Source: https://patents.google.com/patent/US6246568?oq=flatulence
Timestamp: 2018-02-25 10:20:37
Document Index: 744150923

Matched Legal Cases: ['arts 1', 'arts 1', 'art 6', 'art 6', 'art 6', 'art 7', 'art 7']

US6246568B1 - Electric double-layer capacitor and method for manufacturing the same - Google Patents
Electric double-layer capacitor and method for manufacturing the same
US6246568B1
US6246568B1 US09147558 US14755899A US6246568B1 US 6246568 B1 US6246568 B1 US 6246568B1 US 09147558 US09147558 US 09147558 US 14755899 A US14755899 A US 14755899A US 6246568 B1 US6246568 B1 US 6246568B1
US09147558
Kyoushige Shimizu
The invention relates to an electric double layer capacitor for large capacity used in regeneration or electric power storage for various electric appliances and electric vehicles, and its manufacturing method. As the resin to be used in the current collector, by adding low softening point resin, polytetrafluoroethylene resin, latex resin or the like, the flexibility, thick coating performance and winding performance are improved. By preparing the electrode solution for making such current collector by using a high pressure dispersion machine, the capacity and density of the current collector can be enhanced substantially. According to this manufacturing method, the electric double layer capacitor may be further increased in size, increased in capacity and lowered in cost.
The present invention relates to an electric double layer capacitor for large capacity used for regeneration or electric power storage for various electric appliances and electric vehicles, and its manufacturing method.
An electric double layer capacitor is constituted by winding or laminating a plurality of conductive foils of aluminum or the like forming a current collector on a separator, and sealing in a case together with a nonaqueous electrolyte solution. This electric double layer capacitor is, recently, expanding its applications in regeneration or electric power storage for various electric appliances and electric vehicles. Accordingly, the electric double layer capacitor is further demanded to be higher in performance, larger in capacity, superior in reliability, and lower in cost.
The invention is to solve such problems of the prior arts, and presents an electric double layer capacitor capable of further increasing the capacity, increasing the size, reducing the thickness, and lowering the cost, and its manufacturing method.
FIG. 1 is a block diagram of a winding type electric double layer capacitor in an embodiment of the invention, FIG. 2 is a perspective view for explaining a mode of evaluation of winding performance of current collector and conductive foil, FIG. 3 is a block diagram of laminate type electric double layer capacitor, FIG. 4 is a block diagram of a high pressure dispersion machine, and FIG. 5 is a characteristic diagram showing an example of viscosity changes by logarithm.
BEST MODE OF CARRYING OUT THE INVENTION Embodiment 1
FIG. 1 is a block diagram of a winding type electric double layer capacitor in an embodiment of the invention. In FIG. 1, reference numeral 1 is a case, in this case, on the surface of a conductive foil 2, a current collector 3 formed by dispersing at least one of ammonium salt of carboxy methyl cellulose resin, polyvinyl alcohol, methyl cellulose, and hydroxy propyl cellulose resin, together with polytetrafluoroethylene resin (PTFE) is formed, as a feature of the invention, at least on one plane of the conductive foil 2 by binding at density of 0.35 g/cc or more to 1.50 g/cc or less. A plurality of conductive foils, that are conductors, forming this current collector 3 are wound on a separator 4, and a winding 5 a is formed. A plurality of lead-out electrodes 6 are connected to the plurality of conductive foils 2 forming this winding 5 a, and connected to a terminal 8 through a sealing material 7. In the actual electric double layer capacitor, the winding 5 a is sealed in the case 1 together with electrolyte solution.
FIG. 2 explains a mode of evaluating the winding performance of the current collector and conductive foil. In FIG. 2, in a bound state of the current collector 3 having activated carbon and conductive agent of polytetrafluoroethylene resin and binder resin on the surface of the conductive foil 2, evaluation of winding performance of the current collector 3 and conductive film 2 is explained. In FIG. 2, reference numeral 9 is a round bar. Around the round bar 9, the conductive foil 2 cut in a proper width and binding the current collector 3 at least on one surface is wound, and it is evaluated by squeezing the conductive foil 2 forming the current collector 3 in the direction indicated by arrow with a specific force. By this method of evaluation, the winding performance of the current collector 3 is evaluated (whether applicable in winding type electric double layer capacitor, or whether capable of obtaining deflection resistance required even in laminate type electric double layer capacitor). In FIG. 2 (A), the-current collector 3 is peeled off the conductive foil 2, and further the current collector 3 itself forms a fracture 10. In FIG. 2 (B), the current collector 3 is not peeled off the conductive foil 2, and fine cracks 11 are formed on the surface of the current collector 3. Herein, a great difference between the fine cracks 11 and the fracture 10 lies in presence or absence of interface breakage between the current collector 3 and conductive foil 2. In FIG. 2 (C), the conductive film 2 is not peeled off the current collector 3, and a normal surface 12 is formed without fracture or fine cracks 11.
By decreasing the content of polytetrafluoroethylene resin, and using polyvinyl alcohol as conventional water-soluble resin, it was attempted to make insoluble (resistant to water) by polymerizing (curing) the water-soluble resin. First, in 500 parts by weight of purified water, 2 parts by weight of polytetrafluoroethylene resin and 10 parts by weight of polyvinyl alcohol were dissolved, and further zirconia compound was added as a polymerizing agent. In this solution, 100 parts by weight of activated carbon powder and 10 parts by weight of acetylene black were added and dispersed uniformly, and an electrode solution was prepared. This electrode solution was applied on a conductive foil in a thickness of 80 microns on one side. The resistance to water of this electrode coat film was tested, and it was found that to be resistant to water (insoluble) when heated for 5 minutes to 10 minutes at temperature of 120 deg. C. to 150 deg. C. By thus making resistant to water, the residual moisture in the coat film was hardly adsorbed. At temperature exceeding 300 deg. C., since the decomposition of the resin is promoted, the coat film becomes brittle. Without addition of polymerizing agent, meanwhile, the electrode coat film was not sufficiently resistant to wear if heated for 12 hours at 130 deg. C. or less.
In embodiment 4, a laminate type electric double layer capacitor is explained by referring to FIG. 3. In FIG. 3, in a rectangular parallelepiped case 1, a plurality of current collectors 3 formed at least oh one side of a conductive foil 2 are connected through a separator 4. By forming in a laminate 5 b, the appearance of the product may be solid, dead angles are decreased and the effective volume is increased. As a result, the capacity per unit volume (capacity density) is higher by nearly 30% as compared with the winding type. Moreover, in a product thickness of several millimeters, the product size can be increased to scores of centimeters square, and it contributes to thin and small design of appliances.
