JP7081135B2 - Lead-acid battery - Google Patents

Description

The techniques disclosed herein relate to lead acid batteries.

Lead-acid batteries are widely used as secondary batteries. For example, lead-acid batteries are used as an emergency power source for buildings and the like.

The lead storage battery includes a positive electrode plate and a negative electrode plate. The positive electrode plate and the negative electrode plate each have a current collector and an active material supported by the current collector. The current collector includes a substantially quadrangular frame portion composed of four frame bones, an ear portion provided on one frame bone, and an inner portion provided inside the frame portion. The medial portion has a plurality of internal bones (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2012-77906

When a lead-acid battery is used for a long period of time, the internal bones constituting the inner part of the current collector are cut by corrosion, and as a result, the capacity is reduced and the life of the lead-acid battery is reached. It is desired that the life of the conventional lead-acid battery is further extended while avoiding deterioration of other characteristics.

This specification discloses a technique capable of improving the life characteristics of a lead storage battery while avoiding deterioration of other characteristics of the lead storage battery.

The lead storage battery disclosed in the present specification includes an electrode plate having a current collector and an electrode material supported by the current collector, and the current collector has four bones including a first frame bone. It has a frame portion that is substantially square in the first directional view, an ear portion provided on the first frame bone, and an inner portion provided inside the frame portion. The medial portion includes a first internal bone group composed of N1 first internal bones connecting between two the frame bones connected to the first frame bone, and the first internal bone group. It has a second internal bone group composed of N2 second internal bones connecting the frame bone and one said frame bone facing the first frame bone, and said the second. In the inner bone group, the cross-sectional area S2 of the cross section orthogonal to the stretching direction is 0.35 × T0 ² ≦ S2 ≦ 0.65 × T0 ² (where T0 is the thickness of the frame portion in the first direction). ) Is included, and the first internal bone group has a cross-sectional area S1 of a cross section orthogonal to the stretching direction of 0.077 × S2max ≦ S1 ≦ 0.125 × S2max (however). , S2max includes n1 fine internal bones satisfying the relationship (maximum value of the cross-sectional area of the large internal bone), and the thickness is relative to the number N2 of the second internal bones constituting the second internal bone group. The ratio of the number of internal bones n2 (n2 / N2) is 0.7 or more, and the number of fine internal bones n1 with respect to the number N1 of the first internal bones constituting the first internal bone group. The ratio (n1 / N1) is 0.7 or more.

It is a front view which shows the appearance structure of the lead storage battery 100 in this embodiment. It is a top view which shows the appearance structure of the lead storage battery 100 in this embodiment. It is a top view which shows the internal structure of the lead storage battery 100 in this embodiment. It is explanatory drawing which shows the YZ cross-sectional structure of the lead storage battery 100 at the position of IV-IV of FIG. It is explanatory drawing which shows the YZ cross-sectional structure of the lead storage battery 100 at the position of VV of FIG. It is explanatory drawing which shows the XZ cross-sectional structure of a part of the lead storage battery 100 at the position of VI-VI of FIG. It is explanatory drawing which shows the YZ plane structure of the positive electrode current collector 212. It is explanatory drawing which shows the XY cross-sectional structure of the positive electrode current collector 212 at the position of VIII-VIII of FIG. It is explanatory drawing which shows the XZ cross-sectional structure of the positive electrode current collector 212 at the position of IX-IX of FIG. It is explanatory drawing which shows the performance evaluation result. It is explanatory drawing which shows the performance evaluation result. It is explanatory drawing which shows the performance evaluation result. It is explanatory drawing which shows the performance evaluation result.

The techniques disclosed herein can be realized in the following forms.

(1) The lead storage battery disclosed in the present specification is a lead storage battery, comprising an electrode plate having a current collector and an electrode material supported by the current collector, and the current collector is: It is composed of four frame bones including the first frame bone, and is provided inside the frame portion having a substantially square frame portion in the first directional view, the ear portion provided on the first frame bone portion, and the frame portion. A first internal bone composed of an N1 first internal bone connecting between two said frame bones connected to the first frame bone. A second internal bone group composed of an internal bone group and N2 second internal bones connecting the first frame bone and one said frame bone facing the first frame bone. The second internal bone group has a cross-sectional area S2 of a cross section orthogonal to the stretching direction of 0.35 × T0 ² ≦ S2 ≦ 0.65 × T0 ² (where T0 is the first). The first internal bone group includes n2 large internal bones satisfying the relationship (thickness of the frame portion in the direction of), and the cross-sectional area S1 of the cross section orthogonal to the extension direction is 0.077 × S2max ≦. The ratio of the number n2 of the large internal bones to the number N2 of the second internal bones including n1 fine internal bones satisfying the relationship of S1 ≦ 0.125 × S2max and constituting the second internal bone group. (N2 / N2) is 0.7 or more, and the ratio (n1 / N1) of the number n1 of the microinternal bones to the number N1 of the first internal bones constituting the first internal bone group is , 0.7 or more.

As described above, in this lead-acid battery, a relatively high proportion (70% or more) of the N2 second inner bones, which are the inner bones in the direction toward the first frame bone provided with the ear, is used. The bone is considered to be a large internal bone having a large cross ^- sectional area S2 (S2 ≧ 0.35 × T02) within a range not accompanied by a decrease in castability. Therefore, even if the lead-acid battery is used for a long period of time and the internal bone is corroded, the second internal bone, which is the internal bone in the direction toward the first frame bone provided with the ear portion, is cut. It can be suppressed, and as a result, the decrease in capacity can be suppressed and the life characteristics can be improved.

Further, in this lead-acid battery, there is a concern that the weight of the current collector will increase due to the presence of the internal bone, and that the weight of the lead-acid battery will increase. However, within the first internal bone of N1, which is the internal bone connecting between the two frame bones connected to the first frame bone (that is, the internal bone having a small effect on the volume even if cut). A relatively high proportion (70% or more) of the inner bone has a small cross-sectional area S1 (0.077 × S2max ≦ S1 ≦ 0.125 × S2max) as long as the castability and the filling property of the active material are not deteriorated. It is said to be a small internal bone. Therefore, the effect of the increase in the weight of the current collector due to the presence of the thick internal bone can be compensated for by the presence of the fine internal bone, and the increase in the weight of the current collector as a whole can be suppressed. The increase can be suppressed. Therefore, according to the present lead-acid battery, it is possible to improve the life characteristics of the lead-acid battery while avoiding deterioration of other characteristics (weight characteristics, fillability, castability) of the lead-acid battery.

(2) In the lead-acid battery, the ratio of the width W2 of the thick inner bone to the thickness T2 in the first direction in a direction orthogonal to both the first direction and the extending direction of the large internal bone. (W2 / T2) may be configured to be 0.9 or more and 1.1 or less. According to this lead-acid battery, the shape of the cross section orthogonal to the extending direction of the large internal bone can be made into a shape close to an ideal circular shape in terms of preventing cutting, and the internal bone is corroded and cut. Can be effectively suppressed, and the life characteristics of the lead storage battery can be effectively improved. When the ratio of the width W2 to the thickness T2 of the inner bone (W2 / T2) is 0.9 or more and 1.1 or less, the cross-sectional area S2 of the inner bone tends to increase, and eventually the current collector. The weight tends to increase. However, in this lead-acid battery, since the first internal bone in a relatively high proportion (70% or more) is the fine internal bone, the increase in the weight of the current collector as a whole is suppressed, and the thickness of the large internal bone is suppressed. The cross-sectional shape can be an ideal shape (a shape in which W2 / T2 is 0.9 or more and 1.1 or less) in terms of corrosion prevention, and the life characteristics of the lead storage battery can be effectively improved. It is.

