Low-temperature-resistant supercapacitor and preparation method and application thereof
By using organophosphorus compounds as electrolytes and simple physical blending methods to prepare electrolytes, the problem of electrolyte freezing of supercapacitors in low temperature environments is solved, and supercapacitors with high conductivity and stability are achieved, suitable for polar scientific investigations, high-altitude exploration and aerospace fields.
Patent Information
- Application Number
- CN202510792449.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-13
- Publication Date
- 2025-09-05
AI Technical Summary
The existing supercapacitors are prone to freezing in low-temperature environments, resulting in a significant decrease in the ion diffusion rate and deterioration of the electrode-electrolyte interface contact, which seriously limits its capacitance performance and cycling stability, and cannot meet the performance requirements of low-temperature application scenarios.
Organophosphorus compounds are used as the electrolyte, the glass transition temperature of the electrolyte is -60℃~-30℃, the room temperature conductivity is ≥1.0×10-3S/cm, the electrode materials include activated carbon particles, conductive carbon black and polyvinylidene fluoride, and the separator is a Nafion film, etc. The electrolyte is prepared by simple non-covalent physical blending.
Maintaining high conductivity and good stability in low-temperature environments significantly improves the performance and service life of supercapacitors, expands their application range, and is suitable for polar scientific expeditions, high-altitude exploration, and aerospace fields.
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Figure CN120600549A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of electrochemical energy storage, and in particular to a low-temperature resistant supercapacitor and a preparation method and application thereof. Background Art
[0002] A supercapacitor is an electrochemical energy storage device between traditional capacitors and rechargeable batteries. It not only has the characteristics of fast charging and discharging of capacitors, but also has the energy storage characteristics of batteries. In recent years, the demand for supercapacitors in extreme environments (such as low temperature) such as polar scientific expeditions, high-altitude exploration, and aerospace has been growing. However, the electrolytes in existing supercapacitors have many problems in low-temperature environments. The main problem is that the electrolytes are easy to freeze, which will cause the ion diffusion rate to drop significantly and the electrode-electrolyte interface contact to deteriorate, which seriously limits the capacitance performance and cycle stability of supercapacitors and cannot meet the performance requirements of low-temperature application scenarios.
[0003] Therefore, it is of great significance to develop a supercapacitor with excellent low-temperature resistance. Summary of the Invention
[0004] The object of the present invention is to provide a low-temperature resistant supercapacitor and a preparation method and application thereof.
[0005] The technical solution adopted by the present invention is:
[0006] A low-temperature resistant supercapacitor, comprising electrodes, an electrolyte, a diaphragm and a packaging shell, wherein the electrolyte in the electrolyte is an organic phosphorus compound, the glass transition temperature of the electrolyte is -60°C to -30°C, and the room temperature conductivity is ≥1.0×10 - 3 S / cm.
[0007] Preferably, the electrolyte in the electrolyte solution is phytic acid or lithium phytate.
[0008] Further preferably, the electrolyte is a phytic acid aqueous solution or a lithium phytate aqueous solution.
[0009] Preferably, the mass ratio of phytic acid to water in the phytic acid aqueous solution is 1:0.3-0.4.
[0010] Preferably, the mass ratio of lithium phytate to water in the lithium phytate aqueous solution is 1:0.3-0.9.
[0011] Preferably, the electrode comprises a current collector and an electrode material attached to the surface of the current collector.
[0012] Preferably, the current collector is one of aluminum foil, copper foil, titanium foil and foam copper.
[0013] Preferably, the electrode material comprises an electrode active material, conductive carbon black and polyvinylidene fluoride (PVDF).
[0014] Preferably, the electrode active material is at least one of activated carbon particles, activated carbon fibers, carbon nanotubes, and graphene.
[0015] Preferably, the diaphragm is one of a Nafion membrane, a Flemion membrane, a polypropylene (PP) membrane, and a polyethylene (PE) membrane.
[0016] A method for preparing the low-temperature resistant supercapacitor as described above comprises the following steps: dispersing an electrolyte in a solvent to prepare an electrolyte solution, and then assembling electrodes, the electrolyte solution, a diaphragm and a packaging shell to obtain a low-temperature resistant supercapacitor.
