JP6665074B2 - Electrode plate of alkaline secondary battery and alkaline secondary battery - Google Patents

Description

  The present invention relates to an electrode plate of an alkaline secondary battery and an alkaline secondary battery having the electrode plate.

  2. Description of the Related Art In general, a nickel-metal hydride secondary battery, which is a secondary battery having high energy density and excellent reliability, is widely used as a power source for portable devices and portable devices, and as a power source for electric vehicles and hybrid vehicles. The nickel-metal hydride secondary battery includes a positive electrode mainly composed of nickel hydroxide, a negative electrode mainly composed of a hydrogen storage alloy, and an alkaline electrolyte. For example, Patent Literature 1 describes an example of an alkaline secondary battery having such a structure.

  The alkaline secondary battery described in Patent Document 1 is a nickel-metal hydride secondary battery, and includes a positive electrode plate holding a positive electrode active material, a negative electrode plate holding a negative electrode active material, and a separator for separating the positive electrode plate and the negative electrode plate. Contains. The alkaline secondary battery is a cylindrical battery in which a positive electrode plate and a negative electrode plate are stacked with a separator interposed therebetween and spirally wound and housed in a bottomed cylindrical outer can. In this alkaline secondary battery, the width of the negative electrode plate is shorter than the width of the positive electrode plate.

JP 2013-134940 A

According to the technology described in Patent Literature 1, the occurrence of an internal short circuit due to burrs on the side end of the wound positive electrode plate is suppressed.
Incidentally, an electrode group in which flat electrode plates are stacked has a pressed portion pressed at a side end portion of the electrode plate. Of the side end portions of the electrode plate, on the current collector plate side, the ease of welding is improved by increasing the metal density of the substrate constituting the electrode plate, and the opposite side is opposed by compression. The distance between the electrodes is secured to reduce the risk of short circuit between the electrodes. However, if burrs are formed at the corners by pressing, the burrs may damage the separator or penetrate and cause a short circuit.

  The present invention has been made in view of such circumstances, and an object thereof is to provide an electrode plate of an alkaline secondary battery capable of reducing burrs generated on an electrode plate, and an alkaline secondary battery having the electrode plate. It is to provide a battery.

  The electrode plate of the alkaline secondary battery that solves the above problem is an electrode plate of an alkaline secondary battery, including a rectangular substrate having open cells filled with an active material, wherein the substrate is disposed in a thickness direction. A lead portion extended as a compressed portion and connected to the current collecting plate, and a press portion extended as a portion compressed in the thickness direction at a tip portion opposite to the lead portion. And the active material is filled at a filling position that is set with a predetermined separation distance between at least one of the lead material and the press part. Features.

  An alkaline secondary battery that solves the above-mentioned problem has a plurality of positive plates connected to the positive current collector between opposed positive and negative current collectors, and the substrate is filled with a positive electrode active material. And a plurality of negative plates connected to the negative electrode current collector plate and a plurality of negative plates formed by holding a negative electrode active material on a substrate, each of which is laminated via a separator. An alkaline secondary battery including a plate group, wherein the positive electrode plate is extended as a portion compressed in the thickness direction and connected to a positive electrode current collector plate, and a lead portion opposite to the lead portion. A press portion extended as a portion compressed in the thickness direction is provided at the leading end portion, and the positive electrode active material is at least one of between the lead portion and the press portion. Filling position set with a predetermined separation distance between The negative electrode plate is filled with the negative electrode active material in a size corresponding to the size of the filling position of the positive electrode plate, and the electrode plate group is a filling position of the positive electrode plate, The filling position of the negative electrode plate is stacked so that a part thereof does not overlap with the stacking direction.

  When pressing the substrate, if the active material is filled in the portion to be pressed, burrs are generated at the end of the substrate due to stress of the substrate and the active material with respect to the press, and the generated burrs short-circuit the opposite electrode plate. There is a risk. In this regard, according to such a configuration, an unfilled region where the active material is not filled is formed between the lead portion or the press portion and the filling position. Since the unfilled region has a small stress, the occurrence of burrs is reduced.

  In addition, the vibration due to the pressing and the deformation of the substrate may cause the active material filled in the substrate to fall off. In this regard, according to such a configuration, since the region adjacent to the press portion is an unfilled region, the active material is prevented from falling off by the press. Further, a decrease in the capacity of the electrode plate and a short circuit due to the falling off of the active material are prevented.

