Pole piece mixed material of supercapacitor, pole piece, preparation method of pole piece and supercapacitor

Abstract

The invention discloses a pole piece mixed material of a supercapacitor, a pole piece, a preparation method of the pole piece and the supercapacitor. The invention discloses a pole piece mixed material of a super capacitor. The pole piece mixed material comprises a wet-method mixed material or a dry-method mixed material, both the wet-process mixed material and the dry-process mixed material contain a deacidification agent; wherein the wet-process mixed material comprises powder active carbon, a conductive agent, a dispersing agent, a binding agent and a deacidification agent; wherein the dry-method mixed material comprises powder active carbon, a conductive agent, a binder and a deacidification agent. The pole piece mixed material of the super capacitor adopts a new mixed material formula, contains a substance for removing HF generated by side reaction, and reduces or eliminates corrosion of HF to a pole piece aluminum foil, so that the bonding force between pole piece pole powder and the pole piece aluminum foil is ensured, and the service life of the pole piece is prolonged. And the problem that the performance of the supercapacitor device is severely reduced due to sharp increase of the internal resistance of the capacitor and decline of the capacity in a cliff mode caused by falling of the pole piece and the pole powder is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of supercapacitors, and in particular to a supercapacitor pole piece mixed material, a pole piece and a preparation method thereof, and a supercapacitor. Background Art

[0002] Supercapacitor is a new type of energy storage product with the advantages of ultra-long life, wide operating temperature range, green and pollution-free, maintenance-free, and high power density. It is widely used in military electronics, wind power variable pitch, automobile start-stop, energy storage and frequency modulation and other fields.

[0003] The service life of supercapacitors is up to 10 years. The internal resistance increases slowly during the use of the product. However, in the later stage of use, the internal resistance will rise sharply and the capacity will drop precipitously, causing the performance of the device to seriously decline. The working principle of supercapacitors is: the adsorption and desorption of the double layer is a physical process. When charging, the anions in the electrolyte move to the positive electrode and the cations move to the negative electrode, forming adsorption double layers respectively; when discharging, the anions desorb from the positive electrode and the cations desorb from the negative electrode.

[0004] Since the materials and electrolyte used in supercapacitors inevitably contain water, side reactions will occur during long-term use. The anion BF- in the electrolyte will react with water to generate HF. The reaction formula is as follows:

[0005]

[0006] HF penetrates into the interface between the electrode powder and the aluminum foil of the electrode, causing the electrode powder to fall off the aluminum foil of the electrode, the internal resistance of the supercapacitor to rise sharply, the capacity of the supercapacitor to drop drastically, and the device performance to be seriously reduced.

[0007] There are currently the following technical difficulties:

[0008] 1. The activated carbon used in supercapacitors contains abundant micropores, mesopores, and macropores, and the moisture contained in the micropores cannot be completely removed;

[0009] 2. The water content in the electrolyte has reached the ppm level (parts per million), which has entered a bottleneck stage and cannot be significantly improved in a short period of time;

[0010] 3. The diaphragm and other materials and the injection environment also inevitably contain moisture.

[0011] Therefore, there is an urgent need to develop a technology that can remove the HF substance produced by the side reaction, ensure the adhesion between the electrode powder and the electrode aluminum foil, improve the problem of the sharp increase in internal resistance, and extend the device life of the supercapacitor. Summary of the invention

[0012] The purpose of the present invention is to provide a supercapacitor electrode mixed material, an electrode and a preparation method thereof, and a supercapacitor in view of the technical defects existing in the prior art.

[0013] To this end, the present invention provides a supercapacitor electrode mixed material, including wet mixing or dry mixing;

[0014] Both wet and dry mixes contain acid scavengers;

[0015] Among them, the wet mixing includes: powdered activated carbon, conductive agent, dispersant, binder and acid scavenger;

[0016] Among them, the dry mixing includes: powdered activated carbon, conductive agent, binder and acid scavenger;

[0017] The acid scavenger comprises at least one of an oxide, a hydroxide, a metal and CO3 combination, and an organic additive capable of reacting with HF.

[0018] In addition, the present invention also provides a pole piece of a supercapacitor, comprising a pole piece current collector;

[0019] The pole piece mixed material of the supercapacitor as mentioned above is arranged on the pole piece current collector.

[0020] In addition, the present invention also provides a supercapacitor, which includes the pole piece of the supercapacitor as described above.

