CN104810164A - Method for preparing high-energy-density supercapacitor on basis of bioprotein-based nitrogen-doped porous carbon materials - Google Patents

Abstract

The invention provides a method for preparing a high-energy-density supercapacitor based on a biological protein-based nitrogen-doped porous carbon material. The biological protein-based nitrogen-doped porous carbon material is used as the supercapacitor electrode material of the two-electrode system, and different electrolytes are used to assemble a supercapacitor. A practical high-power, high-energy-density supercapacitor device, which has high specific capacitance, good charge-discharge efficiency, good cycle performance, low time constant, low equivalent series resistance, and high-rate charge-discharge capacitance The attenuation is not obvious. It has high rate specific capacitance in 7M KOH electrolyte (for example: the current density is 10A/g, and the specific capacitance of 100A/g reaches 255F/g, 178F/g respectively). Among ionic liquids, those with high power density (122.3W/kg) still have high energy density (102Wh/kg), and the capacity retention rate reaches 94.6% after 10,000 charge-discharge cycles.

Description

A preparation method of high energy density supercapacitor based on biological protein-based nitrogen-doped porous carbon material

technical field

The invention provides a method for preparing a high-energy-density supercapacitor based on a biological protein-based nitrogen-doped porous carbon material, which belongs to the field of electrochemistry.

Background technique

With the depletion of fossil resources and the increasing shortage of resources, human beings urgently need efficient, clean and sustainable energy, as well as related new technologies for energy conversion and storage. Therefore, various new energy technologies and renewable new energy technologies are very important. The common disadvantages of devices such as nickel-cadmium, nickel-metal hydride, lead-acid, and lithium-ion batteries currently on the market are low power density and long charging time. It is difficult to meet the application fields of high power density, so people expect the emergence of a new type of green energy storage device with high power density and high energy density.

Supercapacitor is a new type of energy storage device between rechargeable batteries and traditional capacitors. It has the characteristics of fast charging and discharging, long cycle life, high efficiency, and high safety. It is regarded as the most promising new green energy in this century. It well makes up for the shortcomings of batteries and fuel cells with low power and low energy storage density. , With the continuous application of electric vehicles, mobile communications, information technology, aerospace and defense technology, various countries have formulated supercapacitor development plans and listed them as national key strategic research objects. Especially with the emergence of pure electric vehicles, supercapacitors with high power and high energy density have shown their unprecedented application prospects.

Electrode material is the key factor determining the performance of electrochemical capacitors. At present, activated carbon (especially activated carbon with high specific surface area) is the most commonly used electrode material, but the utilization rate of specific surface area of commercial activated carbon is low. The pores are not conducive to the infiltration of the electrolyte and cannot absorb the charge, which is not conducive to the formation of the electric double layer and affects the energy density and power density of the capacitor. In addition, the capacity of physical adsorption alone is limited. Therefore, the following characteristics need to be considered when developing activated carbon materials with high specific surface area: ① reasonable control of the pore size distribution of carbon materials, ② appropriate doping atoms for carbon materials, Not only can the wettability of carbon materials be improved, but also the pseudocapacitance provided by nitrogen will add additional capacity.

Biological protein is not only rich in resources, but also a renewable resource. Biological protein-based nitrogen-doped porous carbon materials not only have high specific surface area, good surface wettability, high conductivity, adjustable pore size distribution, and controllable content of heteroatoms such as nitrogen, it is an ideal supercapacitor electrode material. Bioprotein-based nitrogen-doped porous carbon materials have the following advantages as high-energy-density supercapacitor electrode materials: 1. Bioprotein-based porous carbon has the advantages of environmental friendliness and regeneration; 2. Higher surface area (about 2500m ² /g ) provides abundant active sites, and the energy density of supercapacitors is high; 3. The hierarchical porous structure can be applied to various electrolyte systems, and the hierarchical structure provides fast channels for ions, and the charging and discharging rate basically has no attenuation; 4. Biological The protein-based nitrogen-doped porous carbon material is used as the electrode material, and the assembled supercapacitor has a small equivalent series resistance, a low time constant, and a high energy density (power density 122.3W/kg, Energy density 102Wh/kg), etc.