A. Embodiment:
A-1. Basic configuration:
(Structure of lead-acid battery 100)
FIG. 1 is a front view showing the external configuration of the lead-acid battery 100 in the present embodiment, FIG. 2 is a top view showing the external configuration of the lead-acid battery 100, and FIG. 3 shows the internal configuration of the lead-acid battery 100. It is a top view (a diagram showing a state in which the lid 14 described later is removed), FIG. 4 is an explanatory diagram showing a YZ cross-sectional configuration of the lead-acid battery 100 at the position of IV-IV in FIG. 2, and FIG. 5 is a diagram. It is explanatory drawing which shows the YZ cross section composition of the lead storage battery 100 at the position of VV of 2, and FIG. 6 is an explanatory view which shows the XZ cross section composition of a part of the lead storage battery 100 at the position of VI-VI of FIG. .. For convenience of illustration, FIG. 3 shows only a part (three) of a plurality of electrode plate groups 20 (and straps 52, 54 connected to the plate group 20) described later, and also in FIG. 4 and FIG. In FIG. 5, a part of the configuration is omitted so that the configuration of the electrode plate group 20 is shown in an easy-to-understand manner. Each figure shows XYZ axes that are orthogonal to each other to identify the direction. In the present specification, for convenience, the Z-axis positive direction is referred to as "upward" and the Z-axis negative direction is referred to as "downward", but the lead-acid battery 100 is actually different from such an orientation. It may be installed facing.

The lead-acid battery 100 of the present embodiment is a control valve type lead-acid battery (sealed lead-acid battery). The control valve type lead-acid battery has a high degree of freedom in the installation posture because it does not have an electrolytic solution that flows inside, and maintenance is easy because there is no need to check the amount of liquid or refill water. For example, there is no control valve type lead-acid battery. It is used as a power source for uninterruptible power supplies, communication base stations, motorcycles, etc. The lead-acid battery 100 includes a housing 10, a positive electrode side terminal member 30, a negative electrode side terminal member 40, and a plurality of electrode plate groups 20. Hereinafter, the positive electrode side terminal member 30 and the negative electrode side terminal member 40 are collectively referred to as “terminal members 30, 40”.

(Structure of housing 10)
The housing 10 has an electric tank 12 and a lid 14. The electric tank 12 is a substantially rectangular parallelepiped container having an opening on the upper surface, and is formed of, for example, a synthetic resin. The lid 14 is a member arranged so as to close the opening of the electric tank 12, and is formed of, for example, a synthetic resin. By joining the peripheral edge portion of the lower surface of the lid 14 and the peripheral edge portion of the opening of the electric tank 12 by, for example, heat welding, a space maintained in airtightness with the outside is formed in the housing 10.

An exhaust plug 15 is arranged on the lid 14. The exhaust plug 15 has a function of collectively exhausting exhaust gas from a rubber valve (not shown) for adjusting internal pressure provided in each cell to the outside of the lead storage battery 100.

The space in the housing 10 is divided into a plurality of cell chambers 16 (six in the present embodiment) arranged in a predetermined direction (X-axis direction in the present embodiment) by a plurality of (five in the present embodiment) partition walls 58. It is partitioned. Hereinafter, the direction in which a plurality of cell chambers 16 are arranged (X-axis direction) is referred to as a “cell arrangement direction”. One electrode plate group 20 is housed in each cell chamber 16 in the housing 10. In the present embodiment, since the space inside the housing 10 is divided into six cell chambers 16, the lead-acid battery 100 includes six electrode plate groups 20.

(Structure of electrode plate group 20)
As shown in FIGS. 4 to 6, the electrode plate group 20 includes a plurality of positive electrode plates 210, a plurality of negative electrode plates 220, and a separator 230. The plurality of positive electrode plates 210 and the plurality of negative electrode plates 220 are arranged so that the positive electrode plates 210 and the negative electrode plates 220 are arranged alternately. Further, the separator 230 is arranged between the positive electrode plate 210 and the negative electrode plate 220 adjacent to each other, and is sandwiched between the positive electrode plate 210 and the negative electrode plate 220. The electrode plate group 20 may include members other than the positive electrode plate 210, the negative electrode plate 220, and the separator 230 (for example, a non-woven fabric sheet arranged between the positive electrode plate 210 and the negative electrode plate 220). Hereinafter, the positive electrode plate 210 and the negative electrode plate 220 are collectively referred to as “polar plate 210, 220”.

The positive electrode plate 210 has a positive electrode current collector 212 and a positive electrode active material 216 supported by the positive electrode current collector 212. The positive electrode current collector 212 is a conductive member having bones arranged in a substantially lattice pattern or a mesh pattern, and is formed of, for example, lead or a lead alloy. Further, the positive electrode current collector 212 has a positive electrode ear portion 214 protruding upward near the upper end thereof. The positive electrode active material 216 contains lead dioxide. The positive electrode active material 216 may further contain other known additives. In the positive electrode plate 210 having such a configuration, for example, a positive electrode active material paste containing lead monoxide, water, and dilute sulfuric acid as main components is applied or filled in the positive electrode current collector 212, and the positive electrode active material paste is dried. After that, it can be produced by performing a known chemical conversion treatment. The positive electrode active material 216 in the present embodiment is obtained by removing the positive electrode current collector 212 from the positive electrode plate 210, and corresponds to the positive electrode material within the scope of the claims.

The negative electrode plate 220 has a negative electrode current collector 222 and a negative electrode active material 226 supported by the negative electrode current collector 222. The negative electrode current collector 222 is a conductive member having bones arranged in a substantially lattice pattern or a mesh pattern, and is formed of, for example, lead or a lead alloy. Further, the negative electrode current collector 222 has a negative electrode ear portion 224 protruding upward near the upper end thereof. The negative electrode active material 226 contains lead (sponge-like lead). The negative electrode active material 226 may further contain other known additives (eg, fiber, carbon, lignin, barium sulfate, etc.). In the negative electrode plate 220 having such a configuration, for example, a paste for a negative electrode active material containing lead is applied or filled in the negative electrode current collector 222, the paste for the negative electrode active material is dried, and then a known chemical conversion treatment is performed. It can be produced by the above.

The separator 230 is a mat-like member made of an insulating material (for example, glass fiber or synthetic resin) and elastically deformable in the thickness direction. The separator 230 is impregnated with an electrolytic solution (for example, dilute sulfuric acid). As described above, the separator 230 has a function of preventing a short circuit between the bipolar plates 210 and 220 and holding the electrolytic solution. In the state where the electrode plate group 20 is housed in the cell chamber 16, the electrode plate group 20 receives a compressive force in the thickness direction (in the present embodiment, the X-axis direction). Therefore, the electrode plates 210 and 220 constituting the electrode plate group 20 are in good contact with the separator 230 holding the electrolytic solution.

As shown in FIGS. 3 to 5, the positive electrode ear portions 214 of the plurality of positive electrode plates 210 constituting the electrode plate group 20 are connected to a positive electrode side strap 52 formed of, for example, lead or a lead alloy. That is, the plurality of positive electrode plates 210 are electrically connected in parallel via the positive electrode side strap 52. Similarly, the negative electrode ear portions 224 of the plurality of negative electrode plates 220 constituting the electrode plate group 20 are connected to the negative electrode side strap 54 formed of, for example, lead or a lead alloy. That is, the plurality of negative electrode plates 220 are electrically connected in parallel via the negative electrode side strap 54. Hereinafter, the positive electrode side strap 52 and the negative electrode side strap 54 are collectively referred to as “straps 52, 54”.