In a preferred configuration, the electrode plate is a positive electrode plate, the substrate is a nickel metal porous body, and the active material is a positive electrode active material.
According to such a configuration, the nickel-metal hydride secondary battery does not cause metal deposition on the electrode plate surface during charge / discharge even if lateral displacement occurs in the electrode plate. It is easy.

As a preferred configuration, the predetermined distance is set to 0.4 mm or more.
According to such a configuration, at the time of filling the active material, the unfilled region can be reliably secured even if the filling position and the spread slightly change.

As a preferred configuration, the length where the portions do not overlap is 2 mm or less in a direction orthogonal to the laminating direction.
According to such a configuration, an alkaline secondary battery, particularly a nickel-metal hydride secondary battery, is not covered with a separator because metal deposition does not occur on the surface of the electrode plate during charge / discharge even if lateral displacement occurs in the electrode plate. In addition, even if the electrode plate has an unfilled region and the position of the filled region is difficult to confirm, it becomes easy to stack the plates.

  According to the electrode plate of the alkaline secondary battery of the present invention and the alkaline secondary battery having the electrode plate, burrs generated on the electrode plate can be reduced.

FIG. 1 is a perspective view schematically showing a nickel-metal hydride secondary battery according to an embodiment in which an alkaline secondary battery having a positive electrode substrate is embodied as a nickel-metal hydride secondary battery. Sectional drawing which shows the cross-section of the electrode group of the nickel hydride secondary battery in the embodiment. The schematic diagram which shows typically the laminated structure of the positive electrode plate and the negative electrode plate of the nickel hydride secondary battery in the embodiment. FIG. 3 is a cross-sectional view showing an enlarged cross-sectional structure of a front end portion of the positive electrode plate in the same embodiment.

  Hereinafter, an embodiment of an electrode plate of an alkaline secondary battery and an alkaline secondary battery having the electrode plate will be described. In the present embodiment, an alkaline secondary battery is described as being embodied as a nickel hydride secondary battery.

  As shown in FIG. 1, a nickel-metal hydride secondary battery 11 in the present embodiment is a rectangular sealed battery and has a plurality of battery cells 12 connected in series. The nickel-metal hydride secondary battery 11 includes an integrated battery case 13 that can accommodate each battery cell 12, and a lid 14 that seals an opening of the integrated battery case 13. The integrated battery case 13 and the lid 14 constitute a storage container.

  The internal space of the integrated battery case 13 is divided into six spaces by partition walls (not shown). One of the battery cells 12 is accommodated in each of those spaces. Therefore, in the present embodiment, six battery cells 12 are accommodated in the integrated battery case 13. The battery cells 12 are connected in series by connecting joining protrusions (not shown) projecting above the opposing current collector plates 21 and 22 (see FIG. 2). The electric power of these battery cells 12 is taken out from terminals 13 a and 13 b provided in integrated battery case 13.

  As shown in FIG. 2, in the battery cell 12, a rectangular plate-shaped positive electrode plate 15 and a rectangular plate-shaped negative electrode plate 16 are stacked and disposed between the above-described opposed current collector plates 21 and 22 with a separator 17 interposed therebetween. An electrode group 20 and an electrolytic solution (not shown) are provided. Lead portions 15a and 16a are formed at ends of the positive electrode plate 15 and the negative electrode plate 16, respectively. The lead portion 15a of the positive electrode plate 15 is perpendicularly joined to the joining surface of the current collector plate 21 of the positive electrode by a joining method such as welding. The lead portion 16a of the negative electrode plate 16 is also perpendicularly joined to the joining surface of the negative electrode current collector plate 22 by welding or the like.

  As shown in FIG. 3, the negative electrode plate 16 includes a negative electrode substrate 30 serving as a core material, and a hydrogen storage alloy 33 supported on the negative electrode substrate 30. The negative electrode substrate 30 is made of a punched metal or the like. The type of the hydrogen storage alloy 33 is not particularly limited. For example, the hydrogen storage alloy 33 may be an alloy of misch metal and nickel, which is a mixture of rare earth elements, or an alloy obtained by partially replacing the alloy with aluminum, cobalt (Co), manganese, or the like. is there. The negative electrode plate 16 is obtained by adding a thickener such as carbon black and a binder such as styrene-butadiene copolymer to the hydrogen storage alloy 33 and processing the negative electrode paste into a paste into a negative electrode substrate 30. It is manufactured by applying, drying, rolling and cutting.

  The negative electrode substrate 30 of the negative electrode plate 16 manufactured in this manner has the above-described lead portion 16 a with the connection end 31 welded to the current collector plate 22, and the front end opposite to the current collector plate 22 following the lead portion 16 a. A negative electrode central portion 32 disposed in the direction; and a pressing portion 34 further distally from the negative electrode central portion 32 and including a distal end portion 35 of the negative electrode substrate 30.

