JP2000337859A - Method and apparatus for measurement of thickness of sheetlike electrode - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus for the measurement of a thickness, in which the measurement can be performed always with high accuracy by reducing or preventing the influence of the surface state, the strain, the vibration in the measurement, or the like of a sheetlike electrode. SOLUTION: In this measuring method, a sheetlike electrode 1 is pressed by a plurality of pairs of pressure rollers 5, 5' which are faced each other and arranged on both sides so as to face the face of the sheetlike electrode 1 within a pressed region, a pair of contact- type displacement sensors 2, 3 are made to abut on the electrode 1 perpendicularly under a set pressure, and the thickness of the sheetlike electrode 1 is measured. In addition, this measuring apparatus is provided with a running mechanism 4 by which a sheetlike electrode 1 is run. The measuring apparatus is provided with a pair of contact-type displacement sensors 2, 3 which sandwich the sheetlike electrode 1 to be run by the running mechanism 4 and which are arranged perpendicularly to the face of the sheetlike electrode 1. The measuring apparatus is provided with a plurality of pairs of pressure roller mechanism 5, 5' which are adjacent to the contact-type displacement sensors 2, 3, which are arranged so as to be slidable and which press the sheetlike electrode 1. At this time, the pressure roller mechanisms 5, 5' are arranged so as to be slidable either in the front and the rear or in the right and the left with reference to the contact-type displacement sensors 2, 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a means for measuring the thickness of a sheet-like electrode, and more particularly to a measurement capable of reducing the influence of distortion of a sheet-like electrode and performing a stable thickness measurement. The present invention relates to a method and a measuring device.

[0002]

2. Description of the Related Art In recent years, with the promotion of cordless, high-performance, and compact and lightweight electronic devices such as portable telephones and portable notebook personal computers (PCs), the main power supply of these electronic devices has been increased. There is a demand for higher performance batteries. As a main power supply for these electronic devices, nickel-metal hydride secondary batteries or lithium secondary batteries capable of achieving higher performance and higher capacity have been put into practical use.

[0003] By the way, this type of nickel-metal hydride secondary battery or the like is generally wound or wound by interposing a separator carrying an electrolyte (electrolyte) between a strip-shaped (sheet-shaped) positive electrode and a negative electrode. An electrode group (power generation element portion) is formed by laminating the electrodes, and the electrode group is liquid-tightly sealed in a battery outer container. Further, an electrode group (electrode element part) of the secondary battery, for example, an electrode group of a nickel-metal hydride secondary battery,
Generally, a band-shaped (sheet-shaped) current collector provided with a positive electrode active material layer containing a nickel compound is used as a positive electrode, and the band-shaped current collector is also a hydrogen absorbing alloy having a CaCu _5- type crystal structure. An anode provided with an anode active material layer containing is constituted as an anode.

The above-mentioned sheet-like electrode is prepared by preparing an electrode active material corresponding to a sheet-like current collector into a paste or gel, and applying the paste-like or gel-like electrode active material to the surface of the current collector. After that, it is dried, further subjected to a process such as pressure bonding, and then cut into a desired size. Here, the application of the electrode active material to the sheet-like current collector surface increases the filling amount (the amount of the electrode active material carried) of the electrode active material in order to increase the capacity or improve the volume efficiency. further,
After drying a coated film of the electrode active material-based paste, the electrode film is pressed to improve the adhesion density of the active material layer, and the capacity or performance of the electrode layer is increased.

[0005] The sheet-like current collector is, for example, a sheet-like metal foil such as aluminum, copper, nickel, titanium, and stainless steel, or a sheet-like wire mesh or sheet-like porous thin plate such as ex-band metal. No. The form of these sheet-like current collectors is
It is a non-porous sheet, a perforated sheet, a net-like (net-like) sheet, etc., and its thickness is about 20 to 50 μm.

[0006] As described above, the thickness and adhesion (filling) density of the coating film of the electrode active material in each sheet-like electrode are important factors that greatly affect battery performance. For example, when the thickness of the sheet-like electrode including the coating film of the electrode active material is small, there is a problem that battery performance is reduced. Conversely, when the thickness of the sheet-like electrode is large, there is a problem that the outer diameter of the spirally wound electrode group becomes large.