In the lead-acid battery 100, the negative electrode side strap 54 housed in one cell chamber 16 is one side (for example, X-axis negative) of the one cell chamber 16 via a connecting member 56 formed of, for example, lead or a lead alloy. It is connected to a positive electrode side strap 52 housed in another cell chamber 16 adjacent to the directional side). Further, the positive electrode side strap 52 housed in the one cell chamber 16 is adjacent to another cell chamber 16 on the other side (for example, the positive direction side of the X-axis) of the one cell chamber 16 via the connecting member 56. It is connected to the negative electrode side strap 54 housed in. That is, the plurality of electrode plate groups 20 included in the lead storage battery 100 are electrically connected in series via the straps 52 and 54 and the connecting member 56. As shown in FIG. 4, the positive electrode side strap 52 housed in the cell chamber 16 located at the end on one side (X-axis positive direction side) of the cell arrangement direction is not a connecting member 56 but a positive electrode column described later. It is connected to 34. Further, as shown in FIG. 5, the negative electrode side strap 54 housed in the cell chamber 16 located at the end on the other side (X-axis negative direction side) in the cell arrangement direction is not a connecting member 56 but a negative electrode column described later. It is connected to 44.

(Structure of terminal members 30 and 40)
As shown in FIGS. 1 and 2, the positive electrode side terminal member 30 is arranged near the end of one side (X-axis positive direction side) of the housing 10 in the cell arrangement direction, and the negative electrode side terminal member 40 is , Is arranged near the end of the housing 10 on the other side (X-axis negative direction side) of the cell arrangement direction.

As shown in FIG. 4, the positive electrode side terminal member 30 includes a positive electrode side bushing 32, a positive electrode column 34, and a positive electrode side terminal portion 36. The positive electrode side bushing 32 is a substantially cylindrical conductive member having holes penetrating in the vertical direction, and is formed of, for example, a lead alloy. The positive electrode side bushing 32 is embedded in the lid 14 by insert molding. The positive electrode column 34 is a substantially cylindrical conductive member, and is formed of, for example, a lead alloy. The positive electrode column 34 is inserted into the hole of the positive electrode side bushing 32, and is joined to the positive electrode side bushing 32 by welding, for example. The lower end of the positive electrode column 34 protrudes downward from the lower end of the positive electrode side bushing 32, and further protrudes downward from the lower surface of the lid 14, and as described above, one side in the cell arrangement direction (X-axis positive direction side). ) Is connected to the positive electrode side strap 52 housed in the cell chamber 16 located at the end. The positive electrode side terminal portion 36 is, for example, a substantially L-shaped conductive member, and is formed of, for example, a lead alloy. The upper end portion of the positive electrode side terminal portion 36 projects upward from the upper surface of the lid 14, and the lower end portion of the positive electrode side terminal portion 36 is electrically connected to the upper end portion of the positive electrode column 34. The periphery of the portion of the upper surface of the lid 14 through which the positive electrode side terminal portion 36 penetrates is sealed with, for example, a resin member 90. The positive electrode side terminal portion 36 and the positive electrode column 34 may be an integral member.

As shown in FIG. 5, the negative electrode side terminal member 40 includes a negative electrode side bushing 42, a negative electrode column 44, and a negative electrode side terminal portion 46. The negative electrode side bushing 42 is a substantially cylindrical conductive member having holes penetrating in the vertical direction, and is formed of, for example, a lead alloy. The negative electrode side bushing 42 is embedded in the lid 14 by insert molding. The negative electrode column 44 is a substantially cylindrical conductive member, and is formed of, for example, a lead alloy. The negative electrode column 44 is inserted into the hole of the negative electrode side bushing 42, and is joined to the negative electrode side bushing 42 by welding, for example. The lower end of the negative electrode column 44 projects downward from the lower end of the negative electrode side bushing 42, and further protrudes downward from the lower surface of the lid 14, and as described above, the other side in the cell arrangement direction (X-axis negative direction side). ) Is connected to the negative electrode side strap 54 housed in the cell chamber 16 located at the end. The negative electrode side terminal portion 46 is, for example, a substantially L-shaped conductive member, and is formed of, for example, a lead alloy. The upper end portion of the negative electrode side terminal portion 46 projects upward from the upper surface of the lid 14, and the lower end portion of the negative electrode side terminal portion 46 is electrically connected to the upper end portion of the negative electrode column 44. Around the portion of the upper surface of the lid 14 through which the negative electrode side terminal portion 46 penetrates, for example, a resin member 90 is sealed. The negative electrode side terminal portion 46 and the negative electrode column 44 may be an integral member.

When the lead storage battery 100 is discharged, a load (not shown) is connected to the positive electrode side terminal portion 36 of the positive electrode side terminal member 30 and the negative electrode side terminal portion 46 of the negative electrode side terminal member 40, and each electrode group 20 The electric power generated by the reaction on the positive electrode plate 210 (reaction in which lead sulfate is generated from lead dioxide) and the reaction on the negative electrode plate 220 (reaction in which lead sulfate is generated from lead (spider-like lead)) is supplied to the load. Further, when charging the lead storage battery 100, a power supply (not shown) is connected to the positive electrode side terminal portion 36 of the positive electrode side terminal member 30 and the negative electrode side terminal portion 46 of the negative electrode side terminal member 40, and is supplied from the power supply. The generated electric power causes a reaction on the positive electrode plate 210 of each electrode group 20 (a reaction in which lead dioxide is produced from lead sulfate) and a reaction on the negative electrode plate 220 (a reaction in which lead (lead (spear-like lead) is produced from lead sulfate)). The lead storage battery 100 is charged.

A-2. Detailed configuration of positive electrode current collector 212:
Next, the detailed configuration of the positive electrode current collector 212 constituting the positive electrode plate 210 will be described. 7 is an explanatory diagram showing the YZ plane configuration of the positive electrode current collector 212, and FIG. 8 is an explanatory diagram showing the XY cross-sectional configuration of the positive electrode current collector 212 at the position of VIII-VIII in FIG. 7. FIG. 9 is an explanatory diagram showing an XZ cross-sectional configuration of the positive electrode current collector 212 at the position of IX-IX in FIG. 7. In the following description, the Z-axis direction is also referred to as "vertical direction", the Y-axis direction is also referred to as "horizontal direction", and the X-axis direction is also referred to as "depth direction". The X-axis direction (depth direction) corresponds to the first direction in the claims.

As shown in FIG. 7, the positive electrode current collector 212 has a frame portion 60, an inner portion 70, and the selvage portion 214 described above. In this embodiment, the positive electrode current collector 212 further has a foot portion 80 provided on the lower side of the frame portion 60.

The frame portion 60 is composed of four frame bones 61 and 62, and has a substantially rectangular shape (in the present embodiment, a substantially rectangular shape) when viewed in the X-axis direction (depth direction). The thickness T0 of the frame portion 60 in the X-axis direction (depth direction) is preferably 4.0 mm or more. In the following description, among the four frame bones constituting the frame portion 60, a pair of frame bones parallel to the Y-axis direction (horizontal direction) is referred to as "horizontal frame bone 61", and is referred to as "horizontal frame bone 61" in the Z-axis direction (vertical direction). A pair of frame bones parallel to each other is called "vertical frame bone 62". Further, among the pair of horizontal frame bones 61, the horizontal frame bone 61 located on the upper side (Z-axis positive direction side) is called "upper horizontal frame bone 61t", and is laterally located on the lower side (Z-axis negative direction side). The frame bone 61 is referred to as "lower horizontal frame bone 61b". Of the pair of vertical frame bones 62, the vertical frame bone 62 located on the negative direction side of the Y axis is referred to as "left vertical frame bone 62l", and the vertical frame bone 62 located on the positive direction side of the Y axis is referred to as "right vertical frame bone 62". It is called "frame bone 62r".