[0017] An application of the low-temperature resistant supercapacitor as described above in a low-temperature environment.
[0018] Preferably, the low temperature environment is an environment with a temperature below 0°C.
[0019] Application of the low-temperature resistant supercapacitor as described above in the field of polar scientific exploration, high-altitude exploration or aerospace.
[0020] The beneficial effects of the present invention are as follows: the supercapacitor of the present invention has the advantages of excellent low-temperature resistance, long service life, green environmental protection, low production cost, etc., is suitable for use in low-temperature environments, and its preparation method is simple and the raw materials are widely available, making it suitable for large-scale industrial production and application.
[0021] Specifically:
[0022] 1) The supercapacitor of the present invention uses an organophosphorus compound as an electrolyte. The organophosphorus compound contains multiple phosphate groups, which can form a stable hydrogen bond network with water molecules, effectively inhibit water crystallization, and improve proton conductivity. This allows the electrolyte to have high conductivity, good stability, and excellent electrochemical properties under low temperature conditions. This significantly improves the performance and service life of the supercapacitor in low temperature environments, expands the application range of the supercapacitor, and enables the supercapacitor to better adapt to energy storage needs in various extreme environments.
[0023] 2) The supercapacitor of the present invention uses an organophosphorus compound as an electrolyte. The organophosphorus compound can remain amorphous at extremely low temperatures (there is no problem of crystallization and freezing at low temperatures that is prone to occur with traditional electrolytes), ensuring the normal operation of the supercapacitor in a low-temperature environment. Moreover, the organophosphorus compound can form a stable protective layer on the electrode surface, avoiding corrosion of the electrode and the packaging shell by the electrolyte, thereby extending the service life of the supercapacitor. In addition, the capacitance performance of the supercapacitor remains good under low-temperature conditions, the CV curve is close to a rectangle, the capacitance performance is excellent, and the rate performance is good;
[0024] 3) The electrolytes used in the supercapacitors of the present invention are all commercial, low-cost industrial products with a wide range of raw material sources and no need for additional processing. The electrolyte is prepared by a simple non-covalent physical blending method. The production process is simple, has good compatibility with conventional battery manufacturing and packaging processes, and has low environmental pollution, making it suitable for large-scale industrial production and application. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figure 1 Schematic diagram of the structure of the low-temperature resistant supercapacitor of the present invention.
[0026] Figure 2 Schematic diagram of the hydrogen bond network of the phytic acid-water system.
[0027] Figure 3 These are WAXS graphs of the phytic acid aqueous solution in Example 2 at different temperatures.
[0028] Figure 4 These are the WAXS graphs of the phytic acid aqueous solution in Comparative Example 3 at different temperatures.
[0029] Figure 5 These are the DSC curves of the phytic acid aqueous solution in Examples 1-2, the phytic acid aqueous solution in Comparative Examples 1-3, and solid phytic acid.
[0030] Figure 6 The conductivity-temperature relationship curves of the phytic acid aqueous solution in Examples 1-2, the phytic acid aqueous solution in Comparative Examples 1-3, and solid phytic acid.
[0031] Figure 7 CV curves of the low-temperature resistant supercapacitor of Example 2 at room temperature and different scan rates.
[0032] Figure 8 CV curves of the supercapacitor of Comparative Example 3 at room temperature and different scan rates.
[0033] Figure 9 CV curves of the low-temperature resistant supercapacitor of Example 2 at -30°C and different voltages.
[0034] Figure 10CV curves of the supercapacitor of Comparative Example 3 at -30°C and different voltages.
[0035] Figure 11 3 and 6 are LSV curves of the low-temperature resistant supercapacitors of Examples 3 to 6 at room temperature. DETAILED DESCRIPTION
[0036] The present invention will be further explained and illustrated below with reference to specific embodiments.
