TWI628833B - Secondary battery - Google Patents

Abstract

Provided is a secondary battery comprising a spacer which can smoothly flow a gas and an electrolyte in a gap between a spacer and a member group of the electrode group disposed at an end portion of the electrode group.

A pair of spacers (23) are disposed at both ends of the laminated electrode group (15) in the stacking direction. The spacer (23) is provided with a plurality of protrusions (25) having a shape in which the tip end portion abuts against the active material layer (18) of the negative electrode plate (17) and can be between the active material layer (18) and the active material layer (18). Form a space (S). The plurality of protrusions (25) are dispersedly arranged to supply a plurality of passages through which gas (oxygen, hydrogen) and electrolyte pass through continuously extending from the bottom wall portion side of the electrolytic cell body (5) toward the opening portion (3) side. (P) to form a space (S).

Description

Secondary battery

The present invention relates to a secondary battery including an electrode that absorbs oxygen at both ends in the stacking direction of the laminated electrode group.

Japanese Patent Publication No. 7-254431 (Patent Document 1) discloses a conventional secondary battery including an electrolytic cell and a laminated electrode group disposed in the electrolytic cell at the end in the stacking direction. An electrode for absorbing oxygen and a spacer are disposed between the electrode and the inner wall of the electrolytic cell to form a space between the electrode and oxygen (gas). In one example of the spacer, a plurality of ribs are provided which are in contact with the surface of the electrode and are disposed at intervals in the space between the electrodes and the space between the electrodes, and extend continuously in the width direction orthogonal to the vertical direction. Further, in another example of the spacer, the rib is formed in a lattice shape.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. Hei 7-254431

In the structure shown in Patent Document 1, a plurality of independent small spaces surrounded by ribs are formed, so that it is difficult to smoothly discharge oxygen and hydrogen generated during formation. In addition, the oxygen generated during charging is retained in a limited small space, so that oxygen can only contact a part of the negative electrode plate, the oxygen absorption efficiency is deteriorated, and the absorption may be incomplete. Further, since the electrolyte cannot flow through the entire surface of the electrode plate, the chemical reaction between the electrolyte and the active material may be uneven in the surface of the active material, and the efficiency of the chemical reaction may be deteriorated and the battery performance may be degraded. Furthermore, the local deterioration of the active material is exacerbated, and it is difficult to maintain the battery design life. In the conventional structure, a pair of spacers disposed on both sides of the laminated electrode group are sandwiched from both sides in the stacking direction, and the laminated electrode group is inserted into the upper end to have an opening. In the case of the electrolytic cell body, slippage occurs between the spacer and the laminated electrode group. Therefore, a situation occurs in which only the laminated type plate group is inserted into the inside of the electrolytic cell body. When such a situation occurs, the inner wall of the electrolytic cell main body and the electrode plate surfaces at both ends in the stacking direction of the laminated electrode group are rubbed, and the active material of the electrode plate surface is damaged.

An object of the present invention is to provide a secondary battery comprising a spacer which can smoothly flow oxygen gas, hydrogen gas and electrolyte between a separator and an electrode for absorbing oxygen.

In addition to the above objects, another object of the present invention is to provide a secondary battery capable of maintaining a positional relationship between a spacer and a laminated electrode group within a certain range.

Still another object of the present invention is to provide a lead storage battery capable of achieving the above object.

The present invention is directed to a secondary battery comprising: an electrolytic cell; and a laminated electrode group disposed in the electrolytic cell; and a spacer disposed at a stacking end of the laminated electrode group Between the electrode assembly member of the portion and the inner wall of the electrolytic cell, a space for supplying gas (oxygen, hydrogen) and electrolyte to the electrode assembly member is formed. In the present invention, the spacer member has a plurality of protrusions having a shape in which the tip end portion abuts against the electrode group group constituent member and forms a space between the electrode group and the electrode group member. In the present specification, the contact is in a state in which the projections are in contact with the constituent members of the electrode group, and the projections are invaded into the constituent members of the electrode group, and both of them are included. In addition, in the present specification, the electrode group constituent member means a member necessary for forming an electrode group such as a positive electrode plate, a negative electrode plate, and a retainer.