A method for preparing a high energy density supercapacitor based on a biological protein-based nitrogen-doped porous carbon material according to the present invention, the method comprises the following steps:

Step 1: Mix different biological protein-based nitrogen-doped porous carbon materials (active materials), conductive agents and binders in a ratio of 88:8:4, add distilled water and ethanol to make a slurry, and then roll the slurry The obtained sheet-shaped electrode material is placed on a current collector of a corresponding size, cold-pressed at 15 MPa for 45 seconds, and then dried at 140° C. to obtain an electrode sheet of a supercapacitor, wherein the electrode material is greater than 12 mg/cm ² .

Step 2: Put the two sides of the diaphragm into the electrode pole pieces, assemble into a "sandwich" structure with the diaphragm as the center, and conduct electrochemical performance tests in different electrolytes.

The invention described in the present invention provides a method for preparing a high energy density supercapacitor based on biological protein-based nitrogen-doped porous carbon material. The performance of supercapacitor devices was tested and characterized by AC impedance method (CHI660D electrochemical workstation), constant current charge and discharge method, and cyclic voltammetry. The assembled supercapacitor device has superior electrochemical performance, that is, it has high capacity, good charge and discharge efficiency and low equivalent series resistance. Therefore, bioprotein-based nitrogen-doped porous carbon is a good electrode material for supercapacitor devices.

Beneficial effect:

1. The present invention provides a method for preparing a high-energy-density supercapacitor based on biological protein-based nitrogen-doped porous carbon materials. The process is simple and easy to industrialize;

2. The present invention provides a supercapacitor device with good rate performance, for example: in an aqueous electrolyte, the current density 10A g ^-1 and 100A g ^-1 can reach 255F g ^-1 and 178F g ^-1 ;

3. The present invention provides a supercapacitor device with high energy density. For example, in the electrolyte of the ionic liquid system, the energy density is 102 Wh kg ^-1 when the power density is 122.3 W kg ^-1 .

Description of drawings

Fig. 1 is the cyclic voltammogram (ionic liquid electrolyte) of the supercapacitor device of the two-electrode system assembled with the bioprotein-based nitrogen-doped porous carbon electrode electrode material of the present invention.

Fig. 2 is the constant current charging and discharging diagrams of different rates (ionic liquid electrolyte) of the supercapacitor device of the two-electrode system assembled with the biological protein-based nitrogen-doped porous carbon electrode electrode material of the present invention.

Fig. 3 is the specific capacitance diagram (ionic liquid electrolyte) of the supercapacitor device of the two-electrode system assembled with the bioprotein-based nitrogen-doped porous carbon electrode electrode material of the present invention at different rates.

Fig. 4 is the AC impedance diagram (ionic liquid electrolyte) of the supercapacitor device of the two-electrode system assembled with the biological protein-based nitrogen-doped porous carbon electrode electrode material of the present invention.

Fig. 5 is a graph of different rate specific capacity (ionic liquid electrolyte) of the supercapacitor device of the two-electrode system assembled with the bioprotein-based nitrogen-doped porous carbon electrode electrode material of the present invention.

Fig. 6 is a cycle performance diagram (ionic liquid electrolyte) of a supercapacitor device of a two-electrode system assembled with a biological protein-based nitrogen-doped porous carbon electrode material according to the present invention.

The following examples will further illustrate the present invention, but do not limit the present invention thereby.

Detailed ways

Example 1

The supercapacitor device prepared by the prepared silk fibroin-based porous carbon with a specific surface area of 2490m ² /g and a nitrogen content of 4.7% was assembled into a two-electrode system and tested in the ionic liquid electrolyte EMIMBF ₄ .

Step 1: Mix silk fibroin-based nitrogen-doped porous carbon material (active material), conductive agent and binder in a ratio of 88:8:4, add distilled water and ethanol to make a slurry, and then roll the slurry The obtained sheet-shaped electrode material is placed on a current collector of a corresponding size, cold-pressed at 15 MPa for 45 seconds, and then dried at 140° C. to obtain an electrode sheet of a supercapacitor, wherein the electrode material is greater than 12 mg/cm ² .