[0037] Example 1:
[0038] A low temperature resistant supercapacitor (structural diagram as shown Figure 1 As shown; the packaging shell is not shown), the preparation method is as follows:
[0039] 1) 10 g of phytic acid and 3 g of deionized water were premixed using a vortex shaker, and then placed in a shaker and shaken at room temperature for 48 h at a speed of 120 rpm to obtain a phytic acid aqueous solution (the hydrogen bond network diagram of the phytic acid-water system is shown in FIG. Figure 2 shown);
[0040] 2) Aluminum foil coated with an electrode material (composed of activated carbon particles, conductive carbon black, and PVDF in a mass ratio of 8:1:1) was used as an electrode, a phytic acid aqueous solution was used as an electrolyte, and a PP membrane (16 μm thick; Dongguan Kelude New Energy Technology Co., Ltd.) was used as a diaphragm was assembled into a 304 stainless steel packaging case to obtain a low-temperature resistant supercapacitor.
[0041] Example 2:
[0042] A low-temperature resistant supercapacitor (with the same structure as in Example 1) is prepared as follows:
[0043] 1) Premix 10 g of phytic acid and 4 g of deionized water using a vortex shaker, and then shake on a shaker at room temperature for 48 h at a speed of 120 rpm to obtain a phytic acid aqueous solution;
[0044] 2) Aluminum foil coated with an electrode material (same as in Example 1) was used as an electrode, a phytic acid aqueous solution was used as an electrolyte, and a PP diaphragm (same as in Example 1) was used as a diaphragm and assembled into a 304 stainless steel packaging shell to obtain a low-temperature resistant supercapacitor.
[0045] Comparative Example 1:
[0046] A supercapacitor (with the same structure as in Example 1) is prepared as follows:
[0047] 1) Premix 10 g of phytic acid and 1 g of deionized water using a vortex shaker, and then shake on a shaker at room temperature for 48 h at a speed of 120 rpm to obtain a phytic acid aqueous solution;
[0048] 2) An aluminum foil coated with an electrode material (same as in Example 1) was used as an electrode, a phytic acid aqueous solution was used as an electrolyte, and a PP diaphragm (same as in Example 1) was used as a diaphragm and assembled into a 304 stainless steel packaging case to obtain a supercapacitor.
[0049] Comparative Example 2:
[0050] A supercapacitor (with the same structure as in Example 1) is prepared as follows:
[0051] 1) Premix 10 g of phytic acid and 2 g of deionized water using a vortex shaker, and then shake on a shaker at room temperature for 48 h at a speed of 120 rpm to obtain a phytic acid aqueous solution;
[0052] 2) An aluminum foil coated with an electrode material (same as in Example 1) was used as an electrode, a phytic acid aqueous solution was used as an electrolyte, and a PP diaphragm (same as in Example 1) was used as a diaphragm and assembled into a 304 stainless steel packaging case to obtain a supercapacitor.
[0053] Comparative Example 3:
[0054] A supercapacitor (with the same structure as in Example 1) is prepared as follows:
[0055] 1) Premix 10 g of phytic acid and 5 g of deionized water using a vortex shaker, and then shake on a shaker at room temperature for 48 h at a speed of 120 rpm to obtain a phytic acid aqueous solution;
[0056] 2) An aluminum foil coated with an electrode material (same as in Example 1) was used as an electrode, a phytic acid aqueous solution was used as an electrolyte, and a PP diaphragm (same as in Example 1) was used as a diaphragm and assembled into a 304 stainless steel packaging case to obtain a supercapacitor.
[0057] Example 3:
[0058] A low-temperature resistant supercapacitor (with the same structure as in Example 1) is prepared as follows:
[0059] 1) Premix 10 g of lithium phytate and 3 g of deionized water using a vortex shaker, and then shake on a shaker at room temperature for 48 h at a speed of 120 rpm to obtain a lithium phytate aqueous solution;
[0060] 2) An aluminum foil coated with an electrode material (same as in Example 1) was used as an electrode, a lithium phytate aqueous solution was used as an electrolyte, and a PP diaphragm (same as in Example 1) was used as a diaphragm and assembled into a 304 stainless steel packaging shell to obtain a low-temperature resistant supercapacitor.