Further, a plurality of protrusions are dispersed and arranged to form a space by a plurality of passages through which the gas and the electrolyte are circulated continuously from the bottom wall portion side of the electrolytic cell toward the upper wall portion side. Since a plurality of protrusions are dispersed and arranged, a space is formed by continuously extending a plurality of passages through which the gas and the electrolyte pass from the bottom wall portion side of the electrolytic cell toward the upper wall portion side, so that the gas can be obtained as compared with the prior art. The circulation of electrolytes becomes a smooth advantage. Further, the distributed arrangement of the plurality of protrusions includes a case where a plurality of protrusions are regularly dispersed, and a case where they are irregularly arranged. Kind.

The plurality of protrusions preferably have a shape in which the cross-sectional area is gradually reduced toward the tip end portion. When the protrusion has such a shape, the active material layer of the electrode is not greatly damaged, and the protrusion can be smoothly intruded into the active material layer of the electrode.

As a result, the positional relationship between the spacer and the electrode assembly member can be maintained within a certain range.

A plurality of protrusions are arranged in a distributed manner to form a plurality of protrusion rows arranged at a predetermined interval. When a plurality of protrusions are dispersed and formed so as to form a plurality of protrusion rows, not only the design and manufacture of the spacers are facilitated, but also a plurality of protrusions can be intruded into the active material without bias, so that the plurality of protrusions do not oppose the gas. The release and oxygen absorption properties have a large impact.

Further, the spacer is preferably integrally formed of a material which is difficult to react with the electrolyte and does not hinder the movement of the gas and the electrolyte in the space. As such a material, for example, a resin material having a compressive strength falling within the range of 1 to 105 MPa such as polypropylene, polyethylene, ABS or denatured PPE can be selected. When these materials are used, the spacer material has an appropriate compressive strength, so that the shape of the entire spacer including the plurality of protrusions is maintained, and the amount of protrusion intrusion is not excessive, and the interval which does not affect the battery performance can be provided. material.

Further, when a negative electrode plate is used as the electrode assembly member, the oxygen absorption performance can be improved. Further, if such a configuration is designed, it is not necessary to increase the number of constituent parts of the secondary battery.

The spacer is preferably formed with an inclined surface or a curved surface at the corner of the electrolytic cell side at the lower end portion to facilitate insertion of the spacer into the electrolytic cell. When such an inclined surface or a curved surface is formed, the spacer can be smoothly inserted into the electrolytic cell.

Further, it is preferable that the spacer is provided with a mark indicating a spacer arrangement direction with respect to the electrode group constituent member. The mark may be a character, a symbol, a figure, or the like, and may be formed by forming a slit or the like at the edge of the spacer.

In the case where the present invention is applied to a lead storage battery, the battery includes an electrolytic cell having an electrolytic cell body having an opening that opens upward, and a lid that blocks the opening; The integrated electrode group is inserted into the inside of the electrolytic cell body from the opening, and the negative electrode plate and the positive electrode plate are alternately laminated via a separator, and the negative electrode plate is disposed at both ends in the stacking direction as an electrode for absorbing oxygen. And the spacer is disposed between the active material layer of the negative electrode plate and the inner wall of the electrolytic cell to form a space between the electrode and the gas (oxygen, hydrogen) and the electrolyte. Further, the spacer has a plurality of protrusions having a shape in which the tip end portion abuts against the active material layer and forms a space between the active material layer and the active material layer. Further, a plurality of protrusions are dispersed and arranged to form a space by a plurality of passages through which the gas and the electrolyte flow are continuously extended from the bottom wall portion side of the electrolytic cell main body toward the opening portion side. According to the lead storage battery of the present invention, the lead storage battery provided with the spacer can be configured with a simple structure.

In the lead storage battery, preferably, the height H of the plurality of protrusions is a value in the range of 0.1 to 0.5 mm; the base of the plurality of protrusions The width dimension is a value in the range of 80 to 120% of the height H of the protrusion; the pitch size between the adjacent two protrusions is 80 to the length dimension L orthogonal to the width dimension of the protrusion. Value in the range of 120%. When a spacer material that satisfies such numerical conditions is used, the gas (oxygen, hydrogen) and the electrolytic solution can be smoothly distributed in the space between the spacer and the negative electrode plate, and the oxygen release during charging and the oxygen during charging can be improved. The absorption performance, in addition, the chemical reaction between the electrolyte and the active material can be efficiently performed.

