CN1006503B - Dual-layer capacitor - Google Patents

Abstract

The present invention relates to an electric double-layer capacitor. An aluminum layer (8) is formed in the electric double-layer capacitor, at least in the inner surface of an anode metal container (9), and an anodic oxide film with stable electrochemistry is formed by the aluminum layer (8) according to an additional voltage. Moreover, the electric double-layer capacitor with voltage resistance of more than 3V is obtained by slickly utilizing the property that the electric resistance of the film is in a lowest practical degree out of question.

Description

Dual-layer capacitor

The invention relates to double charge layer capacitor with the electric double layer that on the interface between polarizable electrode and the electrolyte, forms.

U.S. Pat P 4562511 discloses a kind of double charge layer capacitor, this double charge layer capacitor as shown in Figure 1, with the active carbon particle drawing or will be coated on the collector electrode metal with the activated carbon after the kneading of suitable binding agent or on activated carbon fiber, form the deposited metal of aluminium matter and obtain polarizable electrode 1, these polarizable electrodes are contained in respectively in the rustless steel container 2, make polarizable electrode 1 electrolyte that is situated between with separator 3 and mutually pass through gasket seal 4 and sealed towards, the opening portion of canister 2.

The capacitor of existing another type as shown in Figure 2, is as one of them electrode with a non-polarised electrode 5.

In these conventional device,, propene carbonate, gamma-butyrolacton, N-2 methyl formaldehyde, acetyl nitrile have been used as the solvent of electrolyte.When anode polarization, the stainless steel in the electrolyte can not be made completely passive state and dissolved.The current potential that makes electric current begin to flow that causes owing to this dissolving is 2.3～2.4V, and this current potential depends on the decomposition electric potential of the solvent of negative electrode aspect.Because the oxidation potential energy or the electrolytical decomposition electric potential in the electrolyte that has used these organic solvents of this current potential specific activity carbon are low, so under with the situation of stainless canister 2 as collector electrode, anode potential is subjected to stainless dissolution potential and limits, and the current potential 3V in the electrochemical stability potential range that is determined by polarizable electrode 1 and electrolyte just can not effectively utilize.

For example, when the voltage of an additional surplus and leakage current when beginning to increase, just detected the iron, nickel of volume etc. in the electrode aspect negative electrode, can confirm stainless dissolving and iron ion in view of the above and move to negative electrode from anode.

As mentioned above, when having used stainless steel to make canister 2, be difficult for this current potential of 3V that effectively utilizes in the electrochemical stability scope that is determined by polarizable electrode 1 of activated carbon and electrolyte.In order to obtain the double charge layer capacitor of puncture voltage greater than 3V, must use when anode polarizes in used solvent, with the activated carbon same degree of polarizable electrode 1 or higher current potential the time stream respond electric current material and have the material of the sufficient intensity that uses as container.

As an example, even be the titanium that also forms passive state in electrolyte, as shown in Figure 3, it has puncture voltage higher when using stainless steel, in the electrolyte of the additive of propene carbonate, tetraethyl ammonium gloss plating method, can enlarge the about 0.8V of the field of circulation of kinetic current.But, because internal resistance at this moment increases, when using double charge layer capacitor, make voltage drop become big, so, can not use for actual.

The present invention is the double charge layer capacitor that has the above puncture voltage of 3V in order to solve the above problems a little, to provide.

That is, the present invention has a device, and this device contacts with the electrode of a conduction at the canister member of anode-side, and is provided with aluminium lamination on electrolytical inner surface.Like this, when aluminium lamination forms on electrolytical surface,, in the scope of once having been added voltage, there is not kinetic current to pass through, so can stop solubilizing reaction because auxiliary voltage on aluminium lamination, has just formed oxide-film.Like this, even just can obtain the voltage of additional 3V, also be stable double charge layer capacitor for electrochemistry.

Also have, because when the low-voltage of 3V degree, thin thickness, the resistance of pellumina are low, so not have to find as the phenomenon of the internal resistance rising when using titanium.At this moment, because the also material of double as container of collector electrode metal, so must have sufficient intensity as container material.If but only were used as container material with aluminium, so, its intensity would be just not enough, and because the size of goods is restricted the thickness of container material, can not too increase its thickness.Therefore, no problem on being electrically connected as outside terminal under these restrictive conditions, and have the stainless steel of sufficient intensity and aluminium just to be used to have become effectively.

