Alkaline storage battery
By designing conductive and elastic connecting components in alkaline batteries and extending the positive and negative plates, the problem of separators being punctured by burrs was solved, achieving high capacity and short-circuit suppression, while also enabling high-capacity batteries.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- FDK CORP
- Filing Date
- 2021-03-09
- Publication Date
- 2026-07-21
AI Technical Summary
In existing technologies, increasing the mass of active material on the positive and negative plates can easily cause the separator to be punctured by burrs, leading to internal short circuits in the battery and making it difficult to achieve high capacity.
The feature of using strip-shaped positive and negative electrode plates is that the sealing component is arranged between the sealing body and the positive electrode protrusion, which has conductivity and elasticity, forming a vortex electrode group, and extending the positive and negative electrode plates in the height direction to avoid the separator being punctured by burrs.
This achieves the goal of suppressing internal short circuits while increasing battery capacity, increasing discharge capacity, and reducing the occurrence of short circuits.
Smart Images
Figure CN115336077B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to alkaline batteries, and more particularly to cylindrical alkaline batteries. Background Technology
[0002] An alkaline battery comprises an electrode assembly consisting of a positive electrode, a negative electrode, and a separator stacked together. The separator is positioned between the positive and negative electrodes. In this alkaline battery, for example, the electrode assembly is wound into a vortex shape and housed together with an alkaline electrolyte in a conductive cylindrical casing. In this alkaline battery, a predetermined electrochemical reaction occurs between the positive and negative electrodes, which are separated by the separator, thereby enabling charging and discharging.
[0003] As a battery with a vortex-shaped electrode assembly, for example, Patent Document 1 describes a nickel-metal hydride rechargeable battery. In this battery, an electrode body formed by overlapping a positive electrode plate and a negative electrode plate with a separator is housed inside the battery container. Specifically, in the nickel-metal hydride rechargeable battery described in Patent Document 1, the electrode body includes a positive electrode protrusion protruding from a portion of the positive electrode plate toward the sealing body. This positive electrode protrusion is directly connected to the sealing body, and the positive electrode protrusion of the positive electrode plate is not filled with active material.
[0004] Existing technical documents
[0005] Patent documents
[0006] Patent Document 1: Japanese Patent Application Publication No. 2015-125869 Summary of the Invention
[0007] The technical problem that the invention aims to solve
[0008] To achieve high battery capacity, for example, it is possible to form thin separators and increase the amount of active material coated on the positive and negative plates. However, in the nickel-metal hydride rechargeable battery described in Patent Document 1, when forming thin separators and increasing the amount of positive and negative active material, burrs generated on the positive and negative plates may puncture the separators, causing a short circuit inside the battery.
[0009] The present invention was made in view of the above-mentioned problems, and its object is to provide an alkaline battery that can achieve high capacity while suppressing internal short circuits.
[0010] Technical solutions adopted to solve technical problems
[0011] To achieve the above objectives, the alkaline battery of the present invention is characterized by comprising: a vortex electrode assembly, wherein the vortex electrode assembly is formed by overlapping of a strip-shaped positive electrode plate, a strip-shaped negative electrode plate, and a strip-shaped separator disposed between the positive electrode plate and the negative electrode plate; a housing, the housing having an opening at its upper end, and being a bottomed cylindrical housing for housing the vortex electrode assembly and the alkaline electrolyte; a sealing body for sealing the opening of the housing; and a positive terminal, the positive terminal being connected to the sealing body. The positive electrode plate is electrically connected to the sealing body. The positive electrode plate includes a strip-shaped positive electrode plate body and a positive electrode protrusion that protrudes from a portion of the positive electrode plate body towards the sealing body and is electrically connected to the sealing body. The negative electrode plate includes a strip-shaped negative electrode plate body and a negative electrode protrusion that protrudes from a portion of the negative electrode plate body towards the sealing body and forms a terminal between the sealing body and the negative electrode plate body. The positive electrode plate and the negative electrode plate have positive electrode active material and negative electrode active material respectively in the portions opposite each other separated by the separator.
[0012] In one aspect of the alkaline battery of the present invention, a connecting member is further included, which is disposed between the sealing body and the positive electrode protrusion and has conductivity and elasticity.
