is inserted into the battery case to constitute the battery. There was a problem that it might be damaged. As a structure of a secondary battery that solves such a problem, a positive electrode current collector plate is bonded to one side surface of the electrode plate group, and a negative electrode current collector plate is bonded to another side surface of the electrode plate group, A structure is conceivable in which the current collector plate is housed in the battery case together with the electrolytic solution, and both the current collector plates are connected to the positive electrode terminal and the negative electrode terminal provided in the battery case, respectively. According to this electrode plate unit, since the side surface of the electrode plate group is covered with the current collector plate, damage to the electrode plate during insertion into the battery case can be reduced. In such an electrode plate unit, the connection between the electrode plate group and the current collector plate can be achieved by welding, and the joint strength and current collection efficiency can be improved by providing the welded portions at a plurality of locations. However, further improvement in the bonding strength and current collection efficiency between the electrode plate group and the current collection plate is required.

SUMMARY OF THE INVENTION An object of the present invention is to provide a battery electrode plate unit having improved bonding strength and current collection efficiency between an electrode plate group and a current collector plate bonded to a side surface thereof, and a highly reliable battery using the same. That is.

The first battery electrode plate unit of the present invention, as a plurality of positive electrode plates and a plurality of negative electrode plates are coated with electrode plate group are laminated alternately, the one side surface of the electrode plate assembly with a separator and a plurality of current collecting plates joined plate-like body by a weld, at the junction surface between the electrode plate group of the collector plate, the weld current collector density of the collector plate is high other The region closer to the connection part electrically connected to the battery constituent member is formed such that the interval between the welded parts becomes narrower.

When the current collector plate is provided so as to cover the side surface of the electrode plate group, the variation in the current collection density of the current collector plate tends to increase. Since a large thermal stress is applied to the joint surface, the joint is liable to be broken. However, according to the battery electrode plate unit, since the welded portion is provided densely so as to increase the bonding strength and the current collection efficiency in the portion where the current collection density is high, the current collecting action of the current collection plate The reliability with respect to can be improved.

  The “current collection density” means a current that flows per unit cross-sectional area of the current collector plate. When the current collector plate is joined so as to cover the entire side surface of the electrode plate group, and the external terminal is connected to one end of the current collector plate, the current collection density of the current collector plate is closer to the external terminal region. Get higher.

In the battery electrode plate unit, for example, the current collector plate is arranged so that one end portion protrudes from the electrode plate group, and the welded portion is from the electrode plate group of the current collector plate. It can be set as the structure formed so that the space | interval of the said welding parts may become narrow, so that the area | region near the protruded edge part may become.

  In the structure in which the end portion of the current collector plate protrudes from the electrode plate group, the end portion can function as a connection portion that is electrically connected to another battery constituent member (for example, an external terminal). In this case, the current collection density is higher in the region closer to the end of the current collector plate. Therefore, the welding reliability of the current collector plate can be improved by providing the welded portions densely so that the region closer to the end of the current collector plate has higher bonding strength and current collection efficiency.

A second electrode plate unit for a battery according to the present invention includes a plurality of positive electrode plates and a plurality of negative electrode plates stacked alternately via separators, and a plurality of electrode plate units so as to cover one side surface of the electrode plate group. A plate-like current collector plate joined by a welded portion of each of the electrode plates, and a positioning hole is formed in an edge portion of each of the electrode plates on the side to be joined to the current collector plate. The positioning holes are arranged so that the positioning holes formed in the same electrode plate overlap each other when the electrode plate group is configured, and the welded portion is connected to the electrode plate group of the current collector plate. The positioning hole is formed so as not to be positioned immediately below.

When the current collector plate is joined to the side surface of the electrode plate group, the electrode plate group and the current collector plate are aligned by accurately aligning the edge of each electrode plate on the side surface to be joined to the current collector plate of the electrode plate group. The bonding strength and the reliability of the bonding can be improved. According to the second battery electrode plate unit, since each electrode plate has a positioning hole, the edge of the electrode plate can be accurately aligned by inserting a pin into the positioning hole, As a result, the bonding strength and bonding reliability between the electrode plate group and the current collector plate can be improved.

