JP2018060629A - Lead storage battery and current collector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a control valve-type lead storage battery from being shorten in life.SOLUTION: A lead storage battery comprises a positive electrode current collector 10 including an outer frame part 15 having horizontal frame bones 11, 12 and vertical frame bones 13, 14, and an inner bone 24 located inside the outer frame part. When the cross section of the vertical frame bones is S(mm) and the thickness is t(mm), S>t/2 is satisfied. The inner bone 24 includes an inner thick bone 22 having a cross section larger than t/4. When the volume of a grid formed by the vertical frame bones and the inner thick bone, or the vertical frame bones, the horizontal frame bones and the inner thick bone is V(cm), the length of the vertical frame bones 13, 14 forming the grid is L(mm), and the width of the vertical frame bones 13, 14 is d(mm), a relation given by the following expression (1) is satisfied: (S×d)/(V×L)≥0.002 (1).SELECTED DRAWING: Figure 2

Description

  The present disclosure relates to a lead storage battery and a current collector.

In recent years, power generation facilities using natural energy such as sunlight and wind power are actively installed to reduce CO ₂ . Since these power generation facilities cannot control the timing of power generation, storage battery equipment is used together on the power generation side and / or the consumption side to achieve leveling of power. As a storage battery for this purpose, a lead storage battery is often used.

  For example, Patent Document 1 discloses a lead-acid battery, in particular, a positive grid thereof. The cross-sectional area of the vertical bone of the positive grid is set to be twice or more than the cross-sectional area of the horizontal bone, and the compression ratio of the separator is 1 .1 or more is disclosed.

JP-A-10-188999

  When the lead storage battery is used for power leveling of power generation using natural energy as described above, this corresponds to a cycle application in which charging and discharging are repeated. In this case, the inventor of the present application has found that the life of the conventional lead-acid battery for cycle may be significantly shortened due to breakage of the current collector. Therefore, an object of the technology of the present disclosure is to provide a lead storage battery capable of maintaining the life even when used in the above-described application, and a current collector used therefor.

  In the study for solving the above-mentioned problems, the present inventor has found that a conventional lead-acid battery for cycle has a short life particularly when used in a deep discharge depth range. For example, in a cycle life test where the DoD (Depth of Discharge) is 70% at 25 ° C., the cycle control valve type lead acid battery (VRLA) has a very short life. Furthermore, as a cause of this, it has been found that the positive electrode active material is remarkably expanded along with the charge / discharge cycle, which causes stress on the vertical frame bone of the positive electrode lattice and breaks the vertical frame bone at grain boundaries.

In view of the above, in a lead storage battery including a positive electrode current collector made of lead or a lead alloy according to an embodiment of the present invention, the positive electrode current collector includes the first and second horizontal frame bones, the first and second An outer frame portion having a vertical frame bone, a plurality of inner bones provided to intersect the inner side of the outer frame portion, and a position closer to the first vertical frame bone in the first horizontal frame bone, outside the outer frame portion And a collecting ear provided integrally. For vertical frame bone, the cross-sectional area in a cross section perpendicular to the extending direction S (mm ^2), when a thickness of t (mm), satisfy the relationship of S> t ^2/2, a plurality of inner bone, sectional area in a cross section perpendicular to the extending direction includes UchiFutoshihone exceeding t ^2/4. In addition, the mesh constructed without being traversed by the other internal thick bones by the vertical frame bone and the internal thick bone, or traversed by the other internal thick bones by the vertical frame bone, the lateral frame bone and the internal thick bone For at least one of the meshes that are not formed, the volume of the mesh is V (mm ³ ), the length of the vertical frame bone of the portion constituting the grid is L (mm), and the width of the vertical frame bone is d (mm) ), The following formula (1),
(S × d) / (V × L ² ) ≧ 0.002 (Formula 1)
The relationship represented by is satisfied.

  According to the lead storage battery and the current collector of the present disclosure, it is possible to suppress breakage of the current collector and suppress the shortening of the life of the lead storage battery.