[0021] In addition, the present invention also provides a method for preparing a supercapacitor electrode as described above, which is used for preparing a wet electrode, and the method comprises the following steps:

[0022] The first step is homogenization: the powdered activated carbon, conductive agent, binder and acid scavenger are mixed according to the preset mass ratio, stirred evenly, and then dissolved in the dispersant for dispersion. The viscosity of the electrode slurry is adjusted to 1500-5000cp by adjusting the amount of dispersant added;

[0023] The second step is coating: the slurry is evenly coated on the current collector, and fully dried in an oven to remove the dispersion in the pole piece, and obtain a pole piece with a pole piece membrane on the surface;

[0024] The third step is rolling: rolling the dried electrode with the electrode membrane on the surface until the compaction density of the electrode membrane meets the preset compaction density value range;

[0025] The fourth step is cutting: cutting the rolled electrode into the specified size to obtain the finished electrode.

[0026] In addition, the present invention also provides a method for preparing a supercapacitor electrode as described above, which is used for preparing a dry electrode, and the method comprises the following steps:

[0027] Step S1, powder mixing: powdered activated carbon, conductive agent, binder and acid scavenger are mixed according to a preset mass ratio and stirred evenly;

[0028] Step S2, blowing: the binder is stirred at a speed greater than 40 m / s to form a spider web structure to fix the activated carbon, the conductive agent and the acid scavenger together;

[0029] Step S3, film pressing: the semi-finished product of the second step is rolled to a density of ≥ 0.6 g / cm 3 The pole piece diaphragm;

[0030] Step S4, lamination: laminating the electrode film and the current collector together at a temperature range of 100-150° C. and a pressure of 5-10t to obtain a supercapacitor dry electrode.

[0031] It can be seen from the technical solution provided by the present invention that, compared with the prior art, the present invention provides a supercapacitor electrode mixed material, an electrode and a preparation method and a supercapacitor, which are scientifically designed. The supercapacitor electrode mixed material of the present invention adopts a new mixed material formula, which contains a substance for removing HF generated by side reactions, reducing or eliminating HF corrosion of the electrode aluminum foil (the collectors of the positive and negative electrodes of the supercapacitor are both aluminum foil), thereby ensuring the bonding force between the electrode powder and the electrode aluminum foil, avoiding the sharp increase in capacitor internal resistance and the cliff-like drop in capacity due to the falling of the electrode powder, and then causing the supercapacitor device performance to seriously decline. The problem has great practical significance.

[0032] By applying the present invention, the problem of a sharp increase in internal resistance and a serious decrease in performance of a supercapacitor during use can be solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A method for preparing a supercapacitor electrode provided by the present invention, and a flow chart of wet electrode preparation;

[0034] Figure 2 A method for preparing a supercapacitor electrode provided by the present invention, and a flow chart of preparing the electrode by a dry process;

[0035] Figure 3 The diagram is a schematic diagram of the capacity decay curve obtained by performing a high temperature floating charge test on the supercapacitors of the embodiments of the present invention and the comparative examples at 65°C and 3.0V;

[0036] Figure 4This is a schematic diagram of the internal resistance change curve obtained by performing a high-temperature float charge test on the supercapacitors of the embodiments of the present invention and the comparative example at 65°C and 3.0V. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0039] In order to enable those skilled in the art to better understand the scheme of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and implementation modes.

[0040] The present invention provides a mixed material of a supercapacitor electrode (which may be a positive electrode and / or a negative electrode), including a wet mixing method or a dry mixing method;

[0041] Both wet and dry mixes contain acid scavengers;

[0042] Among them, the wet mixing includes: powdered activated carbon, conductive agent, dispersant, binder and acid scavenger;

[0043] Among them, the dry mixing includes: powdered activated carbon, conductive agent, binder and acid scavenger.

[0044] It should be noted that, in the present invention, the mixed material of the electrode of the supercapacitor contains an acid scavenger, and can be a wet mixture or a dry mixture.

[0045] In the present invention, in a specific implementation, the acid scavenger can react with HF, and the acid scavenger can include: at least one of an oxide, a hydroxide, a metal and CO3 composition, and an organic additive that can react with HF.

