JP3625648B2 - Method for manufacturing battery electrode - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a battery electrode plate in which a metal porous body having three-dimensional continuous pores is filled with an active material slurry, and in particular, an active material slurry unfilled portion is provided in a part of the metal porous body. The present invention relates to a method of filling a material slurry.
[0002]
[Prior art]
As an electrode of a sealed alkaline storage battery, a non-sintered electrode made by filling an active material powder in a metal porous body having three-dimensional continuous pores such as foamed nickel is used. This electrode connects a current collecting terminal to the porous metal body in order to extract electric power to the outside. Since the active metal slurry is filled in the three-dimensional continuous pores in the metal porous body of the electrode, the current collecting terminal cannot be connected.
[0003]
A method for connecting a current collecting terminal to an electrode filled with an active material slurry is described in Japanese Patent Publication No. 57-1863 and Japanese Patent Laid-Open No. 5-13064. In the methods described in these publications, the active material of the attachment portion connecting the current collecting terminals is removed by ultrasonic vibration. A metal current collector terminal is fixed to the mounting portion from which the active material has been removed by electrical resistance welding or ultrasonic welding.
[0004]
However, this method is difficult to sufficiently remove the active material. If the current collector terminal is electrically connected in the state where the active material remains in the porous metal body, the active material such as nickel hydroxide and cadmium hydroxide and the conductivity of the binder and the like are poor, so the welding electrode There is a drawback in that the space cannot be made sufficiently low resistance, sparking is likely to occur, and production efficiency and reliability are lowered.
[0005]
Furthermore, the method of removing an active material with ultrasonic waves damages a felt-like sintered body of nickel fibers and foamed nickel used as a porous metal body. In particular, there is a drawback in that the thin connecting portions forming the three-dimensional continuous pores are cut by ultrasonic vibration, and the strength of the metal porous body is significantly reduced.
[0006]
Japanese Patent Application Laid-Open No. 1-220370 describes a method of covering with a resin in order to expose the core of the portion connecting the current collecting terminals. In this method, after filling the core body with the active material, the core body is heated to remove the resin applied to the mounting portion of the current collecting terminal, thereby exposing the surface of the core body. However, in the method described in this publication, it is difficult to completely remove the resin, and the remaining resin makes it difficult to electrically connect the current collecting terminals. The reason is that since the resin is an insulator, the electric resistance when welding the current collecting terminals is increased. Therefore, the reliability of the part which connects a current collection terminal falls.
[0007]
Furthermore, Japanese Patent Application Laid-Open No. 48-67173 describes a method in which a core is exposed by attaching an adhesive tape to a portion where a current collecting terminal is connected. In this method, an adhesive tape is attached and an active material slurry is applied, and after drying the active material slurry, the adhesive tape is peeled off to expose the core. Since this method uses a disposable adhesive tape, the raw material cost for exposing the core is increased. In addition, since the adhesive tape is accurately attached to a predetermined position and is peeled after the active material slurry is dried, the manufacturing process is complicated and troublesome.
[0008]
[Problems to be solved by the invention]
The present invention was developed for the purpose of solving this drawback, and an important object of the present invention is that it does not damage the porous metal body of the three-dimensional continuous pores and adheres to the unfilled portion. Another object of the present invention is to provide a method for manufacturing a battery electrode that can reduce the amount of active material to be reduced, and can efficiently fill a metal porous body with active material slurry at low cost.
[0009]
[Means for Solving the Problems]
The battery electrode manufacturing method of the present invention is a method of filling an active material slurry into a metal porous body having three-dimensional continuous pores, but after filling an active material slurry into a metal porous body as in the prior art. The active material is not removed from the current collector. The porous metal body is provided with an unfilled portion that is not filled with the active material slurry, and this is used as a current collector.
[0010]
According to a first aspect of the present invention, there is provided a method for producing an electrode, comprising: bringing a porous metal body into contact with a rotating filling roller by adhering an active material slurry to the surface without immersing the porous body in an active material slurry; The active material slurry adhering to the surface is filled into the three-dimensional continuous pores of the metal porous body. The metal porous body is moved while being in contact with a filling roller, and the active material slurry is filled while providing an unfilled portion of the active material slurry continuously in a part of the metal porous body.