FIG. 1 is a schematic view illustrating a positive electrode current collector of a lead storage battery according to an embodiment of the present disclosure. FIG. 2 is a diagram for further explaining the positive electrode current collector of FIG. FIG. 3 is a diagram illustrating a relationship between the parameters of the present disclosure, the number of life cycles of the lead storage battery, and the number of frame bone fractures for the test battery according to an embodiment of the present disclosure. FIG. 4 is a diagram illustrating the relationship between the parameters of the present disclosure and the maximum lateral expansion rate of the positive electrode plate for a test battery according to an embodiment of the present disclosure. FIG. 5 is a diagram illustrating the relationship between the parameters of the present disclosure, the number of life cycles of the lead storage battery, and the number of fractured frame bones for another test battery according to an embodiment of the present disclosure. FIG. 6 is a diagram illustrating a relationship between the parameters of the present disclosure and the maximum lateral expansion rate of the positive electrode plate for another test battery according to an embodiment of the present disclosure. FIG. 7 is a diagram for explaining the occurrence of breakage of the vertical frame bone in the positive electrode current collector of the lead storage battery. FIG. 8 is a diagram showing the ratio of the occurrence of breakage of the vertical frame bone in the positive electrode current collector of the lead storage battery. FIG. 9 is a diagram illustrating an example of a positive electrode current collector of a lead storage battery according to the present disclosure. FIG. 10 is a diagram illustrating another example of the positive electrode current collector of the lead storage battery according to the present disclosure. FIG. 11 is a diagram illustrating still another example of the positive electrode current collector of the lead storage battery according to the present disclosure. FIG. 12 is a diagram illustrating still another example of the positive electrode current collector of the lead storage battery according to the present disclosure. FIG. 13 is a diagram illustrating still another example of the positive electrode current collector of the lead storage battery according to the present disclosure. FIG. 14 is a diagram illustrating a positive electrode current collector of a lead storage battery according to a modification of the embodiment of the present disclosure.

  Hereinafter, a control valve type lead-acid battery (VRLA) according to an embodiment of the present disclosure will be described with reference to the drawings.

  The control valve type lead-acid battery of this embodiment includes a paste-type positive electrode plate and negative electrode plate, a separator disposed between the positive electrode plate and the negative electrode plate and holding an electrolyte, and a battery case that accommodates the positive electrode plate, the negative electrode plate, and the separator. With.

  After the positive electrode plate and the negative electrode plate are filled with an active material paste in a grid-like positive electrode current collector and negative electrode current collector made of lead or a lead alloy (Pb—Ca alloy, Pb—Ca—Sn alloy, etc.) It is formed by aging and drying. Here, in this specification, an active material refers to what remove | excluded the electrical power collector from the electrode plate, and contains an additive etc. The active material is also referred to as an electrode material. As the separator, for example, an AGM palator composed of ultrafine glass fibers and silica powder or the like is used, and the separator is impregnated with dilute sulfuric acid as an electrolytic solution. The battery case is composed of, for example, a battery case body having a rectangular parallelepiped shape with an opening on one side and a lid for closing the opening. For example, the battery case is mainly formed by injection molding of thermoplastic plastic. About these positive electrode plates, a negative electrode plate, a separator, and a battery case, a structure can be suitably selected according to the objective and a use.

(Structure of positive electrode current collector)
Next, the positive electrode plate provided in the control valve type lead storage battery of this embodiment will be further described.

  FIG. 1 is a diagram schematically showing a positive electrode current collector 10 constituting a positive electrode plate in the present embodiment. The positive electrode current collector 10 includes an outer frame portion 15 configured in a rectangular shape, and a plurality of inner bones 24 that intersect with the inner frame portion and form a lattice together with the outer frame portion 15.

  The outer frame portion 15 includes a first horizontal frame bone 11 and a second horizontal frame bone 12, and a first vertical frame bone 13 and a second vertical frame bone 14. A current collecting ear portion 25 is provided at the end of the first horizontal frame bone 11 on the first vertical frame bone 13 side so as to be integrated with the outside of the outer frame portion 15. Further, a foot portion 26 is provided outside the second horizontal frame bone 12. In the present specification, the side on which the current collecting ear 25 of FIG. 1 is provided may be referred to as “upper” and the side on which the foot 26 is provided may be referred to as “lower”. With regard to this point and the descriptions of “vertical” and “horizontal” of the horizontal frame bone 11 and the vertical frame bone 13 and the like, both are expressions for convenience, and the orientation and the like when using the positive electrode current collector 10 are limited. It is not a thing.

The inner bone 24 includes a longitudinal inner bone 21 parallel to the longitudinal frame bones 13 and 14 and lateral inner bones 22 and 23 parallel to the lateral frame bones 11 and 12. The lateral inner bone is classified into a lateral thick bone 22 and a narrower lateral thin bone 23 by a difference in thickness. More specifically, when the thickness of the vertical frame bones 13 and 14 to the (vertical dimension in the plane of FIG. 1) and t, and the transverse profile bone 22 cross sectional area exceeds t ^2/4, the cross-sectional area t ^There are transverse fine bones 23 that are 2/4 or less. In the example of FIG. 1, both the longitudinal inner bone 21 and the lateral thick bone 22 are arranged at equal intervals inside the outer frame portion 15. Further, the horizontal thin bones 23 are arranged at substantially equal intervals between the horizontal thick bones 22 and between the horizontal thick bones 22 and the first horizontal frame bone 11 or the second horizontal frame bone 12. The lateral thin bone 23 closest to the first lateral frame bone 11 and the second lateral frame bone 12 is narrower than the other portions.