[0046] In specific implementation, the acid scavenger is: an oxide capable of reacting with HF, the oxide is preferably SiO2 and / or Al2O3; further preferably: powdered SiO2 or nano-SiO2 dispersion; more preferably nano-SiO2 dispersion.

[0047] In specific implementation, the acid scavenger is: a hydroxide capable of reacting with HF, the hydroxide is preferably Ca(OH)2, CaCO3, Al(OH)3 and / or Mg(OH)2;

[0048] In specific implementation, the acid scavenger is: a metal and CO3 composition capable of reacting with HF;

[0049] The metal and CO3 composition is preferably CaCO3 and MgCO3;

[0050] In the composition, CaCO3 and MgCO3 can be in any composition ratio, as long as the sum of their mass percentages is 100%.

[0051] In specific implementation, the acid scavenger is: an organic additive that can react with HF;

[0052] In a specific implementation, the organic additive is preferably CH3SiONa.

[0053] In the present invention, in a specific implementation, for wet mixing, the conductive agent is: carbon black SP;

[0054] The dispersant is deionized water;

[0055] The binder is styrene butadiene rubber SBR.

[0056] In the present invention, in a specific implementation, for wet mixing, the mass ratio of powdered activated carbon, conductive agent, binder and acid scavenger is: (86%-95%): (3%-8%): (1%-7%): (0.1%~2%).

[0057] In specific implementation, for wet mixing, the mass ratio of powdered activated carbon, conductive agent, binder and acid scavenger is preferably 89.8:5:5:0.2.

[0058] In the present invention, in a specific implementation, for dry mixing, the conductive agent is: carbon black SP;

[0059] The binder is polytetrafluoroethylene (PTFE).

[0060] In the present invention, in a specific implementation, for dry mixing, the mass ratio of powdered activated carbon, conductive agent, binder and acid scavenger is: (86%-95%): (3%-8%): (1%-7%): (0.1%~2%).

[0061] In specific implementation, for dry mixing, the mass ratio of powdered activated carbon, conductive agent, binder and acid scavenger is preferably 89.8:5:5:0.2.

[0062] Based on the above-mentioned supercapacitor electrode mixed material provided by the present invention, the present invention also provides a supercapacitor electrode, which includes an electrode current collector (i.e., foil material, specifically aluminum foil; the current collectors of the positive electrode and the negative electrode of the supercapacitor are both aluminum foil);

[0063] The pole piece mixed material of the supercapacitor as mentioned above is arranged on the pole piece current collector.

[0064] In the present invention, in a specific implementation, the pole piece of the supercapacitor includes a wet pole piece and a dry pole piece;

[0065] A wet-process electrode, comprising the wet-process mixture in the electrode mixture material of the supercapacitor as described above;

[0066] The dry electrode comprises the dry mixture in the electrode mixed material of the supercapacitor as mentioned above.

[0067] Based on the above-mentioned electrode piece of a supercapacitor provided by the present invention, the present invention further provides a supercapacitor, which includes the electrode piece of the supercapacitor as mentioned above.

[0068] It should be noted that, for the present invention, the electrode mixed material of the supercapacitor adopts a new mixing formula, which contains an acid scavenger. The supercapacitor containing the mixture of the present invention can react with the HF produced by the side reaction during the use of the supercapacitor during the use of the supercapacitor, thereby reducing or eliminating the corrosion of the aluminum foil by HF and reducing or eliminating the falling of the electrode powder from the aluminum foil, thereby avoiding the problem of a sharp increase in the internal resistance of the capacitor and a cliff-like drop in capacity due to the falling of the electrode powder, thereby causing a serious decline in device performance.

[0069] The relevant reaction process that occurs is shown below as an example:

[0070] SiO2+4HF=CH4+SiF4;

[0071] Ca(OH)2+2HF=CaF2+2H2O;

[0072] Mg(OH)2+2HF=MgF2+2H2O;

[0073] In the present invention, in a specific implementation, the electrode of the supercapacitor includes a positive electrode and / or a negative electrode, which can be a positive electrode or a negative electrode.

[0074] In order to prepare the electrode of the supercapacitor provided by the present invention, see Figure 1 As shown, the present invention also provides a method for preparing a supercapacitor electrode, which is used for preparing a wet electrode, comprising the following steps:

[0075] The first step is homogenization: mix the powdered activated carbon, conductive agent, binder and acid scavenger according to the preset mass ratio, stir evenly, and then dissolve them in a dispersant (such as deionized water) for dispersion. By adjusting the amount of added dispersant, the viscosity of the electrode slurry is adjusted to 1500-5000cp.