Step 2: Put the two sides of the diaphragm into the electrode pole pieces, assemble into a "sandwich" structure with the diaphragm as the center, and perform electrochemical performance tests in the EMIMBF4 electrolyte.

Example 2

The supercapacitor device prepared by egg white protein-based porous carbon with a specific surface area of 2290m ² /g and a nitrogen content of 5.9% was assembled into a two-electrode system and tested in the ionic liquid electrolyte EMIMBF4.

Step 1: Mix egg white protein-based nitrogen-doped porous carbon material (active material), conductive agent and binder in a ratio of 88:8:4, add distilled water and ethanol to make a slurry, and then roll the slurry to obtain The sheet-shaped electrode material is placed on a current collector of a corresponding size, cold-pressed at 15 MPa for 45 seconds, and then dried at 140°C to obtain an electrode sheet for a supercapacitor, wherein the electrode material is greater than 12mg/cm2.

Step 2: Put the two sides of the diaphragm into the electrode pole pieces, assemble into a "sandwich" structure with the diaphragm as the center, and perform electrochemical performance tests in the EMIMBF4 electrolyte.

Example 3

A supercapacitor device prepared from soybean protein-based porous carbon with a specific surface area of 1995m ² /g and a nitrogen content of 5.9% was assembled into a two-electrode system and tested in the ionic liquid electrolyte EMIMBF4.

Step 1: Mix soybean protein-based nitrogen-doped porous carbon material (active material), conductive agent and binder in a ratio of 88:8:4, add distilled water and ethanol to make a slurry, and then roll the slurry to obtain The sheet-shaped electrode material is placed on a current collector of a corresponding size, cold-pressed at 15 MPa for 45 seconds, and then dried at 140°C to obtain an electrode sheet for a supercapacitor, wherein the electrode material is greater than 12mg/cm2.

Step 2: Put the two sides of the diaphragm into the electrode pole pieces, assemble into a "sandwich" structure with the diaphragm as the center, and perform electrochemical performance tests in the EMIMBF4 electrolyte.

Example 4

The prepared supercapacitor device with a specific surface area of 2490m ² /g and a nitrogen content of 4.7% silk fibroin-based porous carbon is assembled into a two-electrode system, and the ratio of BMIM BF ₄ /AN (acetonitrile) is 1:1 in the test.

Step 1: Mix silk fibroin-based nitrogen-doped porous carbon material (active material), conductive agent and binder in a ratio of 88:8:4, add distilled water and ethanol to make a slurry, and then roll the slurry The obtained sheet-shaped electrode material is placed on a current collector of a corresponding size, cold-pressed at 15 MPa for 45 seconds, and then dried at 140° C. to obtain an electrode sheet of a supercapacitor, wherein the electrode material is greater than 12 mg/cm ² .

Step 2: Put the two sides of the diaphragm into the electrode pole pieces, assemble into a "sandwich" structure with the diaphragm as the center, and perform electrochemical performance tests in the EMIMBF4 electrolyte.

Example 5

A supercapacitor device prepared from egg white protein-based porous carbon with a specific surface area of 2290m ² /g and a nitrogen content of 5.9% was assembled into a two-electrode system in BMIM BF ₄ /AN (acetonitrile) ratio of 1:1 carry out testing.

Step 1: Mix egg white protein-based nitrogen-doped porous carbon material (active material), conductive agent and binder in a ratio of 88:8:4, add distilled water and ethanol to make a slurry, and then roll the slurry to obtain The sheet-shaped electrode material is placed on a current collector of a corresponding size, cold-pressed at 15 MPa for 45 seconds, and then dried at 140°C to obtain an electrode sheet for a supercapacitor, wherein the electrode material is greater than 12mg/cm2.

Step 2: Put the two sides of the diaphragm into the electrode pole pieces, assemble into a "sandwich" structure with the diaphragm as the center, and perform electrochemical performance tests in the EMIMBF4 electrolyte.