However, when the positioning hole is formed in the electrode plate, the strength of the portion is smaller than that of the other portion, so that it is considered that the portion is likely to be deformed or broken by the heat during current collector plate welding. Such deformation or breakage of the electrode plate is a cause of a decrease in the bonding strength and bonding reliability between the current collector plate and the electrode plate group. However, according to the second battery electrode plate unit, since the welded portion is formed to avoid the portion where the positioning hole is formed, the bonding strength between the current collector plate and the electrode plate group and the reliability of the bonding Can be suppressed.

In the second battery electrode plate unit, each of the electrode plates is interposed between an electrode part filled with an active material and the electrode part and the positive electrode current collector plate or the negative electrode current collector plate. It is preferable that the positioning hole is formed in the lead portion.

Further, in the second electrode plate unit, a plurality of the positioning holes are formed in each of the positive electrode plate and the negative electrode plate, at least one of the positioning holes is circular, and at least one of the other positioning holes is long. A circular shape is preferred.

Moreover, in the first and second electrode plate units, it is preferable that the welded portion is linear along the stacking direction of the electrode plates. According to this preferable example, it is possible to further improve the bonding strength and bonding reliability between the current collector plate and the electrode plate group.

In the first and second electrode plate units, it is preferable that a brazing material is disposed between the current collector plate and the electrode plate group in the weld portion. According to this preferred example, since the brazing material can be melted at a relatively low temperature and the current collector plate and the electrode plate group can be welded, the bonding strength between the current collector plate and the electrode plate group and the reliability of the bonding can be improved. Further improvement can be achieved.

  Moreover, the battery of this invention is a battery which accommodated either the said 1st-2nd electrode plate unit in the battery case with electrolyte solution.

According to the first battery plate unit of the present invention, the side surface of the electrode plate group and collector plates are joined by a plurality of welds, the weld, a high current collecting density of the collector plate Since it is formed so that the space | interval of the said welding parts becomes narrow so that it may be an area | region, the reliability with respect to the joining strength and current collection efficiency of a current collection board can be improved.

Further, according to the second battery electrode plate unit of the present invention, the side surface of the electrode plate group and collector plates are joined by a plurality of welds, beneath the weld, constituting the electrode plate assembly Since the welded portion is formed so that the positioning hole is not located in each electrode plate to be performed, the joining strength and the joining reliability of the current collector plate can be improved.

It is a front view which shows an example of the electrode plate unit for batteries of this invention. It is AA direction sectional drawing in FIG. It is a BB direction sectional view in FIG. It is sectional drawing to which the part shown by C of FIG. 3 was expanded. It is a figure which shows an example of a positive electrode plate, the figure (a) is a front view, and the figure (b) is a top view. It is a figure which shows an example of a negative electrode plate, the figure (a) is a front view, and the figure (b) is a top view. It is a figure which shows an example of a current collecting plate, The figure (a) is a front view, The figure (b) is sectional drawing. It is a perspective view which shows the part by which the current collecting plate in the battery electrode plate unit of this invention is arrange | positioned. It is AA direction sectional drawing in FIG. It is a figure which shows an example of the battery of this invention, the figure (a) is a top view, and the figure (b) is a front view. It is AA direction sectional drawing in FIG. It is a fragmentary sectional view which shows another example of the battery of this invention. It is a figure for demonstrating another example of the electrode unit for batteries of this invention, the figure (a) is a schematic diagram, the figure (b) is sectional drawing of central part vicinity, and the figure (c) is the most. It is sectional drawing of the external vicinity. It is a partially broken perspective view which shows the structure of the conventional battery. It is sectional drawing which shows the electrode group which comprises the conventional battery.

(First embodiment)
FIG. 10 is a diagram showing an example of the battery according to the first embodiment of the present invention, where FIG. 10 (a) is a plan view and FIG. 10 (b) is a front view. FIG. 11 is a cross-sectional view in the AA direction of FIG. This battery includes a battery case 10 whose interior is divided into a plurality of sections, and an electrode plate unit 1 housed in each section.