A further detail is described. First, an electric double layer capacitor of ultrathin layer and large laminate type of 1 mm in thickness and 200 mm×300 mm in size was fabricated. The product is desired to have a certain flexibility and resistance to deformation. In such a case, in a conventional rigid current collector, there was a risk of breaking or cracking. Accordingly, from the current collector 3 prepared in embodiment 4, a plurality were cut out in a size of 180 mm×280 mm, and the plurality were laminated through a commercial separator, and sealed in a nonaqueous electrode solution together with lead-out electrode, and an ultrathin electric double layer capacitor was prepared. This capacitor was resistant to bend or warp, and if deflected by force, there was no adverse effect on the electric characteristic or reliability. After such deformation test, the latex part was decomposed and the state of the current collector 3 was inspected, but no abnormality was found.
By way of comparison, using a current collector without undergoing high tension dispersion, a current collector was similarly fabricated, and an electric double layer capacitor of ultrathin layer and large laminate type of 1 mm in thickness and 200 mm×300 mm in size was prepared. In this case, however, the current collector 3 itself was a still plate, having no flexibility and hardly deflecting. When thus prepared capacitor was bent slightly, the electric characteristic dropped suddenly. When analyzed later, it was found that many cracks were formed in the current collector film, and part of the conductive foil was broken, and it was nearly shorted partly. Thus, by high tension dispersion of the electrode solution, fine particles of polytetrafluoroethylene resin were dispersed uniformly, and the performance of the current collector was enhanced.
Pressing of a current collector containing polytetrafluoroethylene resin was experimented. As a result, invention 1 was raised in density by 10% or more, at a pressure of half or less as compared with prior arts 1 and 2, and was also increased in the product capacity. On the other hand, in the case of prior arts 1 and 2 not containing polytetrafluoroethylene resin, the coat film was adhered to the press surface, and peeling of coat film occurred. This is considered partly because adhesion of the current collector to the press was lowered (the peeling performance was improved) by adding polytetrafluoroethylene resin.
Embodiment 6 relates to a method of manufacturing an electric double layer capacity by forming a current collector containing activated carbon and conductive agent, by a resin containing latex, on the surface of a conductive foil. As the activated carbon, commercial powder with specific surface area of 1500 to 2000 square meters/g was used, and as a conductive agent, commercial acetylene black was used. In a mixed aqueous solution of aqueous solution of carboxy methyl cellulose and latex, the activated carbon and acetylene black were added, and dispersed, and an electrode solution was prepared. This electrode solution was applied on both sides of a commercial conductive foil in a dry thickness of 100 microns on each side. A plurality of the current collectors 3 were cut in a specified width as shown in FIG. 1, and wound on a separator 4, starting from the minimum winding diameter of 2 mm and finishing at final winding diameter of 8 mm, and a winding 5 a was prepared. Each lead-out electrode 6 was connected to a plurality of conductive foils forming the winding 5 a, and they were put in a cylindrical case 1 of 10 mm in diameter, and impregnated in a specified electrolyte, and sealed with a sealing material 7 with a terminal 8 (hereinafter called invention 3).
In embodiment 7, the composition ratio of latex and various materials is further optimized. First, in 500 parts by weight of purified water, 12 parts by weight of latex (by dry weight of emulsion with solid content of 50%) was dispersed, and 100 parts by weight of activated carbon powder and 10 parts by weight of acetylene black as conductive agent were further added, and dispersed uniformly, and an electrode solution was prepared. This electrode solution was applied on both sides of a conductive foil (width 100 mm, length 20 m) roughened by chemical etching, by using a coating machine, and a coat film of 80 microns in thickness on each side was formed, and a current collector was prepared.
In embodiment 8, a laminate type electric double layer capacitor is explained by referring to FIG. 3. In FIG. 3, a plurality of current collectors 3 containing latex formed at least on one side of a conductive foil 2 are connected in a rectangular parallelepiped case 1, through a separator 4. By forming into a laminate 5 b, the product appearance may be a cube, and dead angles are decreased and effective volume is increased, so that the capacity per unit volume (capacity density) may be heightened by nearly 30% as compared with the winding type. Moreover, while keeping the product thickness thinly at several millimeters, the product size may be increased to scores of centimeters square, which contributes to thinner layer and smaller size of the object appliance.
A further detail is described below. First, a trial piece of electric double layer capacitor of ultrathin layer and large size laminate type of 1 mm in thickness and 200 mm×300 mm was fabricated. In the case of embodiment 1, the product is required to have a certain elasticity and resistance to deformation. In such a case, in a conventional rigid current collector, it was often cracked or broken. From the current collector 3 prepared in embodiment 8, a plurality of pieces were cut off in dimensions of 180×280 mm, and the plurality were laminated through a commercial separator, and sealed in a nonaqueous electrode solution together with the lead-out electrode, and a ultrathin layer electric double layer capacitor was prepared (hereinafter called invention 5). This invention 5 was resistant to bending and warp, and if deflected by force, adverse effects were not observed in the electric characteristic or reliability. After such deformation test, invention 5 was disassembled, and the current collector 3 was investigated, but no abnormality was detected.
By way of comparison, using carboxy methyl cellulose as conventional current collector, a current collector 3 was prepared similarly, and an electric double layer capacitor of ultrathin layer and large size laminate type of 1 mm in thickness and 200 mm×300 mm was fabricated (hereinafter called prior art 6). In the case of prior art 6, the current collector 3 itself was a stiff plate with no flexibility, hardly deflecting. Damages often occurred in the current collector 3 as shown in FIG. 2 (A) and FIG. 2 (B). In such prior art 6, if bent slightly, the electric characteristic dropped suddenly. As known later by analysis, many cracks were formed in the current collector film, and part of conductive foil was broken, and it was nearly shorted in some parts. Thus, by adding latex to the current collector itself, an electric double layer capacitor of ultrathin layer laminate type can be prepared stably.
In 500 parts by weight of purified water, 12 parts by weight of latex (using emulsion with solid content of 30%) and carboxy methyl cellulose partly replaced with NH4 ions (hereinafter called CMC-NH4) were dispersed, and further 10 parts by weight of activated carbon powder and 10 parts by weight of acetylene black were added and dispersed uniformly, and an electrode solution was prepared. This electrode solution was applied on a roughened conductive foil, and dried, and an electric double layer capacitor was prepared in the same manner as in embodiment 1 (hereinafter called invention 6).