Example 6

The prepared supercapacitor device with a specific surface area of 1995m ² /g and a nitrogen content of 5.9% soybean protein-based porous carbon was assembled into a two-electrode system in BMIM BF ₄ /AN (acetonitrile) ratio of 1:1 carry out testing.

Step 1: Mix soybean protein-based nitrogen-doped porous carbon material (active material), conductive agent and binder in a ratio of 88:8:4, add distilled water and ethanol to make a slurry, and then roll the slurry to obtain The sheet-shaped electrode material is placed on a current collector of a corresponding size, cold-pressed at 15 MPa for 45 seconds, and then dried at 140°C to obtain an electrode sheet for a supercapacitor, wherein the electrode material is greater than 12mg/cm2.

Step 2: Put the two sides of the diaphragm into the electrode pole pieces, assemble into a "sandwich" structure with the diaphragm as the center, and perform electrochemical performance tests in the EMIMBF4 electrolyte.

Example 7

The supercapacitor device prepared by the prepared silk fibroin-based porous carbon with a specific surface area of 2490m ² /g and a nitrogen content of 4.7% was assembled into a two-electrode system and tested in a 7M KOH electrolyte.

Step 1: Mix silk fibroin-based nitrogen-doped porous carbon material (active material), conductive agent and binder in a ratio of 88:8:4, add distilled water and ethanol to make a slurry, and then roll the slurry The obtained sheet-shaped electrode material is placed on a current collector of a corresponding size, cold-pressed at 15 MPa for 45 seconds, and then dried at 140° C. to obtain an electrode sheet of a supercapacitor, wherein the electrode material is greater than 12 mg/cm ² .

Step 2: Put the two sides of the diaphragm into the electrode pole pieces, assemble into a "sandwich" structure with the diaphragm as the center, and perform electrochemical performance tests in the EMIMBF4 electrolyte.

Example 8

A supercapacitor device prepared from egg white protein-based porous carbon with a specific surface area of 2290m ² /g and a nitrogen content of 5.9% was assembled into a two-electrode system and tested in a 7M KOH electrolyte.

Step 1: Mix egg white protein-based nitrogen-doped porous carbon material (active material), conductive agent and binder in a ratio of 88:8:4, add distilled water and ethanol to make a slurry, and then roll the slurry to obtain The sheet-shaped electrode material is placed on a current collector of a corresponding size, cold-pressed at 15 MPa for 45 seconds, and then dried at 140°C to obtain an electrode sheet for a supercapacitor, wherein the electrode material is greater than 12mg/cm2.

Step 2: Put the two sides of the diaphragm into the electrode pole pieces, assemble into a "sandwich" structure with the diaphragm as the center, and perform electrochemical performance tests in the EMIMBF4 electrolyte.

Example 9

A supercapacitor device prepared from soybean protein-based porous carbon with a specific surface area of 1995m ² /g and a nitrogen content of 5.9% was assembled into a two-electrode system and tested in a 7M KOH electrolyte.

Step 1: Mix soybean protein-based nitrogen-doped porous carbon material (active material), conductive agent and binder in a ratio of 88:8:4, add distilled water and ethanol to make a slurry, and then roll the slurry to obtain The sheet-shaped electrode material is placed on a current collector of a corresponding size, cold-pressed at 15 MPa for 45 seconds, and then dried at 140°C to obtain an electrode sheet for a supercapacitor, wherein the electrode material is greater than 12mg/cm2.

Step 2: Put the two sides of the diaphragm into the electrode pole pieces, assemble into a "sandwich" structure with the diaphragm as the center, and perform electrochemical performance tests in the EMIMBF4 electrolyte.

Example 10

The supercapacitor device prepared by silk fibroin-based porous carbon with a specific surface area of 2490m ² /g and a nitrogen content of 4.7% was assembled into a two-electrode system and tested in an electrolyte of 1M H ₂ SO ₄ .

Step 1: Mix silk fibroin-based nitrogen-doped porous carbon material (active material), conductive agent and binder in a ratio of 88:8:4, add distilled water and ethanol to make a slurry, and then roll the slurry The obtained sheet-shaped electrode material is placed on a current collector of a corresponding size, cold-pressed at 15 MPa for 45 seconds, and then dried at 140° C. to obtain an electrode sheet of a supercapacitor, wherein the electrode material is greater than 12 mg/cm ² .