The selvage portion 214 is provided so as to extend upward from the upper lateral frame bone 61t. The upper lateral frame bone 61t corresponds to the first frame bone in the claims.

The medial portion 70 is provided inside the frame portion 60 and has a plurality of internal bones 710 and 720. More specifically, the medial portion 70 is a plurality of first internal bones connecting between two frame bones (that is, left vertical frame bone 62l and right vertical frame bone 62r) connected to the upper lateral frame bone 61t. It has a first internal bone group 71 composed of 710. In the present embodiment, the number N1 of the first internal bones 710 is 14, the extending direction of each first internal bone 710 is parallel to the Y-axis direction (lateral direction), and each first internal bone 710 is parallel. Are arranged substantially evenly in the Z-axis direction (vertical direction). In the following description, the first internal bone 710 is also referred to as "lateral internal bone 710", and the first internal bone group 71 is also referred to as "lateral internal bone group 71".

The medial portion 70 further comprises a plurality of second internal bones 720 connecting the upper lateral frame bone 61t and one frame bone facing the upper lateral frame bone 61t (that is, the lower lateral frame bone 61b). It has a second internal bone group 72 composed of. In the present embodiment, the number N2 of the second internal bones 720 is 7, the extending direction of each of the second internal bones 720 is parallel to the Z-axis direction (longitudinal direction), and each of the second internal bones 720 is parallel. Are arranged substantially evenly in the Y-axis direction (horizontal direction). In the following description, the second internal bone 720 is also referred to as "vertical internal bone 720", and the second internal bone group 72 is also referred to as "longitudinal internal bone group 72".

As described above, the medial portion 70 has a plurality of transverse internal bones 710 constituting the lateral internal bone group 71 and a plurality of longitudinal internal bones 720 constituting the longitudinal internal bone group 72. Each transverse internal bone 710 is connected to each longitudinal internal bone 720 at an intersection with each longitudinal internal bone 720. Therefore, the shape of the inner portion 70 in the X-axis direction (depth direction) is substantially lattice-shaped (stitch-shaped). The medial portion 70 extends from another internal bone (for example, the upper lateral frame bone 61t toward the lower lateral frame bone 61b, but does not reach the lower lateral frame bone 61b and is interrupted in the middle. , The diagonal internal bone connecting the lower horizontal frame bone 61b and the left vertical frame bone 62l) may be provided.

As shown in FIGS. 7 and 8, in the present embodiment, the longitudinal internal bone group 72 includes the large internal bone 720a. Here, the large internal bone 720a is an internal bone in which the cross-sectional area S2 of the cross section orthogonal to the stretching direction satisfies the relationship of the following formula (1). That is, in the thick internal bone 720a, the ratio of the cross-sectional area S2 of the vertical internal bone 720 to the area (= T02) of the virtual ^square VS having the thickness T0 of the frame portion 60 as ^one side (= S2 / T02). (Hereinafter referred to as “vertical bone cross-sectional coefficient K2”) is the vertical internal bone 720 having a length of 0.35 or more and 0.65 or less. The thick inner bone 720a has a relatively large cross-sectional area S2 (although the longitudinal bone cross-sectional coefficient K2 is 0.35 or more), but the cross-sectional area S2 is not excessively large (the longitudinal bone cross-sectional coefficient K2 is 0.65 or less). It can be said that it is a longitudinal internal bone 720. The cross-sectional area S2 of the inner bone 720a is preferably 10.6 mm ² or more and 19.7 mm ² or less, for example.
0.35 × T0 ² ≦ S2 ≦ 0.65 × T0 ² ... (1)
(However, T0 is the thickness of the frame portion 60 in the X-axis direction (depth direction))

In the present embodiment, the ratio (= n2 / N2) of the number n2 of the large internal bones 720a to the number N2 of the vertical internal bones 720 constituting the vertical internal bone group 72 is (hereinafter referred to as “large internal bone ratio R2”). , 0.7 or more. For example, in the example shown in FIG. 7, all of the seven longitudinal internal bones 720 constituting the longitudinal internal bone group 72 are the large internal bones 720a (that is, N2 = 7, n2 = 7). The thick bone ratio R2 is 1.0.

Further, in the present embodiment, as shown in FIG. 8, the X-axis direction and the extension direction of the thick inner bone 720a (that is, the Z-axis direction) with respect to the thickness T2 of the thick inner bone 720a in the X-axis direction (depth direction). ) And the ratio (= W2 / T2) of the width W2 in the direction orthogonal to both (that is, the Y-axis direction) is 0.9 or more and 1.1 or less. That is, the shape of the cross section of the thick inner bone 720a orthogonal to the extending direction is relatively close to a circle.

Further, as shown in FIGS. 7 and 9, in the present embodiment, the lateral internal bone group 71 includes the fine internal bone 710a. The fine internal bone 710a is an internal bone in which the cross-sectional area S1 of the cross section orthogonal to the stretching direction satisfies the relationship of the following formula (2). That is, in the fine internal bone 710a, the ratio (= S1 / S2max) of the cross-sectional area S1 of the lateral internal bone 710 to the maximum value S2max of the cross-sectional area S2 of the large internal bone 720a (hereinafter referred to as “lateral bone cross-sectional coefficient K1”) is determined. Lateral internal bone 710 internal bone of 0.077 or more (that is, 1/13 or more) and 0.125 or less (that is, 1/8 or less). The microinner bone 710a has a relatively small cross-sectional area S1 (although the cross-sectional area S1 is 0.125 or less), but the cross-sectional area S1 is not excessively small (the cross-sectional area K1 is 0.077 or more). It can be said that it is the lateral internal bone 710. The cross-sectional area S1 of the fine internal bone 710a is preferably 1.2 mm ² or more and 2.0 mm ² or less, for example.
0.077 x S2max ≤ S1 ≤ 0.125 x S2max ... (2)
(However, S2max is the maximum value of the cross-sectional area S2 of the large internal bone 720a)

In the present embodiment, the ratio (= n1 / N1) of the number n1 of the small internal bones 710a to the number N1 of the horizontal internal bones 710 constituting the lateral internal bone group 71 (hereinafter referred to as “fine internal bone ratio R1”) is 0. It is 0.7 or more. For example, in the example shown in FIG. 7, of the 14 lateral internal bones 710 constituting the lateral internal bone group 71, 12 lateral internal bones 710 are fine internal bones 710a (that is, N1 = 14, n1 = 12). Therefore, the fine bone ratio R1 is 0.86.

A-3. Effect of this embodiment:
As described above, the lead storage battery 100 of the present embodiment includes a positive electrode plate 210 having a positive electrode current collector 212 and a positive electrode active material 216 supported by the positive electrode current collector 212. The positive electrode current collector 212 is composed of four frame bones 61 and 62 including the upper horizontal frame bone 61t, and has a substantially quadrangular frame portion 60 in the X-axis direction and an ear portion provided on the upper horizontal frame bone 61t. It has 214 and an inner portion 70 provided inside the frame portion 60. The medial portion 70 is a lateral internal bone group 71 composed of N1 lateral internal bones 710 connecting between two frame bones (left vertical frame bone 62l and right vertical frame bone 62r) connected to the upper lateral frame bone 61t. And the longitudinal internal bone group 72 composed of N2 longitudinal internal bones 720 connecting between the upper lateral frame bone 61t and one frame bone (lower lateral frame bone 61b) facing the upper lateral frame bone 61t. And have. In the longitudinal internal bone group 72, the cross-sectional area S2 of the cross section orthogonal to the stretching direction satisfies the relationship of 0.35 × T0 ² ≦ S2 ≦ 0.65 × T0 ² (where T0 is the thickness of the frame portion 60). Includes n2 thick internal bones 720a. The lateral internal bone group 71 has a relationship that the cross-sectional area S1 of the cross section orthogonal to the stretching direction is 0.077 × S2max ≦ S1 ≦ 0.125 × S2max (however, S2max is the maximum value of the cross-sectional area of the large internal bone). Contains n1 microinner bones 710a to fill. The ratio (n2 / N2) of the number n2 of the large internal bones 720a to the number N2 of the vertical internal bones 720 constituting the vertical internal bone group 72 is 0.7 or more. The ratio (n1 / N1) of the number n1 of the microinner bones 710a to the number N1 of the lateral internal bones 710 constituting the lateral internal bone group 71 is 0.7 or more.

