Porphyrin organic molecule composite positive electrode material and preparation method and application thereof

Abstract

The invention relates to the technical field of hybrid capacitors, and discloses a porphyrin organic molecule composite positive electrode material, which comprises a positive electrode active material, a porphyrin derivative, a binder and a conductive agent in a mass ratio of (79-89): (1-10): (5-10): (5-10) in sequence, the preparation method comprises the following steps: uniformly mixing a positive electrode active material, a porphyrin derivative, a binder and a conductive agent according to a mass ratio of (79-89): (1-10): (5-10): (5-10), adding 1-methyl-2-pyrrolidone to prepare a slurry, then coating a perforated aluminum foil with the slurry, and sequentially carrying out drying, rolling and cutting to prepare the porphyrin organic molecule composite positive electrode material. The method is applied to a hybrid supercapacitor. According to the technical scheme, the problems that the energy density, the power density and the cycle life of an existing hybrid supercapacitor are difficult to balance, and actual requirements cannot be met are solved.

Description

Technical Field

[0001] The invention relates to the technical field of hybrid capacitors, and in particular to a porphyrin organic molecule composite positive electrode material and a preparation method and application thereof. Background Art

[0002] The development of renewable energy and clean energy has gradually become the focus of people's attention. As a key link in energy conversion, storage and utilization, electrochemical energy storage devices have been widely used in many fields such as electric vehicles, electronic products, smart grids, and large-scale energy storage.

[0003] At present, the most commonly used electrochemical energy storage devices are lithium-ion batteries (LIBs) and supercapacitors (SCs). Due to their different charging and discharging mechanisms, they have their own characteristics in terms of energy storage: lithium-ion batteries have a high energy density (200-300Wh / Kg), but their power (350W / Kg) and cycle performance (≈1000 times) are limited; supercapacitors have a very high power density (10kW / Kg) and an ultra-long cycle life (>1 million times), but their energy density (<10Wh / Kg) is relatively low. Developing an energy storage device that combines the advantages of both and has the characteristics of "high energy density, high power density, and long cycle life" will undoubtedly become a major breakthrough in the field of energy storage, and it is also the common goal pursued by energy storage researchers.

[0004] Supercapacitors are mainly divided into three types: electrochemical (electric) double layer capacitors (EDLCs), pseudocapacitors (PCs) and hybrid supercapacitors (HSCs). EDLCs have a relatively simple electrostatic working mechanism and their energy density is limited. In common pseudocapacitors, charges can only be stored in an area a few nanometers away from the electrode surface, which not only limits the thickness of the electrode, but also is affected by the Faraday process, so the power density of PCs is usually not high.

[0005] In order to improve the energy density of supercapacitors, hybrid structure design is currently widely used, namely hybrid supercapacitors, which are divided into ordinary hybrid capacitors and battery-capacitor hybrid capacitors. One pole of ordinary hybrid capacitors uses a non-polarized electrode of battery material (such as NCM, NCA materials), and the other pole uses a capacitive polarized electrode (such as activated carbon). This capacitor combines the working mechanism of lithium-ion batteries and double-layer capacitors, and can achieve long life and high power characteristics at the same time with the help of electrostatic adsorption and Faraday redox reaction. For example, the Ni(OH)2 / KOH / AC supercapacitor that has been mass-produced and listed has an energy density of 12Wh / Kg and a cycle life of about 30,000 times; although the energy density of PbO2 / H2SO4 / AC supercapacitors can reach 18Wh / Kg, the cycle life is only 3-5,000 times, and there are environmental pollution problems, so it cannot be mass-produced and applied. Compared with double-layer supercapacitors (3-5Wh / Kg), the energy density of these hybrid capacitors has been significantly improved, but there are still many shortcomings, especially the energy density and cycle life are generally difficult to meet the current actual needs.

[0006] Battery-capacitor hybrid supercapacitors also have important application prospects. They refer to hybrid supercapacitors that have at least one electrode that has both capacitive material ion absorption / desorption and Faraday reaction to achieve energy storage (such as a structure with NCM / AC for the positive electrode and hard carbon for the negative electrode). This type of hybrid supercapacitor has a higher energy density, but its power density and cycle life are lower than those of ordinary hybrid capacitors. This is because the intercalation positive electrode material in the process of charging and discharging, Li + The embedding and extraction in layered materials can easily lead to the collapse of the material structure, and high current density will aggravate the degree of cation mixing, which will lead to a decrease in power density and cycle life. Therefore, in order to meet the current demand for high-power, high-energy-density, and long-life energy storage devices, the development of more stable positive electrode materials is crucial to improving the performance of hybrid supercapacitors. Summary of the invention

[0007] The present invention aims to provide a porphyrin organic molecule composite positive electrode material and a preparation method and application thereof, so as to solve the problem that the energy density, power density and cycle life of the existing hybrid supercapacitors are difficult to balance and cannot meet actual needs.