  The electrode plate unit 1 includes an electrode plate group in which a positive electrode plate, a negative electrode plate, and a separator are stacked, and a positive electrode current collector plate and a negative electrode current collector plate joined to the electrode plate group. The structure of the electrode plate unit 1 will be described in detail later.

  In the battery, the electrode plate units 1 housed in the battery case 10 are electrically connected. For the electrical connection between the electrode plate units 1, for example, a through hole is provided in the partition wall 10 a separating the compartments in the battery case 10, a connecting metal fitting 16 is attached to the through hole, and the electrode plates adjacent to each other with the partition wall 10 a interposed therebetween. This is achieved by connecting the positive electrode current collector plate and the negative electrode current collector plate of the unit 1 to the connection fitting 16 respectively.

  Further, the positive electrode current collector plate of the electrode plate unit housed in a section located at one end of the battery case 10 is connected to the positive electrode external terminal 14. Further, the negative electrode current collector plate of the electrode plate unit housed in the section located at the other end is connected to the negative electrode external terminal 15.

  An electrolytic solution is housed in the battery case 10 together with the electrode plate unit 1. The type of the electrolytic solution is not particularly limited and is appropriately selected according to a desired battery. For example, in the case of a nickel-hydrogen battery, an aqueous solution of potassium hydroxide, sodium hydroxide, lithium hydroxide or the like is used.

  The battery case 10 is closed by a lid 11, and the lid 11 is provided with a safety valve 12 that operates according to the pressure in the battery case 10. Furthermore, the lid 11 may be provided with a mounting portion 13 for mounting a sensor for detecting the battery temperature. In addition, ribs 10b may be provided on the outer surface of the battery case 10 in order to improve heat dissipation when a plurality of batteries are integrated and used.

  FIG. 1 is a front view showing an example of the electrode plate unit 1. 2 is a cross-sectional view in the AA direction of FIG. 1, and FIG. 3 is a cross-sectional view in the BB direction of FIG.

  As described above, the electrode plate unit 1 includes an electrode plate group in which the positive electrode plate 2, the negative electrode plate 3, and the separator 4 are laminated, and the positive electrode current collecting plate 5 and the negative electrode current collecting plate 6 joined to the electrode plate group. Yes.

  5A and 5B are diagrams showing an example of the positive electrode plate 2. FIG. 5A is a front view, and FIG. 5B is a plan view. The positive electrode plate 2 has a structure in which an electrode portion 21 filled with an active material and a lead portion 22 not filled with an active material are formed on a substrate. In addition, a reinforcing plate 24 is preferably laminated on the lead portion 22.

  The material constituting the positive electrode plate 2 is not particularly limited, and is appropriately determined according to the type of battery. For example, in the case of an electrode plate unit constituting a nickel-hydrogen secondary battery, a foamed nickel substrate or a nickel fiber substrate is used as the substrate, and nickel hydroxide is used as the active material.

  FIG. 6 is a diagram illustrating an example of the negative electrode plate 3, in which FIG. 6A is a front view and FIG. 6B is a plan view. The negative electrode plate 3 has a structure in which an electrode part 31 filled with an active material and a lead part 32 not filled with an active material are formed on a substrate.

The material constituting the negative electrode plate 3 is not particularly limited, and is appropriately determined according to the type of battery. For example, in the case of an electrode plate unit constituting a nickel-hydrogen secondary battery, a perforated nickel substrate is used as a substrate, and AB ₅ type or AB ₂ type (A is a typical metal element and B is a transition metal) as an active material. Element)) is used.

  As shown in FIG. 5 and FIG. 6, each electrode plate can have a structure in which the overall shape is rectangular and a lead portion is provided at the edge of one side. At this time, it is preferable that the length (L2, L3) of the side on which the lead portion of the electrode plate is formed is larger than the length (D2, D3) of the side orthogonal thereto.

  Further, the length (L2) of the side of the positive electrode plate 2 on which the lead portion 22 is formed is longer than the length (L3) of the side of the negative electrode plate 3 on which the lead portion 32 is formed.

