CN-122000208-A - Symmetrical cement-based double-electric-layer supercapacitor and preparation method thereof

CN122000208ACN 122000208 ACN122000208 ACN 122000208ACN-122000208-A

Abstract

The invention provides a symmetrical cement-based double-layer supercapacitor and a preparation method thereof, wherein the supercapacitor comprises a positive electrode composite electrode layer, a cement-based solid electrolyte layer and a negative electrode composite electrode layer which are arranged in a sandwich layer structure, the cement-based solid electrolyte layer is formed by hydration and solidification of cement-based materials comprising dead burned magnesium oxide, phosphate, retarder, organic polymer and water, the positive electrode composite electrode layer and the negative electrode composite electrode layer both comprise a current collector and a conductive slurry layer attached to one side of the current collector, and the cement-based solid electrolyte layer and the positive electrode composite electrode layer and the negative electrode composite electrode layer on two sides of the cement-based solid electrolyte layer are solidified into an integral structure.

Inventors

ZHANG YUNPENG
WANG CHAO
Pan Shaoxue
Huo Liangliang
XU GUOWEN

Assignees

中国建筑第八工程局有限公司

Dates

Publication Date: 20260508
Application Date: 20260310

Claims (10)

1. The symmetrical cement-based double-electric-layer supercapacitor is characterized by comprising a positive electrode composite electrode layer, a cement-based solid electrolyte layer and a negative electrode composite electrode layer which are arranged in a sandwich layered structure; The cement-based solid electrolyte layer is formed by hydration and solidification of cement-based materials comprising dead burned magnesia, phosphate, retarder, organic polymer and water; the positive electrode composite electrode layer and the negative electrode composite electrode layer comprise a current collector and a conductive slurry layer attached to one side of the current collector; the cement-based solid electrolyte layer, the positive electrode composite electrode layer and the negative electrode composite electrode layer on two sides of the cement-based solid electrolyte layer are solidified into an integrated structure.
2. The symmetrical cement-based double layer supercapacitor of claim 1, wherein the current collector is nickel foam; The conductive paste layer is formed by uniformly coating and drying composite conductive paste containing active carbon on one side of the current collector.
3. The symmetrical cement-based double electric layer supercapacitor of claim 2, wherein the foamed nickel has a thickness of 1-2 mm and a porosity of 60-98%.
4. The symmetrical cement-based double electric layer supercapacitor of claim 2, wherein the composite conductive paste is prepared by uniformly mixing and grinding active carbon, a conductive additive, a binder and an organic solvent.
5. The symmetrical cement-based double electric layer supercapacitor of claim 4, wherein the activated carbon has a specific surface area of not less than 1500m 2 /g and ash content of less than 0.5%; the conductive auxiliary agent is one or more of conductive carbon black, carbon nano tubes and graphene, and the doping amount is 5-20% of the mass of the active carbon; The binder is polyvinylidene fluoride emulsion, and the mixing amount is 5-15% of the mass of the activated carbon; The organic solvent is 1-methyl-2-pyrrolidone and is used for adjusting the active carbon composite conductive paste to be bright black ink paste.
6. The symmetrical cement-based double electric layer supercapacitor of claim 1, wherein the phosphate is one or a mixture of potassium dihydrogen phosphate or ammonium dihydrogen phosphate; the molar ratio of the re-burned magnesium oxide to the phosphate is 1:1-5:1; the retarder is borax, and the doping amount is 0.2-2.0% of the total mass of the re-burned magnesium oxide and the phosphate; the water-cement ratio of the magnesium phosphate cement matrix is 0.3-0.6.
7. The symmetrical cement-based double layer supercapacitor of claim 1, wherein the organic polymer is polyacrylic acid or polyacrylamide; The mixing amount of the polyacrylic acid is 1-10% of the total mass of the re-burned magnesium oxide and the phosphate; The mixing amount of the polyacrylamide is 0.5-5.0% of the total mass of the dead burned magnesium oxide and the phosphate.
8. The preparation method of the symmetrical cement-based double-electric-layer supercapacitor is characterized by comprising the following steps of: The current collector is taken for cleaning and then dried to remove the greasy dirt and the oxidation layer on the surface; The preparation of the composite conductive paste comprises the steps of uniformly mixing and grinding active carbon, a conductive additive and a binder with an organic solvent to prepare the composite conductive paste in the form of bright black ink; The preparation of the composite electrode comprises the steps of uniformly coating composite conductive slurry on a treated current collector, drying and pressurizing to prepare a composite electrode layer; The preparation of cement-based electrolyte comprises the steps of uniformly dry-mixing the re-burned magnesium oxide, phosphate and retarder to prepare a dry mixture, dissolving polyacrylic acid or polyacrylamide in water to prepare an organic polymer solution, adding the organic polymer solution into the dry mixture, and uniformly stirring to prepare modified magnesium phosphate cement electrolyte slurry; Placing a composite electrode layer with one surface of the conductive slurry layer facing upwards at the bottom of a mould, pouring the modified magnesium phosphate cement electrolyte slurry on the composite electrode layer in the mould before initial setting, vibrating and exhausting and strickling, covering the upper surface of the modified magnesium phosphate cement electrolyte slurry with another composite electrode layer with one surface of the conductive slurry layer facing downwards, slightly applying pressure, and compacting the interface between the composite electrode layer and the cement-based electrolyte; Curing and demolding, namely curing until the magnesium phosphate cement is hardened under the conditions of room temperature or constant temperature and constant humidity, and demolding to obtain the symmetrical cement-based double electric layer supercapacitor.
9. The method for manufacturing a symmetrical cement-based double electric layer supercapacitor according to claim 8, wherein in the step of manufacturing the composite electrode, the coating thickness of the composite conductive paste on the current collector is 100-500 μm.
10. The method for manufacturing a symmetrical cement-based double electric layer supercapacitor according to claim 8, wherein in the assembling and forming steps, the casting thickness of the modified magnesium phosphate cement electrolyte slurry is 2-10 mm.