[0008] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a porphyrin organic molecule composite positive electrode material, comprising a positive electrode active material, a porphyrin derivative, a binder and a conductive agent, and the mass ratios thereof are (79-89): (1-10): (5-10): (5-10) respectively.

[0009] Preferably, the positive electrode active material is any one of NCM622, NCM111 and LiFePO4 or a combination of several thereof.

[0010] Preferably, the structural formula of the porphyrin derivative is: In the formula, R is any one of -COOH, -HSO3, -NH2 and -NO2.

[0011] Preferably, the binder is polyvinylidene fluoride; and the conductive agent is any one or more of Super-P, acetylene black and Ketjen black.

[0012] The present invention also provides another technical solution, a method for preparing a porphyrin organic molecule composite positive electrode material, comprising mixing a positive electrode active material, a porphyrin derivative, a binder and a conductive agent in a mass ratio of (79-89): (1-10): (5-10): (5-10), adding 1-methyl-2-pyrrolidone to prepare a slurry, then coating the slurry on a perforated aluminum foil, and sequentially performing drying, rolling and cutting steps to prepare the porphyrin organic molecule composite positive electrode material.

[0013] Preferably, the drying temperature is 65-80°C.

[0014] The present invention also provides another technical solution, which is an application of a porphyrin organic molecule composite positive electrode material. The porphyrin organic molecule composite positive electrode material is applied to a hybrid supercapacitor.

[0015] Preferably, the hybrid supercapacitor is a lithium metal negative electrode hybrid capacitor.

[0016] Compared with the prior art, the beneficial effects of this solution are: (1) Significantly improved energy density: The lithium metal negative electrode hybrid capacitor of the present invention has a significantly improved energy density compared to ordinary supercapacitors. By in-situ compounding of organic pseudocapacitive materials in battery-type materials, the ionic conductivity and electron transfer rate of the electrode materials are enhanced, effectively improving the energy storage capacity of the capacitor, and better meeting the use requirements of high energy demand occasions.

[0017] (2) Significantly extended cycle life: After adding porphyrin derivatives (TCPP / TSPP / TNPP / TAPP) to the positive electrode active material (NCM / LiFePO4), the cycle life is significantly extended. Taking the addition of TCPP to LiFePO4 as an example, an ultra-long life of 4,200 cycles can be achieved at a rate of 5C. This is because the addition of porphyrin derivatives increases the dispersibility of the composite battery material and the wettability of the electrolyte, thereby effectively improving the stability and cycle performance of the capacitor.

[0018] (3) Significantly improved rate performance: After the porphyrin derivatives were added in situ to the positive electrode active material (NCM / LiFePO4), the rate performance of the lithium metal negative electrode hybrid capacitor was greatly improved. This enables the capacitor to maintain good performance at different charge and discharge rates and adapt to a variety of working scenarios.

[0019] (4) Reducing internal resistance: After adding porphyrin derivatives in situ to the positive electrode active material (NCM / LiFePO4), impedance testing shows that it can effectively reduce the internal resistance of the lithium metal negative electrode hybrid capacitor. The reduction of internal resistance helps to improve the charging and discharging efficiency of the capacitor and reduce energy loss.

[0020] (5) Optimizing the electrode structure: From the SEM analysis of the electrode piece, it can be seen that after the porphyrin derivatives are added in situ to the positive electrode active material (NCM / LiFePO4), the pore structure is richer and the agglomeration of the single-crystal NCM material is weakened. The rich pore structure is conducive to the penetration of the electrolyte and the transport of ions, further improving the performance of the capacitor.

[0021] (6) Improved wettability: Since porphyrin materials are easily functionalized, after combining with electrolyte-philic functional groups (such as carboxyl (TCPP) and sulfonic acid (TSPP)), the electrode contact angle test shows that after in-situ addition of porphyrin derivatives to the positive electrode active material (NCM / LiFePO4), the wettability of the electrode is greatly improved, making the electrode filled with more electrolyte, which is beneficial to improving the efficiency of the electrode reaction and the overall performance of the capacitor.