  Note that the positive electrode current collector 10 of this embodiment is manufactured by a casting method. That is, it is only necessary to use lead or lead alloy as a material by using a mold corresponding to the thickness and arrangement of each bone described above.

  Next, FIG. 2 is a diagram for explaining the configuration of the positive electrode current collector 10 in more detail. Here, I in FIG. 2 corresponds to an enlarged view of the vicinity of the upper right in FIG. However, in FIG. 2, only a smaller number of transverse fine bones 23 are shown. In addition, the positive electrode current collector 10 in the range shown in the drawing is a view from the right (in the drawing) II (however, in addition to the vertical frame bone 14, the first horizontal frame bone 11, the horizontal thick bone 22, and the horizontal frame) The shape of the thin bone 23 is shown by a solid line so as to be seen through), and III, which is a view showing a cross section of the longitudinal frame bone 14 and the longitudinal inner bone 21 when viewed from below, is also shown. The cross section of the lateral frame bone 11 is hexagonal, and the cross section of other bones is rhombus, but this is not restrictive.

  In the positive electrode current collector 10 of the present disclosure, the volume of the mesh formed by the bone including the vertical frame bone 13 or 14 and the length and the cross-sectional area of the vertical frame bone 13 or 14 of the portion configuring the mesh are predetermined. By having such a relationship, it is possible to avoid a short life even when used in a deep discharge depth range.

Specifically, a mesh composed of the second vertical frame bone 14, the vertical inner bone 21 closest thereto, the first horizontal frame bone 11 and the horizontal thick bone 22 closest thereto (in FIGS. 1 and 2). Let us consider the upper right corner when considering the square ignoring the horizontal thin bone 23. The volume of the mesh is V (cm ³ ), the width and cross-sectional area of the second vertical frame bone 14 are d (mm) and S (mm ² ), and the length of the second vertical frame bone 14 of the portion constituting the grid When (here, the distance between the first lateral frame bone 11 and the lateral inner bone 22) is L (mm), the following formula (1)
(S × d) / (V × L ² ) ≧ 0.002 (Formula 1)
By configuring the positive electrode current collector 10 to satisfy the above condition, it is possible to prevent the positive electrode current collector 10 and thus the lead-acid battery from having a short life even when used in a deep discharge range.

  In addition, although the grid between the first horizontal frame bone 11 and the horizontal thick bone 22 (corresponding to the “upper right” of the positive electrode current collector 10 in FIGS. 1 and 2) has been described, The same applies to the meshes sandwiched between the thick bone 22 and the second horizontal frame bone 12, and the same applies to the first vertical frame bone 13 side. For example, in FIG. 2, the horizontal thick bone 22 closest to the first horizontal frame bone 11 and the next horizontal thick bone 22 (this interval is denoted as L ′), the second vertical frame bone 14 and the closest vertical inner bone Considering the mesh composed of the bones 21, the following equation may be satisfied.

(S × d) / (V × L ′ ² ) ≧ 0.002
Further, the volume V of the mesh can be defined as, for example, the product of the area surrounded by each bone constituting the mesh and the thickness t of the vertical frame bone 13 in FIG. Here, the area of the mesh can be an area surrounded by the center line of each bone constituting the mesh. In addition, when a bone having a hexagonal cross section is used as in the case of the horizontal frame bone 11 shown in FIG. 2, the bone cross section is located at both ends in the thickness direction of the positive electrode current collector 10 and inside the mesh. The inside from the apex of the side can be calculated as the volume of the cell. In addition, when the same definition is applied to a bone whose cross section is a rhombus (vertical frame bone 14, vertical inner bone 21, horizontal thick bone 22), a set of apexes located at both ends in the thickness direction of the positive electrode current collector 10 Therefore, it means the bone centerline.

  Moreover, regarding the longitudinal frame bones 13 and 14 and the longitudinal inner bone 21, the sectional area refers to a sectional area by a section perpendicular to the extending direction. Further, the widths of the vertical frame bones 13 and 14 indicate dimensions in the extending direction of the horizontal frame bones 11 and 11.

  In addition, when the width or cross-sectional area of each bone is not uniform in a part included in one square, the cross-sectional area and the width in the longitudinal center part of the vertical frame bone of the corresponding part are used. This is because the stress applied to the bone is the largest in the central portion, and the strength of this portion becomes important.

  Next, the reason why the breakage can be suppressed by satisfying the formula (1) is considered as follows.