Further, when the present invention is applied to a control valve type lead storage battery in which no free electrolyte exists, the capillary solution can be oozing out to fill the space, and the electrolyte can be circulated, so that the electrolyte is inhibited. The specific gravity is poor, and it is difficult to have the effect of stratification. At this time, if the electrode plate surface is vertically arranged with respect to the installation surface, the effect is further increased.

Further, in the control valve type lead storage battery, it is preferable to apply a force of 30 kN/m ² or more to the spacer member in a state of being inserted into the electrolytic cell body. When such a pressurization condition is satisfied, most or all of the tip ends of the plurality of protrusions can be intruded into the active material layer of the negative electrode plate. As a result, the positional relationship between the spacer and the electrode group can be maintained within a certain range.

Further, in the lead storage battery, it is preferable that the width of the space is in the range of 0.1 to 0.5 mm. In a lead storage battery, if a spacer material that satisfies these numerical conditions is used, the battery performance can be improved compared with the prior art.

1‧‧‧ lead battery

3‧‧‧ openings

4‧‧‧Active material layer

5‧‧‧ Electrolytic cell body

7‧‧‧ Cover

9‧‧‧ Electrolyzer

11‧‧‧ next door

13‧‧‧ Storage room

15‧‧‧Layered plate group

16‧‧‧ saddle

17‧‧‧Negative plate

18‧‧‧Active material layer

19‧‧‧ positive plate

21‧‧‧Support plate

23‧‧‧ spacers

25‧‧‧ Protrusion

26‧‧‧ vertex

27‧‧‧protrusion

28‧‧‧Bend surface

29‧‧‧ recess

231‧‧‧ spacer

232‧‧‧ spacer

233‧‧‧ spacers

251‧‧‧ Protrusion

252‧‧‧ Protrusion

S‧‧‧ Space

P‧‧‧ pathway

Fig. 1 is a schematic cross-sectional view showing a lead storage battery of the embodiment.

Fig. 2 is a schematic cross-sectional view showing a state in the middle of a manufacturing process of the lead storage battery of the embodiment.

[Fig. 3] Front view of a spacer.

4] (A) to (C) are partial cross-sectional views of a spacer, and a perspective view of a protrusion of (D).

Fig. 5 (A) to (C) are front views showing a spacer of a modified example of the spacer.

Fig. 6 (A) and (B) are perspective views showing a modification of the projection.

Fig. 7 is a schematic cross-sectional view showing a lead storage battery according to another embodiment of the present invention.

Hereinafter, an example of an embodiment in which the present invention is applied to a lead storage battery will be described with reference to the drawings. Fig. 1 is a schematic cross-sectional view showing a lead storage battery 1 of the present embodiment. 2 is a schematic cross-sectional view showing a part of a manufacturing process of the lead storage battery 1 of FIG. 1. In FIG. 1, the lead storage battery 1 has an electrolytic cell 9 having an electrolytic cell body 5 having an opening 3 that opens upward, and a lid 7 that blocks the opening 3. The electrolytic cell body 5 and the lid body 7 are each formed of an electrically insulating resin. The laminated electrode group 15 is housed in the electrolytic cell 9.

As shown in FIG. 1, the laminated electrode group 15 is such that the negative electrode plate 17 and the positive electrode plate 19 are alternately laminated via the support plate 21. The laminated plate group The 15th system is configured such that the negative electrode plate 17, which is an electrode that absorbs oxygen at both ends in the stacking direction, is disposed as an electrode group member. Further, the number of the negative electrode sheets 17 shown in Fig. 1, the number of the positive electrode sheets 19, and the number of the support sheets 21 can be appropriately set in accordance with the design capacity of the battery. In the present embodiment, a pair of spacers 23 are disposed at both ends of the laminated electrode group 15 in the stacking direction. The pair of spacers 23 are disposed between the active material layer of the negative electrode plate 17 constituting the oxygen absorbing electrode and the inner wall of the electrolytic cell body 5, and form a supply gas between the negative electrode plate 17 constituting the electrode absorbing oxygen gas ( Oxygen, hydrogen) and the space S through which the electrolyte passes. The plurality of negative electrode plates 17 are mechanically and electrically coupled to the straps 22, respectively. Further, a plurality of positive electrode plates 19 are also mechanically and electrically connected to each other by a connecting piece (not shown).