[0022] (7) Improving the performance of full-cell devices: By in-situ adding porphyrin derivatives as positive electrode materials to the positive electrode active material (NCM / LiFePO4) and hard carbon (HC) as the negative electrode material, the cycle life and power density of the full-cell device have been greatly improved, showing good potential in practical applications.

[0023] (8) Significant improvement in overall performance: The performance of capacitors was tested in accordance with the industry standard for automotive supercapacitors (QC / T741-2006). After the porphyrin derivatives were added in situ to the positive electrode active materials (NCM / LiFePO4), the cycle life, energy density and power density of these positive electrode materials could be significantly improved, and the performance of hybrid supercapacitors could be comprehensively optimized to better meet the current demand for high-power, high-energy-density and long-life energy storage devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The UV test spectra of TCPP and TSPP prepared by the present invention; Figure 2 Thermogravimetric spectra of TCPP and TSPP prepared by the present invention; Figure 3The AC impedance test results of button batteries assembled in Example 1 of the present invention and Comparative Examples 1-2; Figure 4 The SEM images of the cut positive electrode sheets of Examples 1-2 and Comparative Example 1 of the present invention are shown. DETAILED DESCRIPTION

[0025] The following is further described in detail through specific implementation methods: A porphyrin organic molecule composite positive electrode material comprises a positive electrode active material, a porphyrin derivative, a binder and a conductive agent, wherein the mass ratios thereof are (79-89): (1-10): (5-10): (5-10) respectively.

[0026] The active material is any one or a combination of NCM622, NCM111 and LiFePO4, and both NCM622 and NCM111 are nickel-cobalt-manganese ternary positive electrode materials; The binder is polyvinylidene fluoride (PVDF); The conductive agent is any one or more of Super-P, acetylene black and Ketjen black; The porphyrin derivative is any one or a combination of 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (TCPP), 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin (TSPP), 5,10,15,20-tetrakis(4-nitrophenyl)porphyrin (TNPP) and 5,10,15,20-tetrakis(4-aminophenyl)porphyrin (TAPP), and its structural formula is: In the formula, R is any one of -COOH, -HSO3, -NH2 and -NO2.

[0027] The preparation method of 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (TCPP) comprises the following steps: S1: Preparation of p-carboxybenzaldehyde solution Dissolve 0.03-0.075 mol of p-carboxybenzaldehyde in 150 mL of propionic acid and heat to 60° C. until the p-carboxybenzaldehyde is completely dissolved to prepare a mixed solution; specifically, the amount of p-carboxybenzaldehyde used is 0.03 mol; S2: Reaction mixing and reflux 2-5 mL of pyrrole was dissolved in 10 mL of propionic acid, and slowly added to the mixed solution obtained in S1 through a constant pressure dropping funnel within 20 minutes. After the addition was completed, the mixture was refluxed at 140°C for 8 hours. After the reaction was completed, the mixture was cooled to room temperature and then placed in a refrigerator to stand overnight. Specifically, the amount of pyrrole used was 1.4 mL. S3: Product washing The product obtained from S2 is filtered, and after the filtration is completed, the filter residue is washed with propionic acid 2-3 times, and then the product is washed with a solution of chloroform and acetone mixed in a volume ratio of 5:1; specifically, after the filtration, the product is washed with propionic acid 3 times; S4: Product drying and collection The product after washing S3 was dissolved in ethanol, and the ethanol solvent was removed by rotary evaporation. Then, the remaining product was dried in a vacuum environment at 50-85°C for 9-13 hours, and the final product, namely 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (TCPP), was collected; specifically, the vacuum drying temperature was 65°C and the drying time was 12 hours.

[0028] The specific reaction process is:

[0029] The preparation method of 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin (TSPP) comprises the following steps: Step 1: Preparation of 5,10,15,20-tetrakis(4-phenyl)porphyrin (TPP) Take a 500mL three-necked round-bottom flask, add 250mL of propionic acid thereto, heat the propionic acid in the flask to a slightly boiling state by oil bath heating, then add 10-20mL of benzaldehyde to the flask, then dissolve 5-7mL of freshly distilled pyrrole in 10-30mL of propionic acid, and slowly add to the flask; specifically, the amount of benzaldehyde added is 10mL, the amount of freshly distilled pyrrole added is 7mL, and the amount of propionic acid added for dissolving the freshly distilled pyrrole is 30mL; Step 2: Obtaining TPP crude product After the addition of the mixed solution of freshly steamed pyrrole and propionic acid is completed, the reaction system is refluxed at 140° C. for 1 hour. After the reaction is completed, it is cooled to room temperature, and the reaction product is placed in a refrigerator and allowed to stand overnight; then, suction filtration is performed, and the filter residue is washed with anhydrous ethanol and water 2-3 times respectively, and finally, the washed filter residue is dried at 65° C. for 8 hours to obtain a purple solid; specifically, the filter residue is washed with anhydrous ethanol and water 3 times respectively; Step 3: Purification of TPP The purple solid obtained by drying in step 2 is fully mixed with silica gel, and then purified by silica gel column chromatography, using a solution of dichloromethane and petroleum ether mixed in a volume ratio of 3:1 as an eluent. After purification, the eluent is removed by rotary evaporation, and then the product is vacuum dried at 50-85°C for 12h, and the product 5,10,15,20-tetrakis(4-phenyl)porphyrin (TPP) is collected, specifically, vacuum dried at 95°C for 4h; Step 4: Sulfonation reaction of TPP Take a 500mL single-necked round-bottom flask, add 1g of TPP obtained in step 3, and dissolve it with a small amount of chloroform, then slowly add 10-100mL of concentrated H2SO4 to the flask, stirring while adding, after the addition is complete, heat the reaction system to 95°C, and reflux at a constant temperature for 8h to finally obtain a green clear solution; specifically, the amount of concentrated H2SO4 added is 10mL; Step 5: Neutralization and desalination After the reaction system is cooled to room temperature, NaHCO3 solution is slowly added thereto until the solution turns into a green clear solution again. Then, the solution is cooled in an ice bath and filtered after cooling to remove the generated Na2SO4 crystals.

[0030] Step 6: Further cleaning Remove the solvent in the solution after filtration in step 5, then dissolve the residue with 150-300 mL of methanol, filter after dissolution, and repeat the "methanol dissolution-filtration" step 2-3 times. Specifically, the amount of methanol used is 100 mL, and the "methanol dissolution-filtration" step is repeated 3 times; Step 7: Recrystallization and collection of TSPP Propanol is added to the solution treated in step 6 for recrystallization. After the recrystallization is completed, filtering is performed to obtain a purple solid product 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin (TSPP).

[0031] The specific reaction process is:

[0032] The prepared TCPP and TSPP were subjected to UV and thermogravimetric tests. Figure 1 It can be seen that the UV data show that TCPP and TSPP were successfully synthesized. In the UV absorption spectrum, the main absorption wavelength of TCPP and TSPP is 420nm, and there is a strong absorption peak at this wavelength. In addition, there are four weak absorption peaks in the range of 500-750nm. Figure 2 This is the thermogravimetric test of TCPP and TSPP. The thermogravimetric test proves that TCPP and TSPP are stable within 120°C. After being made into half-cells and full cells, they will not decompose when dried, which is of guiding significance for subsequent use.

[0033] A method for preparing a porphyrin organic molecule composite positive electrode material comprises the following steps: uniformly mixing a positive electrode active material, a porphyrin derivative, a binder and a conductive agent in a mass ratio of (79-89): (1-10): (5-10): (5-10), adding 1-methyl-2-pyrrolidone (NMP) to prepare a slurry, coating the slurry on a perforated aluminum foil, and sequentially subjecting the slurry to the steps of drying (65-80° C.), rolling and cutting to prepare the porphyrin organic molecule composite positive electrode material, i.e., a positive electrode sheet.

[0034] The invention discloses an application of a porphyrin organic molecule composite positive electrode material. The prepared porphyrin organic molecule composite positive electrode material is applied to a hybrid supercapacitor, which is a lithium metal negative electrode hybrid capacitor.

[0035] Example 1 A porphyrin organic molecule composite positive electrode material comprises NCM622, TCPP, PVDF and Super-P, and the mass ratios thereof are 7:1:1:1 respectively.

[0036] A method for preparing a porphyrin organic molecule composite positive electrode material comprises the following steps: uniformly mixing NCM622, TCPP, PVDF and Super-P in a mass ratio of 7:1:1:1, adding 1-methyl-2-pyrrolidone (NMP) to prepare a slurry, then coating the slurry on a perforated aluminum foil, drying (80° C.), rolling and cutting into electrode pieces with a diameter of φ12 mm, and preparing a lithium metal negative electrode hybrid capacitor.

[0037] (1) Impedance test and constant current charge and discharge test on button batteries Assemble button batteries: Use the cut electrode sheet as the positive electrode, the lithium sheet as the negative electrode, the polypropylene diaphragm as the diaphragm material, and 1 moL / L LiPF6 (EC: DMC: EMC 1:1:1) as the electrolyte to assemble the button batteries.