It was attempted to make insoluble (resistant to water) by decreasing the latex resin, increasing the conventional water-soluble resin, and further polymerizing (curing) the water-soluble resin. First, in 500 parts by weight of purified water, 2 parts by weight of latex and 10 parts by weight of polyvinyl resin were dissolved, and further zirconia compound was added as polymerizing agent. In this mixture, further, 10 parts by weight of activated carbon and 10 parts by weight of acetylene black were added, and dispersed uniformly, and an electrode solution was obtained. This electrode solution was applied on a roughened conductive foil in a thickness of 80 microns on each side. It was attempted to make this electrode coat film resistant to water, and it was found to be resistant to water (insoluble) when heated for about 5 to 10 minutes at temperature of 120 deg. C. to 150 deg. C. By thus making resistant to water, the residual moisture of the coat film was hardly adsorbed. At temperature exceeding 300 deg. C., however, since decomposition of the resin is promoted, the coat film becomes brittle. Without addition of polymerizing agent, if heated for 12 hours at 130 deg. C. or less, the electrode coat film was not sufficiently resistant to water
Pressing of a current collector (invention 6 of embodiment 9) containing latex was experimented. As a result, invention 6 was raised in density by 10% or more, at a pressure of half or less as compared with prior art 7. The flexibility or binding strength was not lowered before and after the pressing test. The current collector was free from elongation (in particular, deformation of conductive foil). Thus, by lowering the press pressure or calender pressure, the facility cost can be lowered and the productivity can be raised. At the same time, elongation of the current collector (in particular, deformation of conductive foil) could be suppressed. On the other hand, in the case of prior art 7, by pressing, the flexibility and binding strength of the coat film were lowered. Moreover, when the pressure was raised, the current collector was deformed.
Embodiment 12 explains the result of experiment on particle size of latex. First, five kinds of latex with particle size of 10 microns, 5 microns, 1 micron, 0.1 micron, and 0.01 micron were prepared. After fabrication of trial products of current collectors as shown in embodiment 1, when latex of 10 microns and 5 microns in particle size was dispersed together with activated carbon powder, aggregates were likely to be formed, and the electric characteristics of the obtained electric double layer capacitor itself were lower than the design values. On the other hand, as for three kinds of latex with particle size of 1 micron, 0.1 micron and 0.01 micron, if dispersed together with activated carbon powder, aggregates were not formed, and the coating performance and mass producibility were excellent, and electric characteristics conforming to the design values were obtained. Thus, by defining the particle size of latex at 1 micron or less, if mixed with activated carbon or conductive agent, aggregate are hardly formed. Meanwhile, if the particle size of latex is less than several angstroms, the pores of the activated carbon surface are filled up to make it hard to form the electric double layer, and hence, the size is preferred to be more than 10 angstroms.
As the resin in the current collector, only latex resin may be used, but it may be also blended with one or more of carboxy methyl cellulose resin, polyvinyl alcohol, methyl cellulose, and hydroxyethyl cellulose. When the electrode solution is prepared by using latex resin only, the viscosity of the obtained electrode solution is too low, and it may be hard to apply. In such a case, by mixing the latex resin with any one of the water-soluble resins mentioned above, the viscosity of the electrode solution may be adjusted.
Incidentally, according to the Standard Dictionary of Chemical Terms edited by Japan Society of Chemistry (Maruzen, 1991), latex is “formerly defined to be a natural rubber latex, but ever since development of synthetic rubber and synthetic resin emulsion other than rubber compound, all of them are collectively called latex.” That is, in this invention, the latex is not limited to natural rubber and synthetic rubber alone, but includes emulsion of synthetic resin, and such resin scatters among particles of activated carbon, acetylene black, Ketienblack, and others, and they cause the particles to contact with each other. In the invention, the emulsion is, according to the same Standard Dictionary of Chemical Terms, “a system of dispersion of other hardly soluble liquid fine particles in a liquid solute,” but aside from liquid fine particles, it may be also tacky or elastic gel fine particles. The solvent may be oil, but considering the environmental problems and working efficiency, water or the like is preferred. Dissolving is, according to same Standard Dictionary of Chemical Terms, “a phenomenon of melting of a substance in liquid to be a uniform liquid phase,” and in the resin material dissolved in the conventional solvent, the product characteristic may be lowered in order to cover the surface of fine particles of activated carbon or the like (and also fine pores on the surface). However, if the emulsion or latex in the invention is dispersed in the electrode solution, it is predicted to scatter in the finished current collector 3, and therefore it is low in possibility of clogging of the activated fine pores with activated carbon.
The viscosity of the electrode solution is preferred to be in a range of 1 poise or more to 200 poise or less in consideration of the coating performance as current collector. The thickness of the current collector is preferred to be 20 microns or more, and there is no problem if more than 500 microns. The thickness difference of the current collector is preferred to be 5 microns or less, and capacity fluctuations of product are decreased, and stable products are presented.
Incidentally, according to the Standard Dictionary of Chemical Terms edited by Japan Society of Chemistry (Maruzen, 1991), latex is “formerly defined to be a natural rubber latex, but ever since development of synthetic rubber and synthetic resin emulsion other than rubber compound, all of them are collectively called latex.” That is, in this invention, the latex is, not limited to natural rubber and synthetic rubber alone, but includes emulsion of synthetic resin, and such resin scatters among particles of activated..carbon, acetylene black, Ketienblack, and others, and they cause the particles to contact with each other. In the invention, the emulsion is, according to the same Standard Dictionary of Chemical Terms, “a system of dispersion of other hardly soluble liquid fine particles in a liquid solute,” but aside from liquid fine particles, it may be also tacky or elastic gel fine particles. The solvent may be oil, but considering the environmental problems and working efficiency, water or the like is preferred. Dissolving is, according to same Standard Dictionary of Chemical Terms, “a phenomenon of melting of a substance in liquid to be a uniform liquid phase,” and in the resin material dissolved in the conventional solvent, the product characteristic may be lowered in order to cover the surface of fine particles of activated carbon or the like (and also fine pores on the surface). However, if the emulsion or latex in the invention is dispersed in the electrode solution, it is predicted to scatter in the finished current collector, and therefore it is low in possibility of clogging of the activated fine pores with activated carbon.
