Long-life cement-based battery and preparation method thereof

Abstract

The invention discloses a long-life cement-based battery and a preparation method thereof. The cement-based battery comprises a cement matrix, an electrolyte, a positive electrode, an insulator diaphragm, a negative electrode, a positive current collector and a negative current collector, the insulator diaphragm is embedded in the cement base body and divides the cement base body into two independent areas, one area is internally provided with a positive electrode, and the other area is internally provided with a negative electrode; the positive current collector is tightly attached to the positive electrode, the negative current collector is tightly attached to the negative electrode, and the positive current collector and the negative current collector both extend to the outer end of the cement base body and are led out; and the electrolyte is filled in internal pores of the cement matrix and gaps among the positive electrode, the negative electrode and the insulator diaphragm. According to the cement-based battery provided by the invention, the nano silicon dioxide, the lanthanum cobaltate, the manganese dioxide and the composite conductive carbon material are added into the conductive concrete, so that the cement-based battery has electrochemical performance and mechanical performance, is long in service life and has extremely high industrial application value.

Description

Technical Field

[0001] This invention relates to a long-life cement-based battery and its preparation method, belonging to the field of cement-based battery technology. Background Technology

[0002] Guided by the "dual carbon" goal, power plants and equipment for clean energy sources such as solar, wind, and hydropower have been built, improved, and put into use. However, solar, wind, and hydropower have different drawbacks due to factors such as season, climate, and geographical location, and excessive power generation capacity can easily overload the power grid system. Therefore, effective energy storage has become one of the key issues for the efficient utilization of clean energy.

[0003] Chemical energy storage batteries are among the most commonly used energy storage devices in the world. They typically employ traditional electrochemical energy storage principles, relying on the chemical reaction between electrodes and electrolytes to store and release energy. Cement-based batteries, as an emerging type of electrochemical energy storage battery, combine cement-based materials (such as concrete) with conductive additives and electrode materials to enable them to perform energy storage. With the development of low-carbon buildings and smart cities, cement-based batteries have become one of the key technologies for "energy storage buildings." Although existing cement-based batteries can achieve building integration, their lifespan is relatively short, making it difficult to meet the energy storage requirements of long-term building structures, thus hindering their commercialization. Therefore, it is necessary to develop a method for preparing cement-based batteries that can improve lifespan while maintaining structural integration and mechanical performance, which has become a pressing technical problem for those skilled in the art. Summary of the Invention

[0004] To address the aforementioned problems in the existing technology, the purpose of this invention is to provide a long-life cement-based battery and its preparation method.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A high-life cement-based battery includes a cement matrix, an electrolyte, a positive electrode, an insulating diaphragm, a negative electrode, a positive current collector, and a negative current collector. The insulating diaphragm is embedded inside the cement matrix, dividing the cement matrix into two independent regions, one region housing the positive electrode and the other region housing the negative electrode. The positive current collector is in close contact with the positive electrode, and the negative current collector is in close contact with the negative electrode. Both the positive and negative current collectors extend to the outer end of the cement matrix and are led out. The electrolyte fills the internal pores of the cement matrix and the gaps between the positive and negative electrodes and the insulating diaphragm. The cementitious matrix is ​​obtained by pouring and curing conductive concrete slurry, which has the following composition and proportions: Cement: 100 parts by weight; Particulate filler: 60-80 parts by weight; Deionized water: 30-40 parts by weight; Nano-silica: 1.0-1.5 parts by weight; Lanthanum cobalt oxide: 2-3 parts by weight; Manganese dioxide: 2-4 parts by weight; Composite conductive carbon material: 3-5 parts by weight; Nonionic dispersant: 0.5-1 parts by weight; Sulfonate dispersant: 0.5-1 parts by weight; Hydration agent: 0.5-1 parts by weight; Lithium nitrate: 0.5-1 parts by weight; Corrosion inhibitor: 0.5-1 parts by weight; Interface modification material: 0.5-1 parts by weight; Air-entraining agent: 0.01-0.05 parts by weight; Porous material: 3-5 parts by weight; The aforementioned composite conductive carbon material is obtained by first modifying reduced graphene oxide by silanization and then by modifying it with a water-reducing agent containing amino terminals to obtain modified reduced graphene oxide mGO. Then, with graphite as the core, mGO is coated on the surface of graphite to obtain a core-shell structured graphite@mGO. Finally, graphite@mGO is composited with carbon fiber.