[0038] Impedance test: Connect the negative electrode of the button battery to the counter electrode and the reference electrode, and the positive electrode to the working electrode. Use the Swiss Metrohm electrochemical workstation to test the AC impedance frequency range of 100000-0.01Hz, amplitude 5mV, and the test results are as follows: Figure 3 shown.

[0039] Constant current charge and discharge test: The button battery was subjected to constant current charge and discharge test using a BlueDian electrochemical workstation. The test results are shown in Table 1.

[0040] (2) Test the performance of the capacitor according to the industry standard for automotive supercapacitors The method for preparing a full battery comprises the following steps: Step 1: Production of positive electrode sheet of soft package device; NCM622, TCPP, PVDF and Super-P were mixed evenly at a mass ratio of 7:1:1:1, and 1-methyl-2-pyrrolidone (NMP) was added to prepare a slurry. Then, the slurry was coated on a perforated aluminum foil, dried (80°C), rolled, and cut into pieces to make a positive electrode sheet with a size of 60*70mm and a blank space of 10mm, and the upper tab was spot welded; Step 2: Preparation of negative electrode sheet of soft package device Hard carbon, conductive carbon black (Super-P), sodium carboxymethyl cellulose (CMC), and styrene-butadiene rubber (SBR) are mixed evenly in a mass ratio of 84:0.017:0.057:0.081, adjusted into slurry with water and ethanol, and then coated on perforated copper foil. After drying (65°C), rolling, and cutting, negative electrode sheets with a size of 60*70mm and a blank space of 10mm are made, and the upper ears are spot welded.

[0041] Step 3: Assemble the full battery Nanocellulose membrane was used as the separator, and 5 positive plates, separator and 6 negative plates were stacked in sequence to form the inner core of the soft-pack battery. The inner core was then sealed with an aluminum-plastic film through a thermal packaging process to form a capacitor. Finally, an electrolyte was injected, which used 1 mol / L LiPF6 as the solute and a solvent of ethylene carbonate (EC), ethyl methyl carbonate (EMC) and dimethyl carbonate (DMC) mixed in a volume ratio of 1:1:1.

[0042] The performance of the capacitor was tested with reference to the industry standard for automotive supercapacitors (QC / T741-2006). The test results are shown in Table 2.

[0043] (3) Use a scanning electron microscope to photograph and observe the cut positive electrode sheet and test the contact angle The cut positive electrode sheets were photographed and observed using a scanning electron microscope, and the results are as follows: Figure 4 shown.

[0044] The contact angle test was performed on the cut positive electrode sheets. The test results are shown in Table 3.

[0045] Example 2 A porphyrin organic molecule composite positive electrode material comprises NCM622, TSPP, PVDF and Super-P, and the mass ratios thereof are 7:1:1:1 respectively.

[0046] A method for preparing a porphyrin organic molecule composite positive electrode material comprises the following steps: uniformly mixing NCM622, TSPP, PVDF and Super-P in a mass ratio of 7:1:1:1, adding 1-methyl-2-pyrrolidone (NMP) to prepare a slurry, then coating the slurry on a perforated aluminum foil, drying (80° C.), rolling and cutting into pole pieces with a diameter of φ12 mm, and preparing a lithium metal negative electrode hybrid capacitor.

[0047] (1) Constant current charge and discharge test on button batteries The assembly method of the button battery is the same as that of Example 1, and will not be described again here.

[0048] The constant current charge and discharge test results are shown in Table 1.

[0049] (2) Test the performance of the capacitor according to the industry standard for automotive supercapacitors The preparation method of the full battery is the same as that of Example 1 and will not be described again here.

[0050] The performance of the capacitor was tested with reference to the industry standard for automotive supercapacitors (QC / T741-2006). The test results are shown in Table 2.

[0051] (3) Use a scanning electron microscope to photograph and observe the cut positive electrode sheet and test the contact angle The cut positive electrode sheets were photographed and observed using a scanning electron microscope, and the results are as follows: Figure 4 shown.

[0052] The contact angle test was performed on the cut positive electrode sheets. The test results are shown in Table 3.

[0053] Example 3 A porphyrin organic molecule composite positive electrode material comprises NCM111, TCPP, PVDF and Super-P, and the mass ratios thereof are 7:1:1:1 respectively.

[0054] A method for preparing a porphyrin organic molecule composite positive electrode material comprises the following steps: uniformly mixing NCM111, TCPP, PVDF and Super-P in a mass ratio of 7:1:1:1, adding 1-methyl-2-pyrrolidone (NMP) to prepare a slurry, then coating the slurry on a perforated aluminum foil, drying (80° C.), rolling and cutting into electrode pieces with a diameter of φ12 mm to prepare a lithium metal negative electrode hybrid capacitor.