[0076] The second step is coating: the slurry is evenly coated on the electrode current collector (such as aluminum foil), and is fully dried in an oven to remove the dispersant (such as deionized water) in the electrode to obtain an electrode with an electrode membrane on the surface;

[0077] The third step is rolling: rolling the dried electrode with the electrode membrane on the surface (by using a rolling machine for rolling) until the compaction density of the electrode membrane meets the preset compaction density value range;

[0078] The fourth step is cutting: cutting the rolled electrode into the specified size (i.e. the required preset size) to finally obtain the finished electrode.

[0079] In the present invention, in a specific implementation, the acid scavenger can react with HF, and the acid scavenger can be an oxide, a hydroxide, a metal and CO3 combination or an organic additive;

[0080] In the first step, in specific implementation, the acid scavenger is: an oxide that can react with HF, the oxide is preferably SiO2 and / or Al2O3; further preferably: powdered SiO2 or nano-SiO2 dispersion; more preferably nano-SiO2 dispersion.

[0081] In the first step, in a specific implementation, the acid scavenger is: a hydroxide that can react with HF, and the hydroxide is preferably Ca(OH)2, CaCO3, Al(OH)3 and / or Mg(OH)2;

[0082] In the first step, in a specific implementation, the acid scavenger is: a combination of a metal that can react with HF and CO3;

[0083] The metal and CO3 composition is preferably CaCO3 and MgCO3;

[0084] In the composition, CaCO3 and MgCO3 can be in any composition ratio, as long as the sum of their mass percentages is 100%.

[0085] In the first step, in specific implementation, the acid scavenger is: an organic additive that can react with HF;

[0086] In a specific implementation, the organic additive is preferably CH3SiONa.

[0087] In the first step, in specific implementation, when preparing the wet electrode, the conductive agent is: carbon black SP;

[0088] The dispersant is deionized water;

[0089] The binder is styrene butadiene rubber SBR.

[0090] In the first step, in specific implementation, for wet mixing, the mass ratio of powdered activated carbon, conductive agent, binder and acid scavenger is: (86%-95%): (3%-8%): (1%-7%): (0.1%~2%).

[0091] In the first step, in specific implementation, when preparing the wet-process electrode, the mass ratio of powdered activated carbon, conductive agent, binder and acid scavenger is preferably 89.8:5:5:0.2.

[0092] In the third step, in specific implementation, the preset compaction density PD value range of the pole piece diaphragm is preferably 0.5g / cm 3 ~0.7g / cm 3 .

[0093] In order to prepare the electrode of the supercapacitor provided by the present invention, see Figure 2 As shown, the present invention also provides a method for preparing a supercapacitor electrode, which is used for preparing a dry electrode, comprising the following steps:

[0094] Step S1, powder mixing: powdered activated carbon, conductive agent, binder and acid scavenger are mixed according to a preset mass ratio and stirred evenly;

[0095] Step S2, blowing: the binder is stirred at a speed greater than 40 m / s to form a spider web structure to fix the activated carbon, the conductive agent and the acid scavenger together;

[0096] Step S3, film pressing: the semi-finished product of the second step is rolled to a density of ≥ 0.6 g / cm 3 The pole piece diaphragm;

[0097] Step S4, lamination: Laminating the electrode film and the current collector at a temperature range of 100-150°C and 5-10t

[0098] (t is tons) pressure, they are laminated together to obtain a supercapacitor dry electrode.

[0099] It should be noted that the powder mixing, wire blowing, film pressing and lamination processes are conventional preparation processes for existing dry-process electrodes, which are mature and well-known technical means in the prior art and will not be described in detail here.

[0100] In step S1, in specific implementation, an acid scavenger may react with HF, and the acid scavenger may include at least one of an oxide, a hydroxide, a metal and CO3 combination, and an organic additive;

[0101] In step S1, in specific implementation, the acid scavenger is: an oxide that can react with HF, the oxide is preferably SiO2 and / or Al2O3; further preferably: powdered SiO2 or nano-SiO2 dispersion; more preferably nano-SiO2 dispersion.

