JP4500620B2 - Manufacturing method of electric double layer capacitor - Google Patents

Description

  The present invention relates to a method for manufacturing an electric double layer capacitor.

  2. Description of the Related Art In recent years, attention has been focused on application technologies for electric double layer capacitors that can be rapidly charged and have a long charge / discharge cycle life as various power storage devices.

In the electric double layer capacitor, a certain number of positive and negative electrodes each composed of a dielectric (activated carbon electrode) and a collecting electrode (aluminum foil) are alternately laminated with a separator interposed therebetween. Lead portions are formed on the collecting electrodes of each positive electrode body and each negative electrode body, and multilayer portions obtained by overlapping the lead portions with the same polarity are joined to terminals (aluminum electrodes) by spot welding or the like. These laminated bodies are immersed in an electrolytic solution, and are accommodated in a container in a state where terminals are projected to the outside (for example, Patent Document 1).
JP2002-280271

  In such an electric double layer capacitor, when joining the multilayer portion of the lead portion and the terminal by spot welding, the current value is high due to aluminum welding, and the welding tip (electrode of the welding machine) is connected to the weld portion ( It is easy to stick to the terminal and wear easily.

  If the contact area of the head portion increases due to wear of the welding tip, the welded state becomes non-uniform and the stability of the connection is lacking. In addition, the resistance value of the coupling portion increases, which affects the performance of the capacitor.

  In addition, due to wear of the welding tip, spatter adheres, which may lead to poor welding. Moreover, the replacement frequency of the welding tip is high.

  This invention is made paying attention to such a subject, and it aims at improving the welding tip and improving the weldability of an electric double layer capacitor.

In the first invention, a certain number of positive electrode bodies and negative electrode bodies are alternately stacked with a separator interposed therebetween, and each positive electrode body and a part of each negative electrode body are used as lead portions of a metal foil. In the method of manufacturing the electric double layer capacitor in which the multilayer portions are joined to the terminals of the metal plates with a spot welder, the spot welder includes an upper welding tip on a holder having an up / down and pressurizing function on an upper side, The lower welding tip is attached to the holder, and the upper welding tip is formed in the center of the front end of the head portion on the end surface of a predetermined small diameter, and the periphery thereof is formed in a hemispherical shape, while the lower welding tip is The head is formed into a shaft having a predetermined small diameter, and a heat-resistant resin pipe is driven and mounted so as to surround the head except for the protruding end of the head. Is the terminal It is characterized by using the.

According to a second invention, in the first invention, the periphery of the end portion of the resin pipe is formed in a conical shape having a small diameter toward the protruding end of the head portion .

  In the first invention, spot welding between the multilayer portion of the lead portion and the terminal can be performed satisfactorily, the performance of the capacitor can be improved, and the welding performance can be improved.

In the first and second inventions , the sticking of the welding tip to the terminal of the head portion becomes weak, and wear of the head portion can be suppressed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  In FIG. 1, reference numeral 10 denotes a capacitor main body (laminated body).

  The capacitor body 10 is formed by alternately stacking a certain number of positive electrode bodies 11 and negative electrode bodies 12 with a separator (not shown) interposed therebetween.

  The positive electrode body 11 and the negative electrode body 12 are formed from collector electrodes 13 and 14 (aluminum foil) and activated carbon electrodes (not shown) disposed on both sides thereof.

  The collector electrode 13 of the positive electrode body 11 and the collector electrode 14 of the negative electrode body 12 are provided with lead portions 15 and 16 at predetermined positions, and the multi-layer portions where the lead portions 15 and 16 of the same polarity are overlapped are respectively terminal plates 17. , 18 (aluminum electrode) by spot welding (described later).

  The capacitor body 10 is immersed in an electrolytic solution, and accommodated in a container (not shown) in a state where the terminal plates 17 and 18 are projected to the outside, and is sealed.

  2 shows a spot welder 20 between the lead portions 15 and 16 of the capacitor body 10 and the terminal plates 17 and 18, and FIG. 3 shows a welding tip (movable electrode) 21 on the upper side of the welder 20. 4 indicates a welding tip (fixed side electrode) 22 on the lower side of the welding machine 20.

  In the spot welding machine 20, a welding tip 21 is attached to a holder 24 having an upper and lowering and pressurizing function, and a welding tip 22 is attached to a lower holder 25.

  As shown in FIG. 3, the welding tip 21 includes a base portion 27 and a head portion 28. The base portion 27 is made of a copper material, and a shaft portion 30 and a shank 31 are formed. The head portion 28 is made of a molybdenum material, the front end center portion 32 is formed on an end surface having a predetermined small diameter, the periphery thereof is formed in a hemispherical shape, and the head rear portion (not shown) is attached to the shaft portion 30 of the base portion 27. It is fitted and fixed in a hole (not shown).

  As shown in FIGS. 4, 5, and 6, the welding tip 22 includes a base portion 33, a head portion 34, and a resin pipe 35. The base portion 33 is made of a copper material, and a shaft portion 36 and a shank 37 are formed. The head portion 34 is made of a molybdenum material and is formed in a shaft shape having a predetermined small diameter, and the head rear portion (not shown) is fitted and fixed in a mounting hole (not shown) of the shaft portion 36 of the base portion 33. The resin pipe 35 is made of a heat-resistant Teflon (registered trademark) (polytetrafluoroethylene) resin, is formed to have a predetermined outer diameter and a predetermined hole diameter, and has a conical shape around its front end portion (a protruding end 38 of the head portion 34). The head portion 34 is driven and mounted so as to surround the head portion 34 (excluding the projecting end 38 of the head portion 34).