In embodiment 15, using latex, results of experiment of high pressure dispersion are shown. In the case of the conventional current collector not containing latex of which thickness is 50 microns, if the winding diameter was 5 mm, the result was as shown in FIG. 4 (C). As the thickness was increased to 80 microns, the result was sometimes inferior winding (Δ) as in FIG. 4 (B). At the thickness exceeding 150 microns, if the winding diameter was 5 mm, it was sometimes impossible to wind (x) as shown in FIG. 4 (A). At the thickness of 50 microns, as the winding diameter was reduced to 4 mm, 3 mm, and 2 mm, the phenomenon of inferior winding (Δ) in FIG. 4 (B) tended to occur. Concerning such winding performance of the current collector, it is empirically known that it is also influenced by the residual moisture in the current collector coat film. Accordingly, by adjusting the residual moisture in the current collector at 30% or more, occurrence of fine cracks 11 or fracture 10 in winding may be decreased. But it is difficult to control the residual moisture accurately, and it was a problem that there were large effects depending on season and ambient temperature.
Embodiment 16 relates to a method of manufacturing an electric double layer capacity by forming a current collector containing activated carbon and conductive agent, by a resin containing latex, on the surface of a conductive foil. As the activated carbon, commercial powder with specific surface area of 1500 to 2000 square meters/g was used, and as a conductive agent, commercial acetylene black was used. In a mixed aqueous solution of aqueous solution of carboxy methyl cellulose and latex, the activated carbon and acetylene black were added, and dispersed at high pressure, and an electrode solution was prepared. This electrode solution was applied on both sides of a commercial conductive foil in a dry thickness of 100 microns on each side. A plurality of the current collectors 3 were cut in a specified width as shown in FIG. 1, and wound on a separator 4, starting from the minimum winding diameter of 2 mm and finishing at final winding diameter of 8 mm, and a winding 5 a was prepared Each lead-out electrode 6 was connected to a plurality of conductive foils forming the winding 5 a, and they were put in a cylindrical case 1 of 10 mm in diameter, and impregnated in a specified electrolyte, and sealed with a sealing material 7 with a terminal 8 (hereinafter called invention 7).
In 500 parts by weight of purified water, 12 parts by weight of latex (using emulsion with solid content of 30%) and carboxy methyl cellulose partly replaced with NH4 ions (hereinafter called CMC-NH4) were dispersed, and further 10 parts by weight of activated carbon powder and 10 parts by weight of acetylene black were added and dispersed uniformly, and an electrode solution was prepared. For this dispersion, a high pressure dispersion machine as shown in FIG. 4 was used. In FIG. 4, reference numeral 13 is an inlet, through which the electrode solution after preliminary kneading is charged. Reference numeral 14 is a pressure unit, which pressurizes the charged electrode solution to a high pressure of over 100 kg/cm2 by a hydraulic pump or the like. Reference numeral 15 is a dispersion mixer, which disperses by spraying the electrode ink at high pressure to a special jig, or colliding electrode solutions ejected at high pressure from a plurality of capillaries with each other. In the pressure unit, the electrode solution is boosted to a high pressure of at least over 100 kg/cm2. The pressure at this time of dispersion can be monitored by mounting a pressure gauge on the pressure unit 14 (or between the pressure unit 14 and the dispersion mixer 15). The inside of the dispersion mixer 15 is partly formed of diamond, ceramic or cemented carbide, so that it can be protected from abrasion. The electrode solution pressurized over 100 kg/cm2 is introduced into the dispersion mixer, and the liquids are collided with each other (or the liquid is collided against the jig) at a speed over the sonic speed to be dispersed. The electrode solution thus dispersed at high pressure is discharged from an outlet 4. As such machine, a pressure type homogenizer manufactured by Gorin, U. S., may be used. By using such machine, by dispersing while applying a high pressure over 100 kg/cm2 (or over 3000 kg/cm2 depending on machine specification) to the electrode solution, the density of the coat film of current collector may be easily raised over 0.50 g/cc. In order to extend the life of the dispersion machine and stabilize dispersion while avoiding entry of impurities into the electrode solution, the dispersion mixer should be preferably made of diamond, ceramic or cemented carbide.
It was attempted to make insoluble (resistant to water) by decreasing the latex resin, increasing the conventional water-soluble resin, and further polymerizing (curing) the water-soluble resin. First, in 500 parts by weight of purified water, 2 parts by weight of latex and 10 parts by weight of polyvinyl alcohol resin were dissolved, and further zirconia compound was added as polymerizing agent. In this mixture, further, 10 parts by weight of activated carbon powder and 10 parts by weight of acetylene black were added, and dispersed uniformly, and an electrode solution was obtained. This electrode solution was applied on a roughened conductive foil in a thickness of 80 microns on each side. It was attempted to make this electrode coat film resistant to water, and it was found to be resistant to water (insoluble) when heated for about 5 to 10 minutes at temperature of 120 deg. C. to 150 deg. C. By thus making resistant to water, the residual moisture of the coat film was hardly adsorbed. At temperature exceeding 300 deg. C., however, since decomposition of the resin is promoted, the coat film becomes brittle. Without addition of polymerizing agent, if heated for 12 hours at 130 deg. C. or less, the electrode coat film was not sufficiently resistant to water
Pressing of a current collector containing latex was experimented. In the case of current collector containing latex, as compared with the current collector without latex, the density was raised by 10% or more at a pressure of half or less. The flexibility or binding strength was not lowered before and after the pressing test. The current collector was also free from elongation (in particular, deformation of conductive foil). Thus, by lowering the press pressure or calender pressure, the facility cost can be lowered and the productivity can be raised, while the elongation of the current collector (in particular, deformation of conductive foil) could be suppressed. On the other hand, in the case of the prior art, by pressing, the flexibility and binding strength of the coat film were lowered. Moreover, when the, pressure was raised, the current collector was deformed.
Incidentally, according to the Standard Dictionary of Chemical Terms edited by Japan Society of Chemistry (Maruzen, 1991), latex is “formerly defined to be a natural rubber latex, but ever since development of synthetic rubber and synthetic resin emulsion other than rubber compound, all of them are collectively called latex.” That is, in this invention, the latex is not limited to natural rubber and synthetic rubber alone, but includes emulsion of synthetic resin, and such resin scatters among particles of activated carbon, acetylene black, Ketienblack, and others, and they cause the particles to contact with each other. In the invention, the emulsion is, according to the same Standard Dictionary of Chemical Terms, “a system of dispersion of other hardly soluble liquid fine particles in a liquid solute,” but aside from liquid fine particles, it may be also tacky or elastic gel fine particles. The solvent may be oil, but considering the environmental problems and working efficiency, water or the like is preferred. Dissolving is, according to same Standard Dictionary of Chemical Terms, “a phenomenon of melting of a substance in liquid to be a uniform liquid phase,” and in the resin material dissolved in the conventional solvent, the product characteristic may be lowered in order to cover the surface of fine particles of activated carbon or the like (and also fine pores on the surface). However, if the emulsion or latex in the invention is dispersed in the electrode solution, it is predicted to scatter in the finished current collector 7, and therefore it is low in possibility of clogging of the activated fine pores with activated carbon.