  In the negative electrode substrate 30, the thickness of the substrate in the electrode plate stacking direction of the electrode plate group 20 is D34 in the lead portion 16a and the pressing portion 34, and D32 in the negative electrode central portion 32. Since the negative electrode substrate 30 having the same thickness as the negative electrode central part 32 is pressed at the connection end and the tip side before pressing, the lead part 16a and the pressed part 34 are formed. , The lead portion 16a and the press portion 34 are thinner than the thickness D32 of the negative electrode center portion 32.

  Further, regarding the arrangement of each part in the substrate width direction which is a direction connecting the two current collector plates 21 and 22, the entire width of the negative electrode substrate 30, the width of the lead portion 16 a is L11, and the width of the negative electrode central portion 32 are different. The width is a width L13, and the width of the press section 34 is a width L12. Steps 32 a and 32 b, which are step portions in the thickness direction, are provided between the lead portion 16 a and the pressing portion 34 and the negative electrode central portion 32, respectively. In addition, the width of the lead portion 16a and the press portion 34 is smaller than the width L13 of the negative electrode central portion 32. The entire width L10 is a width such that when the connection end 31 of the negative electrode substrate 30 is connected to the negative electrode current collector 22, the front end 35 does not contact the positive electrode current collector 21.

  Further, the negative electrode substrate 30 has a predetermined amount of negative electrode paste applied to the negative electrode center portion 32 in a range of a width L14 substantially equal to the width L13. More specifically, first, the negative electrode substrate 30 has a negative electrode central portion 32 set adjacent to a portion to be the lead portion 16a and the press portion 34. Applied. Then, the negative electrode substrate 30 on which the negative electrode paste has been applied is pressed to the vicinity where the negative electrode paste has been applied, thereby forming the lead portion 16a and the pressed portion 34. Conventionally, it has been considered that the paste is good in terms of battery characteristics. Therefore, if a predetermined amount of negative electrode paste (hydrogen storage alloy 33) is used, it is applied to the entire non-pressed portion, that is, the entire negative electrode central portion 32. I was

  The positive electrode plate 15 is a three-dimensional structure made of nickel metal, and includes a nickel substrate 40 as a positive electrode substrate which is a three-dimensional porous body having so-called open cells, and a filler 43 carried on the nickel substrate 40. are doing. The nickel substrate 40 has a function of a carrier for supporting the filler 43 and a function of a current collector.

  The nickel substrate 40 is a non-sintered nickel substrate, and is preferably made of a foamed metal. In the present embodiment, nickel foam, which is one of the foamed metals, is used. Nickel foam has a large number of pores inside and can be easily compressed. The method for producing the foamed nickel is not particularly limited. For example, the foamed nickel is produced by applying nickel plating to the skeleton surface of the foamed urethane and then burning off the foamed urethane. The above-described lead portion 15a is formed by compressing the connection end side of the nickel substrate 40 and welding a metal material such as an iron material to the compressed portion. In FIGS. 3 and 4, the skeleton structure of the foamed nickel constituting the nickel substrate 40 is omitted for convenience.

The filler 43 has a positive electrode active material containing nickel hydroxide (Ni (OH) ₂ ) as a main component, a conductive agent such as a cobalt compound, and the like. The nickel substrate 40 is filled with a positive electrode paste which is a paste processed into a paste by adding a thickening agent such as carboxymethyl cellulose and a binder to the positive electrode active material and the conductive agent. The nickel substrate 40 is filled with the paste for the positive electrode by die coating in the space of the porous body. In die coating, a coating width, which is a width at which the nozzle discharges the paste, is set, and a discharge amount, which is an amount of the paste which the nozzle discharges per unit time, is set. Therefore, the filling amount of the positive electrode active material per unit area with respect to the nickel substrate 40 is determined by the coating speed, the coating width, and the discharge amount. Since the positive electrode paste is appropriately pressed into the nickel substrate 40 by die coating, the porosity of the nickel substrate 40 is set to 80 [%] to 98 [%], and the cell diameter is set to 50 [μm] to 500 [μm]. Is desirable.

Thereafter, the positive electrode plate 15 is manufactured by drying, rolling, and cutting the nickel substrate 40.
The nickel substrate 40 of the positive electrode plate 15 manufactured in this manner has the above-described lead portion 15 a with the connection end 41 welded to the current collector plate 21, and a tip which is a direction opposite to the current collector plate 21 in the lead portion 15 a. A positive electrode central portion 42 of the nickel substrate 40 arranged in the direction, and a pressing portion 44 further distally from the positive electrode central portion 42 and including the distal end portion 45 of the nickel substrate 40 are provided.