[0013] Invention Effects
[0014] According to the alkaline battery of the present invention, the positive electrode plate includes a strip-shaped positive electrode plate body portion and a positive electrode protrusion portion protruding from a portion of the positive electrode plate body portion toward the sealing body and electrically connected to the sealing body. The negative electrode plate includes a strip-shaped negative electrode plate body portion and a negative electrode protrusion portion protruding from a portion of the negative electrode plate body portion toward the sealing body and forming a terminal between the sealing body and the negative electrode plate body portion. Furthermore, the positive electrode plate and the negative electrode plate respectively have positive electrode active material and negative electrode active material in portions facing each other across the separator. Thus, in the alkaline battery of the present invention, the positive electrode plate and the negative electrode plate respectively have positive electrode protrusion and negative electrode protrusion separated from the positive electrode plate body portion and the negative electrode plate body portion, and respectively have positive electrode active material and negative electrode active material in portions facing each other across the separator. In other words, a portion of the positive and negative electrode plates is formed to be longer in the height direction (axial direction of the casing) relative to other portions, thereby achieving high capacity in the battery without forming a thick spiral electrode assembly in the thickness direction (radial direction of the casing). Furthermore, since it is not necessary to form thin separators to achieve high capacity, burrs generated on the positive and negative electrode plates can be prevented from puncturing the separators, thus suppressing internal short circuits in the battery. Therefore, an alkaline battery can be provided that achieves high capacity while suppressing internal short circuits. Attached Figure Description
[0015] Figure 1 It is a cross-sectional view showing a longitudinal section of an alkaline storage battery according to one embodiment.
[0016] Figure 2 It means Figure 1 A top view of the positive electrode substrate of an alkaline storage battery.
[0017] Figure 3 It means Figure 1 The image shows a top view of the positive plate of an alkaline storage battery.
[0018] Figure 4 It means Figure 1 The image shows a top view of the negative electrode core of an alkaline battery.
[0019] Figure 5 It means Figure 1 A top view of the negative electrode plate of an alkaline battery. Detailed Implementation
[0020] The following describes an embodiment of a nickel-metal hydride rechargeable battery 1 (hereinafter referred to as "battery 1") as an example of an alkaline storage battery obtained by embodying the present invention. Furthermore, this embodiment describes the application of the present invention to a cylindrical battery 1 of AA size, but the size of battery 1 is not limited to this; for example, it could be other sizes such as AAA size. Moreover, as an alkaline storage battery, any alkaline solution can be used as the electrolyte; for example, a nickel-cadmium battery could also be used.
[0021] Figure 1 This is a cross-sectional view showing a longitudinal section of a nickel-metal hydride rechargeable battery 1 (alkaline battery) according to one embodiment. Figure 2 It means Figure 1 A top view of the positive electrode substrate 21 of the nickel-metal hydride rechargeable battery 1 shown. Figure 3 It means Figure 1 A top view of the positive plate 20 of the nickel-metal hydride rechargeable battery 1 shown. Figure 4 It means Figure 1 A top view of the negative electrode core 31 of the nickel-metal hydride rechargeable battery 1 shown. Figure 5 It means Figure 1 The diagram shows a top view of the negative electrode plate 30 of the nickel-metal hydride rechargeable battery 1. For clarity, on the axis x of the cylindrical outer casing 10, arrow a is designated as the upper side, and arrow b as the lower side. Here, "upper side" refers to the side of the battery 1 where the positive terminal 70 is located, and "lower side" refers to the side of the battery 1 where the bottom wall 15 is located, and also indicates the opposite side to the upper side. Furthermore, in the direction perpendicular to the axis x (hereinafter referred to as "radial"), the direction away from the axis x is designated as the outer periphery (arrow c direction), and the direction towards the axis x is designated as the inner periphery (arrow d direction).
[0022] like Figure 1 As shown, battery 1 includes a bottomed cylindrical casing 10 with an opening on the upper side (arrow a direction). The casing 10 is conductive, and its bottom wall 15 on the lower side (arrow b direction) functions as a negative terminal. A sealing body 60 for sealing the casing 10 is fixed to the opening. This sealing body 60 is a conductive, circular plate-shaped component. The sealing body 60 and an annular insulating seal 12 surrounding the sealing body 60 are disposed within the opening of the casing 10. The insulating seal 12 is fixed to the opening edge 13 of the casing 10 by riveting. That is, the sealing body 60 and the insulating seal 12 cooperate to provide an airtight seal to the opening of the casing 10.
