JP5737235B2 - battery - Google Patents

Description

  The present invention relates to a battery having an electrolyte storage space.

  In recent years, the need for low-cost batteries has increased. Therefore, for example, as shown in Patent Document 1, in a battery including an electrode group consisting of a positive electrode plate, a negative electrode plate, and a separator impregnated with an electrolyte solution inside the battery case, the costly electrode group is a battery case. Batteries have been developed in which the filler is sealed in the remaining space of the battery case by shortening in the axial direction.

German patent application DE 200 16 231 U1

  In this type of battery, as a method of extending the battery life by increasing the energy density while suppressing the cost, for example, it is conceivable to impregnate the separator with an electrolyte more than usual, but in the battery described above, the separator is excessively electrolyzed. When the liquid is impregnated, the permeability of the gas generated from the positive and negative electrodes during overcharge deteriorates, so the internal pressure of the battery increases. And the problem that a liquid leak will generate | occur | produce and a battery life will be shortened arises.

  The present invention has been made in view of the above problems, and provides a battery with low cost, high energy density and long life.

  That is, the battery according to the present invention includes a cylindrical battery case, a positive electrode plate, a negative electrode plate, and a separator containing an electrolyte solution disposed therebetween, and an electrode group disposed inside the battery case. And an electrolyte solution storage space for storing the electrolyte solution is provided in one or both of the axial directions of the battery case in the electrode group.

If it is such, a cheap battery can be provided by using the electrode group shortened in the axial direction of the battery case. Further, in order to extend the battery life, even when the separator is excessively impregnated with the electrolytic solution and the electrolytic solution leaks from the electrode group, the electrolytic solution can be stored in the electrolytic solution storage space. Furthermore, since the electrolyte storage space is provided, an increase in the internal pressure of the battery can be mitigated, and a battery having a high energy density and a long life can be provided.
In addition, when the battery is installed sideways, if the electrolyte contained in the separator decreases, the leaked electrolyte stored in the electrolyte storage space is again absorbed by the separator due to capillarity or the like. An increase in the internal resistance of the battery can be prevented and a battery having a longer life can be provided.

  In the battery according to the present invention, the electrode group is arranged close to a positive electrode terminal formed on one end surface of the battery case, and the electrolyte solution storage space is formed on the opposite side of the positive electrode terminal side in the electrode group. It is characterized by that.

  Thereby, the distance between the positive electrode terminal provided in the battery case and the electrode group can be shortened, and an increase in electrical resistance and a decrease in discharge efficiency when the positive electrode terminal and the electrode group are connected can be prevented. it can.

  The battery according to the present invention is arranged with a gap in the electrolyte solution storage space, and one end contacts a part of one end surface in the axial direction of the electrode group and the other end is the battery case. And a spacer for fixing the electrode group so as not to move in the axial direction.

  Accordingly, the electrode group can be prevented from entering the electrolytic solution storage space, and the occurrence of a short circuit due to the electrode group moving in the axial direction and being disconnected from the positive electrode terminal can be prevented. Even if the spacer is arranged, a gap is provided between the battery case and the electrode group, so that the electrolyte solution leaking from the electrode group can be stored in the electrolyte storage space without being blocked by the spacer. Can do.

  The battery according to the present invention is characterized in that the spacer is composed of a plurality of plate-like members arranged upright in the axial direction of the battery case.

  Thereby, when the electrode group has a winding structure in which the positive electrode plate, the negative electrode plate, and the separator are wound in a spiral shape, one end surface of the electrode group comes into contact with one end of the plurality of plate-like members, thereby Winding deviation can be prevented. Moreover, since each plate-like member is arranged in an upright state inside the battery case, it is possible to prevent the electrolyte storage space from being greatly narrowed by arranging the spacer.

  The battery according to the present invention is characterized in that the spacer is a columnar member.

  Thereby, it can manufacture easily by cut | disconnecting the columnar-shaped rod member which has fixed length in an axial direction in a desired position. Moreover, when the inside of the columnar member is configured to be hollow, the area of the electrolyte storage space can be provided larger than that of the solid member.