In embodiment 20, it was attempted to increase the thickness of the current collector. In the case of a thick current collector, the problem is occurrence of breakage or crack when winding. FIG. 2 shows an example of method of evaluation of winding performance. In FIG. 2, reference numeral 9 is a round bar, and around the round bar 9, the conductive foil 2 cut in a product width and binding the current collector 3 at least on one surface is wound, and the winding performance of the current collector 3 is evaluated. In FIG. 2 (A), the current collector 3 is peeled off the conductive foil 2, and further the current collector 3 itself forms a fracture 10, and this state corresponds to evaluation of x (winding disabled). In FIG. 2 (B), the current collector 3 is not peeled off the conductive foil 2, and fine cracks 11 are formed on the surface of the current collector 3, and this state corresponds to evaluation of Δ (inferior in winding performance). In FIG. 2 (C), the conductive film 2 is not peeled off the current collector 3, and the surface of the current collector 3 is without fracture 10, cracks 11 or other damage, and this state corresponds to evaluation of o (excellent in winding performance). This performance was evaluated 10 times/100 times each alternately on both sides by forming the current collector 7 on both sides of the conductive foil 6.
FIG. 4 is a conceptual diagram of a high pressure dispersion machine. In FIG. 4, the electrode solution charged from an inlet 13 is pressurized to a pressure over 100 kg/cm2 in a pressure unit 14, dispersed under pressure in a dispersion mixer 15, and discharged from an outlet 16. This electrode solution is applied on a conductive foil, and a current collector is formed. FIG. 1 shows a structural diagram of a winding type electric double layer capacitor fabricated by using this current collector. In FIG. 1, activated carbon and conductive agent are bound on the surface of a conductive foil 2 by a binder resin as a current collector 3 in a case 1. A plurality of conductive foils 2 forming this current collector 3 are wound on a separator 4, and a winding 5 a is formed. A plurality of lead-out electrodes 6 are connected to the plurality of conductive foils 6 forming this winding 5 a, and connected to a terminal 8 through a sealing material 7. In an actual electric double layer capacitor, a winding 9 is sealed in the case 1 together with an electrolyte solution.
Embodiment 22 explains the mode of preparing a specified electrode solution (and specified current collector coat film) by using high pressure dispersion machine, without adding alcohol, ammonia or the like. Thus, by using only purified water (or ion exchange water) as the solvent, exhaust of organic solvent from the coating machine is eliminated, and the product can be manufactured while taking the environments into consideration. It was further dispersed by using the high pressure dispersion machine shown in FIG. 2. FIG. 2 shows a conceptual diagram of the high pressure dispersion machine. In FIG. 2, the electrode solution charged from the inlet 10 is pressurized to a pressure over 100 kg/cm2 in the pressure unit 11, and is dispersed at high pressure in the dispersion mixer 12, and is discharge from the outlet 13. Such dispersion is repeated a plurality of times depending on the necessity.
Thus, by employing the manufacturing method of electric double layer capacitor of the invention, the flexibility, thick coating performance and winding performance of the current collector are improved, and the capacity and density of the current collector can be notably enhanced, and the problems of the electric double layer capacitor about larger size, larger capacity and lower cost can be solved.
1. An electric double layer capacitor wherein a current collector composed of activated carbon, conductive agent, at least one kind of ammonium salt of carboxyl methyl cellulose resin, polyvinyl alcohol, methyl cellulose and hydroxy propyl cellulose resin, and polytetrafluoroethylene resin dispersed together is formed on at least one plane of a conductive foil at a density in the range of 0.35 g/cc to 1.50 g/cc, and
a plurality of said conductive foils are wound or laminated on a separator, and sealed in a nonaqueous electrode solution together with lead-out electrodes.
2. An electric double layer capacitor wherein a current collector composed of activated carbon, conductive agent, at least one kind of ammonium salt of carboxyl methyl cellulose resin, polyvinyl alcohol, methyl cellulose and hydroxy propyl cellulose resin, and latex resin dispersed together is formed on at least one plane of a conductive foil at a density in the range of 0.35 g/cc to 1.50 g/cc, and
3. An electric double layer capacitor wherein a current collector composed of activated carbon, conductive agent, at least one kind of ammonium salt of carboxyl methyl cellulose resin, polyvinyl alcohol, methyl cellulose and hydroxy propyl cellulose resin, and low softening point resin dispersed together is formed on at least one plane of a conductive foil at a density in the range of 0.35 g/cc to 1.50 g/cc, and
4. An electric double layer capacitor wherein a current collector composed of activated carbon, conductive agent, and at least one resin or more of ammonium salt of carboxyl methyl cellulose resin, polyvinyl alcohol, methyl cellulose, hydroxy propyl cellulose resin, low softening point resin, polytetrafluoroethylene resin and latex dispersed together is formed on at least one plane of a conductive foil at a density in the range of 0.35 g/cc to 1.50 g/cc, zirconia or zirconia oxide is contained in said current collector by 1 part by weight to 10 parts by weight in 100 parts by weight of the resin, and
5. A manufacturing method of electric double layer capacitor comprising:
preparing an electrode solution by dispersing activated carbon and conductive agent, in a resin solution composed of an aqueous solution of at least one resin of carboxyl methyl cellulose resin, polyvinyl alcohol, methyl cellulose, hydroxy propyl cellulose resin and latex, and polytetrafluoroethylene resin in emulsion state dispersed in water in a particle size of 1 micron or less, dispersing at pressure of more than 100 kg/cm2 by using a high pressure dispersion machine,
applying said electrode solution on a conductive foil in a specified thickness, and drying to prepare a current collector,
winding or laminating said current collector on a separator, and
sealing in a nonaqueous electrode solution together with lead-out electrodes.
6. A manufacturing method of electric double layer capacitor comprising:
preparing an electrode solution by dispersing a binder resin, in purified water or ion exchange water, together with activated carbon and conductive agent, at a pressure of more than 100 kg/cm2 by using a high pressure dispersion machine,
applying said electrode solution on a conductive foil as a coat film, and drying to prepare a current collector,
7. A manufacturing method of electric double layer capacitor comprising:
dissolving or dispersing at least one resin of carboxyl methyl cellulose resin, polyvinyl alcohol, methyl cellulose and hydroxy propyl cellulose, in water, together with fine particles of latex or polytetrafluoroethylene resin,
then, adding activated carbon and conductive agent,
then, dispersing by using a high pressure dispersion machine,
winding said current collector on a separator, and
(a) a conductor having planes;
(b) a current collector installed at least on one of said planes of said conductor, said current collector including:
(1) an activated carbon,
(2) a conductive agent, and
(3) a water-soluble high polymer material and
(4) at least one resin selected from the group consisting of fluoroplastic, latex resin, low softening point resin, and crosslinking resin, and
said conductor having said current collector being at least one of a wound shape and a laminated shape through a separator;
(c) a nonaqueous electrode solution in which said conductor having said current collector is immersed; and
(d) an electrode connected to said conductor.