Step 2: Put the two sides of the diaphragm into the electrode pole pieces, assemble into a "sandwich" structure with the diaphragm as the center, and perform electrochemical performance tests in the EMIMBF4 electrolyte.

Example 11

The supercapacitor device prepared by egg white protein-based porous carbon with a specific surface area of 2290m ² /g and a nitrogen content of 5.9% was assembled into a two-electrode system and tested in an electrolyte of 1M H ₂ SO ₄ .

Step 1: Mix egg white protein-based nitrogen-doped porous carbon material (active material), conductive agent and binder in a ratio of 88:8:4, add distilled water and ethanol to make a slurry, and then roll the slurry to obtain The sheet-shaped electrode material is placed on a current collector of a corresponding size, cold-pressed at 15 MPa for 45 seconds, and then dried at 140°C to obtain an electrode sheet for a supercapacitor, wherein the electrode material is greater than 12mg/cm2.

Step 2: Put the two sides of the diaphragm into the electrode pole pieces, assemble into a "sandwich" structure with the diaphragm as the center, and perform electrochemical performance tests in the EMIMBF4 electrolyte.

Example 12

A supercapacitor device prepared from soybean protein-based porous carbon with a specific surface area of 1995m ² /g and a nitrogen content of 5.9% was assembled into a two-electrode system and tested in an electrolyte of 1M H ₂ SO ₄ .

Step 1: Mix soybean protein-based nitrogen-doped porous carbon material (active material), conductive agent and binder in a ratio of 88:8:4, add distilled water and ethanol to make a slurry, and then roll the slurry to obtain The sheet-shaped electrode material is placed on a current collector of a corresponding size, cold-pressed at 15 MPa for 45 seconds, and then dried at 140°C to obtain an electrode sheet for a supercapacitor, wherein the electrode material is greater than 12 mg/cm ² .

Step 2: Put the two sides of the diaphragm into the electrode pole pieces, assemble into a "sandwich" structure with the diaphragm as the center, and perform electrochemical performance tests in the EMIMBF4 electrolyte.

Example 13

The supercapacitor device prepared by the silk fibroin-based porous carbon with a specific surface area of 2490m ² /g and a nitrogen content of 4.7% was assembled into a two-electrode system, and the ratio of TEMA BF4/PC in the organic system was 1:4 for electrolysis test in liquid.

Step 1: Mix silk fibroin-based nitrogen-doped porous carbon material (active material), conductive agent and binder in a ratio of 88:8:4, add distilled water and ethanol to make a slurry, and then roll the slurry The obtained sheet-shaped electrode material is placed on a current collector of a corresponding size, cold-pressed at 15 MPa for 45 seconds, and then dried at 140° C. to obtain an electrode sheet of a supercapacitor, wherein the electrode material is greater than 12 mg/cm ² .

Step 2: Put the two sides of the diaphragm into the electrode pole pieces, assemble into a "sandwich" structure with the diaphragm as the center, and perform electrochemical performance tests in the EMIMBF4 electrolyte.

Example 14

The supercapacitor device prepared by the prepared egg white protein-based porous carbon with a specific surface area of 2290m ² /g and a nitrogen content of 5.9% was assembled into a two-electrode system, and the ratio of TEMA BF4/PC in the organic system was 1:4 electrolyte in the test.

Step 1: Mix egg white protein-based nitrogen-doped porous carbon material (active material), conductive agent and binder in a ratio of 88:8:4, add distilled water and ethanol to make a slurry, and then roll the slurry to obtain The sheet-shaped electrode material is placed on a current collector of a corresponding size, cold-pressed at 15 MPa for 45 seconds, and then dried at 140°C to obtain an electrode sheet for a supercapacitor, wherein the electrode material is greater than 12mg/cm2.

Step 2: Put the two sides of the diaphragm into the electrode pole pieces, assemble into a "sandwich" structure with the diaphragm as the center, and perform electrochemical performance tests in the EMIMBF4 electrolyte.