[0055] (1) Constant current charge and discharge test on button batteries The assembly method of the button battery is the same as that of Example 1, and will not be described again here.

[0056] The constant current charge and discharge test results are shown in Table 1.

[0057] (2) Test the performance of the capacitor according to the industry standard for automotive supercapacitors The preparation method of the full battery is the same as that of Example 1 and will not be described again here.

[0058] The performance of the capacitor was tested with reference to the industry standard for automotive supercapacitors (QC / T741-2006). The test results are shown in Table 2.

[0059] (3) Test the contact angle of the cut positive electrode sheet The contact angle test was performed on the cut positive electrode sheets. The test results are shown in Table 3.

[0060] Example 4 A porphyrin organic molecule composite positive electrode material comprises NCM111, TSPP, PVDF and Super-P, and the mass ratios thereof are 7:1:1:1 respectively.

[0061] A method for preparing a porphyrin organic molecule composite positive electrode material comprises the following steps: uniformly mixing NCM111, TSPP, PVDF and Super-P in a mass ratio of 7:1:1:1, adding 1-methyl-2-pyrrolidone (NMP) to prepare a slurry, then coating the slurry on a perforated aluminum foil, drying (80° C.), rolling and cutting into electrode pieces with a diameter of φ12 mm to prepare a lithium metal negative electrode hybrid capacitor.

[0062] (1) Constant current charge and discharge test on button batteries The assembly method of the button battery is the same as that of Example 1, and will not be described again here.

[0063] The constant current charge and discharge test results are shown in Table 1.

[0064] (2) Test the performance of the capacitor according to the industry standard for automotive supercapacitors The preparation method of the full battery is the same as that of Example 1 and will not be described again here.

[0065] The performance of the capacitor was tested with reference to the industry standard for automotive supercapacitors (QC / T741-2006). The test results are shown in Table 2.

[0066] (3) Test the contact angle of the cut positive electrode sheet The contact angle test was performed on the cut positive electrode sheets. The test results are shown in Table 3.

[0067] Example 5 A porphyrin organic molecule composite positive electrode material comprises LiFePO4, TCPP, PVDF and Super-P, and the mass ratios thereof are 7:1:1:1 respectively.

[0068] A method for preparing a porphyrin organic molecule composite positive electrode material comprises the following steps: uniformly mixing LiFePO4, TCPP, PVDF and Super-P in a mass ratio of 7:1:1:1, adding 1-methyl-2-pyrrolidone (NMP) to prepare a slurry, then coating the slurry on a perforated aluminum foil, drying (80°C), rolling and cutting into pole pieces with a diameter of φ12 mm to prepare a lithium metal negative electrode hybrid capacitor.

[0069] (1) Constant current charge and discharge test on button batteries The assembly method of the button battery is the same as that of Example 1, and will not be described again here.

[0070] The constant current charge and discharge test results are shown in Table 1.

[0071] (2) Test the performance of the capacitor according to the industry standard for automotive supercapacitors The preparation method of the full battery is the same as that of Example 1 and will not be described again here.

[0072] The performance of the capacitor was tested with reference to the industry standard for automotive supercapacitors (QC / T741-2006). The test results are shown in Table 2.

[0073] (3) Test the contact angle of the cut positive electrode sheet The contact angle test was performed on the cut positive electrode sheets. The test results are shown in Table 3.

[0074] Example 6 A porphyrin organic molecule composite positive electrode material comprises LiFePO4, TSPP, PVDF and Super-P, and the mass ratios thereof are 7:1:1:1 respectively.

[0075] A method for preparing a porphyrin organic molecule composite positive electrode material comprises the following steps: uniformly mixing LiFePO4, TSPP, PVDF and Super-P in a mass ratio of 7:1:1:1, adding 1-methyl-2-pyrrolidone (NMP) to prepare a slurry, then coating the slurry on a perforated aluminum foil, drying (80°C), rolling and cutting into pole pieces with a diameter of φ12 mm to prepare a lithium metal negative electrode hybrid capacitor.

[0076] (1) Constant current charge and discharge test on button batteries The assembly method of the button battery is the same as that of Example 1, and will not be described again here.

[0077] The constant current charge and discharge test results are shown in Table 1.

[0078] (2) Test the performance of the capacitor according to the industry standard for automotive supercapacitors The preparation method of the full battery is the same as that of Example 1 and will not be described again here.