As described above, in the lead-acid battery 100 of the present embodiment, a relatively high proportion (70%) of the N2 vertical internal bones 720 which are the internal bones in the direction toward the upper horizontal frame bone 61t provided with the ear portion 214. The longitudinal internal bone 720 (above) is said to be a large internal bone 720a having a large cross ^- sectional area S2 (S2 ≧ 0.35 × T02) within a range not accompanied by a decrease in castability. Therefore, even if the lead-acid battery 100 is used for a long period of time and the internal bones 710 and 720 are corroded, the vertical internal bone 720, which is the internal bone in the direction toward the upper lateral frame bone 61t provided with the ear portion 214, is cut. As a result, it is possible to suppress a decrease in capacity and improve life characteristics.

Further, in the lead-acid battery 100 of the present embodiment, there is a concern that the weight of the positive electrode current collector 212 will increase, and eventually the weight of the lead-acid battery 100 will increase due to the presence of the large inner bone 720a. However, the internal bone connecting between the two frame bones (left vertical frame bone 62l and right vertical frame bone 62r) connected to the upper horizontal frame bone 61t (that is, the internal bone having a small effect on the volume even if cut) ), Of the N1 lateral internal bones 710, a relatively high proportion (70% or more) of the lateral internal bones 710 has a small cross-sectional area S1 (0. (077 × S2max ≦ S1 ≦ 0.125 × S2max) It is said that the microinner bone 710a. Therefore, the influence of the increase in the weight of the positive electrode current collector 212 due to the presence of the large internal bone 720a can be compensated for by the presence of the fine internal bone 710a, and the increase in the weight of the positive electrode current collector 212 as a whole can be suppressed. , The increase in the weight of the lead storage battery 100 can be suppressed. Therefore, according to the lead-acid battery 100 of the present embodiment, it is possible to improve the life characteristics of the lead-acid battery 100 while avoiding deterioration of other characteristics (weight characteristics, filling property, castability) of the lead-acid battery 100.

Further, in the lead storage battery 100 of the present embodiment, the X-axis direction and the extension direction of the thick inner bone 720a (that is, the Z-axis direction) with respect to the thickness T2 of the thick inner bone 720a in the X-axis direction (depth direction). The ratio (= W2 / T2) of the width W2 in the direction orthogonal to both (that is, the Y-axis direction) is 0.9 or more and 1.1 or less. According to the lead-acid battery 100 of the present embodiment, the shape of the cross section orthogonal to the stretching direction of the large internal bone 720a can be made into a shape close to an ideal circular shape in terms of preventing cutting, and the large internal bone 720a is corroded. It is possible to effectively suppress the disconnection and effectively improve the life characteristics of the lead-acid battery 100. When the ratio of the width W2 to the thickness T2 of the inner bone 720a (= W2 / T2) is 0.9 or more and 1.1 or less, the cross-sectional area S2 of the inner bone 720a tends to increase, and eventually the positive electrode. The weight of the current collector 212 tends to increase. However, in the lead-acid battery 100 of the present embodiment, since the lateral internal bone 710 has a relatively high ratio (70% or more) as the fine internal bone 710a, the increase in the weight of the positive electrode current collector 212 as a whole is suppressed. , The cross-sectional shape of the thick inner bone 720a can be made into an ideal shape (a shape in which W2 / T2 is 0.9 or more and 1.1 or less) in terms of corrosion prevention, and the life characteristics of the lead-acid battery 100 can be effective. Can be improved.

A-4. Performance evaluation:
A plurality of samples of lead-acid batteries (SA1 to SA14 corresponding to Examples and SA21 to SA26 corresponding to Comparative Examples) were prepared, and the performance of the samples was evaluated. 10 to 13 are explanatory views showing the performance evaluation results. The reference sample SA1 among the plurality of samples is described in common to all of FIGS. 10 to 13 (indicated by a thick frame in each figure).

A-4-1. For each sample:
In each sample, the transverse internal bone group 71 possessed by the positive electrode collector 212 is composed of one type or two types of lateral internal bones 710 having different cross-sectional areas, and the longitudinal internal bone group 72 possessed by the positive electrode collector 212 is composed of one type or two types of lateral internal bones 710 having different cross-sectional areas. It is composed of one type or two types of longitudinal internal bones 720 having different cross-sectional areas. 10 to 13 show the maximum value (hereinafter referred to as “maximum geometrical moment of inertia ^K2max ”) of the above-mentioned geometrical moment of inertia K2 (= S2 / T02) of each longitudinal internal bone 720 for each sample. Has been done. When the longitudinal internal bone group 72 is composed of one type of longitudinal internal bone 720, the longitudinal bone section coefficient K2 of the longitudinal internal bone 720 is the maximum longitudinal bone section coefficient K2max, and the longitudinal internal bone group 72 has two types. In the case of being composed of the vertical internal bone 720, the vertical bone cross-sectional coefficient K2 of the vertical internal bone 720 having the larger cross-sectional area S2 is the maximum vertical bone cross-sectional coefficient K2max. In this performance evaluation, T0 = 5.5 mm.

Similarly, in FIGS. 10 to 13, for each sample, the minimum value of the above-mentioned geometrical moment of inertia K1 (= S1 / S2max) of each lateral internal bone 710 (hereinafter referred to as “minimum geometrical moment of inertia K1min”) is shown. It is shown. When the lateral internal bone group 71 is composed of one type of lateral internal bone 710, the lateral bone cross-sectional coefficient K1 of the lateral internal bone 710 is the minimum lateral bone cross-sectional coefficient K1 min, and the lateral internal bone group 71 has two types of lateral internal bone 710. In the case of the above, the lateral bone sectional coefficient K1 of the lateral internal bone 710 having the smaller cross-sectional area S1 is the minimum transverse bone sectional coefficient K1min.

Further, FIGS. 10 to 13 show the intimal bone ratio R2 for each sample. However, the thick internal bone ratio R2 shown in FIGS. 10 to 13 is the ratio of the number of longitudinal internal bones 720 having the maximum geometrical moment of inertia K2max to the number of longitudinal internal bones 720. When the maximum moment of inertia K2max is within the range satisfying the formula (1) described in the above-described embodiment (that is, 0.35 or more and 0.65 or less), the maximum moment of inertia K2max is taken. Since the longitudinal internal bone 720 corresponds to the large internal bone 720a, the internal bone ratio R2 shown in FIGS. 10 to 13 has the same meaning as the internal bone ratio R2 described in the above-described embodiment. On the other hand, when the maximum longitudinal bone cross-sectional coefficient K2max is outside the above range (0.35 or more, 0.65 or less), the longitudinal internal bone 720 having the maximum longitudinal bone cross-sectional coefficient K2max does not correspond to the large internal bone 720a. Therefore, the thick internal bone ratio R2 shown in FIGS. 10 to 13 does not have the same meaning as the large internal bone ratio R2 described in the above-described embodiment, but the same term is used here for convenience. However, in this case, the numerical values in the column of the large internal bone ratio R2 in FIGS. 10 to 13 are shown in parentheses. In this performance evaluation, the number of longitudinal internal bones 720 was set to 7.