  First, when the present inventor is used in a deep discharge range, the positive electrode active material expands significantly with the charge / discharge cycle, which causes stress on the bone of the positive electrode current collector 10 and causes the bone to become granular. The knowledge that the boundary is broken is obtained. According to this knowledge, in the positive electrode current collector 10, the larger the volume of the mesh made of bone, the larger the dimensional change due to the expansion of the positive electrode active material, so that the stress applied to the bone increases and the fracture tends to occur. It will be.

  Here, in the case of the inner bone 24, since the positive electrode active material is filled on both sides of each bone, the stress accompanying the expansion is applied from both sides of the inner bone 24 and is offset and reduced. On the other hand, the bone constituting the outer frame portion 15 has the positive electrode active material only inside the positive electrode current collector 10, and unlike the inner bone 24, the stress is not offset and the fracture tends to occur.

  The force (counterforce) against the stress applied to the frame bone varies depending on the width, cross-sectional area, and length of the vertical frame bone 13 or 14 constituting the mesh. When the width and cross-sectional area of the vertical frame bones 13 and 14 constituting the mesh are reduced or the length is increased, the opposing force is reduced and breakage is likely to occur. Therefore, the volume of the mesh and the width of the longitudinal frames 13 and 14 constituting the mesh, and the breaking of the mesh so that the stress applied to the longitudinal frames 13 and 14 is reduced, or the opposing force of the longitudinal frames 13 and 14 is increased. By designing the area and length, breakage can be suppressed.

Further, in order to make it easier for current to flow from the current collector ear 25 to the foot 26 side, the longitudinal inner bones 21 are all constituted by thick bones, and the interval between the longitudinal inner bones 21 is larger than the interval between the lateral thick bones 22. Are narrowly arranged, so that the squares surrounded by thick bones are vertically long rectangles. Note that the Futoshihone, bone cross-sectional area exceeds ^t 2/4, specifically, it refers to a YokoFutoshihone 22, the lateral frame bones 11 and 12, and a vertical frame bones 13 and 14. Incidentally, the horizontal frame bones 11 and 12, and for the vertical frame bones 13 and 14, the cross-sectional area is larger, it is assumed that exceeds t ^2/2.

As a result, the vertical frame bone 13 or 14 is more susceptible to fracture than the horizontal frame bone 11 or 12, and therefore the dimensions of the vertical frame bone 13 or 14 are important. Also, if the cross-sectional area are provided with different YokoFutoshihone 22 and YokoHoso bone 23, for the horizontal fine aggregate 23 cross-sectional area is t ^2/4 or less ease of breakage of the positive electrode current collector 10 ( The present inventor has discovered that this does not affect (strength) (this will be described later). Therefore, in the formula (1) and the like, the grid is considered to include the horizontal thick bone 22 regardless of the horizontal thin bone 23. Also, consider a cell that is not crossed by another thick bone. For example, the second vertical frame bone 14, the second bone from the right in the vertical inner bone 21 in FIG. 1, the first horizontal frame bone 11, and the uppermost bone of the horizontal thick bone 22 may also be used. Even though it can be considered that a “square” is formed, the square is crossed by the rightmost bone of the longitudinal inner bones 21. Therefore, such a grid is not considered.

  Next, a control valve type lead-acid battery was manufactured using the current collector 10 as described above.

  First, the lead powder and the synthetic resin fiber were kneaded with water and sulfuric acid to obtain a paste for the positive electrode material. The positive electrode material paste was filled in a positive electrode current collector 10 which is a cast lattice made of a Pb—Ca—Sn alloy, and aged and dried to obtain an unformed positive electrode plate.

In addition, lead powder, synthetic resin fiber, anti-shrink agent, carbon black and BsSO ₄ were kneaded with water and sulfuric acid to obtain a paste of negative electrode material. The paste of the negative electrode material was filled in a cast lattice made of a Pb—Ca—Sn alloy, and aged and dried to obtain an unformed positive plate.

  Next, 8 positive electrode plates and 9 negative electrode plates were laminated via an ultrafine glass mat separator to form an electrode plate group. The electrode plate group was stored in the battery case by applying pressure until the length of the electrode plate group reached the size in the battery case. Using pure lead as the additional lead, a positive strap and a negative strap that connect the same plates were formed. Here, a Pb—Sn alloy can be used for the strap instead of pure lead.

  After adhering the lid to the battery case, sulfuric acid was added as an electrolyte from the liquid injection part of the lid, and the battery case was formed to produce a control valve type lead-acid battery with a nominal capacity of 500 Ah (10 hR (hour rate)) and 2 V. .

Next, Table 1 shows the results of a cycle test on the test battery A produced as described above. The cycle test was performed under the following conditions.
-DoD 70% discharge: 25 ° C, 0.2CA x 3.5h
・ Normal charging: 25 ° C, 2.42 constant voltage (Imax = 0.2CA), charge charge / discharge capacity = 1.02
・ Equal charge: 25 ℃, every 6 cycles, normal charge + 2.42V constant voltage (Imax = 0.2CA) x 8h
-Life judgment condition: The time when the discharge end voltage at the time of DoD 70% discharge falls below 1.7V.