[0079] The performance of the capacitor was tested with reference to the industry standard for automotive supercapacitors (QC / T741-2006). The test results are shown in Table 2.

[0080] (3) Test the contact angle of the cut positive electrode sheet The contact angle test was performed on the cut positive electrode sheets. The test results are shown in Table 3.

[0081] Comparative Example 1 A porphyrin organic molecule composite positive electrode material comprises NCM622, PVDF and Super-P, and the mass ratios thereof are 8:1:1 respectively.

[0082] A method for preparing a porphyrin organic molecule composite positive electrode material comprises the following steps: uniformly mixing NCM622, PVDF and Super-P in a mass ratio of 8:1:1, adding 1-methyl-2-pyrrolidone (NMP) to prepare a slurry, then coating the slurry on a perforated aluminum foil, drying (80°C), rolling and cutting into electrode pieces with a diameter of φ12 mm to prepare a lithium metal negative electrode hybrid capacitor.

[0083] (1) Impedance test and constant current charge and discharge test on button batteries The assembly method of the button battery is the same as that of Example 1, and will not be described again here.

[0084] The impedance test results are shown in Figure 3 .

[0085] The constant current charge and discharge test results are shown in Table 1.

[0086] (2) Test the performance of the capacitor according to the industry standard for automotive supercapacitors The preparation method of the full battery is the same as that of Example 1 and will not be described again here.

[0087] The performance of the capacitor was tested with reference to the industry standard for automotive supercapacitors (QC / T741-2006). The test results are shown in Table 2.

[0088] (3) Use a scanning electron microscope to photograph and observe the cut positive electrode sheet and test the contact angle The cut positive electrode sheets were photographed and observed using a scanning electron microscope, and the results are as follows: Figure 4 shown.

[0089] The contact angle test was performed on the cut positive electrode sheets. The test results are shown in Table 3.

[0090] Comparative Example 2 A porphyrin organic molecule composite positive electrode material comprises TCPP, PVDF and Super-P, and the mass ratios thereof are 8:1:1 respectively.

[0091] A method for preparing a porphyrin organic molecule composite positive electrode material comprises the following steps: uniformly mixing TCPP, PVDF and Super-P in a mass ratio of 8:1:1, adding 1-methyl-2-pyrrolidone (NMP) to prepare a slurry, then coating the slurry on a perforated aluminum foil, drying (80°C), rolling and cutting into electrode pieces with a diameter of φ12 mm to prepare a lithium metal negative electrode hybrid capacitor.

[0092] (1) Impedance test of button battery The assembly method of the button battery is the same as that of Example 1, and will not be described again here.

[0093] The impedance test results are shown in Figure 3 .

[0094] Comparative Example 3 Different from Example 1, a porphyrin organic molecule composite positive electrode material includes NCM111, PVDF and Super-P, and the mass ratio of them is 8:1:1 respectively.

[0095] A method for preparing a porphyrin organic molecule composite positive electrode material comprises the following steps: uniformly mixing NCM111, PVDF and Super-P in a mass ratio of 8:1:1, adding 1-methyl-2-pyrrolidone (NMP) to prepare a slurry, then coating the slurry on a perforated aluminum foil, drying (80°C), rolling and cutting into electrode pieces with a diameter of φ12 mm to prepare a lithium metal negative electrode hybrid capacitor.

[0096] (1) Constant current charge and discharge test on button batteries The assembly method of the button battery is the same as that of Example 1, and will not be described again here.

[0097] The constant current charge and discharge test results are shown in Table 1.

[0098] (2) Test the performance of the capacitor according to the industry standard for automotive supercapacitors The preparation method of the full battery is the same as that of Example 1 and will not be described again here.

[0099] The performance of the capacitor was tested with reference to the industry standard for automotive supercapacitors (QC / T741-2006). The test results are shown in Table 2.

[0100] (3) Test the contact angle of the cut positive electrode sheet The contact angle test was performed on the cut positive electrode sheets. The test results are shown in Table 3.

[0101] Comparative Example 4 A porphyrin organic molecule composite positive electrode material comprises LiFePO4, PVDF and Super-P, and the mass ratios thereof are 8:1:1 respectively.

[0102] A method for preparing a porphyrin organic molecule composite positive electrode material comprises the following steps: uniformly mixing LiFePO4, PVDF and Super-P in a mass ratio of 8:1:1, adding 1-methyl-2-pyrrolidone (NMP) to prepare a slurry, then coating the slurry on a perforated aluminum foil, drying (80°C), rolling and cutting into pole pieces with a diameter of φ12 mm to prepare a lithium metal negative electrode hybrid capacitor.