[0007] The increase in the diameter of this electrode group is a factor in making a battery.
An internal short circuit is likely to occur, and the volume of the electrode group occupying the battery volume increases, which adversely affects the battery internal pressure. Therefore, it is important to measure the thickness of the sheet-shaped electrode with high accuracy and to control the thickness.

[0008]

Conventionally, the thickness of a sheet electrode for a battery is, for example, a laser sensor, a light reflection type,
Alternatively, the measurement is performed by a contact type displacement sensor or the like. However, in the case of the sheet electrode, it can be said that securing or maintaining homogeneity is extremely difficult due to the complexity of the manufacturing process (process).

That is, the manufactured sheet-shaped electrodes not only differ in their surface condition and distortion, but also are affected by vibration during measurement, and thus are liable to cause measurement errors. Therefore, stable and reliable thickness measurement is difficult, and the quality of the sheet electrode thickness cannot be sufficiently controlled.

The present invention has been made in view of the above circumstances, and reduces or avoids the influence of the surface condition, distortion, and vibration during measurement of a sheet-like electrode, and can always perform highly accurate thickness measurement. It is intended to provide a measuring method and a measuring device.

[0011]

According to a first aspect of the present invention, a sheet-like electrode is pressed by a plurality of pairs of pressing rollers opposed to each other on both sides, and the sheet-like electrode surface in the pressed area is pressed. A method of measuring the thickness of the sheet-like electrode by opposing and vertically abutting a pair of contact-type displacement sensors with a constant pressure to measure the thickness of the sheet-like electrode.

According to a second aspect of the present invention, there is provided a traveling mechanism for traveling the sheet-like electrode, and a pair of contact-type displacement sensors sandwiching the sheet-like electrode traveling by the traveling mechanism and disposed perpendicular to the sheet-like electrode surface. , Adjacent to the contact displacement sensor,
A thickness measuring device for a sheet-shaped electrode, comprising: a plurality of pairs of pressing roller mechanisms slidably disposed to press the sheet-shaped electrode.

According to a third aspect of the present invention, in the thickness measuring apparatus for a sheet-like electrode according to the second aspect, a plurality of pairs of pressing rollers are positioned at least one of the front and rear or the left and right with respect to the contact type displacement sensor. It is characterized by being slidably arranged.

According to the first to third aspects of the present invention, the contact type displacement sensor for measuring the thickness of the sheet electrode is shown in FIG.
The operation is performed as schematically shown in FIGS. For example, a sheet electrode 1 having a thickness of 2 mm is applied between a pair of contact type displacement sensors 2 and 3 which are vertically opposed to the sheet electrode 1 at a constant pressure (for example, 0.5 to 1.5 kg).
Suppose that it is sandwiched between f).

At this time, as shown in FIG. 1A, the contact displacement sensor 2 rises by 1 mm and outputs a potential of +1 V, whereas the contact displacement sensor 3 outputs 1 mm. Outputs +1 V potential. That is, with the interposition of the sheet-like electrode 1, the facing distance between the contact type displacement sensors 2 and 3 is maintained at 2 mm and a potential of +2 V is output.

Further, as shown in FIG. 1 (b), when the contact type displacement sensor 2 rises by 2 mm and outputs a potential of +2 V,
The contact type displacement sensor 3 descends by 0 mm (keeps its original position)
0 V potential, and as a result, the contact type displacement sensor 2
The opposing interval of 3 maintains 2 mm and outputs a potential of +2 V. As described above, if the thickness of the sheet-shaped electrode is constant (uniform / uniform), even if the sheet-shaped electrode swings up and down during the thickness measurement, a stable and highly accurate measurement value can be obtained. Will be done.

In the second and third aspects of the present invention,
A traveling mechanism for traveling the sheet-shaped electrode is generally a pair of feed rollers that rotate while sandwiching the sheet-shaped electrode on both sides, and travel the sheet-shaped electrode, a guide roller for guiding the traveling of the sheet-shaped electrode, The configuration includes a rotation drive source for the feed roller.

In the invention of claims 2 and 3,
A plurality of pairs of pressing roller mechanisms for pressing the sheet-like electrode
They are arranged before and after in the direction in which the sheet-shaped electrode travels across the contact-type displacement sensor, or on the left and right of the sheet-like electrode across the contact-type displacement sensor. In other words, the contact type displacement sensor is configured so that the opposite sides of the sheet-like electrode are opposed, slid, and pressed by a plurality of pairs of pressing rollers so that the sheet-like electrode does not shake or shake. I have.