  In the nickel substrate 40, the thickness of the substrate in the electrode plate stacking direction of the electrode plate group 20 is D44 in the lead portion 15a and the press portion 44, and D42 in the center portion 42 of the positive electrode. Since the nickel substrate 40 having the same thickness as the central portion 42 of the positive electrode is press-formed at the connection end and the tip before press forming, the lead portion 15a and the press portion 44 are formed. The thickness of the lead portion 15a and the pressing portion 44 is smaller than the thickness D42 of the central portion 42 of the positive electrode.

  In addition, the nickel substrate 40 has an overall width L20, a width of the lead portion 15a a width L21, a width L21 of the positive electrode central portion 42 with respect to an arrangement of each portion in a substrate width direction which is a direction connecting the two current collecting plates 21 and 22. The width is a width L23, and the width of the press section 44 is a width L22. Note that the width of the lead portion 15a and the press portion 44 is shorter than the width L23 of the positive electrode central portion 42. Further, when the connection end 41 of the nickel substrate 40 is connected to the current collector plate 21 on the positive electrode side, the front end 45 does not contact the current collector plate 22 on the negative electrode side, and The end is of a length that allows the end opposite to the open end disposed on the lead portion 15a to be disposed between the current collector 22 on the negative electrode side. In other words, it is necessary to secure a distance between the leading end 45 and the current collector 22 on the negative electrode side so as to arrange the end of the separator 17 so as not to contact the current collector 22 on the negative electrode side. is there.

  Further, the nickel substrate 40 is filled with a predetermined amount of the paste for the positive electrode in the positive electrode central portion 42 in a range of a width L26 smaller than the width L23. More specifically, first, the nickel substrate 40 has a positive electrode central portion 42 which is set adjacent to a portion to be the lead portion 15a and the press portion 44. The positive electrode paste is filled in the filling portion 42c as a filling position sandwiched between the unfilled portion 42d as the unfilled region and the unfilled portion 42e as the unfilled region on the tip 45 side. Then, press processing is performed at a position where an unfilled portion 42d or an unfilled portion 42e is formed between the nickel substrate 40 coated with the positive electrode paste and the filled portion 42c filled with the positive electrode paste. Thus, a lead portion 15a and a press portion 44 are formed. Conventionally, it has been considered that battery characteristics are good. Therefore, in the case of a specified amount of the filler 43, the filler 43 is not unevenly distributed in a part of the positive electrode central portion 42, but is evenly dispersed and filled throughout. Was. However, the inventors have found that under predetermined conditions, even if the filler 43 is unevenly distributed in a part of the positive electrode central portion 42, the battery characteristics are not significantly affected. In the present embodiment, the positive electrode central portion 42 is sandwiched between the unfilled portion 42d on the connection end portion 41 side, the unfilled portion 42e on the distal end portion 45 side, and the two unfilled portions 42d and 42e in the substrate width direction. The filling part 42c is formed between them.

  As shown in FIG. 4, the nickel substrate 40 has a filling portion 42 c in the center portion 42 of the positive electrode, which is filled with the filler 43, and an unfilled portion 42 e on the tip side at the tip end thereof. A press portion 44 including a tip portion 45 is provided adjacent to 42e. The pressing portion 44 is a portion in which the nickel substrate 40 having the same thickness D42 as the positive electrode central portion 42 is thinly formed by pressing, so that a thickness direction is provided between the positive electrode central portion 42 and the pressing portion 44. A step 42b (in the direction of electrode plate lamination) is formed. The step 42b is formed by shearing or plastically deforming the nickel substrate 40 by press working. In particular, corner portions E1 and E2 as edges near the surface with a large amount of deformation are sheared. Therefore, the corner portions E1 and E2 close to the surface often jump up after shearing and generate burrs as substrate projections when the stress of the nickel substrate 40 against press working is high. Further, the nickel substrate 40 also has a filling portion 42c in the center portion 42 of the positive electrode and filled with the filler 43 and an unfilled portion 42d on the connection end side also on the connection end side. The lead 15a including the connection end 41 is provided adjacent to 42d. The lead portion 15a is a portion in which the nickel substrate 40, which has the same thickness D42 as the positive electrode central portion 42, is thinly formed by pressing, so that the thickness direction is provided between the positive electrode central portion 42 and the lead portion 15a. In addition to the formation of the step 42a in the (electrode plate laminating direction), burrs often occur, similarly to the corner portions E1 and E2 close to the surface.