Fig. 1, Fig. 2 are the sectional views of the existing double charge layer capacitor of expression, Fig. 3 is with stainless steel and the titanium current potential-current characteristics figure as the double charge layer capacitor of collector electrode, Fig. 4 is the sectional view of an embodiment of expression double charge layer capacitor of the present invention, and Fig. 5～Fig. 7 is a sectional view of representing other embodiment of the present invention respectively.

With reference to Fig. 4～Fig. 7, embodiments of the invention are illustrated below.

At first, shown in Figure 4 is at the cloth by activated carbon fiber, or on the one side of the polarizable electrode 6 that the kneading of activated carbon powder and adhesive is shaped, form the electrode 7 of the conduction of aluminium matter with methods such as plasma spray coatings, above-mentioned polarizable electrode 6 is enclosed within the stainless canister member 9,10 that its inner surface is formed with aluminium layer 8, and the electrode 7 of conduction is connected to the inner surface of canister member 9,10 by spot welding.To flood the electrolyte of the tetraethyl ammonium tetrafluoroborate that in propene carbonate, is added with 10% weight at the polarizable electrode 6 aspect the negative electrode, and the separator 11 of ion permeability will be set between polarizable electrode 6 as counterelectrode.Open circumferential at two canister members 9,10 is partly mixed gasket seal 12, the peripheral part of canister member 10 is processed with crimping seal.

Shown in Figure 5 is does not form the embodiment of aluminium lamination 8 at the inner face of the canister member 10 of anode.

Shown in Figure 6 is in the embodiment shown in fig. 4, and the electrode as negative electrode has used non-polarised counterelectrodes 13 such as lithium, has formed aluminium lamination 8 respectively at the inner face of canister member 9,10.

Shown in Figure 7 is to use non-polarised electrode as counterelectrode 13, and the inner surface of the canister member 10 aspect this counterelectrode 13, and the embodiment of aluminium layer 8 is not set.

As canister member 9,10, except that using stainless steel, also can use iron, nickel, titanium, copper alloy etc.

Secondly, illustrate with specific embodiment.

(embodiment 1)

In Fig. 4, embodiment shown in Figure 5, the surface of the polarizable electrode of making at the cloth (thick 0.5mm, specific area 2000m/gr) that with phenol is activated carbon fiber system 6 forms the electrode 7 of conduction of the aluminium lamination of 250 μ m with the plasma spray coating method.With the object of these 2 layers of structures, obtain the electrode body of diameter 2cm with the blanking die sampling.After this electrode body being flooded the electrolyte of the tetraethyl ammonium tetrafluoroborate that in propene carbonate, is added with 10% weight, separator 11 is set between them and makes their mutual coincidences, they only being sealed in has aluminium lamination 8(purity 99.86% at the inner surface that contacts again aspect anode, thick 70 μ m and purity 99.99%, thick 60 μ m) and the inner surface that contacts with the two poles of the earth all have in the canister member 9,10 of stainless steel of aluminium lamination 8.Openend at canister member 9,10 disposes pad 12, and seals with riveted joint.

In No1～3 of table 1, demonstrate various characteristics according to double charge layer capacitor of the present invention.In table 1, in order to compare, studied at the inner surface of the rustless steel container capacitor of the prior art of topped aluminium lamination not, its characteristic is shown in No6.

(embodiment 2)

In that being mixed with the adhesive of being made by polytetrafluoroethylene synthetic resin, the cocoanut shell active carbon particle rubs the thick 0.5mm of polarizable electrode 6(of shaping, specific area 800m/gr) on the surface, forms the electrode 7 of conduction of the aluminium lamination of thick 250 μ m with the plasma spray coating method.The object of these 2 layers of structures is obtained the discoideus electrode body of diameter 2cm with the blanking die sampling.After this electrode body being flooded the electrolyte of the tetraethyl ammonium tetrafluoroborate that in the propylene carbonate enzyme, adds 10% weight, make their mutual coincidences they separator 11 being set, canister member 9,10 with stainless steel clamps again, wherein have only the inner surface of member 9 to have the inner surface of aluminium lamination 8 or member 9,10 that aluminium lamination 8(purity 99.86% is all arranged, thick 70 μ m).Openend at this canister member 9,10 disposes gasket seal 12, and seals with riveted joint.

The No4 of table 1,5 has shown the characteristic according to double charge layer capacitor of the present invention.