  The battery according to the present invention is characterized in that the spacer has elasticity in the axial direction of the battery case, and the dimension in the axial direction can be changed.

  As a result, even if the battery is vibrated in the axial direction in order to re-include the electrolyte stored in the electrolyte storage space in the separator, the spacer acts as a spring, and the short circuit caused by the movement of the electrode group It is possible to prevent the electrode group from shifting due to generation and vibration.

  The battery according to the present invention is preferably a nickel-metal hydride battery in which the positive electrode plate has nickel hydroxide as a main active material and the negative electrode plate has a hydrogen storage alloy as a main material.

  According to the present invention configured as described above, it is possible to provide a battery having a low cost, a high energy density, and a long life while preventing an increase in the internal pressure of the battery.

The sectional view of the battery in a 1st embodiment of the present invention. The perspective view which shows an example of the spacer in 1st Embodiment of this invention. The perspective view which shows an example of the spacer in 1st Embodiment of this invention. The top view which shows an example of the spacer in 1st Embodiment of this invention. The perspective view which shows an example of the spacer in 1st Embodiment of this invention. Sectional drawing of the battery in 2nd Embodiment of this invention. The perspective view which shows an example of the spacer in 2nd Embodiment of this invention. The perspective view which shows another example of the spacer of this invention. The perspective view which shows another example of the spacer of this invention. The perspective view which shows another example of the spacer of this invention. Sectional drawing which shows the sample 2 of Example 1. FIG. Sectional drawing which shows the sample 3 of Example 1. FIG. Sectional drawing which shows the sample 4 of Example 1. FIG.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
The battery 1 according to the present embodiment is an alkaline storage battery such as a nickel / hydrogen storage battery. Specifically, this can be a low capacity type having, for example, an AA capacity of 1800 mAh or less, or an AA capacity of 650 mAh or less.

  The battery 1 according to the first embodiment of the present invention includes a metal battery case 2 whose surface is nickel-plated and an electrode group 3 disposed inside the battery case 2.

  As shown in FIG. 1, the battery case 2 seals the opening of the battery case main body 2a with an insulator and a bottomed cylindrical battery case main body 2a having one end opened and the other end closed. It is comprised from the cover body 2b. The battery case main body 2a becomes a negative electrode terminal of the battery 1 by contacting a negative electrode plate 3c described later. Further, the lid body 2b becomes a positive electrode terminal of the battery 1 by being connected to a positive electrode plate 3a to be described later via a connection terminal 4 having elasticity.

  The electrode group 3 is disposed inside the battery case main body 2a so as to be adjacent to the lid body 2b, and includes a positive electrode plate 3a, a negative electrode plate 3c, and a separator 3b containing an electrolyte disposed therebetween. Have. In the present embodiment, the electrode group 3 has a cylindrical shape in which the positive electrode plate 3a, the negative electrode plate 3c, and the separator 3b are spirally wound, but the positive electrode plate 3a, the negative electrode plate 3c, and the separator 3b are stacked. It may be angular.

  The positive electrode plate 3a is obtained by filling a positive electrode substrate made of nickel foam and a mixture of a nickel hydroxide active material and a cobalt compound of a conductive material in the hollow of the positive electrode substrate. The nickel hydroxide active material is, for example, nickel hydroxide in the case of a nickel / cadmium storage battery, and nickel hydroxide to which calcium hydroxide is added in the case of a nickel / hydrogen storage battery.

The negative electrode plate 3c is made of, for example, a negative electrode current collector made of a flat perforated steel sheet plated with nickel, and a negative electrode active material coated on the negative electrode current collector. The negative electrode active material is, for example, a mixture of cadmium oxide powder and metal cadmium powder in the case of a nickel-cadmium storage battery, and mainly in the case of a nickel-hydrogen storage battery, for example, AB ₅ type (rare earth-Ni system). ), AB _3.0-3.8 type (rare earth- _Mg -Ni series) or AB ₂ type (Laves phase) hydrogen storage alloy powder.