In the present embodiment, the spacer 23 having the structure shown in Figs. 3 and 4 is used. The spacer 23 is formed of a material that is difficult to react with the electrolytic solution, and does not hinder the movement or flow of the gas (oxygen, hydrogen) and the electrolyte in the space S when the electrolytic cell is formed. In the present embodiment, the spacer 23 is integrally molded of polypropylene, polyethylene, ABS, denatured PPE or the like. As shown in the partial cross-sectional shape of FIG. 4(B), the spacer 23 has a plurality of protrusions 25 which are formed so as to be able to enter the active material layer 18 of the negative electrode plate 17 at the tip end portion (in FIG. 4(B) The state in which it is easily understood and indicated by a broken line is in contact with the negative electrode plate 17, and a space S is formed between the active material layer 18. The plurality of protrusions 25 are dispersedly arranged to supply a plurality of passages P through the gas (oxygen, hydrogen) and the electrolyte through continuous extension from the bottom wall portion side of the electrolytic cell body 5 toward the opening portion 3 side (in FIG. 3 Virtual The line indicates a path example of the path) to constitute the space S.

As shown in FIGS. 4(B) and 4(D), the projections 25 provided in the spacer 23 used in the present embodiment have a shape in which the cross-sectional shape is triangular and elongated. In Fig. 3, the apex portion 26 of the protrusion 25 is indicated by a line. Therefore, in the spacer 23, the apexes 26 of the projections 25 are arranged at a predetermined interval and are arranged in parallel on the straight line to form the projection row 27. On the other hand, the seven projection rows 27 are arranged in parallel at a predetermined interval in the direction orthogonal to the direction in which the projection rows 27 extend. As shown in FIG. 4(C), in the spacer 23, a curved surface 28 is formed at each of the corner portions of the lower end portion and the upper end portion. By forming such a curved surface 28, the spacer 23 can be smoothly inserted into the electrolytic cell 9. Alternatively, instead of the curved surface 28, an inclined surface (push-out surface) may be formed at the corner portion of the spacer. Further, the length of the projections 25 and the number of the projection rows 27 can be arbitrarily set. The height H of the projection 25 shown in Fig. 4(B) is preferably about 0.1 to 0.5 mm. Further, the width dimension of the base portion of the plurality of projections 25 is a value within a range of 80 to 120% of the height H of the projection. Further, the pitch size between the adjacent two protrusions 25 is preferably a value in the range of 80 to 120% of the length dimension L orthogonal to the width dimension of the protrusion, and the width dimension of the base portion of the protrusion 25. W is preferably a value in the range of 80 to 120% of the length dimension L.

In the present embodiment, the height H of the protrusion is a value in the range of 0.1 to 0.5 mm. Moreover, a force of 30 kN/m ² or more is applied to the spacer 23 in a state of being inserted into the electrolytic cell body. As a result, the width dimension of the space S (the distance between the plate-like main body portion of the spacer 23 and the negative electrode plate 17) is a value in the range of 0.1 to 0.5 mm. As long as a space having such a width dimension can be formed, the gas (oxygen, hydrogen) and the electrolyte can be circulated in the space, and the oxygen absorption performance during gas release and charging can be sufficiently ensured, and The chemical reaction between the electrolyte and the active material in the space is efficiently performed.

Further, in the spacer 23, a pair of concave portions 29 having a V shape are formed on a pair of opposing sides. The function of the pair of recesses 29 is a mark indicating the arrangement direction with respect to the negative electrode plate 17 (electrode group constituting member) of the spacer 23 . Further, of course, marks such as characters, symbols, and figures may be marked on the surface of the spacer instead of the V-shaped recesses 29.