9. An electric double layer capacitor of claim 8,
wherein said current collector has a density in a range from about 0.35 g/cc to about 1.50 g/cc.
10. An electric double layer capacitor of claim 8,
wherein said water-soluble high polymer material includes at least one material selected from the group consisting of ammonium salt of carboxy methyl cellulose resin, polyvinyl alcohol, methyl cellulose, and hydroxy propyl cellulose resin.
11. An electric double layer capacitor of claim 8,
wherein said current collector is installed on both sides of said conductor.
12. An electric double layer capacitor of claim 8,
wherein said conductive agent is at least one selected from the group consisting of acetylene black, Ketienblack, graphite powder, metal powder, and conductive high polymer material.
13. An electric double layer capacitor of claim 8,
wherein said one resin is said latex resin,
said latex resin is at least one selected from the group consisting of natural latex, styrene-butadiene rubber, nitrile-butadiene rubber, butadiene copolymer, styrene-butadiene copolymer, and carboxy denatured styrene-butadiene copolymer, and
said activated carbon, said conductive agent, and said latex resin are dispersed in said water-soluble high polymer material.
14. An electric double layer capacitor of claim 8,
wherein said one resin is said low softening point resin, and
said low softening point resin has a glass transition temperature of −10 deg. C. or less.
15. An electric double layer capacitor of claim 8,
wherein said one resin is said low softening point resin,
said low softening point resin is at least one selected from the group consisting of vinyl chloride, ethylene-vinyl chloride copolymer resin, vinylidene chloride latex, chlorinated resin, vinyl acetate resin, polyvinyl butyral, polyvinyl formal, bisphenol system epoxy resin, polyurethane resin, styrenebutadiene rubber, butadiene rubber, isoprene rubber, nitrile-butadiene rubber, urethane rubber, silicone rubber and acrylic rubber, and
said activated carbon, said conductive agent, and said low softening point resin are dispersed in said water-soluble high polymer material.
16. An electric double layer capacitor of claim 8,
wherein said at least one resin includes said crosslinking resin,
wherein said crosslinking resin is chemically crosslinked.
17. An electric double layer capacitor of claim 8,
wherein said current collector has a thickness in a range from about 20 microns to about 10 mm.
18. An electric double layer capacitor of claim 8,
wherein said conductor and said current collector installed on said surface of said conductor are wound in a winding diameter of about 5 mm or less.
19. An electric double layer capacitor of claim 8,
wherein said conductor and said current collector installed on one of said planes of said conductor have a plurality of current collectors, and
each current collector of said plurality of current collectors is laminated through said separator.
20. An electric double layer capacitor having a plurality of the electric double layer capacitors of claim 8,
wherein said each electric double layer capacitor is connected in series.
21. An electric double layer capacitor having a plurality of the electric double layer capacitors of claim 8,
wherein said each electric double layer capacitor is connected in parallel.
22. An electric double layer capacitor of claim 8,
wherein the total of said water-soluble high polymer material and said one resin is in a range from about 1 part by weight to about 200 parts by weight, in 100 parts by weight of said activated carbon.
23. An electric double layer capacitor comprising:
(d) an electrode connected to said conductor,
wherein said one resin is fluoroplastic,
said fluoroplastic is polytetrafluoroethylene resin, and
said activated carbon, said conductive agent and said polytetrafluoroethylene resin are dispersed in said water-soluble high polymer material.
24. A manufacturing method of electric double layer capacitor comprising the steps of:
(a) preparing an electrode solution by uniformly mixing a mixture including activated carbon, water-soluble high polymer material, and at least one resin selected from the group consisting of fluoroplastic, latex resin, low softening point resin, and crosslinking resin;
(b) applying said electrode solution on a conductor, and drying to form a current collector;
(c) forming at least one shape of winding shape and laminating shape said conductor having said current collector through a separator; and
(d) installing said conductor having said current collector in a nonaqueous electrode solution,
wherein said one resin is said fluoroplastic, and
said fluoroplastic has particles with a particle size of about 1 micron or less, being in an emulsion state dispersed in water.
25. A manufacturing method of electric double layer capacitor comprising the steps of:
(d) installing said conductor having said current collector in a nonaqueous electrode solution.
26. A manufacturing method of electric double layer capacitor of claim 25,
wherein said water-soluble high polymer material is at least one material selected from the group consisting of ammonium salt of carboxy methyl cellulose resin, polyvinyl alcohol, methyl cellulose and hydroxy propyl cellulose resin.
27. A manufacturing method of electric double layer capacitor of claim 25,
wherein said one resin includes said latex, and
said latex has particles with a particle size of about 1 micron or less, being in an emulsion state dispersed in water.
28. A manufacturing method of electric double layer capacitor of claim 24 or 27,
wherein said emulsion has a surface active agent, with the pH ranging from about 4 to about 12, and
at said step (a), said mixture is mixed while applying a pressure of 100 kg/cm2 or more, so that said uniformly dispersed electrode solution is prepared.
29. A manufacturing method of electric double layer capacitor of claim 25,
wherein said one resin includes said latex, and said latex has particles with a particle size of about 1 micron or less, being in an emulsion state dispersed in water not containing at least one of ammonia and alcohol.
30. A manufacturing method of electric double layer capacitor of claim 25,
wherein said electrode solution has a viscosity in a range from about 1 poise to about 200 poise, and
at said step (b), said electrode solution is applied on a first surface of said conductor at a thickness precision from −10 microns to +10 microns at about 20 microns or more,
then, in a half-dry state until said applied electrode solution is not dried completely, said conductor coated with said electrode solution is wound,
then, said electrode solution is applied on a second surface of said conductor at a thickness precision from −10 microns to +10 microns at about 20 microns or more,
then, said electrode solution applied on said first surface and said second surface are dried simultaneously, and
then, said conductor having said electrode solution installed on said first surface and said second surface is wound again.
31. A manufacturing method of electric double layer capacitor of claim 25,
wherein at said step (a), said mixture is mixed while applying a pressure of 100 kg/cm2 or more, so that said uniformly dispersed electrode solution is prepared.