  The separator 3b is made of, for example, a nonwoven fabric made of polyolefin, and the separator 3b is impregnated with an electrolytic solution mainly composed of potassium hydroxide or sodium hydroxide.

  Therefore, the battery 1 of the present embodiment is configured such that the electrode group 3 is shortened in the axial direction of the battery case 2 (hereinafter referred to as the axial direction) as shown in FIG. An electrolytic solution storage space 6 for storing the electrolytic solution is provided on the side opposite to the terminal side, and a spacer 5 is disposed in the electrolytic solution storage space 6.

  The spacer 5 is made of a material such as acrylic resin, polypropylene resin, nylon resin, or stainless steel that does not react with the electrolytic solution, and one end is a part of one end face of the battery case body 2a that is closed, The other end is disposed so as to contact a part of one end face of the electrode group 3. Therefore, the electrode group 3 is fixed to the battery case 2 with the connecting terminals 4 on the positive terminal side and the spacers 5 on the opposite side of the positive terminal side, so that both sides in the axial direction are sandwiched.

  In addition, as shown in FIG. 2, the spacer 5 has three plate-like members 5a arranged upright at equal angles (120 °) around the axis of the battery case 2, and one end thereof is joined at the center. Are formed integrally. The length of the spacer 5 in the axial direction is configured to be the same as the distance from one end surface of the battery case body 2 a to one end surface of the electrode group 3.

  In addition, as shown in FIG. 3, the spacer 5 may be comprised by the four plate-shaped members 5a arrange | positioned upright at equiangular (90 degrees) centering on the axis | shaft of the battery case 2. FIG.

  Or you may comprise the spacer 5 so that it may have elasticity in an axial direction and the dimension of the axial direction can change. For example, as shown in FIG. 4, one end of the plate-like member 5 a that contacts the electrode group 3 and the other end of the plate-like member 5 a that faces the one end and contacts the battery case 2 are in a twisted position. Alternatively, as shown in FIG. 5, the spacer 5 may be formed in a spring shape.

  The electrolyte storage space 6 is a gap between the electrode group 3 and the battery case main body 2a and in which the spacer 5 is disposed in a part thereof. Since the spacer 5 contacts only a part of the electrode group 3, the electrolyte leaking from the electrode group 3 is guided and stored in this gap without being blocked by the spacer 5.

  According to the battery 1 in this embodiment, since the electrode group 3 shortened in the axial direction of the battery case 2 is used, a low-cost battery can be provided. Moreover, even if the separator 3b is excessively impregnated with an electrolyte to increase the energy density and extend the battery life, the leaked electrolyte from the electrode group 3 can be stored in the electrolyte storage space 6. Furthermore, since the electrolytic solution storage space 6 is provided, an increase in internal pressure of the battery 1 can be reduced, and the battery 1 having a high energy density and a long life can be provided.

  In addition, when the battery 1 in the present embodiment is installed sideways, when the electrolyte contained in the separator 3b decreases, the leaked electrolyte stored in the electrolyte storage space 6 is again absorbed by the separator 3b due to capillary action or the like. Therefore, it is possible to prevent the increase in internal resistance of the battery 1 due to the liquid withering of the separator 3b and to provide the battery 1 with a longer life.

  Moreover, according to the battery 1 in the present embodiment, the electrode group 3 is disposed close to the lid 2b (positive electrode terminal), and is located between the electrode group 3 and the battery case body 2a and on the opposite side of the positive electrode terminal side. In addition, since the electrolytic solution storage space 6 is formed, the distance between the positive electrode terminal provided in the battery case 2 and the electrode group 3 can be shortened, and the positive electrode terminal and the electrode group 3 are connected. The increase in electrical resistance and the decrease in discharge efficiency can be prevented.