[0102] In step S1, in specific implementation, the acid scavenger is: a hydroxide that can react with HF, and the hydroxide is preferably Ca(OH)2, CaCO3, Al(OH)3 and / or Mg(OH)2;

[0103] In step S1, in specific implementation, the acid scavenger is: a metal and CO3 composition that can react with HF;

[0104] The metal and CO3 composition is preferably CaCO3 and MgCO3;

[0105] In the composition, CaCO3 and MgCO3 can be in any composition ratio, as long as the sum of their mass percentages is 100%.

[0106] In step S1, in specific implementation, the acid scavenger is: an organic additive that can react with HF;

[0107] In a specific implementation, the organic additive is preferably CH3SiONa.

[0108] In step S1, in specific implementation, when preparing the dry electrode, the conductive agent is: carbon black SP;

[0109] The binder is polytetrafluoroethylene (PTFE).

[0110] In step S1, in a specific implementation, when preparing the dry electrode, the mass ratio of powdered activated carbon, conductive agent, binder and acid scavenger is: (86%-95%): (3%-8%): (1%-7%): (0.1%~2%).

[0111] In step S1, in a specific implementation, when preparing the dry electrode, the mass ratio of the powdered activated carbon, the conductive agent, the binder and the acid scavenger is preferably 89.8:5:5:0.2.

[0112] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0113] Unless otherwise specified, the reagents used in the embodiments of the present invention can be directly purchased from the market.

[0114] The test methods involved in the following embodiments refer to the standard GB / T34870.1-2017 "Chinese Standard Name: Supercapacitors Part 1: General Principles".

[0115] Preparation Example 1

[0116] In this preparation example, no acid scavenger was added;

[0117] Add an appropriate amount of deionized water to the activated carbon YP, conductive agent SP, and binder SBR in a mass ratio of 90:5:5, and fully stir and mix in a double planetary mixer for 4 hours to adjust the slurry to a viscosity of 1500-5000cp for the preparation of wet-process electrodes.

[0118] Preparation Example 2

[0119] In this preparation example, no acid scavenger was added;

[0120] The activated carbon YP, conductive agent SP, and binder PtFE were mixed evenly in a mass ratio of 90:5:5, and stirred at a high speed of 40m / s to make the PTFE blown into a spider web structure. After film pressing, the density was ≥0.6g / cm 3 The electrode film is laminated with the current collector at a temperature of 120°C and a pressure of 8t to obtain a dry electrode.

[0121] Preparation Example 3

[0122] In this preparation example, an acid scavenger has been added;

[0123] Add appropriate amount of deionized water to activated carbon YP, conductive agent SP, binder SBR and acid scavenger SiO2 in a mass ratio of 89.8:5:5:0.2, and stir well in a double planetary mixer for 4 hours to obtain a slurry with a viscosity of 1500-5000cp for the preparation of wet-process electrodes.

[0124] Preparation Example 4

[0125] In this preparation example, an acid scavenger has been added;

[0126] Add appropriate amount of deionized water to activated carbon YP, conductive agent SP, binder SBR and acid scavenger Mg(OH)2 in a mass ratio of 89.8:5:5:0.2, and stir well in a double planetary mixer for 4 hours to obtain a slurry with a viscosity of 1500-5000cp for the preparation of wet-process electrodes.

[0127] Preparation Example 5

[0128] In this preparation example, an acid scavenger has been added;

[0129] Activated carbon YP, conductive agent SP, binder PTFE, and acid scavenger SiO2 were mixed evenly in a mass ratio of 89.8:5:5:0.2, and stirred at a high speed of 40m / s to make the PTFE blown into a spider web structure. After film pressing, the density was ≥0.6g / cm 3 The electrode film is laminated with the current collector at a temperature of 120°C and a pressure of 8T to obtain a dry electrode.

[0130] Comparative Example 1

[0131] In this comparative example, no acid scavenger was added;

[0132] After mixing activated carbon YP, conductive agent SP, and binder SBR in a mass ratio of 90:5:5, adding an appropriate amount of deionized water, and fully stirring and mixing in a double planetary mixer for 4 hours to obtain a slurry with a viscosity of 1500-5000cp, the obtained slurry (i.e., the slurry obtained in Preparation Example 1) is coated on an aluminum foil to obtain a wet electrode;

[0133] Then, the finished supercapacitor is obtained after winding, assembly, drying and liquid injection. The capacitor is subjected to a high-temperature floating charge test at 65°C and 3.0V, and the test is repeated regularly to record the capacity and internal resistance attenuation.