[0023] Here, the sealing body 60 has a central through hole 61, and a rubber valve core 80 is disposed on the upper surface, i.e., the outer surface, of the sealing body 60 to block the central through hole 61. Furthermore, a flanged metal positive terminal 70 is electrically connected to the outer surface of the sealing body 60, covering the valve core 80. This positive terminal 70 presses the valve core 80 toward the sealing body 60. Additionally, a vent hole 71 is provided on the positive terminal 70.
[0024] Normally, the central through-hole 61 is hermetically closed by the valve core 80. On the other hand, if gas is generated inside the housing 10, causing the gas pressure to rise, the valve core 80 is compressed by the gas pressure, and the central through-hole 61 opens. As a result, the gas is discharged from inside the housing 10 to the outside through the central through-hole 61 and the vent 71 of the positive terminal 70. That is, the central through-hole 61 of the sealing body 60, the valve core 80, and the vent 71 of the positive terminal 70 form a safety valve for the battery 1.
[0025] The outer casing 10 houses a vortex electrode assembly 50. This vortex electrode assembly 50 is formed by overlapping strip-shaped positive electrode plates 20 and 30, and a separator 40. The vortex electrode assembly 50 is formed in a vortex shape with the separator 40 sandwiched between the positive electrode plate 20 and the negative electrode plate 30. That is, the positive electrode plate 20 and the negative electrode plate 30 overlap each other with the separator 40 in between. Furthermore, a circular lower insulating member 17 is disposed between the vortex electrode assembly 50 and the bottom wall 15 of the outer casing 10.
[0026] Furthermore, a predetermined amount of alkaline electrolyte (not shown) is injected into the casing 10. This alkaline electrolyte immerses the vortex electrode assembly 50 within it, and an electrochemical reaction (charge-discharge reaction) occurs between the positive electrode plate 20 and the negative electrode plate 30 during charging and discharging. Preferably, the alkaline electrolyte is an aqueous solution containing at least one of KOH, NaOH, and LiOH as a solute.
[0027] The material used for the separator 40 can be, for example, a material obtained by imparting hydrophilic functional groups to a nonwoven fabric made of polyamide fibers, or a material obtained by imparting hydrophilic functional groups to a nonwoven fabric made of polyolefin fibers such as polyethylene or polypropylene.
[0028] like Figures 1-3 As shown, the positive electrode plate 20 includes a strip-shaped positive electrode plate body portion 22 and a positive electrode protrusion 23 that protrudes from a portion of the positive electrode plate body portion 22 toward an upper side (in the direction of arrow a) serving as a sealing body 60 and is electrically connected to the sealing body 60. Specifically, as Figure 2 As shown, the positive electrode plate body 22 is a strip-shaped member with a predetermined vertical height H2. The positive electrode protrusion 23 is the portion that protrudes upward from the positive electrode plate body 22 within a predetermined length L1 from the winding start edge 24. Here, the predetermined length L1 refers to the length range of the positive electrode plate 20 that abuts against the sealing body 60 in the state of the spiral electrode assembly 50, and more specifically, it refers to the length range of the positive electrode plate 20 located on the inner circumferential side (arrow d direction) of the insulating seal 12 in the state of the spiral electrode assembly 50. The portion of the positive electrode plate 20 with the positive electrode protrusion 23 has a height H1 that is greater than the vertical height H2 of the positive electrode plate body 22. Figure 1 As shown, in the nickel-metal hydride rechargeable battery 1, the positive electrode protrusion 23 abuts against the sealing body 60. That is, the positive electrode plate 20 is directly connected to the sealing body 60, thereby the positive terminal 70 and the positive electrode plate 20 are electrically connected to each other via the sealing body 60.
[0029] like Figure 2 and Figure 3 As shown, the positive electrode plate 20 includes a conductive positive electrode substrate 21 with a porous structure and a positive electrode agent 25 held within the pores of the positive electrode substrate 21. The positive electrode plate 20 has the positive electrode agent 25, which serves as a positive electrode active material, on the portion of the positive electrode plate 20 opposite to the negative electrode plate 30 (described later) separated by a separator 40. Specifically, the positive electrode agent 25 is held on the entire surface (both sides) of the positive electrode substrate 21 of the positive electrode plate 20. For example, nickel foam can be used as the positive electrode substrate 21. The positive electrode agent 25 contains positive electrode active material particles and a binder. Furthermore, positive electrode additives can be added to the positive electrode agent 25 as needed.