In the positive electrode current collector of the test battery A, the distance between the horizontal thick bones 22 and the distance between the horizontal frame bone 11 or 12 and the horizontal thick bone 22 are all equal L. From A-1 to A-15 including a positive electrode current collector in which the thickness t of the vertical frame bone is 6.0 mm, and the width d, the cross-sectional area S, and the length L of the vertical frame bone of the portion constituting the mesh are changed. The relationship between the value of (S × d) / (V × L ² ), which is the left side of formula (1), and the number of life cycles, the number of vertical frame bone fractures, and the maximum lateral plate elongation in Show.

As shown in Table 1, for A-1 to A-4 where (S × d) / (V × L ² ) is smaller than 0.002, the vertical frame bone breaks at least at one location, and (S × d ) / (V × L ² ) is smaller, the larger the number of breaks. On the other hand, with respect to A-5 to A-15 in which (S × d) / (V × L ² ) is 0.002 or more, there is no fracture of the vertical frame bone. This point and other results are shown in the graphs of FIGS. As shown in FIG. 3, when (S × d) / (V × L ² ) exceeds 0.002, the number of frame bone fractures and the number of life cycles are significantly improved. Further, as shown in FIG. 4, (S × d) / (V × L ² ) is remarkably small in the vicinity of the positive electrode plate lateral maximum maximum elongation of 0.002.

  Table 2 shows the results of a cycle test on another test battery B. The test battery B is also a VRLA using a positive electrode current collector 10 that forms a rectangular cell as shown in FIGS. 1 and 2, and is 200 Ah / 10 hR (+ 8 / −9 sheets (8 positive electrode plates and 8 negative electrode plates). 9 sheets) composition).

In the positive electrode current collector of the test battery B, the distance between the horizontal thick bones 22 and the distance between the horizontal frame bone 11 or 12 and the horizontal thick bone 22 are all equal L. For lead storage batteries from B-1 to B-15 having positive current collectors with t changed to 3.8 mm and d, S, and L changed, (S × d) / (V The relationship between the value of (× L ² ), the number of life cycles, the number of longitudinal frame fractures, and the maximum elongation in the horizontal direction of the positive electrode plate is shown.

As shown in Table 2, here, when (S × d) / (V × L ² ) is 0.002 or more, there is no fracture of the vertical frame bone. Furthermore, as shown in the graphs of FIGS. 5 and 6, the number of vertical frame bone fractures and the number of life cycles are remarkably improved at the boundary where (S × d) / (V × L ² ) is 0.002. In addition, a significant improvement is also seen in the maximum elongation in the lateral direction of the positive electrode plate.

  As described above, by satisfying the formula (1), the breakage in the positive electrode current collector 10 is remarkably suppressed, and the life of the lead storage battery is improved.

Further, as shown in Tables 1 and 2 and FIGS. 4 and 6, the following formula (2)
(S × d) / (V × L ² ) ≧ 0.0032 (Formula 2)
If it satisfy | fills, the expansion | extension of the horizontal direction of a positive electrode plate can be suppressed. Similarly, the following formula (3)
(S × d) / (V × L ² ) ≧ 0.0046 (Formula 3)
If it satisfy | fills, the expansion | extension of the horizontal direction of a positive electrode plate can be suppressed more reliably.

(About inner bone)
Next, it will be described that the horizontal thin bone 23 among the inner bones 24 does not affect the easiness of breaking of the positive electrode current collector 10.

  This is shown in Table 3. Table 3 shows the same contents as in Tables 1 and 2 for the test batteries C and D that are 500 Ah / 10 hR (+ 8 / -9 sheets configuration), and shows the number of horizontal fine bones 23 in the positive electrode current collector 10. Show.

The test battery C is the same as A-1 in Table 1 for the values of t, d, L, S, and V. In C1 to C-3, since (S × d) / (V × L ² ) is 0.0011 (smaller than 0.002), the vertical frame bone is broken. Even if the number of transverse fine bones is increased to 16, 24, 34, the number of fractures, the number of life cycles, and the maximum elongation in the lateral direction of the positive electrode plate are substantially the same. It is increasing.

Moreover, the test battery D is the same as A-12 of Table 1 about the value of t, d, L, S, and V. In D-1 to D-3, since (S × d) / (V × L ² ) is 0.0077 (0.002 or more), the vertical frame bone is not broken. Further, even if the number of the horizontal fine bones 23 is changed to 12, 18, and 28, the number of fractures, the number of life cycles, and the maximum elongation in the lateral direction of the positive electrode plate are not substantially affected. In particular, in the case of D-1 in which the number of transverse fine bones 23 is smaller than that in the case of C-1 that causes breakage, breakage does not occur.