[0006] In one embodiment, the particulate filler is selected from one or more of the following: quartz sand, river sand, aeolian sand, copper mine tailings, iron mine tailings, manganese mine tailings, tungsten mine tailings, zinc mine tailings, and red mud. The nonionic dispersant is selected from one or more of PVP, poloxamer, and Tween 80; The hydrating agent is selected from one or more of lithium carbonate, barium nitrate, calcium nitrate, sodium sulfate, and calcium formate; The air-entraining agent is selected from one or more of the following: rosin thermal polymer, sodium dodecylbenzene sulfonate, tea saponin, and fatty alcohol polyoxyethylene ether; The interface modification material is selected from one or more of KH550, KH560, KH570, and TiN / CrN; The corrosion inhibitor is selected from one or more of sodium phosphate, sodium silicate, benzimidazole, and hexadecylamine; The porous material is selected from one or more of zeolite, montmorillonite, and diatomite.

[0007] One embodiment of the preparation of the composite conductive carbon material includes the following steps: 1) Disperse 190-210 parts by weight of reduced graphene oxide (rGO) in an aqueous ethanol solution (ethanol:water mass ratio of 4:1) to obtain an rGO slurry with a solid content of 5%; add the rGO slurry to a reaction vessel, disperse at high speed, adjust the pH to 5.3-5.7 with hydrochloric acid, raise the temperature to 58-62℃, add 28-32 parts by weight of GPTMS dropwise, and after the addition is complete, keep the temperature for 1-3 hours. After the reaction is completed, cool down to below 40℃, separate the solid and liquid, and wash the separated solid with ethanol 1-3 times to obtain a silanized reduced graphene oxide (GO-EP) wet filter cake; 2) Redisperse the GO-EP wet filter cake in water, adjust the solid content to 15%, add NaOH aqueous solution to adjust the pH to 8.3-8.7, add 230-250 parts by weight of amino-terminated water-reducing agent on a dry basis, and then stir the reaction at 78-82℃ for 3-5 hours. After the reaction is completed, cool down to below 50℃, separate the solid and liquid, wash and dry the separated solid to obtain modified redox graphene mGO; 3) Mix 49-51 parts by weight of mGO, 0.4-0.6 parts by weight of sodium hexametaphosphate and 440-460 parts by weight of deionized water evenly to obtain an mGO coating solution; Add 490-510 parts by weight of graphite to a fluidized bed, use hot air at 78-82℃ to fluidize for 20-40 minutes to preheat the material evenly, and then spray the mGO coating liquid. After coating, dry, cool and sieve to obtain graphite@mGO with a core-shell structure. 4) Mix 9-11 parts by weight of hydrophobic silica, 1.8-2.2 parts by weight of antistatic agent and 19-21 parts by weight of ethanol evenly to form a uniform slurry; spray the obtained slurry onto 49-51 parts by weight of graphite@mGO, dry to remove ethanol, and obtain SiO2 masterbatch. Add 790-810 parts by weight of graphite@mGO to a mixer, add the SiO2 masterbatch, mix them evenly, then add 178-182 parts by weight of carbon fiber, mix for 45-60 minutes, sieve the resulting mixture, homogenize it, and obtain the composite conductive carbon material.

[0008] In a preferred embodiment, in step 3), the graphite is flake graphite or expanded graphite.

[0009] In a preferred embodiment, in step 3), the graphite is pretreated by air jet milling (milling to D50=50±5μm), drying (fluidized drying at 120℃ for 2 hours until moisture content <0.5%), and sieving (passing through a 100-mesh sieve to remove coarse particles) before being added to the fluidized bed.

[0010] In a preferred embodiment, in step 4), the carbon fiber is pretreated by opening and wetting before being added to the mixer. The wetting agent used during wetting is a 5% aqueous solution of polyvinylpyrrolidone (PVP), and the amount of wetting agent is 10% of the mass of the carbon fiber.

[0011] In a preferred embodiment, in step 4), the antistatic agent is dioctadecyldimethylammonium chloride.