[0030] Alternatively, a conductive and elastic connecting member (not shown) can be disposed between the sealing body 60 and the positive electrode protrusion 23. This connecting member can be connected to... Figure 1The positive electrode protrusion 23 shown is shaped like a vortex to correspond to the terrain, or it can be formed into a circular plate with a diameter that is the same as or approximately the same as the outermost diameter of the positive electrode protrusion 23. Furthermore, the shape of the connecting member is not particularly limited, as long as it electrically connects at least a portion of the positive electrode protrusion 23 to the sealing body 60. For example, the connecting member could be a member in which a conductive component such as a metal foil or nickel sponge is mounted on the circumferential surface of an elastic component such as rubber. The connecting member is not limited to the examples described above, as long as it possesses conductivity and elasticity.
[0031] The aforementioned binder can achieve the following effects: it can bond the positive electrode active material particles together and it can also bond the positive electrode active material particles to the positive electrode substrate 21. Here, as a binder, for example, hydroxymethyl cellulose, methyl cellulose, PTFE (polytetrafluoroethylene) dispersion, HPC (hydroxypropyl cellulose) dispersion, etc., can be used. Furthermore, as a positive electrode additive, for example, yttrium oxide, chromium hydroxide, etc., can be used.
[0032] Nickel hydroxide ions, commonly used in nickel-metal hydride rechargeable batteries, are used as the positive electrode active material particles. Higher-order nickel hydroxide particles are preferably used. These positive electrode active material particles are manufactured using methods commonly used in nickel-metal hydride rechargeable batteries.
[0033] Next, the positive electrode plate 20 can be manufactured, for example, in the following manner. First, a positive electrode substrate 21 shaped into a predetermined shape is prepared in advance. Figure 2 On the other hand, a positive electrode slurry containing positive electrode active material particles, water, and a binder is prepared. The prepared positive electrode slurry is filled into a nickel foam sheet serving as the positive electrode substrate 21 and dried. After drying, the nickel foam sheet filled with nickel hydroxide particles, etc., is rolled and cut to manufacture the positive electrode plate 20. Figure 3 ).
[0034] Next, the negative electrode plate 30 will be described. The negative electrode plate 30 includes a strip-shaped negative electrode plate main body 32 and a negative electrode protrusion 33 that protrudes from a portion of the negative electrode plate main body 32 toward the sealing body 60 (i.e., the upper side) and forms a terminal between the sealing body 60 and the negative electrode plate main body 32. Specifically, as Figure 4 As shown, the negative electrode plate body 32 is a strip-shaped member with a predetermined vertical height H3. The negative electrode protrusion 33 is a portion that protrudes upward from the negative electrode plate body 32 within a predetermined length L3 from the starting edge 34 of the winding of the negative electrode plate body 32. Here, the predetermined length L3 refers to the length range of the negative electrode plate 30 opposite to the positive electrode protrusion 23 of the positive electrode plate 20 in the state of the spiral electrode assembly 50. The portion of the negative electrode plate 30 with the negative electrode protrusion 33 has a height H4 that is greater than the vertical height H3 of the negative electrode plate body 32. Figure 1As shown, in the nickel-metal hydride rechargeable battery 1, the negative electrode protrusion 33 abuts against the sealing body 60. That is, the negative electrode plate 30 is not connected to the sealing body 60.
[0035] like Figure 4 and Figure 5 As shown, the negative electrode plate 30 includes a metallic negative electrode core 31 and a negative electrode mixture 35 containing negative electrode active material held in the negative electrode core 31. The negative electrode core 31 is conductive. Specifically, the negative electrode plate 30 has negative electrode active material in the portion opposite to the positive electrode plate 20 separated by a separator 40. Specifically, the negative electrode mixture 35 is held on the entire surface (both sides) of the negative electrode core 31 of the negative electrode plate 30. The negative electrode plate 30 is electrically connected to the housing 10, which constitutes the negative terminal of the nickel-metal hydride rechargeable battery 1, when in contact with the inner peripheral surface of the housing 10.
[0036] The negative electrode core 31 is a strip-shaped metal material with distributed through holes (not shown), for example, a perforated metal sheet can be used. The negative electrode mixture 35 is formed from a negative electrode mixture containing a negative electrode active material. The negative electrode mixture 35 not only fills the through holes of the negative electrode core 31, but is also layered on the surface and back of the negative electrode core 31 to form a layered negative electrode mixture 35. The negative electrode mixture 35 contains hydrogen storage alloy particles capable of storing and releasing hydrogen as the negative electrode active material, a conductive agent, a binder, and a negative electrode auxiliary agent.