  That is, the portion of the nickel substrate 40 where the filler 43 is filled is hard, has a high stress, and has a stress difference between the nickel substrate 40 and the filler 43, so that burrs tend to occur. In this regard, the inventors of the present application have found that when a portion of only the nickel substrate 40 that is not filled with the filler 43 is pressed, burrs are unlikely to occur even at the corner portions E1 and E2 close to the surface. Was. Therefore, conventionally, it has been general to spread and fill the filler 43 over the entirety of the positive electrode central portion 42. However, in the present embodiment, the portion adjacent to the lead portion 15a of the positive electrode central portion 42 and the press portion 44 are filled. Unfilled portions 42d and 42e are provided in adjacent portions. Thus, by forming unfilled portions 42d and 42e with low stress in portions adjacent to the lead portion 15a and the pressed portion 44 to be pressed, burrs are suppressed at corner portions E1 and E2 close to the surface. .

  Further, as described above, conventionally, it has been general that the filler 43 is spread and filled over the entirety of the positive electrode central portion 42. Therefore, when a portion adjacent to the filling portion 42c is formed in the pressing portion 44 by pressing, the impact of the pressing and the deformation and pressing of the nickel substrate 40 reduce the shape of the filler 43 filled in the nickel substrate 40. The filler 43 has fallen from the nickel substrate 40 due to collapse or weakening of the bonding with the nickel metal. Dropping of the filler 43 has been a factor of causing a decrease in electric capacity and causing a short circuit due to the dropped filler 43. However, in the present embodiment, the lead portion 15a and the press portion 44 of the central portion 42 of the positive electrode are adjacent to the unfilled portions 42d and 42e. As a result, the deformation and pressing of the nickel substrate 40 during the press working are absorbed by the unfilled portions 42d and 42e, and the influence of the deformation and pressing on the filling portion 42c is reduced, and the nickel substrate 40 is filled. The agent 43 is prevented from falling off. As a result, a decrease in the battery capacity and a short circuit due to the falling off of the filler 43 are suppressed, and the battery capacity is maintained.

  In the present embodiment, for example, the widths L24 and L25 of the unfilled portions 42d and 42e in the width direction are set to “0.5 mm”. Since the tolerance of the position to be pressed is about “0.2 mm” to “0.3 mm” due to the precision of the substrate arrangement, the precision of the pressing, etc., the width of the unfilled portions 42 d and 42 e is set to “0.5 mm”. It is set to secure only. As a result, even if the pressing position is shifted by the maximum tolerance, the unfilled portions 42d and 42e are secured between the press portion and the filled portion 42c, and burrs are generated at the corner portions E1 and E2 close to the surface. As a result, the falling off of the filler 43 from the nickel substrate 40 is reliably suppressed. Since the tolerance is "0.2 mm" to "0.3 mm", it is sufficient that the width of the unfilled portions 42d and 42e is "0.4 mm" or more.

  Further, the inventors have found that when the unfilled portions 42d and 42e are stacked on the positive electrode plate 15 and the negative electrode plate 16, the positions opposed to each other in the stacking direction may be slightly shifted in the width direction. In the case of a nickel-metal hydride secondary battery, it has been found that even if a slight shift occurs, the battery performance is not affected.

The configuration of the electrode plate group 20 will be described with reference to FIG.
In addition, the opposing surfaces of the positive electrode plate 15 and the negative electrode plate 16 are usually provided so that the areas of the same width are opposed to each other because hydrogen ions are exchanged by charging and discharging. For example, in the substrate width direction, the width L14 of the negative electrode central portion 32 where the negative electrode paste is applied on the negative electrode substrate 30 and the width of the filling portion 42c of the positive electrode central portion 42 where the positive electrode paste is filled on the nickel substrate 40. L26 has substantially the same width. For the sake of design, there is a difference of about 1 mm between the width L14 of the negative electrode central portion 32 where the paste for the negative electrode is applied and the width L26 of the filled portion 42c of the positive electrode central portion 42. There may be. In the present embodiment, it is assumed that the filling position of the negative electrode central portion 32 has a width corresponding to the filling portion 42c of the positive electrode central portion 42 including this difference. Although not shown, the length of the negative electrode central portion 32 in the current collector plate extending direction where the negative electrode paste is applied and the length of the filling portion 42c of the positive electrode central portion 42 in the current collector plate extending direction are substantially equal to each other. They are the same length. Note that there may be a difference of about 1 mm in the length of the current collector plate extending direction.