(Method of inserting the plate group)

When the lead storage battery of the above-described embodiment is assembled, as shown in FIG. 2, the spacers 23 are placed on both sides in the stacking direction of the laminated electrode group 15 so that the projections 25 face the negative electrode plate 17. Further, the spacer 23 is disposed in a posture in which the concave portion 29 is positioned in the vertical direction. Then, the spacer 23 is pressed against the laminated electrode group 15 to abut the plurality of protrusions 25 to the active material layer of the negative electrode plate 17. Then, a force is applied to the pair of spacers 23 from both sides in the stacking direction of the laminated electrode group, and the laminated electrode group 15 is inserted into the electrolytic cell body 5 in a state where the laminated electrode group 15 is compressed in the stacking direction. Inside the room 13. At this time, since the pair of spacers 23 function as a guard, the electrode group 15 is not damaged. Further, the positional relationship between the spacer 23 and the laminated electrode group 15 is not shifted, and when the electrode group 15 is inserted into the electrolytic cell body 5, it is possible to effectively prevent only the electrode group from being inserted into the electrolytic cell. Thereafter, the opening portion 3 of the electrolytic cell body 5 is blocked by the lid body 7 to electrolyte The liquid is injected into the electrolytic cell 9, and chemical conversion treatment is performed to complete the battery.

(Modification of spacer)

5(A) to (C) show a configuration modification of the projection provided on the spacer. In the spacer 231 of FIG. 5(A), the protrusions 25 of the adjacent two protrusion rows (for example, 27A and 27B) among the plurality of protrusion rows 27A to 27G are alternately arranged (or alternately arranged), and the protrusions are arranged. 25. In such an arrangement, the passage P through which the gas (oxygen, hydrogen) passes is mainly a meandering passage as indicated by a broken line. Further, in the spacer 232 of FIG. 5(B), the protrusions 25' in the protrusion row 27 are inclined at a certain angle with respect to the extending direction of the protrusion row 27. According to this spacer, since the projections 25' are inclined, it is possible to effectively suppress the gas (oxygen, hydrogen) from remaining on the lower surface of the projections 25'. Further, in the spacer 233 of Fig. 5(C), the two types of protrusions 25' and 25" in the protrusion row 27 are alternately arranged with respect to the extending direction of the protrusion row 27. Two types of protrusions 25' and protrusions 25 ", its tilt direction is opposite. According to the spacer 233, as in the spacer 232, it is possible to effectively suppress the gas (oxygen, hydrogen) from remaining on the lower surface of the protrusion 25.

(Modification of protrusion)

The shape of the protrusion may be any, that is, the tip end portion can intrude into the electrode group constituent member (the negative electrode plate 17 in the embodiment), and the space S is formed between the electrode group member and the spacer. And can supply gas by continuously extending from the bottom wall portion side of the electrolytic cell 9 toward the upper wall portion side. The space S is formed by a plurality of passages P (oxygen, hydrogen) and electrolyte. 6(A) and (B) respectively show a modification of the protrusion. The protrusion 251 of Fig. 6(A) has a pyramid shape. Further, the projection 252 of Fig. 6(B) has a shape in which a cube-shaped base portion B has a projecting portion C having a triangular cross section. According to the projection 252, the base B serves as a stopper, and the intrusion size of the projection can be restricted. Therefore, the width dimension of the space can be made uniform.

In the above embodiment, the projections 25, 25', and 25" are regularly arranged in a distributed manner, but the projections may of course be dispersed and arranged irregularly without regularity.

(applies to multiple battery cells)

In the above embodiment, the present invention is applied to a single cell type lead-acid storage battery in which one battery cell is disposed in one electrolytic cell. However, as shown in FIG. 7, the present invention can of course be applied to a lead storage battery having a plurality of battery cells. In the embodiment of Fig. 7, the inside of the electrolytic cell 9 is partitioned by five partition walls 11, and the laminated electrode group 15 is accommodated in each of the six storage chambers 13 partitioned by the partition wall 11. One or more saddle portions 16 are provided at the bottom of the electrolytic cell body 5. The saddle portion 16 has a plate shape, and a plurality of sheets are provided at predetermined intervals in the direction of the paper surface of FIG. 7, and the laminated electrode group 15 is inserted into each of the storage chambers 13 of the electrolytic cell main body 5, and then the opposite polarity is performed. The connecting pieces 12 may be welded to each other.

(Other variants)

Further, in the above embodiment, the present invention is applied to a lead storage battery, but the present invention can of course be applied to a battery having an oxygen absorbing structure such as a nickel cadmium battery.

In the above-described embodiment, the negative electrode plate is used as the electrode assembly member disposed at the end portion of the electrode group. However, depending on the type of the battery, the positive electrode plate may be used as the electrode assembly member or may be supported. The plate is formed as a member of the electrode group and is disposed at the end of the electrode group.