  Spot welding of the multilayer portions of the lead portions 15 and 16 of the capacitor body 10 and the terminal plates 17 and 18 is performed by setting the capacitor body 10 on the jig 26 of the spot welder 20. The terminal plates 17 and 18 are disposed on the lower surface of the multilayer portion of the lead portions 15 and 16, and the respective portions are welded in order.

  First, the welding portion between the terminal plate 17 and the multilayer portion of the lead portion 15 is moved between the welding tips 21 and 22, the lower welding tip 22 is applied to the terminal plate 17, and the upper welding tip 21 is attached to the lead portion 15. It is abutted against the multilayer portion with a predetermined pressure, and a predetermined current is applied for a predetermined short time to perform welding.

  Next, it moves to another welding part of the terminal plate 17 and the multilayer portion of the lead portion 15, similarly, the lower welding tip 22 is applied to the terminal plate 17, and the upper welding tip 21 is superimposed on the multilayer portion of the lead portion 15. A part is abutted with a predetermined pressure, a predetermined current is passed for a predetermined short time, and welding is performed.

  Thereafter, the welding portion between the terminal plate 18 and the multilayer portion of the lead portion 16 is moved between the welding tips 21 and 22, the lower welding tip 22 is applied to the terminal plate 18, and the upper welding tip 21 is attached to the lead portion. It is abutted against the sixteen layers with a predetermined pressure, and a predetermined current is applied for a predetermined short time to perform welding.

  Next, it moves to another welding part of the terminal plate 18 and the multilayer portion of the lead portion 16, similarly, the lower welding tip 22 is applied to the terminal plate 18, and the upper welding tip 21 is superimposed on the multilayer portion of the lead portion 16. A part is abutted with a predetermined pressure, a predetermined current is passed for a predetermined short time, and welding is performed.

  As described above, spot welding is performed between the multilayer portions of the lead portions 15 and 16 of the capacitor main body 10 and the terminal plates 17 and 18, so that a good coupling state between the multilayer portions of the lead portions 15 and 16 and the terminal plates 17 and 18 can be obtained. It can be secured.

  An example of this welding will be described. The diameter of the head portion 34 of the welding tip 22 with respect to the lead portions 15 and 16 having a thickness of, for example, 0.05 mm, the number of pieces being, for example, 21 to 22, and the terminal plates 17 and 18 having a thickness of, for example, 0.6 mm. When the welding current value is, for example, 8.2 to 9.2 KA (energization time is, for example, 8 to 11 ms), a uniform welding state can be secured, and the nugget diameter can be secured to 1 mm or more, and the resistance of the joint portion It has been confirmed that the value can be 0.6 mΩ or less.

  Further, since the resin pipe 35 that surrounds the head portion 34 of the welding tip 22 except for the projecting end 38 of the head portion 34 is attached, the sticking of the head portion 34 to the terminal plates 17 and 18 becomes weak and the head portion 34 wears. Can be suppressed.

  Therefore, it is possible to prevent spatter from adhering due to wear of the head portion 34 and causing poor welding.

  Further, the contact area of the head portion 34 does not increase due to wear of the head portion 34, and a uniform welded state can be ensured as described above. Moreover, the replacement frequency of the welding tip 22 can be lowered.

  Therefore, stable coupling can be secured, the performance of the capacitor can be improved, welding can be performed well, and the welding performance can be improved.

  In addition, as the upper welding tip 21 of the welding machine 20, a head having a hemispherical shape at the front end of the head portion is used.

  When the welding tip 21 having a hemispherical head front end is used as the upper welding tip of the welding machine 20, the number of the lead portions 15 and 16 is relatively large (21 to 22) as described above ( In the case of using a capacitor having a large capacity) that can perform welding well and has an upper welding tip of the welding machine 20 configured in the same manner as the lower welding tip 22, A uniform welded state can be secured for a small number of sheets.

Moreover, although the Teflon resin was used for the resin pipe 35 attached to the head part 34 of the welding tip 22, bakelite (thermosetting phenol resin) may be used.
Is done.

It is the schematic of a capacitor main body. It is a side view of a spot welder. It is a side view of an upper welding tip. It is a side view of a lower welding tip. It is a side view of the base part and head part of a lower welding tip. It is a side view of a resin pipe.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Capacitor main body 11 Positive electrode body 12 Negative electrode body 13, 14 Collector electrode 15, 16 Lead part 17, 18 Terminal board 20 Spot welder 21 Welding chip 22 Welding chip 28 Head part 34 Head part 35 Resin pipe

Claims (2)

A certain number of positive and negative electrode bodies are alternately stacked with a separator interposed therebetween, and each positive electrode body and a part of each negative electrode body are used as metal foil lead portions, and the overlapping portions of the same polarity are respectively metal plates. In the method of manufacturing an electric double layer capacitor to be joined to a terminal of a spot welding machine, the spot welding machine has an upper welding tip on a holder having an upper and lowering and pressurizing function, and a lower welding on a lower holder. A tip is attached, and the upper welding tip is formed in a semispherical shape around the front end center portion of the head portion with a predetermined small diameter, while the lower welding tip has a head portion with a predetermined small diameter. The heat-resistant resin pipe is driven and attached so as to surround the head portion except for the protruding end of the head portion, and the welding tip attached with the resin pipe is attached to the terminal side. Use Method of manufacturing an electric double layer capacitor according to claim.   2. The method of manufacturing an electric double layer capacitor according to claim 1, wherein the periphery of the end portion of the resin pipe is formed in a conical shape having a small diameter toward the protruding end of the head portion.

Images