  The width L23 of the positive electrode central portion 42 is a length obtained by adding the width L26 of the unfilled portion 42d and the width L25 of the unfilled portion 42e to the width L26 of the filled portion 42c. Therefore, the width L21 of the lead portion 15a of the positive electrode plate 15 is smaller than the width L11 of the negative electrode plate 16.

  In the present embodiment, the overlap of the filling portion 42c of the positive electrode central portion 42 and the hydrogen storage alloy 33 of the negative electrode central portion 32 in the laminating direction is slightly shifted in the width direction. For example, with respect to the range where the hydrogen storage alloy 33 is coated on the negative electrode central portion 32, the filling portion 42 c of the positive electrode central portion 42 is shifted by the length L <b> 30 in the direction of the current collector plate 21 for the positive electrode. At the same time, the connection end 41 side is shifted by the length L31 in the direction of the current collector plate 21 for the positive electrode. Specifically, the length L30 can be changed in a range from “0 mm” to “2.0 mm”. In other words, the filling portion 42c of the positive electrode central portion 42 does not partially overlap the range of the negative electrode central portion 32 where the hydrogen storage alloy 33 is applied, and the length of the non-overlapping portion is perpendicular to the lamination direction of the substrate. Is less than or equal to “2.0 mm” in the width direction.

  As described above, conventionally, for example, it has been considered that the lengths L30 and L31 are desirably “0”. In fact, a lithium ion battery has a straightness in the movement of lithium ions and goes to the electrode plate at the shortest distance.Therefore, if there is a lateral displacement at the position facing the electrode plate, the other side opposite to one surface will Lithium ions are concentrated and deposited, and there is a possibility that a minute short circuit may occur. In this regard, the nickel-hydrogen secondary battery has low linearity in the movement of hydrogen ions, so that even if the opposing substrate has a slight lateral displacement in the width direction, there is no risk of metal precipitation or the like, and The inventors have found that the battery characteristics do not significantly deteriorate. Therefore, as the displacement in the width direction between the filling portion 42c and the hydrogen storage alloy 33, the displacement of the lengths L30 and L31 may be provided. In the present embodiment, the two lengths L30 and L31 are the same length. That is, the negative electrode plate 16 is filled with the negative electrode active material in a size corresponding to the size of the filling portion 42 c of the positive electrode plate 15, and the electrode plate group 20 includes the filling portion 42 c of the positive electrode plate 15 and the negative electrode plate 16. The width L14 to which the negative electrode paste is applied is laminated so that a part thereof does not overlap in the laminating direction.

  As described above, according to the electrode plate of the alkaline secondary battery using the nickel substrate of the present embodiment as the positive electrode and the alkaline secondary battery, the following effects can be obtained.

  (1) When the nickel substrate 40 is pressed, if the active material is filled in the pressed portion, the corners E1 and E2 of the nickel substrate 40 are pressed by the stress of the nickel substrate 40 and the filler 43 containing the active material against the press. Burrs may be generated, and the generated burrs may short-circuit the opposed positive electrode plate 15 and negative electrode plate 16. In this regard, in this embodiment, unfilled portions 42d and 42e not filled with the active material are formed between the lead portion 15a, the press portion 44, and the filled portion 42c. Since the unfilled portions 42d and 42e have small stress, the occurrence of burrs is reduced.

  In addition, vibrations caused by pressing and deformation of the nickel substrate 40 may cause the filler 43 containing the active material filled in the nickel substrate 40 to fall off. In this regard, according to such a configuration, since the regions adjacent to the pressed portion are the unfilled portions 42d and 42e, the filler 43 containing the active material is prevented from falling off by pressing. In addition, a decrease in the capacity of the positive electrode plate and a short circuit due to the falling off of the active material are prevented.

  (2) The nickel-metal hydride secondary battery does not cause metal deposition on the surface of the electrode plate during charging / discharging even if the electrode plate is displaced laterally. Therefore, the nickel-hydrogen secondary battery may be stacked even if it has unfilled portions 42d and 42e. Easy.

  (3) Since the predetermined separation distance as the width of the unfilled portions 42d and 42e is set to 0.5 mm or more, even if the filling position and the spread slightly change when the active material is filled, it is ensured. , Unfilled portions 42d and 42e are secured.

  (4) Alkaline secondary batteries, especially nickel-metal hydride secondary batteries, are not covered with the separator 17 because metal deposition does not occur on the surface of the electrode plate during charge / discharge even if the electrode plate is displaced. The filling portions 42d and 42e are formed, and it becomes easy to stack the positive electrode plates 15 in which the position of the filling portion 42c is difficult to confirm.

