TWI284997B - Electrochemical electrode for high-power application - Google Patents

Abstract

The present invention provides a novel electrode which contains an electrode coating thereon, an electrochemical component having the novel electrode and the fabrication method thereof. The electrode coating contains at least a ferrite of a spinel structure having the chemical composition represented by M1+xFe2-xO4, where -0.2 <= x <= 0.2 and M is one of non-Fe transition metal elements and the combination thereof. The electrochemical component relates to an electrochemical cell which has the high-power capability and is suitable for supercapacitor applications.

Description

1284997 IX. Description of the invention: [Technical field to which the invention pertains] The present invention relates to a capacitor formed by an electrochemical electrode and a combination thereof, and a method for preparing the same, in particular, a combination of an electrode using ferrite and a combination thereof Ultra-high capacitor and its preparation method. [Prior Art] Batteries have long been the most commonly used energy storage devices. Although secondary batteries provide better energy density, they are not sufficient for excessive power output. It is known that in the case of high power charge and discharge, the battery is easily damaged and the cycle life is drastically reduced. This shortcoming will result in the battery not meeting the power needs of machines that need to supply large currents in an instant, such as electric vehicles, so it is urgent to develop a south power storage component that is sufficient to match the battery. A supercapacitor is also known as an electrochemical capacitor. Since 1990, ultra-high capacitors have been regarded as a new energy storage component between batteries and traditional ceramic capacitors, φ to store up to thousands of farads of capacitance in a limited volume, with high power blanket, 咼Charge and discharge cycles and high coulombic efficiency characteristics. Due to the above characteristics, ultra-high capacitors can be used directly as a backup power source for small appliances. More importantly, it can be used as a portable high-current supply for portable Xuan products, Wei starters and electric vehicles. This concept is derived from the hybrid surface of ultra-high capacitors and batteries. When the two are connected in parallel, any ultra-high capacitors provide any instantaneous current, and the battery can discharge at a specific current; The effect will extend the life of the battery. Depending on the charge storage mechanism, ultra-high capacitors can be roughly divided into 5 two, one is an electric double layer capacitor, and the other is a pseudo capacitor. Among them, the electric storage method of the electric double layer capacitor is derived from the electrostatic charge separation at the interface between the electrode and the electrolyte, and the operation only involves a simple physical adsorption behavior. In general, electric double layer capacitors are mainly used as electrode materials with high ratio silk stone carbon materials. On the other hand, pseudocapacitors have a different power storage mechanism. The capacitance of the pseudocapacitor is mainly derived from the electric double layer capacitor, which is mainly caused by the electrosorption or Faraday reaction of the active material on the surface of the electrode. Since only the substance located near the surface area participates in the reaction, the charge and discharge rate It is much faster than the battery, but still meets the characteristics of the capacitor and is widely used. In addition, because the unit capacitance of the pseudo-capacitor is much higher than that of the electric double-layer capacitor, recent research on super-tantalum capacitors has been bet on the pseudo-capacitor. The prior art discloses that the electrode material of the pseudo capacitor is mainly concentrated in the transition metal oxide and the conductive polymer, and the transition metal oxide is further developed. In recent years, ruthenium oxide (Ru〇2) has been widely studied and applied in the category of ultra-high capacitors. Journal of the Electrochemical Society, 142, pp 2699-2703 (1995) reveals that 'amorphous oxidized sulphur in sulfur A specific capacity of up to 720 F/g can be provided in the solution. However, since cerium oxide is very expensive, it does not have substantial benefits. Prior art includes Gf s〇lid