Similarly, FIGS. 10 to 13 show the fine bone ratio R1 for each sample. However, the fine internal bone ratio R1 shown in FIGS. 10 to 13 is the ratio of the number of lateral internal bones 710 having the minimum moment of inertia of area K1 min to the number of lateral internal bones 710. When the minimum moment of inertia K1min is within the range satisfying the formula (2) described in the above-described embodiment (that is, 0.077 or more and 0.125 or less), the minimum moment of inertia K1min is taken. Since the transverse internal bone 710 corresponds to the fine internal bone 710a, the fine internal bone ratio R1 shown in FIGS. 10 to 13 has the same meaning as the fine internal bone ratio R1 described in the above-described embodiment. On the other hand, when the minimum lateral bone cross-sectional coefficient K1min is outside the above range (0.077 or more, 0.125 or less), the lateral internal bone 710 having the minimum lateral bone cross-sectional coefficient K1min does not correspond to the fine internal bone 710a. , The fine internal bone ratio R1 shown in FIGS. 10 to 13 does not have the same meaning as the fine internal bone ratio R1 described in the above-described embodiment, but the same term is used here for convenience. However, in this case, the numerical values in the column of the fine bone ratio R1 in FIGS. 10 to 13 are shown in parentheses. In this performance evaluation, the number of lateral internal bones 710 was 14.

Each sample shown in FIG. 10 differs only from the reference sample SA1 in the maximum moment of inertia of area K2max. Further, each sample shown in FIG. 11 differs only from the reference sample SA1 in the thick internal bone ratio R2. Further, each sample shown in FIG. 12 differs from the reference sample SA1 only in the minimum moment of inertia of area K1 min. Further, each sample shown in FIG. 13 differs only in the fine bone ratio R1 from the reference sample SA1.

A-4-2. Evaluation items and evaluation methods:
In this performance evaluation, four items of life, weight, filling property of active material, and castability of current collector were evaluated using each of the above-mentioned samples.

The life was evaluated as follows according to the JIS overcharge life test method. That is, each sample of the fully charged lead-acid battery is continuously overcharged with a current of 0.2 × I ₁₀ (0.02C ₁₀ A). During the overcharge life test, a 1-hour rate capacity test is performed every 30 days to confirm the capacity. The test is terminated when the capacity becomes less than 80%, and the number of days elapsed at that time is defined as the life. The measured life is the life of a lead-acid battery having a conventional configuration (specifically, a lead-acid battery having a frame portion 60 having a thickness T0 of less than 4.0 mm in the X-axis direction (depth direction)) (hereinafter, ". If it is 1.5 times or more of the conventional life (referred to as "conventional life"), it is judged as "excellent" (◎), and if it is 1.3 times or more and less than 1.5 times the conventional life, it is "good" (〇). ), And when it was less than 1.3 times the conventional life, it was judged as "defective" (x).

The weight was evaluated as follows. That is, the weight of each sample is measured, and when the measured weight is less than 1.5 times the weight of the lead-acid battery having the above-mentioned conventional configuration (hereinafter referred to as "conventional weight"), it is "excellent" (◎). ), And if it is 1.5 times or more and less than 1.8 times the conventional weight, it is judged as "good" (○), and if it is 1.8 times or more the conventional weight, it is "bad". It was determined to be (x).

The filling property was evaluated as follows. That is, the positive electrode current collector 212 is filled with the active material paste, and the frame is dropped (when the active material paste is relatively soft after the active material paste is filled and before being placed in the preheating and drying furnace, the positive electrode current collector is used. When a part of the paste for active material in the squares of the body 212 falls off completely) or when the back circumference (a phenomenon in which the inner bone is exposed by 10% or more) occurs, it is regarded as poor workmanship. If the incidence of is less than 0.2%, it is judged as "excellent" (◎), and if it is 0.2% or more and less than 0.3%, it is judged as "good" (○). , If it was 0.3% or more, it was judged as "defective" (x).

The castability was evaluated as follows. That is, a positive current collector 212 is produced by casting, and a cavity (a phenomenon in which a cavity is formed inside), a burnout (a phenomenon in which the bone becomes brittle and breaks and cracks occur), and a crosspiece (a phenomenon in which the bone becomes too thin) are produced. When at least one of (phenomenon of cutting off in the middle) occurs, it is judged as poor workmanship, and when the occurrence rate of poor workmanship is less than 0.2%, it is judged as "excellent" (◎), and 0.2% or more. , If it was less than 0.3%, it was judged as "good" (〇), and if it was 0.3% or more, it was judged as "bad" (x).

A-4-3. Evaluation results:
First, each sample (SA1 to SA3, SA21, SA22) shown in FIG. 10 will be described. Of these samples, samples SA1 to SA3 were judged to be "good" (○) or higher for all evaluation items, while sample SA22 was judged to be "poor" (x) for the evaluation item of "lifetime". In the sample SA21, the evaluation items of "weight" and "castability" were determined to be "defective" (x).

For the transverse bone group 71, the conditions are the same for all the samples shown in FIG. That is, in all the samples, since the minimum moment of inertia K1min is within the range satisfying the formula (2) described in the above-described embodiment (that is, 0.077 or more and 0.125 or less), the minimum transverse bone The transverse internal bone 710 having a section coefficient of K1 min corresponds to the fine internal bone 710a. Further, the fine bone ratio R1 is within the range described in the above-described embodiment (that is, 0.7 or more).

On the other hand, regarding the longitudinal internal bone group 72, the conditions are different for each sample shown in FIG. Specifically, in the sample SA22, the maximum longitudinal bone cross-sectional coefficient K2max is lower than the range (that is, 0.35 or more and 0.65 or less) that satisfies the formula (1) described in the above-described embodiment (0. 30) Therefore, since the cross-sectional area S2 of the longitudinal internal bone 720 having the maximum longitudinal bone cross-sectional coefficient K2max is small, the longitudinal internal bone 720 does not correspond to the large internal bone 720a. Therefore, in the sample SA22, since the cross-sectional area S2 of the longitudinal internal bone 720 constituting the longitudinal internal bone group 72 is relatively small as a whole, the volume reduction due to the corrosion and cutting of the longitudinal internal bone 720 is reduced. It is probable that the "lifetime" evaluation was lowered because it could not be sufficiently suppressed.

Further, in the sample SA21, the maximum longitudinal bone cross-sectional coefficient K2max is a value (0.70) higher than the range satisfying the formula (1) described in the above-described embodiment (that is, 0.35 or more and 0.65 or less). Therefore, since the cross-sectional area S2 of the longitudinal internal bone 720 having the maximum longitudinal bone cross-sectional coefficient K2max is excessively large, the longitudinal internal bone 720 does not correspond to the large internal bone 720a. Therefore, in the sample SA21, since the cross-sectional area S2 of the longitudinal internal bones 720 constituting the longitudinal internal bone group 72 is excessively large as a whole, the weight of the longitudinal internal bone group 72 is excessively increased and the “weight” evaluation is low. At the same time, it is probable that the “castability” evaluation was lowered due to the tendency for cavities and burnout to occur.