Here, it is desirable that at least one of the pressing roller pairs is configured to resiliently contact and separate so as to easily correspond to the thickness of the sheet-like electrode.
Further, it is also possible to adopt a configuration in which one of the pair of pressing rollers is incorporated in the contact-type displacement sensor so that the contact-type displacement sensor comes into contact with or separates from the contact-type displacement sensor in a resilient manner. Furthermore, the arrangement of the pressing roller pair may be at least one of the front and rear positions or the left and right positions of the contact type displacement sensor.

According to the first to third aspects of the present invention, the influence of the distortion of the sheet-like electrode is reduced without being affected by the surface condition of the sheet-like electrode that has been intermittently or continuously driven, and the stability is improved. The applied pressing force is applied to the sheet-shaped electrode surface. In other words, the influence of the surface condition and distortion of the sheet-like electrode is reduced or avoided, and the contact-type displacement sensor pair is constantly pressed with a constant pressing force against the sheet-like electrode surface, thereby stably and reliably. It is possible to carry out measurement of thickness with high flexibility.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described below with reference to FIGS. 2, 3 and 4. FIG.

FIGS. 2 to 4 schematically show the structure of a main part of a sheet-like electrode thickness measuring apparatus. FIG. 2 is a side view and FIG.
Is a front view, and FIG. 4 is a top view. 2 to 4,
Reference numeral 4 denotes a traveling mechanism that causes the sheet electrode 1 to travel. Here, the traveling mechanism 4 includes at least a pair of feed rollers 4a, 4a 'for traveling the sheet electrode 1 in a predetermined direction, and guide rollers 4b, 4c, for guiding the traveling of the sheet electrode 1 in a predetermined direction. 4d and 4e. The feed rollers 4a and 4a 'are made of metal and have an outer diameter of about 80 mm and a length of about 4 mm.
About 200 mm, and guide rollers 4b, 4c, 4d, 4e
Is made of metal and has an outer diameter of about 40 mm and a length of about 200 mm.

Reference numerals 2 and 3 denote a pair of contact-type displacement sensors sandwiching the sheet-like electrode 1 traveled by the traveling mechanism 4 and arranged perpendicular to the surface of the sheet-like electrode 1. here,
The contact type displacement sensor 2 includes a support 2 on which a spring 2a is mounted.
b, 2b 'and supporting plates 2c, 2 supported by the columns 2b, 2b'
The contact type displacement sensor contact 2d fixed to c 'and attached with elasticity by a spring 2a' is provided. On the other hand, the contact type displacement sensor 3 includes a support plate 3c,
3c 'is provided with a contact-type displacement sensor contact 3d which is attached with elasticity provided by a spring 3a.

The contact type displacement sensor main bodies 2d and 3d of the contact type displacement sensors 2 and 3 have their opposing front ends on both opposing surfaces of the sheet electrode 1 at a constant pressure by the sprinkles 2a 'and 3a. On the other hand, the contact type displacement sensor is configured to output a signal corresponding to the movement / displacement of the contact position with respect to the axial direction of the contact sensors 2d and 3d.

Further, reference numerals 5 and 5 'denote a plurality of pairs of pressing roller mechanisms which are arranged adjacent to the contact type displacement sensors 2 and 3 and press the sheet electrode 1. Here, the pressing roller mechanism 5 includes a pair of contact members 5a, 5b, 5c and 5d before and after the contact type displacement sensor 2 in the traveling direction of the sheet-like electrode 1, and the pressing roller mechanism 5 'includes a contact type sensor. Each pair 5a ', left and right in the traveling direction of the sheet electrode 1 with the displacement sensor 3 interposed therebetween.
5b ', 5c' and 5d 'are arranged respectively.

Incidentally, the plurality of pairs of pressing roller mechanisms 5, 5
Of the 5 ', the pressing rollers 5a, 5b, 5a', 5b 'are integrally mounted on the support frame side of the contact type displacement sensor 2, and are resilient by a spring 2a mounted on the columns 2b, 2b'. Is attached in a state where is attached. Pressing roller 5
c, 5d, 5c ', and 5d' are supported by the frame on the contact type displacement sensor 3 side.

Next, an example of measurement by the above-described measuring device will be described.