[0037] The aforementioned binder serves the following functions: it bonds the hydrogen storage alloy particles and conductive agent to each other, and simultaneously bonds the hydrogen storage alloy particles and conductive agent to the negative electrode core 31. Here, there are no particular limitations on the binder; binders commonly used in nickel-metal hydride rechargeable batteries, such as hydrophilic or hydrophobic polymers, carboxymethyl cellulose, etc., can be used. Furthermore, as a negative electrode auxiliary agent, styrene-butadiene rubber, sodium polyacrylate, etc., can be used. The hydrogen storage alloy in the hydrogen storage alloy particles is not particularly limited, but a hydrogen storage alloy commonly used in nickel-metal hydride rechargeable batteries is preferred. As a conductive agent, a conductive agent commonly used in the negative electrode of nickel-metal hydride rechargeable batteries is used. For example, carbon black, etc., can be used.
[0038] The negative electrode plate 30 can be manufactured, for example, as follows. First, a negative electrode core 31 shaped into a predetermined form is prepared in advance. Figure 4 On the other hand, an aggregate of hydrogen storage alloy particles, namely hydrogen storage alloy powder, a conductive agent, a binder, and water, is prepared and mixed to prepare a paste for the negative electrode mixture. The resulting paste is applied to the negative electrode core 31 and dried. After drying, the density of the negative electrode mixture 35 is adjusted to a specified value through a rolling process that rolls the entire negative electrode plate 30. The negative electrode plate 30 is manufactured in this manner.
[0039] The positive electrode plate 20 and negative electrode plate 30, manufactured as described above, are wound into a vortex shape with the separator 40 in between, thereby forming a vortex electrode assembly 50. The resulting vortex electrode assembly 50 is housed within the casing 10. Next, a predetermined amount of alkaline electrolyte is injected into the casing 10. Then, the casing 10 containing the vortex electrode assembly 50 and the alkaline electrolyte is sealed using a sealing body 60 having a positive terminal 70, thereby obtaining a battery 1 according to one embodiment. The battery 1 undergoes an initial activation treatment to bring it to a usable state.
[0040] Next, the function and effects of the battery 1 according to one embodiment of the present invention will be explained. As described above, according to the nickel-metal hydride rechargeable battery 1 according to one embodiment, the positive electrode plate 20 includes a strip-shaped positive electrode plate main body 22 and a positive electrode protrusion 23 that protrudes from a portion of the positive electrode plate main body 22 toward the sealing body 60 and is electrically connected to the sealing body 60. In addition, the negative electrode plate 30 includes a strip-shaped negative electrode plate main body 32 and a negative electrode protrusion 33 that protrudes from a portion of the negative electrode plate main body 32 toward the sealing body 60 and forms a terminal between the sealing body 60 and the negative electrode plate main body 32. Moreover, the positive electrode plate 20 and the negative electrode plate 30 have positive electrode active material and negative electrode active material respectively in the portions facing each other across the separator 40. Thus, in one embodiment of the battery 1, the positive electrode plate 20 and the negative electrode plate 30 each have a positive electrode protrusion 23 and a negative electrode protrusion 33 that are separate from the positive electrode plate main body 22 and the negative electrode plate main body 32, respectively, and positive electrode active material and negative electrode active material are respectively provided in the portions opposite each other with the separator 40 in between. That is, by forming a portion of the positive electrode plate 20 and the negative electrode plate 30 in the height direction (the x-direction of the axis of the casing 10) for a longer period, it is possible to achieve a high capacity of the battery 1 without forming a thick vortex electrode assembly 50 in the thickness direction (the radial direction of the casing 10). Moreover, it is not necessary to form a thinner separator 40 to achieve a high capacity of the battery 1, so it is possible to suppress burrs generated by the positive electrode plate 20 and the negative electrode plate 30 from puncturing the separator 40, and to suppress short circuits inside the battery 1. In this way, a battery 1 can be provided that can achieve a high capacity while suppressing internal short circuits.
[0041] Furthermore, one embodiment of the battery 1 also includes a conductive and elastic connecting member disposed between the sealing body 60 and the positive electrode protrusion 23. Thus, in one embodiment of the battery 1, for example, even when the positive electrode protrusion 23 is not in direct contact with the sealing body 60, an electrical connection can be reliably formed between the sealing body 60 and the positive electrode plate 20.