Table 1

The invention goods	N O	Container structure	Use activated carbon	Capacity (F)	Internal resistance (Ω)	Withstand voltage (V)	High-temperature load life-spans 3.0 V70 ℃ 1000 hours
								1	Anode: aluminium covers stainless steel (aluminium purity: negative electrode 99.86%): stainless steel	Phenol is activated carbon fiber	3	0.16	3	(volume change)-5%
	2	Anode: aluminium covers stainless steel (aluminium purity: negative electrode 99.99%): stainless steel	Phenol is activated carbon fiber	3	0.16	3	-5％
								3	Anode: aluminium covers stainless steel, and (aluminium purity: negative electrode 99.99%): aluminium covers stainless steel (aluminium purity: 99.86%)	Phenol is activated carbon fiber	3	0.16	3	-5％
	4	Anode: aluminium covers stainless steel (aluminium purity: negative electrode 99.86%): stainless steel	The cocoanut shell active carbon particle	0.8	0.1	3	-5％
								5	Anode: aluminium covers stainless steel, and (aluminium purity: negative electrode 99.86%): aluminium covers stainless steel (aluminium purity: 99.99%	The cocoanut shell active carbon particle	0.8	0.1	3	-5%

Prior art

6

Anode, negative electrode: stainless steel

Phenol is activated carbon fiber

3

0.16

2.3

-95％

(embodiment 3)

As Fig. 6, shown in Figure 7, at cloth (thick 0.5mm with the acrylic compounds activated carbon fiber, the surface of the polarizable electrode 6 that specific area 800m/gr) causes, with wait from metallikon form the electrode 7 of conduction of the aluminium lamination of thick 250 μ m, object with these 2 layers of structures, with the blanking die sampling, just obtain the discoideus anode electrode body of diameter 2cm.Between this electrode body and non-polarised electrode body of making by lithium etc. as the diameter 2cm of cathodic electricity polar body, separator 11 is set, and makes their mutual coincidences, become the pair of electrodes body.With this a pair of electrode body, flooded after the electrolyte of the LiBF4 that in propene carbonate, is added with 10% weight, clamp with stainless steel metal container member 9,10, wherein have only the inner surface of stainless steel metal container member 9 that aluminium lamination 8 is arranged, or the inner surface of member 9,10 all is coated with aluminium lamination 8(purity 99.99%, thick 60 μ m).Openend at canister member 9,10 disposes gasket seal 12, and seals with riveted joint.

No1,2 at table 2 demonstrates the various characteristics according to double charge layer capacitor of the present invention.In table 2,, will there be the characteristic of the tectal capacitor that studies of aluminium to be shown in No3 at the inner face of stainless steel metal container in order to compare.

Table 2

Invention goods prior art	N O	Container structure	Combination of electrodes	Capacity (F)	Internal resistance (Ω)	Withstand voltage (V)	High-temperature load life-spans 3.0 V70 ℃ 1000 hours
								1	Anode: aluminium covers stainless steel (aluminium purity: negative electrode 99.99%): stainless steel	The subtend type of polarizable electrode and non-polarised electrode	6	0.15	3	(volume change)-5%
	2	Anode: aluminium covers stainless steel, and (aluminium purity: negative electrode 99.99%): aluminium covers stainless steel	”	6	0.15	3	－5％
								3	Anode, negative electrode: stainless steel	”	6	0.15	2.8	－50％

As mentioned above, the present invention's inner surface of the canister aspect anode at least forms aluminium lamination, because auxiliary voltage, it is stable anode oxide film that aluminium lamination is formed for electrochemistry, and the resistance that has effectively utilized this oxygen film is low to moderate the character of complete unchallenged degree in practicality, thereby can easily obtain to have the double charge layer capacitor of the above puncture voltage of 3V.

Claims (5)

1, a kind of double charge layer capacitor, comprise that one simultaneously forms the polarizable electrode of conductive electrode at it, another side at this polarizable electrode disposes counterelectrode across electrolyte and separator, in 2 canister members that their are enclosed respectively with above-mentioned polarizable electrode and counterelectrode electrically are connected, it is characterized in that, in said canister member, on the electrode of the conduction of the canister member aspect polarizable electrode and face that electrolyte contacts, be provided with aluminium lamination at least.

2, the described double charge layer capacitor of claim 1 is characterized in that, said counterelectrode is to have formed the activated carbon fiber of the electrode that conducts electricity or the polarizable electrode of activated carbon powder in the one side.

3, the described double charge layer capacitor of claim 1 is characterized in that, said counterelectrode is non-polarized electrode.

4, the described double charge layer capacitor of claim 1 is characterized in that, the electrode of said conduction is formed from aluminium.

5, the described double charge layer capacitor of claim 1 is characterized in that, said canister member is that a kind of material selected from stainless steel, iron, nickel, titanium, copper alloy is made.

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