  In this regard, when the lead storage battery is used (or the life test is performed), the positive electrode current collector 10 is gradually corroded. The transverse thin bone 23 is a thin bone provided mainly for facilitating filling of the positive electrode current collector 10 with the active material paste, and is corroded within a relatively short time after the start of use of the lead-acid battery. It is considered that the strength of the positive electrode current collector 10 is not affected.

Incidentally, with respect to the thickness t of the vertical frame bone, the cross-sectional area of the lateral bone is t ^2/4 or less, clearly not affect the rupture of the positive electrode current collector 10. Thus, for YokoFutoshihone 22 cross sectional area exceeds t ^2/4, is an element constituting the square considered in Equation (1).

  As described above, since the horizontal fine bone 23 does not affect the easiness of breaking of the positive electrode current collector 10, only the horizontal thick bone 22 is considered as the design of the positive electrode current collector 10 for suppressing breakage. Just do it. The transverse fine bones 23 are preferably provided in the meshes considered in the formula (1) for the filling of the active material paste, and the arrangement and the like can be designed separately from the ease of breaking. . Thereby, the design of the positive electrode current collector 10 can be simplified.

(Location of breakage in the positive electrode current collector)
Next, with reference to FIG.7 and FIG.8, the location where the fracture | rupture in the positive electrode electrical power collector 10 tends to produce is demonstrated. FIG. 7 shows an electrode plate 50 produced using the positive electrode current collector 10 of FIG. Here, the electrode plate 50 is divided into four equal parts in the vertical direction, and areas A, B, C, and D are considered from the upper part to the lower part on the current collecting ear part 25 side (the first horizontal frame bone 11 side). . Similarly, on the side opposite to the current collecting ear portion 25 (second vertical frame bone 14 side), regions E, F, G, and H are considered from the top to the bottom. In addition, since the positive electrode collector 10 shown in FIG. 1 includes three horizontal thick bones 22 at equal intervals, the positions of the horizontal thick bones 22 coincide with the boundaries between the regions. However, the position of the horizontal thick bone 22 is not determined as a boundary between regions. Therefore, when the lattice shape, for example, the number and arrangement of the horizontal thick bones 22 are different (for example, FIGS. 10 to 12 described later), the boundary between the regions and the position of the horizontal thick bone 22 are different.

  Here, about the 1st and 2nd vertical frame bone | frames 13 and 14 in the battery of A-1 shown in Table 1 (8 positive electrode collectors 10 are provided), the fracture | rupture location is represented by AH of FIG. Then, the distribution is as shown in the graph of FIG. As apparent from FIG. 8, the break is the most in the region E, that is, the uppermost (on the side of the first horizontal frame bone 11) and the farthest (on the side of the second vertical frame bone 14) side of the current collecting ear 25. Many have occurred. Further, the lower side (the side of the foot part 26), the smaller the breakage. If the heights are the same (A and E, B and F, etc.), there are many breaks on the side far from the current collecting ear part 25.

  Therefore, by setting so as to surely satisfy the formula (1) for a portion having a lot of fractures, the fracture of the longitudinal frame bone can be sufficiently suppressed even if the formula (1) is not satisfied for other portions. it can. Furthermore, if it is not necessary to satisfy the formula (1) for a portion where breakage does not easily occur, the filling amount of the active material paste relative to the positive electrode current collector 10 can be increased.

  The positive electrode current collector 10 based on such an idea is illustrated as a schematic diagram in FIGS. In these drawings, the first and second horizontal frame bones 11 and 12, the longitudinal inner bone 21, and the horizontal thick bone 22 are shown as lines, and the horizontal thin bone 23 is not shown.

  In the case of FIG. 9, compared with the case of FIG. 1, the first horizontal frame bone 11 and the adjacent horizontal thick bone 22 (the first vertical frame bone 22) are connected so as to connect only the second vertical frame bone 14 and the adjacent vertical inner bone 21. An additional horizontal thick bone 22a is provided between the vertical frame bone 13 and the second vertical frame bone 14). As a result, in the region E in FIG. 7 where breakage is most likely to occur, the value of V can be reduced by dividing it into two half-sized squares so that Equation 1 can be satisfied.

  Next, in the case of FIG. 10, compared to the case of FIG. 1, an additional horizontal thick bone 22 b (a horizontal thick bone extending from the first vertical frame bone 13 to the second vertical frame bone 14 is provided in the vicinity of the first horizontal frame bone 11. Yes, the structure is the same as the horizontal thick bone 22). Thereby, in the areas A and E in FIG. 7, the value of V can be reduced by dividing the area into two half-sized squares, and the expression 1 can be satisfied.