[0061] Example 4:
[0062] A low-temperature resistant supercapacitor (with the same structure as in Example 1) is prepared as follows:
[0063] 1) Premix 10 g of lithium phytate and 5 g of deionized water using a vortex shaker, and then shake on a shaker at room temperature for 48 h at a speed of 120 rpm to obtain a lithium phytate aqueous solution;
[0064] 2) An aluminum foil coated with an electrode material (same as in Example 1) was used as an electrode, a lithium phytate aqueous solution was used as an electrolyte, and a PP diaphragm (same as in Example 1) was used as a diaphragm and assembled into a 304 stainless steel packaging shell to obtain a low-temperature resistant supercapacitor.
[0065] Example 5:
[0066] A low-temperature resistant supercapacitor (with the same structure as in Example 1) is prepared as follows:
[0067] 1) Premix 10 g of lithium phytate and 7 g of deionized water using a vortex shaker, and then shake on a shaker at room temperature for 48 h at a speed of 120 rpm to obtain a lithium phytate aqueous solution;
[0068] 2) An aluminum foil coated with an electrode material (same as in Example 1) was used as an electrode, a lithium phytate aqueous solution was used as an electrolyte, and a PP diaphragm (same as in Example 1) was used as a diaphragm and assembled into a 304 stainless steel packaging shell to obtain a low-temperature resistant supercapacitor.
[0069] Example 6:
[0070] A low-temperature resistant supercapacitor (with the same structure as in Example 1) is prepared as follows:
[0071] 1) Premix 10 g of lithium phytate and 9 g of deionized water using a vortex shaker, and then shake on a shaker at room temperature for 48 h at a speed of 120 rpm to obtain a lithium phytate aqueous solution;
[0072] 2) An aluminum foil coated with an electrode material (same as in Example 1) was used as an electrode, a lithium phytate aqueous solution was used as an electrolyte, and a PP diaphragm (same as in Example 1) was used as a diaphragm and assembled into a 304 stainless steel packaging shell to obtain a low-temperature resistant supercapacitor.
[0073] Performance testing:
[0074] 1) Wide angle X-ray scattering (WAXS) images of the phytic acid aqueous solution at different temperatures in Example 2 are as follows: Figure 3 As shown, the WAXS patterns of the phytic acid aqueous solution in Comparative Example 3 at different temperatures are as follows Figure 4 shown.
[0075] Depend on Figure 3 It can be seen that the phytic acid aqueous solution in Example 2 does not crystallize at different temperatures, indicating that it has excellent low-temperature resistance.
[0076] Depend on Figure 4 It can be seen that the phytic acid aqueous solution in Comparative Example 3 exhibited crystallization behavior, indicating that its low-temperature resistance was poor.
[0077] 2) The differential scanning calorimetry (DSC) curves of the phytic acid aqueous solution in Examples 1 to 2, the phytic acid aqueous solution in Comparative Examples 1 to 3, and the solid phytic acid are as follows: Figure 5 shown.
[0078] Depend on Figure 5 It can be seen that the glass transition temperatures (T g ) are -44°C, -57°C, 5°C, -27°C, -69°C and 34°C, respectively. The phytic acid aqueous solutions in Examples 1-2 and Comparative Examples 1-2 have no crystallization peaks, while the phytic acid aqueous solution in Comparative Example 3 has a crystallization peak within the test temperature range, indicating that an appropriate amount of water molecules as a plasticizer can effectively reduce the T g , thereby enhancing its chain segment movement ability.
[0079] 3) The conductivity-temperature relationship curves of the phytic acid aqueous solution in Examples 1 to 2, the phytic acid aqueous solution in Comparative Examples 1 to 3, and the solid phytic acid are as follows: Figure 6 shown.
[0080] Depend on Figure 6 It can be seen that:
[0081] a) The electrical conductivity of the phytic acid aqueous solution in Example 1 and Example 2 at 20°C was 1.8×10 -3 S / cm and 3.4×10 -3 S / cm, with high conductivity;
[0082] b) The electrical conductivity of the phytic acid aqueous solution in Comparative Examples 1 to 3 at 20°C was 1.7×10 -5 S / cm, 2.7×10 -4 S / cm and 8.0×10 -3 S / cm, the conductivity of the phytic acid aqueous solution in Comparative Examples 1 and 2 is relatively low, and although the phytic acid aqueous solution in Comparative Example 3 has a high conductivity, a sudden drop in conductivity occurs at its crystallization temperature.