  Positioning holes 23 and 33 are preferably formed in the lead portions 22 and 32 of the respective electrode plates. The positioning holes of each electrode plate are arranged so that the positioning holes formed in the electrode plates of the same polarity overlap when the electrode plate group is configured.

  As shown in FIG. 1, the positive electrode plate 2 and the negative electrode plate 3 are alternately stacked via separators 4 so that the electrode portions face each other. Thereby, the electrode group is comprised.

  The separator 4 preferably wraps at least one electrode plate with the lead portion exposed. For example, a plurality of bag-like materials can be used as the separator 4, and at least one of the positive electrode plate 2 and the negative electrode plate 3 can be included in each of them. Moreover, it is also possible to use a structure in which a zigzag band is used as the separator 4 and electrode plates are inserted one by one between the folded surfaces. In addition, it does not specifically limit about the material of the separator 4, For example, a porous film, a nonwoven fabric, a woven fabric etc. are used.

  As shown in FIGS. 1 and 2, in the electrode group, the lead portion of the positive electrode plate 2 protrudes from the edge of the negative electrode plate 3 on one side surface. The positive electrode current collector plate 5 is joined to this side surface. In another aspect, the lead portion of the negative electrode plate 3 protrudes from the edge portion of the positive electrode plate 2. A negative electrode current collector plate 6 is joined to this side surface. Thereby, the electrode plate unit 1 is configured.

  Further, as shown in FIGS. 1 and 3, in the electrode plate unit 1, the edge portion of the positive electrode plate 2 is the edge portion of the negative electrode plate 3 on the side surface where the current collecting plates of the electrode plate group are not joined. Than protruding. Therefore, as shown in FIG. 4, even when the burr 2 a is present at the edge of the positive electrode plate 2, the burr 2 a does not contact the negative electrode plate 3, thereby suppressing occurrence of a short circuit between the positive and negative electrodes. FIG. 4 is an enlarged view of a portion C in FIG.

  Although the length (X of FIG. 4) of the part which protruded from the negative electrode plate 3 of the positive electrode plate 2 is not specifically limited, For example, it is 0.3-2 mm.

  As shown in FIGS. 1 and 2, the current collector plates 5 and 6 are plate-like objects that cover at least a part of the side surface of the electrode plate group. 7A and 7B are diagrams showing an example of the positive electrode current collector plate 5. FIG. 7A is a plan view and FIG. 7B is a cross-sectional view. 8 is a perspective view showing a form of joining of the positive electrode current collector plate 5 and the electrode plate group, and FIG. 9 is a cross-sectional view taken along the line AA of FIG. 7 to 9 and the following description relate to the form of bonding between the positive electrode current collector plate 5 and the electrode plate group, the same applies to the bonding between the negative electrode current collector plate 6 and the electrode plate group. It can be in the form.

  A plurality of welds 7 are formed on the joint surface between the positive electrode current collector plate 5 and the electrode plate group. In this embodiment, although it does not specifically limit about the space | interval of welding parts 7, It is preferable to change according to the current collection density of a current collecting plate so that it may demonstrate in 2nd Embodiment. Furthermore, as described in the third embodiment, it is preferable to form the welded portion 7 while avoiding the portion where the positioning hole is formed.

  Moreover, it is preferable that the welding part 7 is linear along the lamination direction of an electrode plate. Furthermore, it is preferable that a brazing material 8 such as nickel brazing is interposed between the positive electrode current collector plate 5 and the electrode plate group in each welded portion 7.

  The electrode plate unit 1 can be manufactured, for example, by the following method.

  First, the foamed nickel plate is cut to produce a positive plate substrate, and an electrode portion and a lead portion are formed thereon. The electrode part is formed by filling a region containing the electrode part of the positive electrode substrate with a paste containing an active material and then drying the paste. The lead portion is formed by pressurizing and compressing a region for forming the lead portion of the positive electrode substrate in the thickness direction and bonding a reinforcing plate to the surface. Further, a positioning hole is formed in the lead portion, and a positive electrode plate is manufactured. A plurality of the positive plates are produced, and each positive plate is covered with a bag-like separator with the lead portion exposed.