[0011]
The electrode manufacturing method according to claim 2 of the present invention uses a roller having a plurality of grooves on the surface as the filling roller. Furthermore, this filling roller is rotated at a speed that moves relative to the surface of the metal porous body to fill the metal porous body with the active material slurry. When the filling roller is rotated in the transfer direction of the metal porous body, the peripheral speed is made faster or slower than the transfer speed of the metal porous body. Moreover, a filling roller and a metal porous body can also be moved relatively by rotating a filling roller reversely with the transfer direction of a metal porous body.
[0012]
According to a third aspect of the present invention, there is provided a method for producing an electrode, comprising: a pressing plate provided on both sides of a porous metal body corresponding to an unfilled portion of the active material slurry; Prevent filling.
[0013]
In the electrode manufacturing method according to claim 4 of the present invention, a presser plate is provided on the entire upper surface of the metal porous body, and a presser plate is provided only on a portion to be an unfilled portion on the lower surface. Fill with active material slurry.
[0014]
In the electrode manufacturing method according to claim 5 of the present invention, a part of the active material slurry adhering to the surface of the filling roller is removed with a scraper. The portion of the active material slurry removed by the scraper is in contact with the metal porous body and is not filled with the active material slurry. The filling roller is a portion where the active material slurry is not removed, and fills the metal porous body with the active material slurry.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. However, the example shown below illustrates the manufacturing method of the electrode for embodying the technical idea of the present invention, and the present invention does not specify the manufacturing method of the electrode as follows.
[0016]
1 to 3 show an apparatus for filling an active material slurry into a porous metal body 1 having three-dimensional continuous pores. This apparatus includes a slurry tank 3 filled with an active material slurry 2, a filling roller 4 disposed horizontally inside the slurry tank 3, a press plate 5 provided with an unfilled portion in the metal porous body 1, And a scraper 6 disposed on the discharge side of the porous metal body 1. As shown in FIG. 1, the metal porous body 1 is transferred while being sandwiched between transfer rolls 7.
[0017]
The slurry tank 3 is filled with the active material slurry 2. The active material slurry varies depending on the type of battery. For example, nickel hydroxide is the main component, 0.1% by weight of sodium hexametaphosphate, 0.1% by weight of hydroxypropylcellulose (HPC), and 30% by weight of water are added. The viscosity is 3000 CP.
[0018]
The filling roller 4 has a plurality of grooves 4A on the surface. The groove 4 </ b> A stores the active material slurry 2 and supplies it to the porous metal body 1. The illustrated filling roller 4 is provided with a U-shaped groove 4A extending vertically. The groove can also be provided with a slight inclination with respect to the axial direction of the filling roller. The filling roller 4 has a lower part immersed in the active material slurry 2 and an upper part disposed outside the active material slurry 2. The filling roller 4 is rotated in a direction indicated by an arrow by a reduction motor (not shown). When the filling roller 4 is rotated in the direction opposite to the transfer direction of the metal porous body 1 as indicated by an arrow, the active material slurry 2 can be efficiently filled. However, the filling roller 4 can be rotated in the direction opposite to the arrow.
[0019]
The filling roller 4 is provided with a non-supply portion that does not supply the active material slurry 2 to the metal porous body 1 by reducing the outer diameter of the portion in which the metal porous body 1 is not filled with the active material slurry 2. The non-supplying portion is a portion that does not contact the metal porous body 1, and the presser plate 5 is disposed here. In the filling apparatus shown in the figure, a part of one filling roller 4 is thinned to form a non-feeding part.
[0020]
However, the filling apparatus can also arrange a plurality of filling rollers in a straight line and provide a non-feeding portion between the filling rollers. Furthermore, the filling roller can be provided with a non-feeding part as a whole with a cylindrical shape having the same outer diameter. The non-supplying portion is in contact with the inner surface of the metal porous body, but the active material slurry is not attached. The non-feeding portion of the filling roller has a smooth surface, and the scraper removes the active material slurry by bringing the tip edge of the scraper into contact with the smooth surface. A scraper is arrange | positioned in the position shown with the chain line of FIG. 1, scrapes off an active material slurry, and makes a non-supply part contact a metal porous body.