  The battery 1 in the present embodiment is disposed with a gap in the electrolyte storage space 6, one end contacts a part of one end surface in the axial direction of the electrode group 3, and the other end is one of the battery case 2. A spacer 5 is provided in contact with the end face to fix the electrode group 3 so as not to move in the axial direction. Thereby, the electrode group 3 can be prevented from entering the electrolytic solution storage space 6, and the occurrence of a short circuit due to the electrode group 3 moving in the axial direction and being disconnected from the positive electrode terminal can be prevented. Even when the spacer 5 is arranged, a gap is provided between the battery case 2 and the electrode group 3, so that the electrolyte solution leaking from the electrode group 3 is not blocked by the spacer 5 and is stored in the electrolyte solution. It can be stored in the space 6.

  Further, by arranging the spacers 5 so as to stand in the axial direction, the electrode group 3 has a winding structure in which the positive electrode plate 3a, the negative electrode plate 3c, and the separator 3b are wound in a spiral shape. When the one end face comes into contact with one end of the plurality of plate-like members 5a, it is possible to prevent the electrode group 3 from being unwound. Moreover, since each plate-like member 5a is disposed inside the battery case 2 in an upright state, the electrolyte storage space 6 can be prevented from being greatly narrowed by the spacer 5 being disposed.

  Or you may comprise the spacer 5 so that it may have elasticity in an axial direction and the dimension of the axial direction can change. With this configuration, even if the battery 1 is vibrated in the axial direction so that the electrolyte solution stored in the electrolyte solution storage space 6 is included again in the separator 3b, the spacer 5 is bent and the dimensions are deformed. By playing a role like a spring, it is possible to prevent the occurrence of a short circuit due to the movement of the electrode group 3, the pole group displacement of the electrode group 3 due to vibration, and the like.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS.
The battery 10 according to the second embodiment of the present invention differs from the first embodiment in the configuration of the spacers. Since other configurations are the same as those in the first embodiment, description thereof is omitted.

  In the second embodiment, in the battery case 2, the first spacer 11 is disposed on the positive electrode terminal side of the electrode group 3, and the second spacer 12 is disposed on the opposite side to the positive electrode terminal side of the electrode group 3. Yes.

  As shown in FIG. 7, the first spacer 11 has a disk shape in which a hole 11 a for arranging the connection terminal 4 is formed at the center. As shown in FIG. 6, the first spacer 11 is arranged so that one end surface is in contact with the battery case body 2 a and the other end surface is in contact with the electrode group 3. Note that a plurality of holes may be formed in the first spacer 11 in addition to the holes 11 a for arranging the connection terminals 4.

  As shown in FIG. 7, the second spacer 12 is provided integrally with a disc 12 a having a hole in the center and one surface side of the disc 12 a, and stands up at an equal angle around the axis of the battery case 2. And a plurality of plate members 12b arranged. And it arrange | positions so that one surface of the disk 12a in which the board member 12b is not provided contacts the electrode group 3, and the end surface of the board member 12b contacts the battery case main body 2a.

  Both the first spacer 11 and the second spacer 12 are made of a material having rigidity such as a resin such as acrylic resin, polypropylene resin, nylon resin, or stainless steel, as in the first embodiment. And since the 1st spacer 11 is arrange | positioned at the positive electrode terminal side and the 2nd spacer 12 is arrange | positioned at the reverse side of the positive electrode terminal side, the electrode group 3 is fixed to the battery case 2 with both sides in the axial direction being sandwiched.

Between the electrode group 3 and the battery case main body 2a, the first spacer 11 and the second spacer 12 are disposed in a part thereof . Since the first spacer 11 and the second spacer 12 are in contact with only a part of the electrode group 3, the electrolyte leaking from the electrode group 3 is not blocked by the first spacer 11 and the second spacer 12, and this gap To be stored.

  Since the battery 10 in the second embodiment is fixed by sandwiching both ends of the electrode group 3 in the axial direction between the first spacer 11 and the second spacer 12, the electrode group 3 is securely fixed to the battery case 2, The occurrence of a short circuit due to the movement of the electrode group 3 can be reliably prevented.

  The present invention is not limited to the first and second embodiments. For example, the present invention can be applied to a secondary battery such as a lithium ion secondary battery in addition to an alkaline storage battery, or applied to a primary battery. Also good.