State Chemistry, 144, PP „ 220-223 (1999) paper and US Patent No. M1M75 6,339,538 a manganese (Mn〇2) is a potential pseudocapacitor electrode material, in addition to price, and environmentally friendly characteristics, The combination of the towel water (4) solution does not cause pollution to the environment. _, the biggest missing is the electronic 'electricity is not good' of the amorphous sulphide Mn. Therefore, the material is mostly coated with a thin film. 84997 = used on the carrier, in order to get the car rate, = material flipping thickening _ _ lin red charge and discharge work 6,762) 926 which is the electrode material of the ultra-high capacitor, F emulsified three iron (FeA) is higher The capacitance value. The autumn is poor and the thief capacity is from the Yin Xuan's oxidation is slower. Therefore, the capacitance value drops sharply at the high enthalpy rate, which is not suitable for the application of charge and discharge power. The structure of the Japanese stone, the structure is formed by oxygen atoms - the face of the heart (4) in the position of the gold handle Xuanyuan, the 1/3 of the iron ions occupy the tetrahedron, the center of the body m + the iron ions occupy the eight sides f Medium and position. Sub-set _ third of the number of iron ions can still obtain a multi-component gasification of ferr (four), upper vermiculite 4, commonly known as ferrite thunder, its capacity, secret capacitance and charge and discharge The power is much higher than that of pure Fe3〇4. The purpose of i is to develop a material that is cheaper than the price of oxygen. Another object of the invention is that the electrode material has the electronic conductivity from the bribe. The content of the invention is to provide an electrochemical electrode comprising an -electrode coating. The electrode coating is coated on the substrate, and at least one of the iron oxides has a chemical composition of M1. +XFe2 is, where x S 0·2, and Μ is a non-ferrous (Fe) transition metal element. According to the above concept, the substrate is a metal piece. 7 2 The above concept 'where the iron oxide has - Technical stone structure. 2 conception, wherein M is selected from one of the group consisting of bell (four)), copper (cu) and combinations thereof. The second concept of the above is to provide a chemical element, which includes A special electrochemical electrode. According to the above concept, the electrochemical component is electrically-electricized. According to the above concept, the metal inorganic and the metal organic salt contain one of the elements of the age-old metal element. According to the above concept, the + surface metal element contains Chain (Li), sodium (Na), potassium (K), ruthenium (Rb), ruthenium (cs), and combinations thereof. According to the above concept, the soil member of the soil test group includes beryllium (Be) and magnesium (Mg). Calcium (Ca), strontium (sr), strontium (Ba), and combinations thereof. According to the above concept, the metal inorganic surface of the towel further comprises a vapor, sulfur. According to the above concept, the scientific component further comprises an electrolyte, the electrolysis Negative one metal-inorganic bribe and one-gold ejector _ one of them. Oxides, sulphur oxides, nitrates, and combinations thereof. According to the above concept, the metal organic surface of the towel further comprises hexafluorosean oxide, tetrafluoroborate, peroxy oxide, Sandon methyl feldspar oxide and combinations thereof. The third concept of the present invention is to provide a A method for preparing an electrode coating, comprising the steps of: (8) preparing a solution containing Fe3+ ions and M2+ ions' and a concentration ratio of Fe ions to m2+ ions of 2:1; (8) adding the solution to an alkaline solution To form a precipitate; (c) heat treating the precipitate to form an iron oxide powder; (d) adding an adhesive and a solvent in the "1284997 iron oxide body" to form a mixed polymer; And (6) applying the mixed polymer to a metal sheet substrate. According to the above concept, the lanthanide is one selected from the group consisting of 猛η, )(Cu), nickel(Ni), copper(Cu), and combinations thereof. According to the above concept, the alkaline solution further comprises a porous electrically conductive material. According to the above concept, the preparation method further comprises after step (b): (bl) mixing the solution to complete the reaction; (b2) washing the precipitate with excess deionized water; and drying) The precipitate. According to the above concept, in the step (6), the precipitate is heat-treated in an oxygen-free environment. According to the above concept, in the step (c), the precipitate is heat-treated at a temperature ranging from 350 oc to 600 〇c. According to the above concept, wherein the hybrid agent is selected from the group consisting of: polyvinylidene fluoride resin (PVdF), polystyrene butadiene rubber touch (tetra), and one of acrylic resin (Acrylic resin). According to the above concept, its towel is one of the waters. In the present invention, the following drawings and detailed descriptions can be used to further the reader-understand: [Embodiment] The detailed preparation steps of the electrode coating of the present invention and the electrochemical electrode including the electrode coating layer will be described in detail below, and The results of the paste analysis are indicated in the figure, and the advantages of the Japanese electrochemical electrode and the electrochemical element 1284997 are further advanced. [Please refer to the figure-method flow chart for explaining the main steps of the method for preparing the m layer of the present invention. First, a solution system containing Fe3+ ions and M2+ ions is prepared, as shown in step u, wherein the concentration ratio of the Fe3+ ions to the M2+ ions is 2:1. Next, the solution is added to an assay solution, as shown in step 12, at which point a precipitate forms in the solution. The solution is continuously mixed to complete the reaction and the precipitate is washed with excess deionized water, as shown in steps 13 and 14; after the precipitate is dried, the precipitate is heat treated in an anaerobic environment. To form - iron oxide powder, respectively, step 15 and step 16. Finally, an adhesive and a solvent (as shown in step 17) are added to the iron oxide body to form a slurry of the electrode coating, which can be further coated on the button to form an electrochemical f. Extreme, as shown in step 18. The following will be the details of the rhyme carving and analysis results of the actual invention: _ [Example 1] 0.024 mol Feci3 · 6H2〇 and 〇·〇ΐ2 Moer MC12, where _ M is Fe, Co, Ni or Cu, or 〇·〇ΐ2 Moer MnS04 · H20 is dissolved in 20 liters of 1MHC1 deoxygenated water solution, at which time the concentration ratio of solution Fe3+ to another metal (Co, Ni, Cu or Μη) is 2 :1. This acidic salt solution was then added dropwise to 2 mL of a 15 M NaOH solution, followed by a brown-black precipitate and stirring was continued for 30 minutes to complete the precipitation reaction. After washing the brown-black precipitate with excess deionized water to remove excess ions, the precipitate was taken out and dried at 5 ° C air towel, except for 10 1284997