[0021]
The presser plate 5 is disposed in the non-supplying portion of the filling roller 4. In the illustrated apparatus, the presser plate 5 is disposed so as to contact the upper and lower surfaces of the metal porous body 1 and the metal porous body 1. The presser plate 5 is provided so as to extend in the transfer direction of the porous metal body 1. The presser plate 5 presses the upper and lower surfaces of the metal porous body 1. In other words, the presser plate 5 blocks the upper and lower surfaces of the metal porous body 1 and prevents the active material slurry 2 from being filled. Therefore, the apparatus for bringing the presser plate 5 into contact with the upper and lower surfaces of the metal porous body 1 can reliably prevent the active material slurry 2 from being filled in the unfilled portion of the metal porous body 1.
[0022]
However, it is not always necessary to provide the presser plate 5 in the non-feeding portion of the filling roller 4. This is because the non-feeding portion of the filling roller 4 is not in contact with the metal porous body 1 or the active material slurry is not adhered, and this portion does not feed the active material slurry 2 to the metal porous body 1. Further, the presser plate 5 can be disposed only on the lower surface of the metal porous body 1. This filling device can prevent the active material slurry 2 from being filled in the unfilled portion by closing the lower surface of the metal porous body 1 with the presser plate 5 provided in the non-feeding portion of the filling roller 4.
[0023]
Further, as shown in FIG. 4, the holding plate 5 can be disposed on the entire upper surface of the metal porous body 1. In this apparatus, the entire upper surface of the metal porous body 1 is closed by the holding plate 5, so that the active material slurry 2 supplied to the lower surface of the metal porous body 1 permeates the upper surface of the metal porous body 1. There is no. For this reason, the active material slurry 2 which permeate | transmitted the metal porous body 1 does not accumulate on the upper surface.
[0024]
The scrapers 6 are disposed on the upper and lower surfaces on the discharge side of the porous metal body 1 to remove excess active material slurry 2. In the apparatus shown in FIGS. 2 to 3, the plate-shaped scraper 6 is disposed on both surfaces of the porous metal body 1 and the leading edge thereof is brought into contact with or close to the surface of the porous metal body 1 so that the excess activity is achieved. Material slurry 2 is removed. In the apparatus of FIG. 4, the presser plate 5 is disposed on the entire upper surface of the metal porous body 1, and this can be used together with the scraper. Therefore, in this apparatus, the scraper 6 is provided only on the lower surface of the porous metal body 1. The scraper 6 may be a roll disposed on the surface of the porous metal body. The scraper adjusts the filling amount of the active material slurry at the interval.
[0025]
Using the apparatus shown in the figure, an active material slurry is filled into a metal porous body having three-dimensional continuous pores as follows.
The production method of the present invention does not specify the metal porous body and the active material slurry. As the metal porous body having three-dimensional continuous pores, for example, a metal porous body having three-dimensional continuous pores, such as a felt-like sintered body of nickel fibers and foamed nickel, can be used.
[0026]
The filling roller 4 is rotated in the direction indicated by the arrow and brought into contact with the lower surface of the porous metal body 1 transferred in the direction of the arrow. Since the lower part of the filling roller 4 is immersed in the active material slurry 2, the active material slurry 2 is attached to the surface, and the active material slurry is supplied to the metal porous body 1 from the lower surface. The filling roller 4 shown in the figure stores the active material slurry 2 also in the groove 4A on the surface, and supplies it to the porous metal body 1 from the lower surface.
[0027]
The filling roller 4 in contact with the lower surface of the metal porous body 1 supplies the active material slurry 2 on the surface to the metal porous body 1 for filling. The active material slurry 2 supplied from the filling roller 4 to the metal porous body 1 penetrates and fills the three-dimensional continuous pores. In particular, as shown in the figure, when the surface of the filling roller 4 is moved relative to the porous metal body 1, the active material slurry 2 attached to the surface of the filling roller 4 is more efficiently three-dimensional. It is filled so as to push into the continuous holes. As shown in FIG. 1, part of the active material slurry 2 supplied to the metal porous body 1 passes through the metal porous body 1 and is transferred to the upper surface.
[0028]
However, when the active material slurry 2 is filled with the apparatus shown in FIG. 4, the entire upper surface of the metal porous body 1 is closed with the presser plate 5, so that the active material slurry 2 passes through the metal porous body 1 and the metal There is no accumulation on the upper surface of the porous body 1.