Description

Symmetrical cement-based double-electric-layer supercapacitor and preparation method thereof Technical Field The invention belongs to the technical field of building functional materials, and particularly relates to a symmetrical cement-based double-electric-layer supercapacitor and a preparation method thereof. Background Building energy storage is one of main forms of distributed energy storage at a user side, has the advantages of being close to a using end, low in power transmission loss and the like, and along with the rising of green building and intelligent building concepts, the integration of energy storage devices into building structures becomes a research hot spot. The traditional battery or super capacitor usually uses liquid electrolyte, and has the problems of easy leakage, difficult packaging, incapacity of bearing mechanical load and the like, and is difficult to be directly applied to the inside of a building structure. Cement, which is the most widely used building material, has great application potential if it can be endowed with energy storage function. The development of the cement-based capacitor technology realizes the organic combination of a large amount of building materials and a novel energy storage technology, and the cement-based capacitor belongs to a solid electrolyte capacitor, and has the characteristics of high storage speed, long cycle life, safety, stability and the like, and is highly matched with the energy storage requirement of a building. However, portland cement has extremely low ionic conductivity and a pore structure is not connected, although it has high strength, resulting in extremely high internal resistance and extremely low specific capacitance of a capacitor based on portland cement. As a novel cementing material, the Magnesium Phosphate Cement (MPC) has the characteristics of quick hardening, early strength, high cohesive force, good compatibility, easy regulation and control of pore structure and the like. However, the pore structure and water retention of pure MPC matrices still have difficulty meeting the requirements of high performance solid state electrolytes. Therefore, there is a need to design a supercapacitor with good mechanical strength and ion transmission performance to solve the technical problems faced at present. Disclosure of Invention Aiming at the defects existing in the prior art, the invention provides a symmetrical cement-based double-electric-layer supercapacitor with good mechanical strength and ion transmission performance and a preparation method thereof. The technical scheme of the invention is that the symmetrical cement-based double-electric-layer supercapacitor is characterized by comprising a positive electrode composite electrode layer, a cement-based solid electrolyte layer and a negative electrode composite electrode layer which are arranged in a sandwich layered structure; The cement-based solid electrolyte layer is formed by hydration and solidification of cement-based materials comprising dead burned magnesia, phosphate, retarder, organic polymer and water; the positive electrode composite electrode layer and the negative electrode composite electrode layer comprise a current collector and a conductive slurry layer attached to one side of the current collector; the cement-based solid electrolyte layer, the positive electrode composite electrode layer and the negative electrode composite electrode layer on two sides of the cement-based solid electrolyte layer are solidified into an integrated structure. Further, the current collector is foam nickel; The conductive paste layer is formed by uniformly coating and drying composite conductive paste containing active carbon on one side of the current collector. Further, the thickness of the foam nickel is 1-2 mm, and the porosity is 60-98%. Further, the composite conductive paste is prepared by uniformly mixing and grinding active carbon, a conductive additive, a binder and an organic solvent. Further, the specific surface area of the activated carbon is not less than 1500m 2/g, and the ash content is less than 0.5%; the conductive auxiliary agent is one or more of conductive carbon black, carbon nano tubes and graphene, and the doping amount is 5-20% of the mass of the active carbon; The binder is polyvinylidene fluoride emulsion, and the mixing amount is 5-15% of the mass of the activated carbon; The organic solvent is 1-methyl-2-pyrrolidone and is used for adjusting the active carbon composite conductive paste to be bright black ink paste. Further, the phosphate is one or two of potassium dihydrogen phosphate or ammonium dihydrogen phosphate; the molar ratio of the re-burned magnesium oxide to the phosphate is 1:1-5:1; the retarder is borax, and the doping amount is 0.2-2.0% of the total mass of the re-burned magnesium oxide and the phosphate; the water-cement ratio of the magnesium phosphate cement matrix is 0.3-0.6. Further, the organic polymer is polyacrylic acid or