Fe3〇4 is already a crystalline phase, and the rest is a non-crystalline phase of 〇4 powder; 600 in a nitrogen atmosphere. (: The precipitate was heat-treated for 2 hours to crystallize it. From the X-ray diffraction pattern of each of the crystal powders of the second figure, it was confirmed that the diffraction peak derived from the synthesized powder belongs to the structure of spinel. The above-mentioned powder is first added to the conductive carbon black in a weight percentage and then an appropriate amount of adhesive and solvent are added, wherein the adhesive is polyvinylidene fluoride resin (PVdF) and the solvent is n-decylpyrrolidone (NMP). That is, an electrode coating slurry is formed; the slurry is uniformly coated on a titanium substrate to complete the fabrication of the electrochemical electrode. Finally, the electrode is dried in a vacuum at 12 ° C for 6 hours to remove the solvent. This experiment uses cyclic voltammetry (CV) to perform electrochemical analysis of the electrode. This analysis uses a three-electrode system to measure in 1M NaCl electrolyte; in the W-Tai system, the working electrode, auxiliary electrode and The reference electrodes are MnFhO4 electrode, platinum mesh and Ag/Agci/saturated KC1 solution (the potential is relative to the standard hydrogen electrode (U97V). The capacitance C of the electrode material can be evaluated by the following formula (1): C = Γi/s dV/ Wh (1) where i is the current (early ampere)' s Potential sweep rate (in volts per second), w is weight (in grams), Vi and Vf are voltage ranges (in volts, Vi and Vf are 0.0V and 0.7V, respectively). (1) Calculating the capacitance of various Mpe2Q powders by counting the nose and deducting the black-skinned ones. Table (1) Comparing the capacitances of different MFe2〇4 electrodes in the 1Μ electrolyte. As shown in Table (1), the present invention The capacitance values of MFezO4 substituted by different transition metals are better than those of the conventional 11 • 1284997 high. Among them, MnFe2〇4 and CoFe2〇4 are the best. Table (1) Component phase capacitance ff/g) Fe304 1.2 MnFe2〇4 14.9 CoFe2〇4 7.1 NiFe204 2.0 CuFe204 3.0 In addition, in order to further increase the capacitance value of MFe204, the powder crystallization temperature and synthesis method are preferably selected in the following examples. [Example 2] 0.024 Moxi Feci3 · 6H20 and 0.012 Mo Er MnS04 · H20 were dissolved in 20 ml of iM HC1 aqueous solution at this time, the ratio of Fe3+ to Μη ion concentration in the solution was 2:1. Then 2.76 g of carbon black was ground. Add the aforementioned solution and continue to stir 3 0 minutes, so that the carbon black can be evenly dispersed in the solution • towel. Then add this solution dropwise to 200 ml of ΐ·5Μ NaOH aqueous solution, then produce a brown-black phlegm, and continue to stir for 3 以 minutes to make the precipitation reaction. - $全. (d) Excessive deionized water cleaning This brown-black wash removes excess excess money, removes the sinking material and dries it in air, and then heats it at 35G C for 2 hours in a nitrogen atmosphere. X-ray diffraction analysis revealed that the composite powder contained a crystalline phase of MnFe204. ^ The heat-treated MnFeA/carbon black composite powder is added and added to the appropriate amount, and the adhesive is pvdF, the solvent is NMp, and the loading sentence is uniformly distributed on the titanium substrate to complete Electrode and place this electrode at (10). c 12 1284997 Dry in vacuo for 6 hours to remove solvent. Similarly, using the cyclic voltammetry (CV) to carry out the electrochemical separation of the electrodes, the MnFe2〇4 electrode of the II 丨 Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na Na The analysis wire is not as shown in the third figure. This analysis still uses a three-electrode system. As can be seen from the third figure, this CV curve: almost has a _ rectangle except for the X-ray redox peak, and when the electrode is reversed, the current quickly reaches a reverse stable value, approaching a typical capacitor. Furthermore, the electrode turns almost the same at the different scanning rate, which shows that MnFe204 has good f-capacitance characteristics, reaction reversibility, and π-power transmission. According to the formula (1), after subtracting the capacitance of the carbon black component, the capacitance contributed by Μ_〇4 can be netted to 1〇2 F/g. [Comparative Example 1] The VInFe2〇4 powder of Example 2 was replaced with a heat treatment condition, and it was heat-treated at 200 ° C for 2 hours in a nitrogen atmosphere. The cyclic voltammetric analysis of the electrode prepared from the above powder was also carried out, and the cyclic voltammetry analysis result of the sweeping cat rate of 2 〇mV/s in an aqueous solution of 1 M NaCl was as shown in the fourth®. The analysis still uses a three-electrode wire system. Instead of exhibiting a typical capacitive behavior, it is a redox reaction. This phenomenon reveals that if the heat treatment temperature is too low, the formed non-spinel crystal form of MnFe2〇4 does not have the potential as an ultrahigh capacitor electrode material. [Example 3]