[0083] 4) The CV curves of the low-temperature resistant supercapacitor of Example 2 at room temperature and different scan rates are as follows: Figure 7 As shown, the CV curves of the supercapacitor of Comparative Example 3 at room temperature and different scan rates are as follows Figure 8 shown.
[0084] Depend on Figure 7 and Figure 8It can be seen that the low-temperature resistant supercapacitor of Example 2 and the supercapacitor of Comparative Example 3 both have good rate performance and cycle stability at room temperature.
[0085] 5) The CV curves of the low-temperature resistant supercapacitor of Example 2 at -30°C and different voltages are as follows: Figure 9 As shown, the CV curves of the supercapacitor of comparative example 3 at -30°C and different voltages are as follows: Figure 10 shown.
[0086] Depend on Figure 9 and Figure 10 It can be seen that:
[0087] a) The low-temperature resistant supercapacitor of Example 2 still maintains good capacitance performance at low temperatures, indicating that it has excellent low-temperature resistance;
[0088] b) The capacitance performance of the supercapacitor of Comparative Example 3 is significantly reduced at low temperatures. The reason is that the crystallization of free water in the electrolyte forms ice crystals, which causes the volume of the electrolyte to expand and destroys the good contact between the electrode and the electrolyte.
[0089] 6) The LSV curves of the low temperature resistant supercapacitors of Examples 3 to 6 at room temperature are as follows: Figure 11 shown.
[0090] Depend on Figure 11 It can be seen that the low-temperature resistant supercapacitors of Examples 3 to 6 have a relatively high voltage window, indicating that they have good ion conductivity and stability.
[0091] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.
Claims
1. A low-temperature resistant supercapacitor, characterized in that: The composition includes electrodes, electrolyte, diaphragm and packaging shell; the electrolyte in the electrolyte is an organic phosphorus compound; the glass transition temperature of the electrolyte is -60℃~-30℃, and the room temperature conductivity is ≥1.0×10 -3 S / cm.
2. The low-temperature resistant supercapacitor according to claim 1, characterized in that: The electrolyte in the electrolyte solution is phytic acid or lithium phytate.
3. The low-temperature resistant supercapacitor according to claim 2, characterized in that: The electrolyte is a phytic acid aqueous solution or a lithium phytate aqueous solution.
4. The low-temperature resistant supercapacitor according to claim 3, characterized in that: The mass ratio of phytic acid to water in the phytic acid aqueous solution is 1:0.3-0.
4.
5. The low-temperature resistant supercapacitor according to claim 3, characterized in that: The mass ratio of lithium phytate to water in the lithium phytate aqueous solution is 1:0.3-0.
9.
6. The low-temperature resistant supercapacitor according to any one of claims 1 to 5, characterized in that: The electrode comprises a current collector and an electrode material attached to the surface of the current collector; the current collector is one of aluminum foil, copper foil, titanium foil, and foam copper; the electrode material comprises an electrode active material, conductive carbon black, and polyvinylidene fluoride; the electrode active material is at least one of activated carbon particles, activated carbon fibers, carbon nanotubes, and graphene.
7. The low-temperature resistant supercapacitor according to any one of claims 1 to 5, characterized in that: The diaphragm is one of a Nafion membrane, a Flemion membrane, a polypropylene membrane, and a polyethylene membrane.
8. A method for preparing a low-temperature resistant supercapacitor according to any one of claims 1 to 7, characterized in that: The following steps are involved: The electrolyte is dispersed in a solvent to prepare an electrolyte solution, and then the electrodes, electrolyte solution, diaphragm and packaging shell are assembled to obtain a low-temperature resistant supercapacitor.
9. Use of the low-temperature resistant supercapacitor according to any one of claims 1 to 7 in a low-temperature environment.
10. Use of the low-temperature resistant supercapacitor according to any one of claims 1 to 7 in the field of polar scientific exploration, high-altitude exploration, or aerospace.