32. A manufacturing method of electric double layer capacitor of claim 25,
wherein at said step (a), said mixture is mixed by using a dispersion machine having at least one mixing unit made of at least one material selected from the group consisting of diamond, ceramic and cemented carbide, so that said uniformly dispersed electrode solution is prepared.
33. A manufacturing method of electric double layer capacitor of claim 25,
wherein said one resin is said fluoroplastic,
said fluoroplastic has particles with a particle size of about 1 micron or less, being in an emulsion state dispersed in water, and
34. A manufacturing method of electric double layer capacitor of claim 25,
wherein said current collector has a density ranging from about 0.35 g/cc to about 1.50 g/cc.
35. A manufacturing method of electric double layer capacitor of claim 25,
36. A manufacturing method of electric double layer capacitor of claim 25,
wherein at said step (a), said mixture is mixed, together with at least one of purified water and ion exchange water, while applying a pressure of 100 kg/cm2 or more, so that said uniformly dispersed electrode solution is prepared.
37. A manufacturing method of electric double layer capacitor of claim 25,
wherein at said step (a), said water-soluble resin and at least one resin of said fluoroplastic and said latex are mixed,
then, said activated carbon and said conductive agent are added to prepare said mixed solution,
then, said mixture is mixed while applying a pressure of 100 kg/cm2 or more, so that said uniformly dispersed electrode solution is prepared.
38. A manufacturing method of electric double layer capacitor comprising the steps of:
said fluoroplastic has particles with a particle size of about 1 micron or less, being in an emulsion state dispersed in water,
wherein said emulsion has a surface active agent, with pH ranging from about 4 to about 12.
39. A manufacturing method of electric double layer capacitor comprising the steps of:
(b) applying said electrode solution on a conductor and drying to form a current collector;
(c) forming at least one shape of winding shape and laminating shape said conductor having said current collector through a separator;
(d) installing said conductor having said current collector in a nonaqueous electrode solution, and
processing said current collector by at least one means of pressing and calendering to enhance at least one of characteristics of density and surface smoothness.
40. A manufacturing method of electric double layer capacitor comprising the steps of:
wherein said one resin includes said fluoroplastic,
said emulsion has the pH ranging from about 5 to about 12.
41. A manufacturing method of electric double layer capacitor comprising the steps of:
wherein said electrode solution has a viscosity ranging from about 1 poise to about 200 poise, and
said electrode solution is applied as to form said current collector in a thickness of about 20 microns or more, at thickness precision ranging from −5 microns to +5 microns.
42. An electric double layer capacitor comprising:
(1) activated carbon,
(2) conductive agent, and
(3) at least one resin selected from the group consisting of water-soluble high polymer material, fluoroplastic, latex resin, low softening point resin, and crosslinking resin, and said conductor having said current collector being at least one of a wound shape and a laminated shape through a separator;
wherein said crosslinking resin contains at least one catalyst of zirconia and zirconia compound, and
said crosslinking resin is chemically crosslinked by the action of said catalyst.
43. A manufacturing method of electric double layer capacitor comprising the steps of:
said latex has particles with a particle size of about 1 micron or less, being in an emulsion state dispersed in water,
44. An electric double layer capacitor comprising:
45. An electric double layer capacitor of claim 42, 43 or 44,
46. An electric double layer capacitor of claim 42, 43 or 44,
47. An electric double layer capacitor of claim 42, 43 or 44,
48. An electric double layer capacitor of claim 42, 43 or 44,
49. An electric double layer capacitor of claim 42, 43 or 44,
50. An electric double layer capacitor of claim 42, 43 or 44,
wherein said conductor and said current collector installed on said surface of said conductor have a plurality of current collectors, and
51. An electric double layer capacitor having a plurality of the electric double layer capacitors of claim 42, 43 or 44,
52. An electric double layer capacitor having a plurality of the electric double layer capacitors of claim 42, 43 or 44,
53. An electric double layer capacitor comprising:
US09147558 1997-06-16 1998-06-12 Electric double-layer capacitor and method for manufacturing the same Active US6246568B1 (en)
JP15837697 1997-06-16
JP9-158376 1997-06-16
JP20125797 1997-07-28
JP9-201257 1997-07-28
JP1021098 1998-01-22
JP10-010210 1998-01-22
PCT/JP1998/002603 WO1998058397A1 (en) 1997-06-16 1998-06-12 Electric double-layer capacitor and method for manufacturing the same
US6246568B1 true US6246568B1 (en) 2001-06-12
ID=27278882
US09147558 Active US6246568B1 (en) 1997-06-16 1998-06-12 Electric double-layer capacitor and method for manufacturing the same
US (1) US6246568B1 (en)
JP (1) JP3780530B2 (en)
KR (2) KR100532258B1 (en)
CN (1) CN1178242C (en)
EP (1) EP0948005A4 (en)
WO (1) WO1998058397A1 (en)
US6356432B1 (en) * 1997-12-30 2002-03-12 Alcatel Supercapacitor having a non-aqueous electrolyte and an active carbon electrode
US6508846B2 (en) * 2000-01-17 2003-01-21 Sanyo Electric Co., Ltd. Process and apparatus for fabricating solid electrolytic capacitors
EP1477997A1 (en) * 2002-01-29 2004-11-17 Power Systems Co., Ltd Electrode formulation for polarized electrode and method for preparation thereof, and polarized electrode using the electrode formulation
US20060139846A1 (en) * 2003-06-30 2006-06-29 Hidekazu Mori Method for producing electrode for electric double layer capacitor
US20070287064A1 (en) * 2005-02-10 2007-12-13 Kenji Suzuki Binder resin emulsion for energy device electrode and energy device electrode and energy device that use same
US20090224198A1 (en) * 2005-05-26 2009-09-10 Hidekazu Mori Electrode material for electrochemical element and composite particle