On the other hand, in the samples SA1 to SA3, since the maximum longitudinal bone cross-sectional coefficient K2max is within the range satisfying the formula (1) described in the above-described embodiment (that is, 0.35 or more and 0.65 or less), the maximum longitudinal axis is obtained. The longitudinal internal bone 720 having the bone cross-sectional coefficient K2max corresponds to the large internal bone 720a having a relatively large cross-sectional area S2 but not excessively large. Therefore, in the samples SA1 to SA3, it is possible to suppress a decrease in volume due to corrosion and cutting of the longitudinal internal bone 720 constituting the longitudinal internal bone group 72, and the "lifetime" evaluation is high and the evaluation is high. The increase in the weight of the longitudinal bone group 72 can be suppressed, the "weight" evaluation is high, and the occurrence of cavities and burnout can be suppressed, and the "castability" evaluation is high. it is conceivable that.

Next, each sample (SA1, SA4 to SA6, SA23) shown in FIG. 11 will be described. Among these samples, in samples SA1 and SA4 to SA6, all the evaluation items were judged to be "good" (○) or higher, while in sample SA23, the evaluation item of "lifetime" was "poor" (×). Was determined.

For the transverse bone group 71, the conditions are the same for all the samples shown in FIG. That is, in all the samples, since the minimum moment of inertia K1min is within the range satisfying the formula (2) described in the above-described embodiment (that is, 0.077 or more and 0.125 or less), the minimum transverse bone The transverse internal bone 710 having a section coefficient of K1 min corresponds to the fine internal bone 710a. Further, the fine bone ratio R1 is within the range described in the above-described embodiment (that is, 0.7 or more).

On the other hand, regarding the longitudinal internal bone group 72, the conditions are different for each sample shown in FIG. Specifically, in the sample SA23, since the maximum geometrical moment of inertia K2max is within the range satisfying the formula (1) described in the above-described embodiment (that is, 0.35 or more and 0.65 or less), it is the maximum. The longitudinal internal bone 720 having the geometrical moment of inertia K2max corresponds to the large internal bone 720a having a relatively large cross-sectional area S2 but not excessively large. However, in the sample SA23, the intimal bone ratio R2 is a value (0.6) lower than the range (that is, 0.7 or more) described in the above-described embodiment. Therefore, in the sample SA23, among the vertical internal bones 720 constituting the vertical internal bone group 72, the number of the vertical internal bones 720 corresponding to the large internal bones 720a is small, so that the vertical internal bones 720 are corroded and cut. It is probable that the decrease in capacity due to the above could not be sufficiently suppressed, and the "lifetime" evaluation was lowered.

On the other hand, in the samples SA1 and SA4 to SA6, the intimal bone ratio R2 is within the range described in the above-described embodiment (that is, 0.7 or more). Therefore, in the samples SA1 and SA4 to SA6, among the longitudinal internal bones 720 constituting the longitudinal internal bone group 72, the number of longitudinal internal bones 720 corresponding to the large internal bone 720a is large, and the longitudinal internal bone group 72 is formed. It is considered that the decrease in volume due to the corrosion and cutting of the longitudinal internal bone 720 could be suppressed, and the "lifetime" evaluation was improved.

Next, each sample (SA1, SA7 to SA10, SA24, SA25) shown in FIG. 12 will be described. Among these samples, in samples SA1 and SA7 to SA10, all the evaluation items were judged to be "good" (○) or higher, while in sample SA25, the evaluation items of "weight" and "fillability" were "". It was determined to be "defective" (x), and in the sample SA24, it was determined to be "defective" (x) with respect to the evaluation items of "fillability" and "castability".

For the longitudinal bone group 72, the conditions are the same for all the samples shown in FIG. That is, in all the samples, since the maximum geometrical moment of inertia K2max is within the range satisfying the formula (1) described in the above-described embodiment (that is, 0.35 or more and 0.65 or less), the maximum longitudinal bone The longitudinal internal bone 720 having the moment of inertia of area K2max corresponds to the large internal bone 720a. In addition, the thick bone ratio R2 is within the range described in the above-described embodiment (that is, 0.7 or more).

On the other hand, regarding the lateral internal bone group 71, the conditions are different for each sample shown in FIG. Specifically, in the sample SA25, the minimum transverse bone cross-sectional coefficient K1min is higher than the range (that is, 0.077 or more and 0.125 or less) that satisfies the formula (2) described in the above-described embodiment (0. Since 133), the transverse internal bone 710 does not correspond to the fine internal bone 710a because the cross-sectional area S1 of the lateral internal bone 710 having the minimum transverse bone cross-sectional coefficient K1 min is large. Therefore, in the sample SA25, since the cross-sectional area S1 of the lateral internal bone 710 constituting the lateral internal bone group 71 is relatively large as a whole, the weight increase due to the longitudinal internal bone group 72 including the large internal bone 720a is added to the lateral internal bone. It is probable that the weight reduction of group 71 could not be sufficiently compensated and the "weight" rating was lowered. Further, in the sample SA25, since the cross-sectional area S1 of the lateral internal bone 710 constituting the lateral internal bone group 71 is relatively large as a whole, each square of the positive electrode current collector 212 becomes excessively small, and the “fillability” evaluation is low. It is thought that it has become.

Further, in the sample SA24, the minimum transverse bone cross-sectional coefficient K1min is a value (0.071) lower than the range satisfying the formula (2) described in the above-described embodiment (that is, 0.077 or more and 0.125 or less). Therefore, since the cross-sectional area S1 of the lateral internal bone 710 having the minimum lateral bone cross-sectional coefficient K1 min is excessively small, the lateral internal bone 710 does not correspond to the fine internal bone 710a. Therefore, in the sample SA24, since the cross-sectional area S1 of the lateral internal bone 710 constituting the lateral internal bone group 71 is excessively small as a whole, the cross-section is likely to occur, the "castability" evaluation is lowered, and the cross-section is broken. It is probable that the "castability" evaluation was also lowered due to the influence.

On the other hand, in the samples SA1 and SA7 to SA10, since the minimum geometrical moment of inertia K1min is within the range satisfying the formula (2) described in the above-described embodiment (that is, 0.077 or more and 0.125 or less). The transverse internal bone 710 having the minimum geometrical moment of inertia K1 min corresponds to the small internal bone 710a having a relatively small cross-sectional area S1 but not excessively small. Therefore, in the samples SA1 and SA7 to SA10, the weight increase due to the longitudinal internal bone group 72 including the large internal bone 720a could be sufficiently compensated by the weight reduction of the lateral internal bone group 71, and thus the "weight" evaluation was performed. It was possible to prevent the squares of the positive electrode current collector 212 from becoming excessively small and to suppress the occurrence of cross-cutting, so that the "castability" and "fillability" evaluations were high. Conceivable.

Next, each sample (SA1, SA11 to SA14, SA26) shown in FIG. 13 will be described. Among these samples, in samples SA1 and SA11 to SA14, all the evaluation items were judged to be "good" (○) or higher, while in sample SA26, the evaluation item of "weight" was "poor" (×). Was determined.

For the longitudinal bone group 72, the conditions are the same for all the samples shown in FIG. That is, in all the samples, since the maximum geometrical moment of inertia K2max is within the range satisfying the formula (1) described in the above-described embodiment (that is, 0.35 or more and 0.65 or less), the maximum longitudinal bone The longitudinal internal bone 720 having the moment of inertia of area K2max corresponds to the large internal bone 720a. In addition, the thick bone ratio R2 is within the range described in the above-described embodiment (that is, 0.7 or more).

On the other hand, regarding the lateral internal bone group 71, the conditions are different for each sample shown in FIG. Specifically, in the sample SA26, since the minimum geometrical moment of inertia K1min is within the range satisfying the formula (2) described in the above-described embodiment (that is, 0.077 or more and 0.125 or less), it is the minimum. The transverse internal bone 710 having a geometrical moment of inertia K1 min corresponds to the small internal bone 710a having a relatively small cross-sectional area S1 but not excessively small. However, in the sample SA26, the fine bone ratio R1 is a value (0.6) lower than the range (that is, 0.7 or more) described in the above-described embodiment. Therefore, in the sample SA26, among the lateral internal bones 710 constituting the lateral internal bone group 71, the number of the lateral internal bones 710 corresponding to the fine internal bones 710a is small, and therefore the weight due to the longitudinal internal bone group 72 including the large internal bones 720a. It is probable that the increase could not be sufficiently compensated by the weight reduction of the lateral internal bone group 71, and the "weight" evaluation was lowered.