[0134] Comparative Example 2

[0135] In this comparative example, no acid scavenger was added;

[0136] The activated carbon YP, the conductive agent SP, and the binder PTFE are mixed in a mass ratio of 90:5:5, blown, pressed, and laminated to obtain a dry electrode.

[0137] Then, the finished supercapacitor is obtained after winding, assembly, drying and liquid injection. The capacitor is subjected to a high-temperature floating charge test at 65°C and 3.0V, and the test is repeated regularly to record the capacity and internal resistance attenuation.

[0138] Example 1

[0139] Activated carbon YP, conductive agent SP, binder SBR, and acid scavenger SiO2 were mixed in a mass ratio of 89.8:5:5:0.2, and an appropriate amount of deionized water was added. The mixture was fully stirred in a double planetary mixer for 4 hours to obtain a slurry with a viscosity of 1500-5000cp. The obtained slurry (i.e., the slurry obtained in Preparation Example 3) was coated on aluminum foil.

[0140] Then, the wet electrode is obtained after further drying, and the finished supercapacitor is obtained after winding, assembly, drying and liquid injection. The capacitor is subjected to a high-temperature floating charge test at 65°C and 3.0V, and the test is repeated regularly to record the capacity and internal resistance attenuation.

[0141] Example 2

[0142] Activated carbon YP, conductive agent SP, binder SBR, and acid scavenger Mg(OH)2 were mixed in a mass ratio of 89.8:5:5:0.2, and an appropriate amount of deionized water was added. The mixture was fully stirred in a double planetary mixer for 4 hours to obtain a slurry with a viscosity of 1500-5000cp. The obtained slurry (i.e., the slurry obtained in Preparation Example 4) was coated on aluminum foil.

[0143] Then, the wet electrode is obtained after further drying, and the finished supercapacitor is obtained after winding, assembly, drying and liquid injection. The capacitor is subjected to a high-temperature floating charge test at 65°C and 3.0V, and the test is repeated regularly to record the capacity and internal resistance attenuation.

[0144] Example 3

[0145] Activated carbon YP, conductive agent SP, binder PTFE, and acid scavenger SiO2 are mixed in a mass ratio of 89.8:5:5:0.2, and then blown, pressed, and laminated to obtain a dry electrode.

[0146] Then, the finished supercapacitor is obtained after winding, assembly, drying and liquid injection. The capacitor is subjected to a high-temperature floating charge test at 65°C and 3.0V, and the test is repeated regularly to record the capacity and internal resistance attenuation.

[0147] The internal resistance changes of the supercapacitors obtained in the above Comparative Examples 1 to 2 and Examples 1 to 3 in the high temperature floating charge test under the condition of 65°C-3.0V are shown in Table 1.

[0148] The capacity attenuation of the supercapacitors obtained in the above comparative examples 1 to 2 and embodiments 1 to 3 under the condition of 65°C-3.0V in a high temperature floating charge test is shown in Table 2. Table 1:

[0149]

[0150] Table 2:

[0151]

[0152] Combining Table 1 and Table 2 above, we can draw Figure 2 The supercapacitors of the embodiment of the present invention and the comparative example are subjected to a high temperature floating charge test at 65°C and 3.0V, and the capacity decay curves are schematically shown; and Figure 3 The supercapacitors of the embodiment of the present invention and the comparative example are subjected to a high temperature floating charge test at 65° C. and 3.0 V to obtain a schematic diagram of the internal resistance variation curve.

[0153] from Figure 3It can be seen that with the extension of the test time, the capacity retention rates of the supercapacitor experiments of the five groups (i.e., Example 1, Example 2, Example 3, Comparative Example 1 and Comparative Example 2) gradually decreased. After 1000 hours, the capacity retention rates of Comparative Example 1 and Comparative Example 2 decreased sharply and quickly fell below 80% (qualified value). The capacity retention rates of Example 1, Example 2 and Example 3 remained stable, and at 1500 hours, they were still higher than 80%, meeting the national standard requirements.

[0154] from Figure 4 It can be seen that with the extension of the test time, the internal resistance change rate of the five groups (i.e., Example 1, Example 2, Example 3, Comparative Example 1 and Comparative Example 2) supercapacitor experiments gradually increases. After 1000h, the internal resistance change rate of the comparative example increases sharply to more than 200% (qualified value), and the internal resistance change rate of the embodiment remains stable, and after 1500h, it is still less than 200%, meeting the national standard requirements.