  On the other hand, the nickel plate is cut to produce a substrate for a negative electrode plate, and an electrode portion and a lead portion are formed thereon. The electrode portion is formed by forming a plurality of holes in a region where the electrode portion of the negative electrode substrate is formed, applying a paste containing an active material, and drying. Further, the lead portion does not particularly require processing for forming the lead portion. Further, a positioning hole is formed in the lead portion, and a negative electrode plate is produced.

  The positive electrode plate coated with the separator and the negative electrode plate are alternately laminated to prepare an electrode plate group. Subsequently, positioning pins are inserted into the positioning holes of the positive electrode plate and the negative electrode plate, respectively. Thus, the lead portion of the positive electrode plate protrudes from one side surface of the electrode plate group, the lead portion of the negative electrode plate protrudes from the other side surface, and the edge portion of the positive electrode plate protrudes from the other side surface. Position each electrode plate. At the same time, the edge of each electrode plate is aligned on the side surface where the lead portion of the positive electrode plate of the electrode plate group protrudes and the side surface where the lead portion of the positive electrode plate protrudes.

  In addition, when two types of positioning holes, circular and oval, are formed in each electrode plate, pins are inserted into the circular positioning hole and the oval positioning hole. The oval hole serves to prevent the electrode plate from rotating. Thereby, the tolerance of the dimension of each electrode plate and the positioning hole forming position can be absorbed, and positioning and edge edge alignment can be performed efficiently.

  A positive electrode current collector plate is joined to the side surface from which the lead portion of the positive electrode plate of the electrode plate group protrudes. The positive current collector plate is joined by irradiating an electron beam or a laser on the surface of the positive current collector plate opposite to the surface to be joined with the positive current collector plate while pressing the positive current collector plate toward the electrode plate group side. Is implemented.

  Subsequently, after the positioning pins inserted into the positioning holes of the positive electrode plate are extracted, the negative electrode current collector plate is joined to the side surface of the electrode plate group from which the negative electrode plate lead portion protrudes. This step is performed in the same manner as the joining of the positive electrode current collector plate. Thereafter, the positioning pin inserted in the positioning hole of the negative electrode plate is extracted, and the electrode plate unit is completed. The positioning pin of the positive electrode plate may be removed together with the positioning pin of the negative electrode plate after the joining of the negative electrode current collector plate is completed.

(Second Embodiment)
The battery according to the second embodiment of the present invention is the same as that of the first embodiment except that in the electrode plate unit, the welded portion is provided in a specific arrangement on the joint surface between the electrode plate group and the current collector plate. It has the same structure. The battery of this embodiment has a structure as shown in FIGS. 10 and 11, for example.

  The electrode plate unit of this embodiment has a structure as shown in FIGS. 1 to 4, for example, and is joined to an electrode plate group in which the positive electrode plate 2, the negative electrode plate 3 and the separator 4 are laminated. A positive current collector plate 5 and a negative current collector plate 6 are provided.

  The positive electrode plate 2 and the negative electrode plate 3 have a structure as shown in FIGS. 5 and 6, for example. The structure and constituent materials of each electrode plate are the same as those in the first embodiment. However, in this embodiment, the relationship between the side length (L2) of the positive electrode plate 2 and the side length (L3) of the negative electrode plate 3 is not particularly limited. However, as described in the first embodiment, it is preferable that the L2 is longer than the L3.

  As shown in FIGS. 1 and 2, the positive electrode plate 2 and the negative electrode plate 3 are alternately stacked via separators 4 to form an electrode plate group. On one side of the electrode plate group, the lead portion of the positive electrode plate 2 protrudes from the edge of the negative electrode plate 3, and the positive electrode current collector plate 5 is joined thereto. Moreover, in another one side surface, the lead part of the negative electrode plate 3 protrudes from the edge part of the positive electrode plate 2, and the negative electrode current collecting plate 6 is joined here. Although not particularly limited, in the present embodiment as well, in the same manner as in the first embodiment, the positive electrode plate 2 protrudes from the negative electrode plate 3 on the side surface where the current collecting plates of the electrode plate group are not joined. Preferably it is.