On the other hand, in the samples SA1 and SA11 to SA14, the fine bone ratio R1 is within the range described in the above-described embodiment (that is, 0.7 or more). Therefore, in the samples SA1, SA11 to SA14, among the lateral internal bones 710 constituting the lateral internal bone group 71, the number of the lateral internal bones 710 corresponding to the fine internal bones 710a is large, and the longitudinal internal bone group 72 has the large internal bones 720a. It is probable that the weight increase due to the inclusion could be sufficiently compensated by the weight reduction of the lateral internal bone group 71, and the "weight" evaluation was improved.

As described above, according to this performance evaluation, the longitudinal internal bone group 72 has a longitudinal bone cross-sectional coefficient K2 of 0.35 or more and 0.65 or less (that is, a cross-sectional area S2 of 0.35 × T0 ² ≦ S2 ≦ 0). The lateral internal bone group 71 includes the large internal bone 720a (which satisfies the relationship of .65 × T02), and the lateral bone cross ^- sectional coefficient K1 is 0.077 or more and 0.125 or less (that is, the cross-sectional area S1 is 0.077). (Satisfying the relationship of × S2max ≦ S1 ≦ 0.125 × S2max) The large internal bone, which is the ratio of the number of the large internal bones 720a to the number of the vertical internal bones 720s including the fine internal bones 710a and constituting the vertical internal bone group 72. If the ratio R2 is 0.7 or more and the fine internal bone ratio R1 which is the ratio of the number of small internal bones 710a to the number of horizontal internal bones 710 constituting the lateral internal bone group 71 is 0.7 or more, lead. It was confirmed that the life characteristics of the lead storage battery can be improved while avoiding deterioration of the weight characteristics, fillability and castability of the storage battery.

In general, in lead-acid batteries, "lifetime" among the four evaluation items in this performance evaluation is often given the highest priority. As shown in FIG. 10, in the samples SA1 and SA2 having the maximum longitudinal bone cross-sectional coefficient K2max of 0.5 or more and 0.65 or less, the evaluation item of "lifetime" was judged to be "excellent" (◎). , The longitudinal internal bone group 72 has a relationship that the longitudinal bone cross-sectional coefficient K2 is 0.5 or more and 0.65 or less (that is, the cross-sectional area S2 is 0.5 × T0 ² ≦ S2 ≦ 0.65 × T0 ² ). It can be said that the inclusion of the thick internal bone 720a (satisfies) can further improve the life characteristics and is more preferable. Further, as shown in FIG. 11, in the sample SA1 in which the thick internal bone ratio R2 is 1.0, the evaluation item of "lifetime" was judged to be "excellent" (◎), so that the large internal bone ratio R2 was determined. When it is 1.0, the life characteristics can be further improved, which is more preferable.

B. Modification example:
The technique disclosed in the present specification is not limited to the above-described embodiment, and can be transformed into various forms without departing from the gist thereof, and for example, the following modifications are also possible.

The configuration of the lead-acid battery 100 in the above embodiment is merely an example and can be variously modified. For example, in the above embodiment, the extension directions of the plurality of transverse internal bones 710 constituting the lateral internal bone group 71 are parallel to the Y-axis direction (lateral direction), but at least a part of the plurality of lateral internal bones 710 is extended. The direction may be different from the Y-axis direction (horizontal direction). Similarly, in the above embodiment, the extension direction of the plurality of longitudinal internal bones 720 constituting the longitudinal internal bone group 72 is parallel to the Z-axis direction (longitudinal direction), but at least of the plurality of longitudinal internal bones 720. A part of the stretching direction may be different from the Z-axis direction (longitudinal direction).

Further, in the above embodiment, the configuration of the positive electrode collector 212 has been described in detail, but the negative negative collector 222 has the same configuration as the above-mentioned positive current collector 212 (the longitudinal internal bone group forms the large internal bone). The ratio of the number of large internal bones to the number of vertical internal bones constituting the vertical internal bone group is 0.7 or more, and the number of lateral internal bones constituting the lateral internal bone group is included. The ratio of the number of fine internal bones to the number of fine internal bones is 0.7 or more). In this case, the configuration of the positive electrode current collector 212 may be another configuration.

Further, the method for manufacturing the lead-acid battery 100 in the above embodiment is merely an example and can be variously modified.

10: Housing 12: Electric tank 14: Lid 15: Exhaust plug 16: Cell chamber 20: Electrode plate group 30: Positive electrode side terminal member 32: Positive electrode side bushing 34: Positive electrode pillar 36: Positive electrode side terminal part 40: Negative electrode side terminal Member 42: Negative electrode side bushing 44: Negative electrode column 46: Negative electrode side terminal part 52: Positive electrode side strap 54: Negative electrode side strap 56: Connection member 58: Partition 60: Frame part 61: Horizontal frame bone 61b: Lower horizontal frame bone 61t : Upper horizontal frame bone 62: Vertical frame bone 62l: Left vertical frame bone 62r: Right vertical frame bone 70: Medial part 71: Lateral internal bone group 72: Vertical internal bone group 80: Foot 90: Resin member 100: Lead storage battery 210 : Positive electrode plate 212: Positive electrode current collector 214: Ear part 216: Positive electrode active material 220: Negative electrode plate 222: Negative electrode current collector 224: Ear part 226: Negative electrode active material 230: Separator 710: Lateral inner bone 710a: Fine inner bone 720 : Vertical internal bone 720a: Large internal bone

Claims (2)

It ’s a lead-acid battery.
An electrode plate having a current collector and an electrode material supported by the current collector is provided.
The current collector
It is composed of four frame bones including the first frame bone, and has a substantially quadrangular frame part in the first directional view.
The ear portion provided on the first frame bone and
An inner portion provided inside the frame portion and an inner portion
Have,
The inner part is
A first internal bone group composed of N1 first internal bones connecting between two said frame bones connected to the first frame bone, and a first internal bone group.
A second internal bone group composed of N2 second internal bones connecting the first frame bone and one said frame bone facing the first frame bone, and a second internal bone group.
Have,
In the second internal bone group, the cross-sectional area S2 of the cross section orthogonal to the stretching direction is 0.35 × T0 ² ≦ S2 ≦ 0.65 × T0 ² (however, T0 is the frame portion in the first direction). Includes n2 large internal bones that satisfy the relationship (thickness)
In the first internal bone group, the cross-sectional area S1 of the cross section orthogonal to the stretching direction is 0.077 × S2max ≦ S1 ≦ 0.125 × S2max (however, S2max is the maximum value of the cross-sectional area of the large internal bone). Including n1 fine internal bones that satisfy the relationship
The ratio (n2 / N2) of the number n2 of the large internal bones to the number N2 of the second internal bones constituting the second internal bone group is 0.7 or more.
A lead-acid battery in which the ratio (n1 / N1) of the number n1 of the fine internal bones to the number N1 of the first internal bones constituting the first internal bone group is 0.7 or more. The lead-acid battery according to claim 1.
The ratio (W2 / T2) of the width W2 of the lead-acid bone to the thickness T2 in the first direction in the direction orthogonal to both the first direction and the extension direction of the lead-acid bone is 0. Lead-acid battery with 0.9 or more and 1.1 or less.

Images