  Moreover, you may comprise the spacer 5 in 1st and 2nd embodiment with the columnar member 13, as shown in FIGS. At this time, as shown in FIGS. 8 to 10, the columnar shape may be configured in a polygonal column shape such as a triangle, a square, or a hexagon, or may be configured in a columnar shape or the like although not illustrated. . Thereby, the spacer 5 can be easily manufactured by cutting the columnar rod member having a certain length in the axial direction at a desired position.

  In addition, as shown to Fig.8 (a)-(c), you may comprise the columnar member 13 hollow, and as shown to Fig.9 (a)-(c), only the framework of the columnar member 13 is sufficient. It may be configured. By comprising in this way, the area | region of the electrolyte storage space 6 can be provided more largely compared with a solid thing. Further, since the contact area between the spacer 5 and the separator 3b is smaller than that of the solid one, when the battery 1 is installed sideways, the leaked electrolyte stored in the electrolyte storage space 6 is transferred to the separator 3b. It can be absorbed easily and quickly.

  The present invention can be variously modified without departing from the spirit of the present invention.

  Below, the test which compared the battery 1 which concerns on 1st Embodiment, and another battery was done. The results are shown in Table 1.

<Test material>
The batteries of Samples 1 to 4 shown in Table 1 will be described below.
Samples 1 to 4 are nickel metal hydride storage batteries. Specifically, an electrode group wound in a spiral shape is housed in a cylindrical metal case having an inner dimension of 42 mm in height and a diameter of 13.42 mm. After injecting 1.3 g (1.00 cc) of 4MKOH + 3MNaOH + 0.8MLiOH mixed electrolyte, it was sealed with a metal lid provided with a safety valve. Here, since the samples 1 to 4 have different sizes and arrangements of the electrode groups, different portions will be described below.
(Sample 1)
Sample 1 is a battery 1 according to the first embodiment, and as shown in FIGS. 1 and 2, a resin such as polypropylene, acrylic, polyethylene, nylon, or the like having a height of 21 mm and a thickness of 0.5 mm at the bottom of the case. A spacer 5 made of a metal such as stainless steel is disposed, and an electrode group 3 having a height of 21 mm and a space inner diameter of 3 mm is disposed on the spacer 5. An electrolyte storage space 6 is provided in a region where the spacer 5 is disposed. One end of the electrode group 3 is electrically connected to the positive electrode terminal provided on the metal lid through the connection terminal 4.
(Sample 2)
In sample 2, as shown in FIG. 11, a cylindrical filler 15 having a height of 21 mm and a diameter of 13.42 mm made of a resin such as epoxy, acrylic, polyethylene, nylon, or a metal such as stainless steel is disposed at the bottom of the case. Then, the electrode group 3 having a height of 21 mm and a space inner diameter of 3 mm is disposed on the filler 15.
(Sample 3)
A sample 3 is an embodiment of the present invention, and as shown in FIG. 12, an electrode group 3 having a height of 21 mm and a space inner diameter of 3 mm is arranged at the bottom of the case. One end of the electrode group 3 is electrically connected to a positive electrode terminal provided on the metal lid through a connection terminal 40. An electrolytic solution storage space 6 is provided between the electrode group 3 and the positive electrode terminal.
(Sample 4)
As shown in FIG. 13, the sample 4 has an electrode group 30 having a height of 42 mm and a space inner diameter of 7.62 mm arranged inside the case. The electrode group 30 has a higher height than the electrode group 3 of Samples 1 to 3, and has a small number of windings of the positive electrode plate, the negative electrode plate, and the separator and a large space inner diameter.
(Production method of electrode group)
In addition, the electrode group of the samples 1-4 mentioned above was produced with the following method.
(Preparation method of positive electrode plate)
As an active substance of the positive electrode plate, a nickel hydroxide containing 3% by mass of zinc and 0.6% by mass of cobalt in a solid solution state is coated with 7% by mass of cobalt hydroxide, and 1% at 110 ° C. What was subjected to air oxidation treatment using 18M sodium hydroxide for a time was used. Then, a paste is prepared by mixing the above-described positive electrode active material, an aqueous solution in which a thickener (carboxymethylcellulose) is dissolved, and 2% by mass of ytterbium oxide, and filled in foamed nickel having a substrate surface density of 320 g / m2. After being dried, it was pressed to a porosity of 20% and cut into a predetermined size to produce a positive electrode plate having a positive electrode capacity of 1 Ah.
(Production method of negative electrode plate)
An aqueous solution in which a thickener (methylcellulose) is dissolved in 100 parts by mass of hydrogen storage alloy powder of La0.64Pr0.20Mg0.16Ni3.45Al0.15 composition pulverized to an average particle size D50 = 50 μm is added, and a binder (styrene) is added. 1 part by weight of butadiene rubber) is applied to both sides of a 35 μm-thick perforated steel sheet (opening ratio 50%), dried, and pressed to a porosity of 18%. A negative electrode plate having a negative electrode capacity of 1.3 Ah was prepared by cutting into sizes.
The positive electrode plate and the negative electrode plate manufactured by the above-described method were wound in a spiral shape through a separator subjected to sulfonation treatment to prepare an electrode group.