[0012] One embodiment of the preparation of lanthanum cobalt oxide includes the following steps: Lanthanum nitrate hexahydrate and cobalt nitrate hexahydrate are dissolved in water to obtain a metal ion solution; Citric acid, ethylene glycol and water are stirred and mixed evenly to obtain a complexing agent solution; The metal ion solution is slowly added dropwise to the complexing agent solution, while stirring continuously and heating to 80°C. The temperature is maintained and the water is evaporated until a dark blue, transparent, viscous sol is formed. Stirring continues to form a wet gel. The wet gel was redispersed with an appropriate amount of deionized water to form a homogeneous solution, which was then transferred to the liner of the reaction vessel. The reaction vessel was placed in a microwave synthesizer and subjected to hydrothermal reaction at 175-185℃ for 50-70 minutes, and then allowed to cool naturally to room temperature. The microwave hydrothermal products were centrifuged and separated. The separated solids were washed (washed three times alternately with deionized water and ethanol) and dried (dried at 80°C for 12 hours) to obtain precursor powder. The precursor powder was placed in a crucible and then placed in a muffle furnace. It was calcined at 550-600℃ for 2-3 hours in air atmosphere, cooled to room temperature with the furnace, and then ground to obtain lanthanum cobalt oxide nanopowder.

[0013] In a preferred embodiment, during the preparation of lanthanum cobaltate, the total concentration of metal ions in the metal ion solution is 0.1-0.3 mol / L; n(citric acid) : n(total metal ions) = (1-2) : 1.

[0014] In one embodiment, the electrolyte in the cement-based battery has the following composition and proportions: Potassium hydroxide: 10-15 parts by weight; Potassium silicate: 5-10 parts by weight; Lithium nitrate: 0.5-2 parts by weight; Deionized water: 52-58 parts by weight; Sodium carboxymethyl cellulose: 3.5-5 parts by weight; Polyvinyl alcohol: 1.5-2.5 parts by weight; Glycerin: 7-10 parts by weight; Polyethylene glycol: 3-5 parts by weight; Silane coupling agent: 0.3-0.8 parts by weight; Boric acid: 0.4-0.8 parts by weight.

[0015] In a preferred embodiment, the preparation of the electrolyte includes the following steps: Add the specified amount of polyvinyl alcohol to 60% of the specified amount of deionized water, stir at 85-90℃ until it is completely dissolved, then cool down to 70-75℃, add the specified amount of sodium carboxymethyl cellulose, stir until it is completely dissolved, then cool down to below 40℃, add the specified amounts of glycerol, polyethylene glycol and silane coupling agent in sequence, stir evenly to obtain the main polymer solution. Dissolve the specified amount of potassium hydroxide in 40% deionized water to obtain a potassium hydroxide solution. Add potassium hydroxide solution to the main polymer solution and stir to mix evenly. Then add the specified amounts of potassium silicate and lithium nitrate and stir to dissolve them to obtain a gel solution. Then slowly add the specified amount of boric acid to the gel solution and stir to mix evenly to obtain a gel-like electrolyte.

[0016] In one embodiment, both the positive and negative electrodes are made of carbon fiber cloth, both the positive and negative current collectors are made of aluminum strips, and the insulating diaphragm is made of polyethylene film or polypropylene film with a thickness of 0.1-0.3 mm.

[0017] A method for preparing a long-life cement-based battery includes the following steps: a) Preparation of conductive concrete grout: Mix all the components in the specified proportions evenly to ensure that all components are mixed uniformly and without particle agglomeration, thus obtaining conductive concrete slurry. b) Casting and Curing: The conductive concrete slurry is poured into the pre-set mold, and the lower unit of the positive electrode cement matrix and the lower unit of the negative electrode cement matrix are poured respectively. Then, positive electrode material and negative electrode material are laid on the top surface of the positive electrode cement matrix unit and the negative electrode cement matrix unit respectively. The size of the positive electrode material and the negative electrode material is slightly smaller than the mold. One side of the positive electrode material and the negative electrode material is fixed with positive current collector material and negative current collector material respectively. Wires are welded on the positive current collector material and the negative current collector material respectively and led out of the mold. Continue pouring conductive concrete slurry into the mold, and pour the upper positive and lower negative cement matrix units on top of the lower positive and lower negative cement matrix units respectively. The lower positive and lower negative cement matrix units, the upper positive and lower negative cement matrix units together form the cement matrix. After pouring, vibrate to compact and eliminate internal air bubbles. Then, place the formed concrete specimen in a constant temperature and humidity environment for 5-8 days to ensure that the concrete is fully hardened, and obtain the positive cement matrix-electrode-current collector assembly and the negative cement matrix-electrode-current collector assembly. c) Soaking in potassium hydroxide solution: The cured positive electrode cement matrix-electrode-current collector assembly and negative electrode cement matrix-electrode-current collector assembly were respectively immersed in a 20-30 wt% potassium hydroxide aqueous solution at room temperature for 2-3 days. After immersion, they were taken out and air-dried. d) Coating and penetration of electrolyte: The gel-like electrolyte is evenly coated on the surface of the positive and negative cement matrix in the assembly. Then the coated assembly is placed in a constant temperature and humidity environment and left to stand for 24-48 hours to allow the electrolyte to fully penetrate and solidify. e) Battery molding: When the electrolyte gel coated on the surface of the positive and negative electrode cement substrates has solidified to the touch-dry state, the insulating diaphragm is inserted between the positive and negative electrode cement substrates, and the insulating diaphragm and the assembly are pressed together to obtain a cement-based battery.