US20090310281A1 (en) * 2005-12-01 2009-12-17 Eri Hirose Wound electric double-layer capacitor
US20100315761A1 (en) * 2009-06-16 2010-12-16 George Georgopoulos Sealed and impregnated wound capacitor assemblies
US20130286542A1 (en) * 2010-09-06 2013-10-31 OÜ Skeleton Technologies Super capacitor of high specific capacity and energy density and the structure of said super capacitor
KR101415416B1 (en) 2010-04-09 2014-07-04 해리스 코포레이션 Simulated degradation of snr in decoded digital audio correlated to wireless link bit-error rate
US9171675B2 (en) 2010-12-20 2015-10-27 Jsr Corporation Electrical storage device, lithium ion capacitor and negative electrode for lithium ion capacitor
FR2793600B1 (en) * 1999-05-10 2001-07-20 Europ Accumulateurs Electrode ultracapacitor, supercapacitor and method of manufacture
EP1256966A1 (en) * 2001-05-08 2002-11-13 Ness Capacitor Co., Ltd Electric double layer capacitor and method for manufacturing the same
KR100614118B1 (en) 2006-02-24 2006-08-11 주식회사 비츠로셀 Hybrid battery
JP2010087314A (en) * 2008-09-30 2010-04-15 Nippon Chemicon Corp Electrode for electric double layer capacitor
CN103137334B (en) * 2011-12-01 2016-06-08 上海奥威科技开发有限公司 The method of making an electrode sheet for supercapacitors and supercapacitors
KR101494622B1 (en) * 2013-05-08 2015-02-23 한국세라믹기술원 Composite for supercapacitor electrode and manufacturing method of supercapacitor electrode using the composite
JP5975953B2 (en) * 2013-08-06 2016-08-23 日本バルカー工業株式会社 Method for producing an electric double layer capacitor electrode film
CN104008892A (en) * 2014-01-28 2014-08-27 宁波南车新能源科技有限公司 Paste viscosity control method for supercapacitor and device for method
CN106571246A (en) * 2016-10-26 2017-04-19 安徽飞达电气科技有限公司 Binder used for super capacitor electrode
JPS5760828A (en) 1980-09-09 1982-04-13 Matsushita Electric Ind Co Ltd Method of producing electric double layer capacitor
JPS5784120A (en) 1980-11-14 1982-05-26 Matsushita Electric Ind Co Ltd Low impedance electric double layer capacitor
JPS6216506A (en) 1985-03-06 1987-01-24 Murata Manufacturing Co Electric double layer capacitor
JPS62179711A (en) 1986-02-03 1987-08-06 Murata Manufacturing Co Electric double-layer capacitor
JPS63104316A (en) 1986-10-21 1988-05-09 Nakamura Yoshiro Electric double-layer capacitor
JPS63190318A (en) 1987-02-03 1988-08-05 Taiyo Yuden Kk Electric double-layer capacitor
JPS63196028A (en) 1987-02-10 1988-08-15 Hitachi Maxell Electric double-layer capacitor
JPS63316422A (en) 1987-06-19 1988-12-23 Asahi Glass Co Ltd Electric double layer capacitor
JPH01164017A (en) 1987-12-21 1989-06-28 Asahi Glass Co Ltd Manufacture of electrode for electric double layer condenser
JPH01227417A (en) 1988-03-08 1989-09-11 Asahi Glass Co Ltd Electric double layer capacitor
JPH03280518A (en) 1990-03-29 1991-12-11 Matsushita Electric Ind Co Ltd Electric double layer capacitor and manufacture thereof
JPH06203849A (en) 1992-12-25 1994-07-22 Tokyo Gas Co Ltd Manufacture of solid high polymer fuel cell
JPH06316784A (en) 1993-04-30 1994-11-15 Tanaka Kikinzoku Kogyo Kk Production of powdery carbon black-ptfe uniform mixture
JPH07331201A (en) 1994-06-13 1995-12-19 Nisshinbo Ind Inc Electrically conductive adhesive and bonded structure using the same
JPH08203536A (en) 1995-01-30 1996-08-09 Fuji Electric Co Ltd Fuel electrode of fuel battery, catalyst manufacture thereof and battery operation method
JPH08250380A (en) * 1995-03-07 1996-09-27 Matsushita Electric Ind Co Ltd Polarizable electrode and its manufacture
US6005765A (en) * 1996-01-12 1999-12-21 Nippon Zeon Co., Ltd. Collector and electric double layer capacitor
US4488203A (en) * 1979-02-09 1984-12-11 Matsushita Electric Industrial Co., Ltd. Electrochemical double-layer capacitor and film enclosure
US7491352B2 (en) 2002-01-29 2009-02-17 Junji Ito Method for preparing an electrode material for a polarized electrode
US20050116375A1 (en) * 2002-01-29 2005-06-02 Junji Ito Electrode formulation for polarized electrode and method for preparation thereof, and polarized electrode using the eletrode formulation
US20090152510A1 (en) * 2002-01-29 2009-06-18 Junji Ito Electrode material for a polarized electrode
EP1477997A4 (en) * 2002-01-29 2007-08-22 Power Systems Co Ltd Electrode formulation for polarized electrode and method for preparation thereof, and polarized electrode using the electrode formulation
US8124474B2 (en) * 2003-06-30 2012-02-28 Zeon Corporation Method for producing electrode for electric double layer capacitor
US7881043B2 (en) * 2005-12-01 2011-02-01 Panasonic Corporation Wound electric double-layer capacitor
CN101140829B (en) 2006-09-04 2014-08-20 富士重工业株式会社 Lithium-ion capacitor
US8174817B2 (en) * 2009-06-16 2012-05-08 High Energy Corp. Sealed and impregnated wound capacitor assemblies
US9111693B2 (en) * 2010-09-06 2015-08-18 Ou Skeleton Technologies Group Super capacitor of high specific capacity and energy density and the structure of said super capacitor
KR100532257B1 (en) 2005-11-29 grant
WO1998058397A1 (en) 1998-12-23 application
KR100532258B1 (en) 2005-11-29 grant
KR20000068119A (en) 2000-11-25 application
CN1178242C (en) 2004-12-01 grant
JP3780530B2 (en) 2006-05-31 grant
KR20050084457A (en) 2005-08-26 application
CN1229517A (en) 1999-09-22 application
EP0948005A4 (en) 2006-03-22 application
EP0948005A1 (en) 1999-10-06 application
US6585915B2 (en) 2003-07-01 Process for producing a carbon material for an electric double layer capacitor electrode, and processes for producing an electric double layer capacitor electrode and an electric double layer capacitor employing it
US20070190424A1 (en) 2007-08-16 Dry-particle packaging systems and methods of making same
US6403261B2 (en) 2002-06-11 Carbon-containing material and a method of making porous electrodes for chemical sources of electric current
US20100097741A1 (en) 2010-04-22 Ultracapacitor electrode with controlled sulfur content
US20080028583A1 (en) 2008-02-07 Process for producing electrode for electric double layer capacitor and process for producing electric double layer capacitor employing the electrode
EP0712143A2 (en) 1996-05-15 An electric double-layer capacitor and method for manufacture of an electrode therefor
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:NAKAO, KEIICHI;SHIMIZU, KYOUSHIGE;YAMAGUCHI, TAKUMI;REEL/FRAME:009851/0853