<Test method>
The internal resistance value, discharge capacity ratio, and internal pressure value of Samples 1 to 4 were measured by the following methods.
(Internal resistance value)
Terminals were placed on the top lid and can bottom of samples 1 to 4, and the internal resistance value was measured using a Hioki Electric 3560 Hitester.
(Discharge capacity ratio)
First, samples 1 to 4 were charged at 0.1 ItA (100 mA) for 16 hours in a measurement environment at a temperature of 20 ° C., then rested for 1 hour, and discharged until 0.2 V (200 mA) until 1 V was reached. Then, a 0.2 ItA discharge capacity value (hereinafter also referred to as a low rate capacity value) was measured.
Next, samples 1 to 4 were charged at 0.1 ItA (100 mA) for 16 hours in a measurement environment at a temperature of 20 ° C., then rested for 1 hour, and discharged to 3 V at 1 It (3000 mA). Then, the 3 ItA discharge capacity value (hereinafter also referred to as a high rate capacity value) was measured.
Using the above results, 3ItA discharge capacity / 0.2ItA discharge capacity × 100 was calculated, and the discharge capacity ratio of the high rate capacity value to the low rate capacity value was calculated.
(Internal pressure value)
A hole was made in Samples 1 to 4 and an internal pressure measuring jig was attached, and charging was performed at 1 ItA (1000 mA) for 1.5 hours in a measurement environment at a temperature of 20 ° C., and the maximum internal pressure at that time was measured.
(About initialization)
In addition, before performing an above-described test, initialization was performed to the samples 1-4 with the following procedures.
First, under an environment of a temperature of 20 ° C., charging was performed at 0.1 ItA for 12 hours, then discharging was performed at 0.2 ItA until reaching 1 V, and this was repeated for two cycles. After storing for 48 hours in an environment at a temperature of 40 ° C., the battery is charged at 0.1 ItA for 16 hours in an environment at a temperature of 20 ° C., paused for 1 hour, and discharged until 0.2 V at 1 ItA. This was repeated 3 cycles to complete the formation.

<Test results>

  Here, since the internal pressure of sample 4 cannot be tested and cannot be compared with others, sample 1, sample 2, and sample 3 will be compared below.

  Comparing sample 1 and sample 3 with sample 2, samples 1 and 3 have a larger discharge capacity ratio and a lower internal pressure value than sample 2. This is probably because samples 1 and 3 are provided with an electrolyte storage space, so that the increase in internal pressure of the battery is suppressed and the discharge capacity ratio is increased. Therefore, the battery provided with the electrolytic solution storage space prevents a rise in internal pressure and has a higher capacity than a battery without the electrolytic solution storage space.