  As shown in FIGS. 1 and 2, the current collector plates 5 and 6 are plate-like objects that cover at least a part of the side surfaces of the electrode plate group, and one end thereof protrudes from the electrode plate group. The protrusions 5a and 6a are connections for electrically connecting the electrode plate unit and other battery components (for example, the external terminals 15 and 16 or the connection fitting 16 in the battery shown in FIGS. 10 and 11). It functions as a part.

  As shown in FIG. 8, a plurality of welds 7 are formed on the joint surface between the positive electrode current collector plate 5 and the electrode plate group. The interval between the welded portions 7 is set so that the region closer to the protruding portion 5a of the positive electrode current collector plate is narrower and the region farther from the protruding portion 5a is wider. In other words, the interval between the welded portions 7 is set so as to become narrower in the region where the current collection density is higher in the positive electrode current collector plate.

  Moreover, it is preferable that the welding part 7 is linear form along the lamination direction of an electrode plate similarly to 1st Embodiment. Furthermore, it is preferable that a brazing material 8 such as nickel brazing is interposed between the positive electrode current collector plate 5 and the electrode plate group in each welded portion 7.

  7 to 9 and the above description relate to the form of bonding between the positive electrode current collector plate 5 and the electrode plate group, the same applies to the bonding between the negative electrode current collector plate 6 and the electrode plate group. It can be in the form.

  The electrode plate unit of this embodiment can be manufactured by the same method as in the first embodiment, for example. In this case, in the step of joining the current collector plate to the electrode plate group, an electron beam or a laser is irradiated to a plurality of locations at appropriate intervals in the longitudinal direction of the electrode plate group side surface. It sets so that the area | region close | similar to the protrusion part of a current collector plate may become narrow, and the area | region far from a protrusion part may become wide. Thereby, a some welding part is formed with the arrangement | positioning form as mentioned above.

(Third embodiment)
The battery according to the third embodiment of the present invention is the first plate except that in the electrode plate unit, the welded portion is provided so as to avoid a specific location on the joint surface between the electrode plate group and the current collector plate. It has the same structure as the embodiment. The battery of this embodiment has a structure as shown in FIGS. 10 and 11, for example.

  The electrode plate unit of this embodiment has a structure as shown in FIGS. 1 to 4, for example, and is joined to an electrode plate group in which the positive electrode plate 2, the negative electrode plate 3 and the separator 4 are laminated. A positive current collector plate 5 and a negative current collector plate 6 are provided.

  The positive electrode plate 2 and the negative electrode plate 3 have a structure as shown in FIGS. 5 and 6, for example. The structure and constituent materials of each electrode plate are the same as those in the second embodiment. However, positioning holes 23 and 33 are necessarily formed in the positive electrode plate 2 and the negative electrode plate 3 in the present embodiment.

  As shown in FIGS. 1 and 2, the positive electrode plate 2 and the negative electrode plate 3 are alternately stacked via separators 4 to form an electrode plate group. On one side of the electrode plate group, the lead portion of the positive electrode plate 2 protrudes from the edge of the negative electrode plate 3, and the positive electrode current collector plate 5 is joined thereto. Moreover, in another one side surface, the lead part of the negative electrode plate 3 protrudes from the edge part of the positive electrode plate 2, and the negative electrode current collecting plate 6 is joined here. Although not particularly limited, in the present embodiment as well, in the same manner as in the first embodiment, the positive electrode plate 2 protrudes from the negative electrode plate 3 on the side surface where the current collecting plates of the electrode plate group are not joined. Preferably it is.

  As shown in FIGS. 1 and 2, the current collector plates 5 and 6 are plate-like objects that cover at least a part of the side surfaces of the electrode plate group, and one end thereof protrudes from the electrode plate group.