Example 15

The supercapacitor device prepared by the prepared soybean protein-based porous carbon with a specific surface area of 1995m ² /g and a nitrogen content of 5.9% was assembled into a two-electrode system, and the ratio of TEMA BF4/PC in the organic system was 1:4 electrolyte in the test.

Step 1: Mix soybean protein-based nitrogen-doped porous carbon material (active material), conductive agent and binder in a ratio of 88:8:4, add distilled water and ethanol to make a slurry, and then roll the slurry to obtain The sheet-shaped electrode material is placed on a current collector of a corresponding size, cold-pressed at 15 MPa for 45 seconds, and then dried at 140°C to obtain an electrode sheet for a supercapacitor, wherein the electrode material is greater than 12 mg/cm ² .

Step 2: Put the two sides of the diaphragm into the electrode pole pieces, assemble into a "sandwich" structure with the diaphragm as the center, and perform electrochemical performance tests in the EMIMBF4 electrolyte.

The specific description above further elaborates the purpose, technical solution and beneficial effect of the invention. It should be understood that the above description is only a specific embodiment of the present invention and is not used to limit the protection of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims (7)

1. A preparation method of high energy density supercapacitor based on biological protein-based nitrogen-doped porous carbon material It is characterized in that: the biological protein-based nitrogen-doped porous carbon electrode material is used as the supercapacitor electrode material of the two-electrode system, and a practical high-power and high-energy-density supercapacitor device is assembled with different electrolytes. 2. A method for preparing a high-energy-density supercapacitor based on biological protein-based nitrogen-doped porous carbon material, the method comprising the steps of: Step 1: Mix different biological protein-based nitrogen-doped porous carbon materials (active materials), conductive agents and binders in a ratio of 88:8:4, add distilled water and ethanol to make a slurry, and then roll the slurry The obtained sheet-shaped electrode material is placed on a current collector of a corresponding size, cold-pressed at 15 MPa for 45 seconds, and then dried at 140° C. to obtain an electrode sheet of a supercapacitor, wherein the electrode material is greater than 12 mg/cm ² . Step 2: Put the two sides of the diaphragm into the electrode pole pieces, assemble into a "sandwich" structure with the diaphragm as the center, and conduct electrochemical performance tests in different electrolytes. 3. A method for preparing a high-energy-density supercapacitor based on biological protein-based nitrogen-doped porous carbon material as claimed in claim 1, wherein the precursor for preparing nitrogen-doped porous carbon electrode material is biological protein, or contains Biological protein, or products treated with biological protein, biological protein includes silk fibroin, egg white protein, soybean protein and so on. 4. according to the preparation method of a kind of high energy density supercapacitor based on biological protein-based nitrogen-doped porous carbon material according to claim 2, it is characterized in that: the current collector in step 2 is a kind of material with electrical conductivity, which can be One of the materials used: aluminum foam, nickel foam, carbon-coated aluminum foil, aluminum foil, copper foil, fiber carbon cloth, etc. 5. according to the preparation method of a kind of high energy density supercapacitor based on biological protein-based nitrogen-doped porous carbon material according to claim 2, it is characterized in that: the binding agent described in step 2 is polyvinylidene fluoride (PVDF) , at least one of polytetrafluoroethylene (PTFE), acrylic resin, styrene-butadiene rubber, sodium alginate, polyvinyl alcohol, and carboxymethyl cellulose. 6. according to the preparation method of a kind of high energy density supercapacitor based on biological protein-based nitrogen-doped porous carbon material according to claim 2, it is characterized in that: the diaphragm described in step 2 is a kind of following material: glass fiber paper PP, nylon cloth, polyvinyl alcohol, cotton fiber membrane, asbestos, PE microporous membrane, etc. 7. A kind of preparation method based on the high energy density supercapacitor of biological protein-based nitrogen-doped porous carbon material as claimed in claim 2, it is characterized in that: the electrolytic solution described in step 2 is organic electrolytic solution or ionic liquid electrolytic solution or aqueous electrolyte. Wherein the aqueous electrolyte may be one of alkaline, acidic and neutral.