An ultrahigh capacitor was fabricated according to Example 2, wherein the electrolyte was changed to a 1 M 13 • 1284997 KC1 aqueous solution. According to the analysis, its capacitance is 94 F/g. [Example 4] The MnFe2?4 electrode was prepared in the same manner as in Example 2, and the two-electrode system was used for cyclic voltalysis. In this analysis, the electrodes with the same composition are placed in the channel NaCl electrolyte. The fifth figure shows the results of the cycle of the four electrodes in the m system! (four) lion rate is the v / s cycle (four) test results. Since the two-pole system can be regarded as a series connection of two capacitors, its equivalent capacitance is expressed as follows:

(2) (3)

1/Ce = 1/C + 1/0 2/C C = 2Ce The capacitance of the early electrode is the actual measured value _ times, and the contribution capacity of the application _4 is calculated according to the formulas (1) and (3). When the potential sweeping cat rate is increased to 2GGmV/S, the capacitance value drops to about 78F/g, which is estimated.

The charge and discharge power of MnFe204 is about! 5 k §. This output power is more than 1〇 of the conventional Fe304 electrode.

The sixth figure is that the electrodes are in the 1M NaC1 aqueous solution with a fixed W mAW current.

The charge-discharge curve in the wide voltage range is close to a straight line and shows a potential drop, which is a typical capacitor. ^, page 1R [Example 5] An electrochemical capacitor was produced according to Example 2, in which an aqueous solution of 1 _4 was used. After analysis, the stolen amount was 63F/g-MnFe204. #盗之令 [Example 6] 1284997 0.024 Mo Er FeCl3,6H20 and 0.012 MoC CoCl2 · 6H20 were sequentially dissolved in 20 ml of iM HC1 aqueous solution, at this time j?e3+ and Co2+ ions in the solution The concentration ratio was 2:1; then 2.815 g of carbon black was ground and added to the above solution and stirring was continued for 30 minutes to allow the carbon black to be uniformly dispersed in the solution. This solution was then added dropwise to 200 ml of an aqueous solution of i.5 M NaOH, followed by a brown-black precipitate, which was stirred continuously for 30 minutes to allow the precipitation to proceed completely. After washing the brown-black precipitate with excess deionized water to remove excess ions, the precipitate was taken out and dried in 5 (TC air, and then heat treated at 400 ° C for 2 hours in a nitrogen atmosphere. Next, proceed according to Example 2. The electrode was prepared and the electrode was still electrochemically tested (ie, cyclic voltammetry) using a two-pole system. After analysis and calculations of equations (1) and (3), it is known that the contribution capacity of c〇Fe204 is 45F/ g. [Example 8] 0.0216 moles of FeCb · 6 Å and 0.0144 moles of MnS04 · H20 were sequentially dissolved in 20 ml of 1 M HCl aqueous solution, and the ratio of ion concentration in the solution to Mn 2+ was m2. The gram of carbon black was ground and added to the above solution and stirring was continued for 30 minutes to uniformly disperse the carbon black in the solution, and then the solution was added dropwise to 2 (8) ml of 1.5 M NaOH aqueous solution previously heated to 8 〇〇c. A brown-black precipitate was then produced and stirring was continued for 3 minutes to complete the precipitation reaction. After washing the brown-black precipitate with fresh water to remove excess ions, the precipitate was taken out and dried in air at 5 °c. At this time the powder It has the chemical composition of Mn^Feuh. The electrode is also fabricated according to the method disclosed in Example 2, and the cyclic voltammetry is performed using a two-pole system; the seven-figure diagram is the use of the three-pole system 1284997 in 1M NaC1. The cyclic voltammogram of the electrode was tested in an aqueous solution, and after eight analysis, the capacitance of the electrode material prepared in this example was 4 〇F/g.

The various kinds of powders produced by Na Na have spinel... The gj state of each Jinlinzi has high mutual solubility, so it can be different from the metal ions, M, M, =Mn, Co, Ni. 'CiiH^ = the same ratio is combined to form _, WFe2.x〇4, where _〇.2汹).2; when the χ falls within the range of -0.2 to 0.2, the capacitance value of the prepared electrode material^ If the value is outside the range, the capacitance value will decrease rapidly. The invention provides a series of cheaper new _ high electric dance electric material return materials, and she is known in the art of ferroferric oxide (Fe3〇4) 'provided by the present invention More crystalline charge and discharge power. ^, ', No &amp; The above description, the present invention is a novel, progressive and industrially practical invention, which has profound development value. The invention may be modified by a person skilled in the art, without departing from the scope of the application. [Simple description of the map]

The first figure is a method flow chart for explaining the main steps of the electrode coating method of the present invention; I The second figure is an X-ray diffraction pattern, which confirms that the diffraction peak of the powder prepared by the present invention belongs to The structure of the spinel, the Si (l 11) peak in the map is derived from the added internal standard material. The second figure is a cyclic voltammetric analysis result of a three-electrode system of MnFe2〇4 electrode prepared according to the preferred embodiment of the present invention, wherein the heat of MnFe204 is 1284997 and the temperature is 35〇°c; The result of cyclic voltammetry analysis of the MnFe204 electrode prepared in the comparative example of the present invention, wherein the heat treatment temperature of MnFe204 is 200 〇C; the fifth figure is a MnFe2〇4 electrode prepared according to the preferred embodiment of the present invention. The result of the cyclic voltammetry analysis of the electrode system, wherein the potential scanning rate is 20 mV/s; the sixth figure is the result of the two-electrode system of the MnFe2〇4 electrode prepared according to the preferred embodiment of the present invention, The battery is charged and discharged with a constant current of Q 5 mA/cm 2 current density; and the seventh diagram is a three-electrode system cyclic voltammetric analysis of the MnuFe^O 4 electrode prepared according to another preferred embodiment of the present invention. . [Main component symbol description] 11~18 steps