  Next, in the case of FIG. 11, the horizontal thick bone 22 is increased with respect to the case of FIG. 1, and the distance between the first horizontal frame bone 11 and the horizontal thick bone 22 is increased from the first horizontal frame bone 11 side. The width is gradually increased toward the side of the two lateral frame bones 12. Thereby, it can be made to satisfy | fill Formula 1 more reliably as the square of the 1st horizontal frame bone 11 side.

  In the case of FIG. 12, the number of the horizontal thick bones 22 is increased in the upper half (the first horizontal frame bone 11 side) compared to the lower half (the second horizontal frame bone 12 side). To make it smaller. Thereby, it can satisfy | fill Formula 1 about an upper side mesh | cell. In addition, you may arrange | position the horizontal thick bone 22 not only to upper side "half" but to make several rows of small squares from the upper side.

  In the case of FIG. 13, the interval between the two longitudinal frame bones 13 and 14 and the longitudinal inner bone 21 that is closest to each of them is made narrower than the interval between the longitudinal inner bones 21. Thereby, about the grid which uses the vertical frame bones 13 and 14 as a part of the structure, the vertical frame bones 13 and 14 are not included while suppressing the breakage of the vertical frame bones 13 and 14 by satisfying the expression (1). The filling amount of the active material paste can be increased with respect to the mesh that is configured (for example, by the two horizontal thick bones 22 and the two vertical inner bones 21).

  In addition to the above, the breakage can be suppressed by adjusting the size of the mesh so as to satisfy the formula (1) particularly in the portion where the breakage easily occurs shown in FIGS. . 9 to 13 all show a schematic structure, and do not show an absolute dimensional relationship or the like. In addition, there is no problem even if the expression (1) is satisfied, except for the mesh described as satisfying the expression (1) (including the vertical frame bone 13 or 14 as a constituent element). 9 to 13 can be used in various combinations.

(Modification)
In the above description, the positive current collector 10 has been described in which the longitudinal inner bone 21 is parallel to the longitudinal frame bones 13 and 14 and the lateral inner bones 22 and 23 are parallel to the lateral frame bones 11 and 12. However, it is not limited to this. FIG. 14 shows a modified positive electrode current collector 10a. In the positive electrode current collector 10a, an outer frame portion is configured by the first horizontal frame bone 11 and the second horizontal frame bone 12, and the first vertical frame bone 13 and the second vertical frame bone 14, and the horizontal thick bone 22 Further, the provision of the lateral thin bone 23, the current collecting ear portion 25, and the foot portion 26 is the same as that of the positive electrode current collector 10 shown in FIG.

  On the other hand, in the positive electrode current collector 10a of FIG. 14, the longitudinal inner bone 31 is not parallel to the longitudinal frame bones 13 and 14, but from the side of the current collecting ear 25 as it goes from the upper side to the lower side. It is provided diagonally so as to move away.

  Also in this case, if the square mesh including a part of the vertical frame bone 13 or 14 is made to satisfy the formula (1), breakage of the vertical frame bone 13 or 14 can be suppressed.

  FIG. 14 exemplifies the “mesh” in this case. For example, the mesh 41 in FIG. 14 is a portion constituted by a part of the second vertical frame bone 14, the first horizontal frame bone 11, two adjacent vertical inner bones 31, and the horizontal thick bone 22. FIG. 14 shows an elongated pentagonal shape. The meshes 42 and 43 are parts constituted by a part of the second vertical frame bone 14 or a part of the first vertical frame bone 13, two adjacent vertical inner bones 31, and the horizontal thick bone 22. .

As with the positive electrode current collector 10 of FIG. 1, the width and cross-sectional area of the first or second vertical frame bone 13 or 14 are d (mm) and S (mm ² ), and the volume of the mesh 41 is Va (cm ³ ), Assuming that the length of the second vertical frame bone 14 of the portion constituting the mesh 41 is La, the formula (1) is (S × d) / (Va × La ² ) ≧ 0.002.
Thus, the fracture of the vertical frame bone can be suppressed by designing to satisfy this.

  Also for the meshes 42 and 43, the fracture of the vertical frame bone is suppressed by satisfying the expression (1) for the respective volumes Vb and Vc and the lengths Lb and Lc of the vertical frame bones of the corresponding portions. be able to.

  In the positive electrode current collector 10a, the longitudinal inner bones 31 are parallel to each other. However, this is not essential, and they may be arranged radially, for example. Moreover, it is not essential for the horizontal thick bone 22 to be parallel to the first horizontal frame bone 11 and the second horizontal frame bone 12 or between the horizontal thick bones 22. Furthermore, it is not essential for the longitudinal inner bone and the lateral inner bone to be linear, and a curved line may be drawn. In any case, if the grid including the first or second vertical frame bone 13 or 14 is made to satisfy the formula (1), breakage of the vertical frame bone in the grid can be suppressed.