[0155] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A supercapacitor electrode mixed material, characterized in that: Including wet mixing, or dry mixing; Both wet and dry mixes contain acid scavengers; Among them, the wet mixing includes: powdered activated carbon, conductive agent, dispersant, binder and acid scavenger; Among them, the dry mixing includes: powdered activated carbon, conductive agent, binder and acid scavenger; The acid scavenger comprises at least one of an oxide, a hydroxide, a metal and CO3 combination, and an organic additive capable of reacting with HF.

2. The supercapacitor electrode mixed material according to claim 1, characterized in that: The oxide capable of reacting with HF is SiO2 and / or Al2O3; The hydroxide capable of reacting with HF is Ca(OH)2, CaCO3, Al(OH)3 and / or Mg(OH)2; The metal and CO3 combination capable of reacting with HF is CaCO3 and MgCO3; The organic additive is preferably CH3SiONa.

3. The supercapacitor electrode mixed material according to claim 1, characterized in that: For wet mixing, the conductive agents are: carbon black SP; The dispersant is deionized water; the binder is styrene-butadiene rubber SBR; For dry mixing, the conductive agent is carbon black SP; the binder is polytetrafluoroethylene PTFE.

4. The supercapacitor electrode mixed material according to claim 1, characterized in that: For wet mixing, the mass ratio of powdered activated carbon, conductive agent, binder and acid scavenger is: (86%-95%): (3%-8%): (1%-7%): (0.1%-2%); and / or, For dry mixing, the mass ratio of powdered activated carbon, conductive agent, binder and acid scavenger is: (86％-95％)：(3％-8％)：(1％-7％)：(0.1％～2％)。 5. The supercapacitor electrode mixed material according to claim 4, characterized in that: For wet mixing, the mass ratio of powdered activated carbon, conductive agent, binder and acid scavenger is 89.8:5:5:0.

2. For dry mixing, the mass ratio of powdered activated carbon, conductive agent, binder and acid scavenger is 89.8:5:5:0.

2.

6. A pole piece of a supercapacitor, characterized in that: Including a pole piece current collector; The pole piece mixed material of the supercapacitor according to any one of claims 1 to 5 is arranged on the pole piece current collector.

7. The pole piece of the supercapacitor according to claim 6, characterized in that: Including wet electrode and dry electrode; Wet-processed electrodes, including wet-processed mixed materials in mixed electrode materials for supercapacitors; Dry electrode, including dry mixture in the electrode mixture material of supercapacitor.

8. A supercapacitor, characterized in that: A pole piece of a supercapacitor comprising the method according to claim 6.

9. A method for preparing a supercapacitor electrode according to claim 6, characterized in that: Used for the preparation of wet electrode, this method The following steps are involved: The first step is homogenization: the powdered activated carbon, conductive agent, binder and acid scavenger are mixed according to the preset mass ratio, stirred evenly, and then dissolved in the dispersant for dispersion. The viscosity of the electrode slurry is adjusted to 1500-5000cp by adjusting the amount of dispersant added; The second step is coating: the slurry is evenly coated on the current collector, and fully dried in an oven to remove the dispersion in the pole piece, and obtain a pole piece with a pole piece membrane on the surface; The third step is rolling: rolling the dried electrode with the electrode membrane on the surface until the compaction density of the electrode membrane meets the preset compaction density value range; The fourth step is cutting: cutting the rolled electrode into the specified size to obtain the finished electrode.

10. A method for preparing a supercapacitor electrode as claimed in claim 6, characterized in that: For the preparation of dry-process electrode, the method comprises the following steps: Step S1, powder mixing: powdered activated carbon, conductive agent, binder and acid scavenger are mixed according to a preset mass ratio and stirred evenly; Step S2, blowing: the binder is stirred at a speed greater than 40 m / s to form a spider web structure to fix the activated carbon, the conductive agent and the acid scavenger together; Step S3, film pressing: the semi-finished product of the second step is rolled to a density of ≥ 0.6 g / cm 3 The pole piece diaphragm; Step S4, lamination: laminating the electrode film and the current collector together at a temperature range of 100-150° C. and a pressure of 5-10t to obtain a supercapacitor dry electrode.

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