  As shown in FIG. 8, a plurality of welds 7 are formed on the joint surface between the positive electrode current collector plate 5 and the electrode plate group. This weld 7 is formed avoiding the region where the positioning hole 23 is formed. That is, as shown in FIGS. 8 and 9, the welded portion 7 is formed so that the positioning hole 23 is not located immediately below the welded portion 7.

  The distance (Y) between the welding part 7 and the positioning hole 23 is set to 2 mm or more, for example.

  Further, although not particularly limited, as in the second embodiment, the interval between the welded portions 7 is narrower in a region closer to the protruding portion 5a of the current collector plate, and wider in a region farther from the protruding portion 5a. It is preferable to set to.

  Furthermore, similarly to the first embodiment, the welded portion 7 is preferably linear along the electrode plate stacking direction. Furthermore, it is preferable that a brazing material 8 such as nickel brazing is interposed between the positive electrode current collector plate 5 and the electrode plate group in each welded portion 7.

  7 to 9 and the above description relate to the form of bonding between the positive electrode current collector plate 5 and the electrode plate group, the same applies to the bonding between the negative electrode current collector plate 6 and the electrode plate group. It can be in the form.

  The electrode plate unit of this embodiment can be manufactured by the same method as that of the second embodiment, for example. In this case, in the step of joining the current collector plate to the electrode plate group, an electron beam or a laser is irradiated to a place avoiding directly above the positioning hole. Thereby, a some welding part is formed in a position as mentioned above.

(Fourth embodiment)
FIG. 12 is a cross-sectional view showing an example of a battery according to the fourth embodiment of the present invention. This battery includes a cylindrical battery case 40 and an electrode plate unit 41 accommodated therein.

  The electrode plate unit 41 includes a positive electrode plate 42, a negative electrode plate 43, and a separator 44. Further, a positive electrode lead 45 drawn from the positive electrode plate 42 and a negative electrode lead 46 drawn from the negative electrode plate are provided. The structure of the electrode plate unit 41 will be described in detail later.

  The battery case 40 is closed by a lid 48 having a safety valve 47. The positive electrode lead 45 of the electrode plate unit is electrically connected to a lid 48 that also functions as a positive electrode terminal, and the negative electrode lead 46 is electrically connected to the battery case 40 that also functions as a negative electrode terminal.

  In the battery case 40, an electrolytic solution is stored together with the electrode plate unit 41. The kind of electrolyte solution is not specifically limited, For example, the thing similar to 1st Embodiment can be used.

  Next, the structure of the electrode plate unit 41 will be described. The electrode plate unit 41 has a structure in which a positive electrode plate 42, a negative electrode plate 43, and a separator 44 are stacked and further wound.

  Each of the positive electrode plate 42 and the negative electrode plate 43 is a band-shaped substrate filled with an active material. Moreover, it does not specifically limit as a board | substrate and active material which comprise each electrode plate, For example, the thing similar to 1st Embodiment can be used.

  For example, the positive electrode plate 42 is produced by filling a substrate produced by cutting a foamed nickel plate with an active material. The cutting of the foamed nickel plate may cause burrs at the edge of the positive electrode plate. This burr protrudes in a specific direction from the plane of the foamed nickel plate, and the projecting direction is determined by the direction of movement of the cutting blade with respect to the foamed nickel plate during processing.

  In the present embodiment, the long side of the positive electrode plate 42 is set to be longer than the long side of the negative electrode plate 43. The difference between the two is, for example, 0.3 to 2 mm. As long as this condition is satisfied, the specific dimensions of each electrode plate are not particularly limited, and can be appropriately determined according to the size of the battery.

  The positive electrode plate 42 and the negative electrode plate 43 are laminated via a separator 44 to constitute an electrode plate group. In this electrode plate group, the positive electrode plate 42 and the negative electrode plate 43 are laminated such that, when a burr exists at the end of the positive electrode plate 42, the burr protrudes toward the negative electrode plate 43 side.

  As the separator 44, a strip-shaped separator can be used. Although the dimension is not particularly limited, it is preferable that the long side and the short side are longer than the long side and the short side of the positive electrode plate, respectively. Moreover, as a material of the separator 44, the thing similar to 1st Embodiment can be used, for example.