  In the above description, the positive electrode current collector formed by casting has been described as an example. However, the present invention is not limited to this, and the positive electrode current collector may be formed by other methods such as a punched lattice. Moreover, although the VRLA battery was demonstrated as an example, it is not limited to this, It can also use for a liquid-type battery etc.

  According to the lead storage battery and the current collector of the present disclosure, it is possible to suppress the shortening of the life, and in particular, it is useful as a lead storage battery that can be used for a long time even when used in a deep discharge depth range.

DESCRIPTION OF SYMBOLS 10 Positive electrode collector 10a Positive electrode collector 11 1st horizontal frame bone 12 2nd horizontal frame bone 13 1st vertical frame bone 14 2nd vertical frame bone 15 Outer frame part 21 Vertical internal bone 22 Horizontal thick bone 22a Additional horizontal thickness Bone 22b Additional transverse thick bone 23 Lateral fine bone 24 Inner bone 25 Current collecting ear 26 Foot 31 Longitudinal bone 41 Claw 42 Claw 43 Claw 50 Pole plate

Claims (8)

A positive current collector made of lead or a lead alloy is provided.
The positive electrode current collector includes an outer frame portion having first and second horizontal frame bones and first and second vertical frame bones, and a plurality of inner bones provided so as to intersect inside the outer frame portion. And a current collecting ear portion integrally provided outside the outer frame portion at a position near the first vertical frame bone in the first horizontal frame bone,
For the vertical frame bone, the cross-sectional area in a cross section perpendicular to the extending direction S (mm ^2), when a thickness of t (mm), satisfy the relationship of S> t ^2/2,
It said plurality of inner bone includes UchiFutoshihone sectional area in the cross section perpendicular exceeds t ^2/4 in the extending direction,
The vertical frame bone and the inner thick bone are configured without crossing the other inner thick bone, or the vertical frame bone, the horizontal frame bone and the inner thick bone, For at least one of the meshes configured without being traversed by the bone, the volume of the meshes is V (cm ³ ), the length of the vertical frame bone of the portion constituting the meshes is L (mm), and the vertical frame When the width of the bone is d (mm), the following formula (1),
(S × d) / (V × L ² ) ≧ 0.002 (Formula 1)
Lead-acid battery characterized by satisfying the relationship represented by: The lead acid battery of claim 1,
The lead-acid battery characterized in that the mesh formed by the first horizontal frame bone, the second vertical frame bone, and the inner thick bone satisfies the formula (1). The lead acid battery of claim 2,
The lead storage battery characterized in that the mesh formed by the first horizontal frame bone, the first vertical frame bone, and the inner thick bone satisfies the formula (1). In the lead acid battery of any one of Claims 1-3,
The lead cell including the second vertical frame bone satisfies the formula (1). In the lead acid battery of any one of Claims 1-4,
The lead storage battery according to claim 1, wherein the inner bone includes at least one of a vertical bone parallel to the vertical frame bone and a horizontal bone parallel to the horizontal frame bone. In the lead acid battery of any one of Claims 1-5,
It said plurality of inner bone, the cross-sectional area further comprises t ^2/4 or less of the inner fine aggregate,
A lead-acid battery, wherein the inner fine bone is provided inside the mesh. In the lead acid battery of any one of Claims 1-6,
The following formula (2),
(S × d) / (V × L ² ) ≧ 0.0032 (Formula 2)
Lead-acid battery characterized by satisfying the relationship represented by: An outer frame portion having first and second horizontal frame bones and first and second vertical frame bones, a plurality of inner bones provided so as to intersect inside the outer frame portion, and the first horizontal frame A current collecting ear portion integrally provided outside the outer frame portion at a position near the first vertical frame bone in the bone;
For the vertical frame bone, the cross-sectional area in a cross section perpendicular to the extending direction S (mm ^2), when a thickness of t (mm), satisfy the relationship of S> t ^2/2,
It said plurality of inner bone includes UchiFutoshihone sectional area in the cross section perpendicular exceeds t ^2/4 in the extending direction,
A mesh constructed without traversing the other internal thick bone by the vertical frame bone and the internal thick bone, or another internal thick bone by the vertical frame bone, the horizontal frame bone and the internal thick bone For at least one of the meshes configured without being traversed, the volume of the mesh is V (cm ³ ), the length of the vertical frame bone of the portion constituting the grid is L (mm), When the width is d (mm), the following formula (1),
(S × d) / (V × L ² ) ≧ 0.002 (Formula 1)
A current collector satisfying the relationship represented by:

Images