17

Claims (1)

1284997 X. Patent application scope: L-type f chemical electrode, comprising: a substrate; an electrode coating coated on the substrate, the electrode coating layer containing an iron oxide, The chemical composition is M1+xFe2_x04, where -2 2 &lt; · : X$0·2, and Μ is a non-ferrous (Fe) transition metal element. 2. The electrochemical electrode of claim 1, wherein the substrate is a metal sheet. 3. The electrochemical electrode of claim 1, wherein the iron oxide has a spinel structure. 4. The electrochemical electrode according to claim 1, wherein the lanthanide is one selected from the group consisting of Mn, @(Cu), _, copper (Cu), and combinations thereof. 5. An electrochemical element 'which comprises an electrochemical electrode as described in pp. • 6. The electrochemical component of claim 5, which is an electrochemical energy storage component. 7. The invention relates to the electrochemical element of the fifth item, and further comprises an electrolyte, the electrolyte system - the metal inorganic salt and the metal organic salt, wherein - 8. The electrochemical method of claim 7 An element, wherein the metal inorganic salt and the metal organic impurity further comprise - a metal element; and 2 one of the earth metal elements. 9. The electrochemical component of claim 8, wherein the gold-based element of the gold-receiving group comprises lithium (Li), sodium (Na), potassium (K), antimony (Rb), planer (Cs), and Its combination. 10. The electrochemical component of claim 8, wherein the alkaline earth metal element comprises beryllium (Be), town (Mg), calcium (Ca), sor (Sr), barium (Ba), and combinations thereof. U. The electrochemical component of claim 7, wherein the metal inorganic salt further comprises a chloride, a sulfur oxide, a sulfurous oxide, a nitrate, and combinations thereof. U. The electrochemical component of claim 7, wherein the metal organic salt further comprises hexafluorophosphorus oxide, tetrafluoroborate, over-gas oxide, m-methyl sulfide emulsion, and combinations thereof. . 13. A method for preparing an electrode coating comprising the following steps: (8) preparing a solution containing Fe3+ ions and m2+ ions, and a concentration ratio of Fe3+ ions to M2+ ions is 2:1; (b) The solution is added to an alkaline solution to form a precipitate; (c) heat treating the precipitate to form an iron oxide powder; (d) adding an adhesive and a solvent to the iron oxide body to form a mixed polymer; and (e) applying the mixed slurry to a metal sheet substrate. 14. The preparation method of claim 13, wherein one of the group consisting of manganese (Mn), cobalt (Cu), nickel (Ni), steel (Cu), and combinations thereof is selected. The preparation method of claim 13 wherein the test solution further comprises a porous conductive material. 1284997. The preparation method of claim 15, wherein the porous conductive material is selected from the group consisting of carbon black, a metal oxide, and a combination thereof. It comprises in step (b): &amp; (bl) continuously stirring the solution to complete the reaction; (b2) washing the precipitate with excess deionized water; and (b3) drying the precipitate. 18. The preparation method of claim 13, wherein in the step, the precipitate is heat treated in an oxygen-free environment. 19. The preparation method of claim 13, wherein in step (e), the precipitate is heat-treated at a temperature ranging from 350 ° C to 600 ° C. 20. The preparation method of claim 13, wherein the adhesive is selected from the group consisting of a polyvinylidene fluoride resin (PVdF), a polystyrene butadiene rubber (Styrene-Butadiene-Rubber), and an acryl. One of the resins (Acrylic resin). 21. The preparation method of claim 13, wherein the solvent is one of the following: one of the N and the water. 20