[0042] [Example]
[0043] Table 1 below shows the results obtained by comparing the number of short circuits and discharge capacity of the batteries involved in this embodiment and Comparative Examples 1 and 2, with 100 cells manufactured respectively. In this test condition, the charging time was set to "0.1C × 16H", the rest time was set to "1H", and the discharge time was set to "0.2C". Here, "C" refers to the charging and discharging rate, and "1C" refers to the current value of a complete charge or discharge in 1H. That is, in this test condition, the battery is charged for 16H at a charging rate of 10 hours for a complete charge, then stopped for 1H, and then discharged at a discharging rate of 5 hours for a complete discharge. In addition, the numbers in Table 1 are ratios based on the experimental values in the embodiment.
[0044] [Table 1]
[0045]
[0046] [Battery Height]
[0047] In this embodiment, the battery height, i.e., along Figure 1 The distance between the lower surface of the bottom wall 15 along the x-axis and the upper surface of the positive terminal 70 is set as reference "1". The battery heights of Comparative Examples 1 and 2 are the same as those of the battery in the embodiment.
[0048] [positive electrode]
[0049] In this embodiment, the total length L2 of the positive electrode plate 20 (refer to...) Figure 2 (1) is the reference. The total length of the positive electrode plate in Comparative Examples 1 and 2 is the same as the total length of the positive electrode plate 20 in the embodiment.
[0050] In this embodiment, the height of the positive electrode plate 20 is H2, which is the height of the positive electrode plate main body 22. Figure 2 Set the reference to "1", and set the height H1 of the positive electrode protrusion 23 of the positive electrode plate 20 to "1". Figure 2 The value is set to "1.04". At this time, L1:L2 = 1:1.72. The height of the positive electrode plate in Comparative Examples 1 and 2 is the same as the height H2 of the main body 22 of the positive electrode plate in the embodiment. That is, the positive electrode plates in Comparative Examples 1 and 2 are rectangles with length L2 and height H2.
[0051] In this embodiment, the thickness of the positive electrode plate 20, including the positive electrode substrate 21 and the positive electrode agent 25, is set as a reference "1". The thickness of the positive electrode plate in Comparative Example 1 is the same as the thickness of the positive electrode plate 20 in the embodiment, and the thickness of the positive electrode plate in Comparative Example 2 is "1.02" relative to the thickness of the positive electrode plate 20 in the embodiment. That is, in Comparative Example 2, a larger amount of positive electrode agent than that in this embodiment is coated.
[0052] As described above, a positive electrode substrate shaped into a specified form is prepared in advance. Figure 2 On the other hand, a positive electrode slurry containing positive electrode active material particles, water, and a binder is prepared. The prepared positive electrode slurry is then filled into a nickel foam sheet serving as the positive electrode substrate and dried. After drying, the nickel foam sheet filled with nickel hydroxide particles, etc., is rolled and cut to manufacture a positive electrode plate. 100 such positive electrode plates are manufactured (…). Figure 3 ).
[0053] [negative electrode]
[0054] In this embodiment, the total length L4 of the negative electrode plate 30 (refer to...) Figure 4 (1) is the reference. The total length of the negative electrode plate in Comparative Examples 1 and 2 is the same as the total length of the negative electrode plate 30 in the embodiment.
[0055] In this embodiment, the height of the negative electrode plate is H3, which is the height of the negative electrode plate body 32. Figure 4 Set the reference to "1", and set the height H4 of the negative electrode protrusion 33 of the negative electrode plate 30 to "1". Figure 4 The value is set to "1.04". At this time, L3:L4 = 1:2.72. The height of the negative electrode plate in Comparative Examples 1 and 2 is the same as the height H3 of the negative electrode plate body 32 in the embodiment. That is, the negative electrode plate in Comparative Examples 1 and 2 is a rectangle with length L4 and height H3.
[0056] In this embodiment, the thickness of the negative electrode plate 30, including the negative electrode core 31 and the negative electrode mixture 35, is set as a reference "1". The thickness of the negative electrode plate in Comparative Example 1 is the same as the thickness of the negative electrode plate 30 in the embodiment, and the thickness of the negative electrode plate in Comparative Example 2 is "1.02" relative to the thickness of the negative electrode plate 30 in the embodiment. That is, in Comparative Example 2, a larger amount of negative electrode mixture than that in this embodiment is applied.