(Other embodiments)
Note that the above embodiment can be implemented in the following forms.
[Unfilled part]
-In above-mentioned embodiment, the case where width L24, L25 of the unfilled part 42d, 42e in the width direction was set to "0.5 mm" was illustrated. However, the present invention is not limited to this. Even if the pressing position is shifted by the maximum tolerance, the length is set to be shorter than “0.5 mm” as long as an unfilled portion can be secured between the pressed portion and the filled portion. Alternatively, it may be set longer than “0.5 mm”. In addition, when the pressing position is shifted by the maximum tolerance, even if the length is such that an unfilled portion is not secured between the pressed portion and the filled portion, even if the length is smaller than the maximum tolerance, the filled portion If an unfilled portion can be ensured between the first and second steps, the occurrence of burrs and the falling off of the filler can be reduced.

  -In above-mentioned embodiment, the case where the filler 43 was not filled in the unfilled parts 42d and 42e was illustrated. However, the present invention is not limited to this, and the filler may be slightly filled in the unfilled portion as long as the stress can be reduced or the falling-off can be reduced as compared with the case where the filler is filled. That is, the filler may slightly protrude from the filling portion due to a manufacturing process such as die coating or spray filling.

[Opposite relation of electrode plates]
In the above embodiment, the case where the width L14 of the negative electrode paste applied to the central portion 32 of the negative electrode is substantially the same as the width L26 of the filling portion 42c of the nickel substrate 40 has been described. However, the present invention is not limited to this, and the length applied to the central portion of the negative electrode may be different from the length of the filled portion of the nickel substrate. As described above, in the nickel-metal hydride secondary battery, even if there is some lateral displacement of the electrode plate with respect to the lamination direction of the electrode plate, there is little possibility that metal deposition occurs or battery performance is reduced. Therefore, if the magnitude of the lateral displacement is within a predetermined range, the width of the filled portion of the nickel substrate may be longer than the width of the negative electrode paste applied at the center of the negative electrode, or conversely, shorter. Is also good.

  At this time, assuming that the width L14 of the negative electrode paste applied to the negative electrode center portion 32 and the width L26 of the filling portion 42c of the nickel substrate 40 are substantially the same, the nickel substrate 40 The filler 43 was filled. Therefore, if the width L26 of the filling portion 42c of the nickel substrate 40 is smaller than the width of the negative electrode center portion 32 of the negative electrode paste applied, the filling amount may be reduced. Therefore, the width L26 of the narrowed filling portion 42c of the nickel substrate 40 may be filled with the same amount of the filler 43 as before the narrowing, to increase the packing density. Thereby, a decrease in the electric capacity of the positive electrode plate 15 can be suppressed. As described above, in the nickel-metal hydride secondary battery, since the linearity of the movement of the hydrogen ions is not high, even if the surface area is reduced, there is no possibility that the metal is deposited and the battery performance is not deteriorated. In addition, the reactivity may be improved by increasing the packing density. Therefore, even if the size of the substrate is restricted in the positive electrode plate 15, there is a high possibility that an unfilled portion can be provided. On the other hand, when the linearity of movement of lithium ions is high as in a lithium ion battery, when the substrate is displaced laterally, metal deposition occurs on the other side opposite to one surface, or the battery performance deteriorates. It may decrease. That is, since the battery is a nickel-metal hydride secondary battery, it is possible to provide an unfilled portion in the existing positive electrode plate by slightly narrowing the range of the filled portion.

  In the above embodiment, the case where the unfilled portions 42d and 42e are provided on the lead portion 15a side and the tip portion 45 side of the nickel substrate 40, respectively, is illustrated. However, the present invention is not limited thereto, and the unfilled portion may be only one of the lead portion side and the tip portion side. Even if only one of them is used, the generation of burrs and the falling off of the filler can be suppressed.

  In the above-described embodiment, the case where the unfilled portions 42d and 42e are provided in the nickel substrate 40 is illustrated. However, the present invention is not limited to this. In addition to the unfilled portion of the nickel substrate, or when there is no unfilled portion in the nickel substrate, an uncoated portion of the hydrogen storage alloy is provided in the center of the substrate constituting the negative electrode plate. Is also good. Thereby, at the time of pressing the substrate of the negative electrode plate, at least one of suppression of generation of burrs such as a hydrogen storage alloy and suppression of separation of the hydrogen storage alloy and the like can be achieved.