A sheet-like electrode having a thickness of about 0.2 to 0.7 mm is prepared, and the contact type displacement sensors 2 and 3 are intermittently driven by the traveling mechanism 4.
Pass and run through the placement area. That is, the sheet-like electrode is intermittently run by the feed rollers 4a and 4a 'while being guided by the guide rollers 4b to 4e. After this intermittent running, both sides of the sheet electrode 1 are temporarily pressed and fixed by the pressing roller mechanisms 5 and 5 ', while the contact type displacement sensor contacts 2d and 3d of the contact type displacement sensors 2 and 3 are held. Is pressed at a constant pressure, and the thickness of the sheet-like electrode 1 is measured.

That is, the area of the sheet-like electrode 1 where the contact type displacement sensor contacts 2d and 3d of the contact type displacement sensors 2 and 3 face and contact each other has the elasticity of the pressing roller mechanisms 5 and 5 '. Pressing and fixing by the pressing rollers 5a, 5b, 5a ', 5b' and the pressing rollers 5c, 5d, 5c ', 5d' maintain the uniformity of the surface condition of the part to be measured. Reduced. On the other hand, the area surface of the sheet-like electrode 1 is sandwiched between the contact type displacement sensor contacts 2d and 3d which face and contact with each other at a constant pressure (about 0.5 to 1.5 kgf). Therefore, the measured pressure on the sheet-like electrode 1 by the pair of contact-type displacement sensors 2 and 3 is stable.
The configuration can be measured with high reliability in combination with the effect of the run-out and the like being reduced or avoided.

The present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the invention. For example, press roller mechanisms 5, 5 '
May be any one of them, or the number of pairs of feed rollers, the number of guide rollers, or the material thereof may be appropriately changed.

[0031]

According to the first aspect of the present invention, the thickness of the sheet electrode can be easily and accurately measured without being affected by the surface state, distortion, or runout of the sheet electrode at the time of measurement. it can. In other words, in a stable state, the thickness measurement by the contact-type displacement sensor pair can be performed at all times, so that appropriate quality control of the sheet-like electrode can be performed, which greatly contributes to providing a high-performance battery with a good yield. I do.

According to the second and third aspects of the present invention,
Since the thickness of the sheet electrode can be measured mass-produced and highly reliable without the need for complicated operations or advanced skills,
It greatly contributes to the productivity of high performance batteries.

[Brief description of the drawings]

1 (a) and 1 (b) are side views schematically showing a state of thickness measurement by a pair of contact type displacement sensors.

FIG. 2 is a side cross-sectional view showing a configuration of a main part of a sheet-like electrode thickness measuring apparatus according to an embodiment.

FIG. 3 is a front sectional view showing a configuration of a main part of a sheet-like electrode thickness measuring apparatus according to an embodiment.

FIG. 4 is a top view showing a configuration of a main part of a sheet-like electrode thickness measuring apparatus according to the embodiment.

[Explanation of symbols]

 1 ... sheet electrode 2, 3 ... contact type displacement sensor 2a, 2a ', 3a ... spring 2b, 2b' ... support column 2c, 2c ', 3c, 3c' ... support plate 2d, 3d ... contact Type displacement sensor contact 4 Running mechanism 4a, 4a 'Feed roller 4b, 4c, 4d, 4e Guide roller 5, 5' Pressing roller pair 5a, 5b, 5a ', 5b' Upper side Pressing roller 5c, 5d, 5c ', 5d' ... Lower pressing roller

Claims (3)

[Claims] 1. A step of pressing a sheet-like electrode with a plurality of pairs of pressing rollers facing and arranged on both sides, and a pair of contact-type displacement sensors vertically facing a sheet-like electrode surface in the pressed area. Measuring the thickness of the sheet-like electrode by contacting the sheet-like electrode with a constant pressure. 2. A traveling mechanism for traveling the sheet-like electrode, a pair of contact-type displacement sensors sandwiching the sheet-like electrode traveling by the traveling mechanism and disposed perpendicular to the sheet-like electrode surface, and the contact-type displacement. A plurality of pairs of pressing roller mechanisms arranged adjacent to the sensor and slidably pressed to press the sheet-like electrode;
A thickness measuring device for a sheet-shaped electrode, comprising: 3. A sheet-like sheet according to claim 2, wherein a plurality of pairs of pressing rollers are slidably disposed at least one of front, rear, left and right with respect to the contact type displacement sensor. Electrode thickness measuring device.