[0057] As described above, a negative electrode core shaped into a specified form is prepared in advance. Figure 4 On the other hand, an aggregate of hydrogen storage alloy particles, namely hydrogen storage alloy powder, a conductive agent, a binder, and water, as described above, is prepared and mixed to prepare a paste for the negative electrode compound. The resulting paste is applied to the negative electrode core and dried. After drying, the density of the negative electrode compound is adjusted to a specified value through a rolling process of rolling the entire negative electrode plate, thereby manufacturing the negative electrode plate. 100 such negative electrode plates were manufactured.
[0058] [Whirlpool Electrode Assembly]
[0059] The positive and negative electrode plates, manufactured as described above, are wound into a vortex shape with a separator in between, thereby forming a vortex electrode assembly. This vortex electrode assembly is then housed within a casing. Next, a predetermined amount of alkaline electrolyte is injected into the casing. Afterward, the casing containing the vortex electrode assembly and the alkaline electrolyte is sealed with a sealing body having the positive terminal, thus obtaining a battery. The battery undergoes an initial activation treatment to bring it to a usable state.
[0060] [Short circuit occurrence, discharge capacity]
[0061] The battery manufactured in this way was subjected to loading under the above test conditions, and the results shown in Table 1 were obtained. As shown in Table 1, it can be confirmed that the battery according to this embodiment can increase the discharge capacity compared to the battery of Comparative Example 1, and can reduce the number of batteries that experience short circuits compared to the battery of Comparative Example 2.
[0062] The preferred embodiments have been described above. However, the present invention is not limited to the nickel-metal hydride rechargeable battery 1 described in the above embodiments, but may also include all aspects contained within the concept and scope of the claims of the present invention. The various structures can be appropriately and selectively combined. Furthermore, the shape, material, configuration, size, etc. of the structural elements in the above embodiments can be appropriately modified according to the specific embodiments of the present invention.
[0063] Label Explanation
[0064] 1. Nickel-metal hydride rechargeable battery (alkaline battery)
[0065] 10. Outer shell
[0066] 20 Positive Plate
[0067] 22 Positive electrode plate main body
[0068] 23 positive electrode convex part
[0069] 30 Negative electrode plate
[0070] 32 Negative electrode plate main body
[0071] 33 Negative electrode convex part
[0072] 40 Separators
[0073] 50 vortex electrode assembly
[0074] 60 sealing body
[0075] 70 Positive extreme.
Claims
1. An alkaline storage battery, characterized in that, include: A vortex electrode assembly is formed by overlapping a strip-shaped positive electrode plate, a strip-shaped negative electrode plate, and a strip-shaped separator disposed between the positive electrode plate and the negative electrode plate, so that the negative electrode active material of the negative electrode plate is exposed to the outermost part of the vortex electrode assembly. The outer casing, which has an opening at the top, is a bottomed cylindrical casing that houses the vortex electrode assembly together with the alkaline electrolyte. A sealing body that seals the opening of the outer casing; as well as The positive terminal is electrically connected to the sealing body. The positive electrode plate includes a strip-shaped positive electrode plate body portion and a positive electrode protrusion portion that protrudes from a portion of the positive electrode plate body portion toward the sealing body and is electrically connected to the sealing body. The negative electrode plate includes a strip-shaped negative electrode plate body portion and a negative electrode protrusion portion that protrudes from a portion of the negative electrode plate body portion toward the sealing body and forms a terminal between the sealing body and the negative electrode plate body portion. The positive electrode plate and the negative electrode plate have positive active material and negative active material respectively in the opposite portions separated by the separator. The positive electrode active material is disposed on the entire surface of each side of the positive electrode plate, which includes the positive electrode protrusion, opposite to the negative electrode and separated by the separator. The negative electrode active material is disposed on the entire surface of each side of the negative electrode plate, which is opposite to the positive electrode and includes the negative electrode protrusion, separated by the separator. The negative electrode plate is electrically connected to the outer casing when it is in contact with the inner circumferential surface of the outer casing. The outer casing has an inner surface that is in direct physical contact with the negative electrode active material exposed to the outermost part of the vortex electrode assembly, thereby electrically connecting it to the negative electrode plate.
2. The alkaline storage battery as described in claim 1, characterized in that, It also includes a connecting member disposed between the sealing body and the positive electrode protrusion, which has conductivity and elasticity.