[Alkaline secondary battery]
In the above embodiment, the nickel-metal hydride secondary battery 11 is composed of six battery cells 12, but may be composed of a plurality of battery cells 12 other than six. Further, the nickel-metal hydride secondary battery 11 may be composed of one battery cell 12.

In the above embodiment, nickel foam is exemplified as the three-dimensional porous body, but the foam metal may be one produced by a method other than the method using urethane foam.
In the above embodiment, the alkaline secondary battery is configured to include the electrode group 20 in which the plate-shaped positive electrode plate 15 and the negative electrode plate 16 are stacked with the separator 17 interposed therebetween. You may. For example, a cylindrical alkaline secondary battery in which the positive electrode plate 15 and the negative electrode plate 16 are spirally wound and housed in a case together with the electrolytic solution may be used.

  In the above-described embodiment, the case where the alkaline secondary battery is the nickel-metal hydride secondary battery 11 is illustrated. However, the present invention is not limited to this, and the alkaline secondary battery may be a nickel cadmium battery, a nickel zinc secondary battery, or the like. Good. Even in this case, when the pressed portion is provided at the end of the substrate, the non-filled portion of the active material is provided between the pressed portion and the filled portion of the active material to reduce the generation of burrs as described above. It is possible to obtain the effect of reducing material dropout and suppressing reduction in electric capacity.

[Application of secondary battery]
In the above embodiment, the case where the nickel-metal hydride secondary battery 11 is applied to the vehicle has been illustrated, but the vehicle may be an electric vehicle, a hybrid vehicle, a gasoline vehicle, a diesel vehicle, or the like. Further, the nickel-metal hydride secondary battery may be used as a power source for fixed installation of a moving object such as a railway, a ship, an aircraft or a robot, or an electric product such as an information processing device.

  DESCRIPTION OF SYMBOLS 11 ... Nickel hydrogen secondary battery, 12 ... Battery cell, 13 ... Integrated battery case, 13a, 13b ... Terminal, 14 ... Lid, 15 ... Positive electrode plate, 15a ... Lead part, 16 ... Negative electrode plate, 16a ... Lead part, Reference Signs List 17: separator, 20: electrode plate group, 21, 22, current collector plate, 30: negative electrode substrate, 31: connection end portion, 32: negative electrode center portion, 32a, 32b: step, 33: hydrogen storage alloy, 34: press Part, 35 ... tip part, 40 ... nickel substrate, 41 ... connection end part, 42 ... positive electrode center part, 42 ... filling part, 42a, 42b ... step, 42c ... filling part, 42d, 42e ... unfilled part, 43 ... Filler, 44 ... Press part, 45 ... Tip, E1 ... Corner, E2 ... Corner.

Claims (5)

An electrode plate of an alkaline secondary battery,
With a rectangular substrate having open cells filled with active material,
The substrate has a lead portion extended as a portion compressed in the thickness direction and connected to the current collector plate, and a portion compressed in the thickness direction at a tip end opposite to the lead portion. The active material is provided with a predetermined separation distance between at least one of the active material and the lead portion, and the press portion. An electrode plate for an alkaline secondary battery, wherein the electrode plate is filled in a position. The electrode plate is a positive electrode plate,
The substrate is a nickel metal porous body,
The electrode plate of the alkaline secondary battery according to claim 1, wherein the active material is a positive electrode active material. The electrode plate of the alkaline secondary battery according to claim 1, wherein the predetermined distance is set to 0.4 mm or more. A plurality of positive plates connected to the positive current collector and having a positive electrode active material filled in a substrate, between the opposed positive current collector and the negative current collector; An alkaline secondary battery including an electrode group in which a plurality of anode plates connected to a current collector and a plurality of anode plates each including an anode active material held on a substrate and a separator interposed therebetween are provided. ,
The positive electrode plate is extended in the thickness direction as a portion that is compressed and connected to the positive electrode current collector plate, and is compressed in the thickness direction at a tip end opposite to the lead portion. And the positive electrode active material is set to have a predetermined separation distance between at least one of the positive electrode active material and the lead portion, and the press portion. Filling position
The negative electrode plate is filled with the negative electrode active material in a size corresponding to the size of the filling position of the positive electrode plate,
The electrode group, wherein a filling position of the positive electrode plate and a filling position of the negative electrode plate are stacked so that a part thereof does not overlap with the stacking direction. . 5. The alkaline secondary battery according to claim 4, wherein the length in which the portions do not overlap is 2 mm or less in a direction orthogonal to the direction in which the layers are stacked.