  Further, comparing sample 1 and sample 3, sample 1 has a smaller internal resistance value and a larger discharge capacity ratio than sample 3. This is because sample 1 has a shorter distance between the electrode group and the positive electrode terminal than sample 3, so that the increase in electrical resistance and the decrease in discharge efficiency are suppressed, the internal resistance value is reduced, and the discharge capacity ratio is increased. it is conceivable that. Therefore, in order to prevent an increase in internal resistance and obtain a high capacity battery, the distance between the electrode group and the positive electrode terminal is preferably short.

  Next, using the battery 1 according to the first embodiment, a test was performed in which the amount of electrolyte solution impregnated in the separator 3b was changed. The results are shown in Table 2.

<Test material>
Samples 1 and 5 to 8 are nickel metal hydride storage batteries 1 according to the first embodiment. Specifically, as shown in FIGS. 1 and 2, a spacer 5 is disposed on the bottom of a cylindrical metal case. The electrode group 3 is disposed on the spacer 5. Then, for each sample, a predetermined amount of 4MKOH + 3MNaOH + 0.8MLiOH mixed electrolyte shown in Table 2 is injected into the case, and then sealed with a metal lid provided with a safety valve. Here, since the liquid amount value per unit positive electrode capacity of the electrolyte contained in the separator of the normal battery is 0.8 to 1 cc / Ah, the samples 6 to 8 are impregnated with the electrolyte more than usual. Sample 1 is the same as Table 1, and the inner dimensions of the cases of Samples 1 and 5 to 8, the spacer 5, the electrode group, and the like are the same as those of the test material of Example 1 described above. Is omitted.

<Test method>
The discharge capacity ratios and internal pressure values of Samples 1 and 5 to 8 were measured. Note that the test method or the initialization method is the same as the test method of Example 1 described above, and thus the description thereof is omitted here.

<Test results>

  As shown in Table 2, as the amount of electrolyte impregnated in the separator 3b increases, the discharge capacity ratio increases and the internal pressure value also increases. Here, the battery preferably has a lower internal pressure value, more specifically 2.5 MPa or less. However, in the battery 1 according to the first embodiment, the amount of the electrolyte contained in the separator 3b Even if the value increases somewhat, the internal pressure value of the battery can be suppressed to 2.5 MPa or less. Therefore, in a battery provided with an electrolytic solution storage space, even if the separator 3b is excessively impregnated with an electrolytic solution in order to extend the battery life, the leakage electrolytic solution can be stored in the electrolytic solution storage space. Thus, a battery having a high energy density and a long life can be obtained.

DESCRIPTION OF SYMBOLS 1 ... Battery 2 ... Battery case 3 ... Electrode group 3a ... Positive electrode plate 3b ... Separator 3c ... Negative electrode plate 4 ... Connection terminal 5 ... Spacer 5a ... Plate -Shaped member 6 ... electrolyte storage space

Claims (6)

A cylindrical battery case;
A positive electrode plate, a negative electrode plate, and a separator including an electrolyte solution disposed between the positive electrode plate, the negative electrode plate, and a separator that is spirally wound and disposed inside the battery case; An electrode group configured to be short in the direction;
In either one or both of the axial directions of the battery case in the electrode group, an electrolytic solution storage space in which the electrolytic solution is stored,
A spacer disposed in the electrolyte storage space,
The battery is characterized in that the spacer is made of a plate-like member arranged upright in the axial direction of the battery case. The electrode group is disposed close to a positive electrode terminal formed on one end surface of the battery case,
The battery according to claim 1, wherein the electrolyte storage space is formed on a side opposite to the positive electrode terminal side in the electrode group.   The spacer has one end contacting a part of one end surface in the axial direction of the electrode group and the other end contacting one end surface of the battery case to fix the electrode group so as not to move in the axial direction. The battery according to claim 1 or 2. The battery according to any one of claims 1 to 3 , wherein the spacer includes a columnar member. Said spacer, said resilient in the axial direction of the battery case, battery according to any one of claims 1 to 4, characterized in that the dimensions in the axial direction can be changed. The positive electrode plate has nickel hydroxide as a main active material,
The negative electrode plate, battery according to any one of claims 1 to 5, characterized in that the hydrogen storage alloy as a main material.