[0103] (1) Constant current charge and discharge test on button batteries The assembly method of the button battery is the same as that of Example 1, and will not be described again here.

[0104] The constant current charge and discharge test results are shown in Table 1.

[0105] (2) Test the performance of the capacitor according to the industry standard for automotive supercapacitors The preparation method of the full battery is the same as that of Example 1 and will not be described again here.

[0106] The performance of the capacitor was tested with reference to the industry standard for automotive supercapacitors (QC / T741-2006). The test results are shown in Table 2.

[0107] (3) Test the contact angle of the cut positive electrode sheet The contact angle test was performed on the cut positive electrode sheets. The test results are shown in Table 3.

[0108] Table 1 Constant current charge and discharge test results

[0109] Table 2 Full battery system performance test results

[0110] Table 3 Pole contact angle / surface tension test results

[0111] Depend on Figure 3 It can be seen that the in-situ addition of TCPP to NCM622 can reduce the internal resistance of the lithium metal negative electrode hybrid capacitor.

[0112] As can be seen from Table 1, after rolling the electrodes and assembling them into button cells, the cycle life was significantly extended after TCPP or TSPP was added to the NCM622, NCM111 or LiFePO4 positive electrode materials. After TCPP was added to LiFePO4, an ultra-long life of 4200 cycles could be achieved at a rate of 5C, which proves that porphyrin derivatives can significantly improve the rate performance and cycle life of NCM622, NCM111 or LiFePO4 positive electrode materials.

[0113] It can be seen from Table 2 that adding TCPP or TSPP to NCM622, NCM111 or LiFePO4 positive electrode materials can significantly improve the cycle life, energy density and power density of NCM622, NCM111 or LiFePO4 positive electrode materials.

[0114] Depend on Figure 4It can be seen that after adding TCPP or TSPP to the NCM622 positive electrode material, the pore structure is richer and the agglomeration of the single-crystal NCM material is weakened. Electrolyte filling is a quality-critical and cost-intensive process. Since porphyrin materials are easily functionalized, after combining electrolyte-philic functional groups such as carboxyl (TCPP) and sulfonic acid (TSPP), the electrode is filled with rich electrolyte. Through the pole piece contact angle test, it can be seen from Table 3 that after adding TCPP or TSPP to the NCM622, NCM111 or LiFePO4 positive electrode materials, the wettability of the pole piece is greatly improved.

[0115] The above is only an embodiment of the present invention, and the common knowledge such as the known specific technical solutions and / or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several modifications and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A porphyrin organic molecule composite positive electrode material, characterized in that: It includes positive electrode active material, porphyrin derivative, binder and conductive agent, and the mass ratios thereof are (79-89): (1-10): (5-10): (5-10) respectively.

2. The porphyrin organic molecular composite positive electrode material according to claim 1, characterized in that: The positive electrode active material is any one of NCM622, NCM111 and LiFePO4 or a combination of several thereof.

3. A porphyrin organic molecular composite positive electrode material according to claim 2, characterized in that: The structural formula of porphyrin derivatives is: In the formula, R is any one of -COOH, -HSO3, -NH2 and -NO2.

4. The porphyrin organic molecular composite positive electrode material according to claim 3, characterized in that: The binder is polyvinylidene fluoride; the conductive agent is any one or more of Super-P, acetylene black and Ketjen black.

5. A method for preparing a porphyrin organic molecule composite positive electrode material, characterized in that: The positive electrode active material, porphyrin derivative, binder and conductive agent are uniformly mixed in a mass ratio of (79-89): (1-10): (5-10): (5-10), and 1-methyl-2-pyrrolidone is added to prepare a slurry. Then, the slurry is coated on a perforated aluminum foil, and then dried, rolled and cut into pieces to prepare a porphyrin organic molecular composite positive electrode material.

6. The method for preparing a porphyrin organic molecule composite positive electrode material according to claim 5, characterized in that: The drying temperature is 65-80℃.

7. An application of a porphyrin organic molecule composite positive electrode material, characterized in that: The porphyrin organic molecule composite positive electrode material described in any one of claims 1 to 4 or the porphyrin organic molecule composite positive electrode material prepared by the preparation method of the porphyrin organic molecule composite positive electrode material described in any one of claims 5 to 6 is applied to a hybrid supercapacitor.

8. The use of a porphyrin organic molecular composite positive electrode material according to claim 7, characterized in that: Hybrid supercapacitors are lithium metal anode hybrid capacitors.

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