  The electrode plate group is wound in a cylindrical shape along the long side direction. Further, the positive electrode lead 45 is drawn out from the positive electrode plate 42, and the negative electrode lead 46 is drawn out from the negative electrode plate 43, thereby constituting the electrode plate unit 41.

  FIG. 13A is a schematic view for explaining the structure of the electrode plate unit. FIG. 4B is a cross-sectional view showing the structure near the center of the electrode plate unit, and FIG. 4C is a cross-sectional view showing the structure near the outermost part of the electrode plate unit.

  As shown in FIGS. 13 (b) and 13 (c), the electrode plate unit is wound on the side surface on the short side of the electrode plate group 49, that is, the side surface (A) of the end portion where winding starts. On the side surface (B) of the end that is the end, the edge of the positive electrode plate 42 protrudes beyond the edge of the negative electrode plate 43. Although the length (X in the figure) of the part which protruded from the negative electrode plate 43 of the positive electrode plate 42 is not specifically limited, For example, it is 0.3-2 mm.

  In such an electrode plate unit 41, as shown in FIG. 13, even when a burr 42 a is present at the edge of the positive electrode plate 42, the burr 42 a does not contact the negative electrode plate 43. Occurrence is suppressed.

Further, in the electrode plate unit 41, it is preferable that the edge of the positive electrode plate 42 protrudes from the edge of the negative electrode plate 43 on the side surface on the long side of the electrode plate group.

DESCRIPTION OF SYMBOLS 1,41 Electrode plate unit 2,42 Positive electrode plate 3,43 Negative electrode plate 4,44 Separator 5 Positive electrode current collecting plate 6 Negative electrode current collecting plate 7 Welding part 21,31 Electrode part 22,32 Lead part 23,33 Positioning hole

Claims (8)

A group of electrode plates in which a plurality of positive electrode plates and a plurality of negative electrode plates are alternately laminated via separators, and a plate-like body joined by a plurality of welds so as to cover one side surface of the electrode plate group. Including electrical board,
In the joint surface of the current collector plate with the electrode plate group, the welded portion is closer to a connection portion that is electrically connected to another battery component having a higher current collection density of the current collector plate. An electrode plate unit for a battery , characterized in that it is formed so that the interval between welds is narrow. The current collector plate is disposed so that one end portion thereof protrudes from the electrode plate group, the end portion serves as the connection portion, and the weld portion protrudes from the electrode plate group of the current collector plate. 2. The electrode plate unit for a battery according to claim 1, wherein the electrode plate unit is formed so that a distance closer to the welded portion is closer to a region closer to the end. A group of electrode plates in which a plurality of positive electrode plates and a plurality of negative electrode plates are alternately laminated via separators, and a plate-like body joined by a plurality of welds so as to cover one side surface of the electrode plate group. Including electrical board,
Positioning holes are formed at the edge portions of the electrode plates on the side to be joined with the current collector plates, and the positioning holes of the electrode plates are formed on the same electrode plate when constituting the electrode plate group. It is arranged so that the formed positioning holes are overlapped with each other , and the welding portion is formed so that the positioning hole is not located immediately below the joining surface of the current collector plate with the electrode plate group. A battery electrode plate unit. Each of the electrode plates is interposed between the electrode part filled with an active material, the electrode part and the positive electrode current collector plate or the negative electrode current collector plate, and provided at the edge of the electrode plate. The battery electrode plate unit according to claim 3, further comprising a lead portion, wherein the positioning hole is formed in the lead portion. 5. The battery according to claim 3, wherein a plurality of the positioning holes are formed in each of the positive electrode plate and the negative electrode plate, at least one of the positioning holes is circular, and at least one of the positioning holes is oval. use the electrode plate unit. The battery electrode plate unit according to claim 1, wherein the welded portion has a linear shape along the stacking direction of the electrode plates. The battery electrode plate unit according to claim 1, wherein a brazing material is disposed between the current collector plate and the electrode plate group in the welded portion. A battery in which the battery electrode plate unit according to claim 1 is housed in a battery case together with an electrolytic solution.

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