[Industry Utilization]

According to the invention, the plurality of protrusions of the spacer are dispersedly arranged, and the space is formed by a plurality of passages through which gas (oxygen, hydrogen) and electrolyte pass through continuously extending from the bottom wall portion side of the electrolytic cell toward the upper wall portion side. Therefore, compared with the prior art, it is possible to obtain an advantage of smoothing the flow of gas (oxygen, hydrogen) and electrolyte. Further, the tip end portions of the plurality of protrusions can be prevented from coming into contact with the electrode group group member in an intrusion state, and the positional relationship between the spacer member and the laminated electrode group can be prevented from being deviated within a certain range. When the plate group is housed in the electrolytic cell together, it is possible to effectively prevent the electrode plate group from falling into the electrolytic cell before the spacer material.

Claims (10)

A secondary battery comprising: an electrolytic cell; and a laminated electrode group disposed in the electrolytic cell; and a spacer disposed on a plate group located at an end portion of the laminated electrode group in a stacking direction Between the member and the inner wall of the electrolytic cell, a space for flowing a gas and an electrolyte is formed between the member and the electrode assembly member; and the spacer has a plurality of protrusions having a shape and a tip end The portion abuts against the electrode group constituting member, and the space can be formed between the electrode group and the electrode group constituting member, and the plurality of protrusions are dispersed and arranged to form a plurality of protrusion rows arranged at a predetermined interval. a space extending continuously from the bottom wall portion side of the electrolytic cell toward the upper wall portion side and through which the gas and the electrolyte pass are formed, and the plurality of protrusions have a smaller cross-sectional area toward the tip end portion. shape. The secondary battery according to claim 1, wherein the electrode assembly member is a negative electrode plate or a retainer. The secondary battery according to claim 1 or 2, wherein the spacer is integrally formed of a material that is difficult to react with the electrolytic solution and does not inhibit the movement of the electrolyte in the space. The secondary battery according to claim 3, wherein the material is any one of polypropylene, polyethylene, ABS, and denatured PPE. The secondary battery according to claim 1, wherein the spacer is formed at a corner portion of the lower end portion on the side of the electrolytic cell A beveled or curved surface for easy insertion of the aforementioned spacer. The secondary battery according to claim 1, wherein the spacer is provided with a mark indicating an arrangement direction of the spacer with respect to the electrode group constituent member. A lead storage battery comprising: an electrolytic cell having: an electrolytic cell body having an opening that opens upward; and a lid that blocks the opening; and a laminated electrode group inserted from the opening The inside of the electrolytic cell main body is configured such that a negative electrode plate and a positive electrode plate are laminated via a support plate, and the negative electrode plate is disposed at both ends in the stacking direction as an electrode for absorbing oxygen; and the spacer is disposed to constitute the electrode. Between the active material layer of the negative electrode plate and the inner wall of the electrolytic cell, a space for oxygen, hydrogen, and electrolyte to pass therethrough is formed between the electrode and the electrode; the spacer has a plurality of protrusions, and the shape thereof is a tip end. The portion is formed to form the space between the active material layer and the active material layer, and the plurality of protrusions are dispersed and arranged to form a plurality of protrusion rows arranged at a predetermined interval so as to be electrolyzed from the foregoing The bottom wall portion side of the groove body continuously extends toward the opening portion side and is formed by a plurality of passages through which the oxygen, hydrogen, and electrolyte are passed. Space, the plurality of projections, having a shape more toward the tip portion of the gradient is smaller cross-sectional area. The lead storage battery according to Item 7, wherein the height dimension H of the plurality of protrusions is in the range of 0.1 to 0.5 mm. a value; a width dimension of the base of the plurality of protrusions being a value in a range of 80 to 120% of a height H of the protrusion; a pitch size between the adjacent two protrusions and a width of the protrusion A value in the range of 80 to 120% of the length dimension L of the orthogonal dimension. The lead storage battery according to claim 8, wherein a force of 30 kN/m ² or more per unit area is applied to the spacer in a state of being inserted into the electrolytic cell body. The lead storage battery according to claim 9, wherein the space has a width dimension ranging from 0.1 to 0.5 mm.