[0029]
Since the non-feeding part of the filling roller 4 does not contact the lower surface of the metal porous body 1 or the active material slurry is not attached, the metal porous body 1 passing through this part is not filled with the active material slurry 2. Part. Since the metal porous body 1 is continuously transferred and filled with the active material slurry 2, the unfilled portion is continuous in a band shape. Furthermore, in the apparatus in which the holding plate 5 is provided on the non-supplying portion on the lower surface of the porous metal body, the lower surface of the porous metal body 1 is closed with the holding plate 5 on the lower surface, and the active material slurry 2 is filled in the unfilled portion. Surely prevent it. Therefore, the portion passing through the presser plate 5 in contact with the lower surface of the metal porous body 1 becomes an unfilled portion and is not filled with the active material slurry 2.
[0030]
When the metal porous body 1 filled with the active material slurry 2 passes between the scrapers 6, the excess active material slurry 2 is removed, and in this step, the three-dimensional continuous pores ensure that there is no gap. The active material slurry 2 is filled.
[0031]
The metal porous body 1 filled with the active material slurry 2 was provided between the filling portions 8 as shown in FIG. 5, for example, as shown in FIG. The unfilled portion 9 is cut and processed into a battery electrode.
[0032]
【The invention's effect】
The battery electrode manufacturing method of the present invention can eliminate cracks and breaks in the metal porous body and expose the metal porous body. In particular, the manufacturing method of the present invention does not remove the metal porous body after the active material slurry is filled as in the conventional method, but exposes the porous metal body, so that the filling roller is brought into contact with the porous metal body to form an unfilled portion. Is filled with the active material slurry. In this method, the amount of the active material slurry in the portion where the porous metal body is exposed can be greatly reduced as compared with the conventional method of the filled active material slurry. For this reason, when the current collecting terminal is electrically connected to the exposed portion of the metal porous body, the contact resistance between the current collecting terminal and the metal porous body can be remarkably reduced. Therefore, when connecting the current collecting terminals by a method such as electric welding, it is possible to reduce the welding defects and to make electrical connection of the current collecting terminals reliably.
[0033]
Furthermore, in the method for producing an electrode of the present invention, the active material slurry is filled into the metal porous body so that an unfilled portion can be formed using a filling roller. Therefore, after the active material slurry is dried, the active material slurry is No removal process is required. For this reason, it has the advantage that it can be mass-produced efficiently at a low cost with a simple process. Furthermore, in order to expose the porous metal body, it is not necessary to attach an adhesive tape or apply a resin as in the conventional case. Thus, the production method of the present invention has the advantage that the electrode can be produced more efficiently and at a low cost.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a filling apparatus used in the electrode manufacturing method of the present invention. FIG. 2 is a perspective view showing a usage state of the filling apparatus shown in FIG. FIG. 4 is a perspective view of another filling device used in the electrode manufacturing method of the present invention. FIG. 5 is a plan view showing a state in which a metal porous body filled with an active material is cut. [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Metal porous body 2 ... Active material slurry 3 ... Slurry tank 4 ... Filling roller 4A ... Groove 5 ... Holding plate 6 ... Scraper 7 ... Transfer roll 8 ... Filling part 9 ... Unfilled part

Claims (5)

A method for producing an electrode for a battery, in which an active material slurry is filled in a porous metal body having three-dimensional continuous pores ,
Without immersing the porous metal body in the active material slurry, the active material slurry is adhered to the surface and brought into contact with the rotating filling roller, and the active material slurry adhering to the surface of the filling roller is made porous. In the method of filling the three-dimensional continuous pores of the body ,
The battery is characterized by filling the active material slurry while providing an unfilled portion of the active material slurry continuously with a part of the metal porous body by moving the metal porous body in contact with the filling roller. Electrode manufacturing method. The filling roller uses a roller having a plurality of grooves on the surface, and rotates the filling roller at a speed that moves relative to the surface of the metal porous body to fill the metal porous body with the active material slurry. Item 4. A method for producing a battery electrode according to Item 1. 2. The battery for a battery according to claim 1, wherein a holding plate is provided on both surfaces of the porous metal body corresponding to the unfilled portion of the active material slurry, and the active plate slurry is prevented from being filled into the porous metal body by the holding plate. Electrode manufacturing method. The method for producing a battery electrode according to claim 3, wherein a press plate is provided on the entire upper surface of the porous metal body, and the active material slurry is filled in the porous metal body. The manufacturing method of the electrode for batteries described in Claim 1 which removes the active material slurry adhering to the surface of a filling roller with a scraper, and provides an unfilled part in a metal porous body.

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