[0018] In one embodiment, step a) of preparing the conductive concrete slurry includes the following steps: 100 parts by weight of cement, 60-80 parts by weight of granular filler, 1.0-1.5 parts by weight of nano-silica, 2-3 parts by weight of lanthanum cobalt oxide, 2-4 parts by weight of manganese dioxide and 3-5 parts by weight of porous material are stirred and mixed evenly to obtain a dry powder mixture. Mix 21-28 parts by weight of deionized water, 0.5-1 parts by weight of nonionic dispersant, 0.5-1 parts by weight of sulfonate dispersant, 0.5-1 parts by weight of hydrating agent, 0.5-1 parts by weight of lithium nitrate and 0.5-1 parts by weight of corrosion inhibitor evenly to obtain liquid base material. 9-12 parts by weight of deionized water, 3-5 parts by weight of composite conductive carbon material and 0.5-1 parts by weight of interface modification material are stirred and mixed evenly to obtain nano-slurry. The liquid base material is slowly added to the dry powder mixture and stirred until it is evenly mixed. Then, the nano-slurry is added and stirred until it is evenly mixed. Finally, 0.01-0.05 parts by weight of air-entraining agent is added and stirred until it is evenly mixed to obtain conductive concrete slurry.

[0019] In one embodiment, in step d), the coating thickness of the electrolyte is 0.5-1 mm.

[0020] Compared with the prior art, the present invention has the following significant advantages: The cement-based battery provided by this invention incorporates nano-silica, lanthanum cobalt oxide, manganese dioxide, and composite conductive carbon materials into the conductive concrete. This allows the cement-based battery to possess both electrochemical and mechanical properties, as well as a long service life, making it highly valuable for industrial applications. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the cement-based battery provided by the present invention; The labels in the diagram are as follows: 1. Electrolyte; 2. Positive electrode; 3. Insulating membrane; 4. Negative electrode; 5. Positive current collector; 6. Negative current collector. Detailed Implementation

[0022] The technical solution of the present invention will be further described in detail and completely below with reference to the embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. Experimental methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or as recommended by the manufacturer. Example 1

[0023] 1) Preparation of composite conductive carbon materials: 1) 200 parts by mass of reduced graphene oxide rGO (Suzhou Carbon-rich Technology) were dispersed in an ethanol-water solution (ethanol:water mass ratio of 4:1) to obtain an rGO slurry with a solid content of 5%; the rGO slurry was added to a reaction vessel and dispersed at high speed (1500 rpm), the pH was adjusted to 5.5 with 5 wt% hydrochloric acid, the temperature was raised to 60℃, and 30 parts by mass of GPTMS (Nanjing Shuguang Chemical, epoxy value 0.45-0.55) were added dropwise. After the addition was completed, the reaction was kept at the temperature for 2 hours. After the reaction was completed, the temperature was lowered to below 40℃, and the solid was separated by centrifugation. The solid obtained was washed three times with ethanol to obtain a silanized reduced graphene oxide GO-EP wet filter cake. 2) The GO-EP wet filter cake was redispersed in water, the solid content was adjusted to 15%, 10wt% NaOH aqueous solution was added to adjust the pH to 5, and 600 parts by weight of amino-terminated water-reducing agent (Jiangsu Subote PCA®-I, solid content 40%, dry basis 240 parts by weight) was added. Then the reaction was stirred at 80℃ for 4 hours. After the reaction was completed, the temperature was lowered to below 50℃, the solid and liquid were separated, the separated solid was washed and dried to obtain modified redox graphene mGO; 3) Mix 50 parts by weight of mGO, 0.5 parts by weight of sodium hexametaphosphate and 450 parts by weight of deionized water evenly to obtain an mGO coating solution; Flake graphite (Qingdao Chenyang graphite) was pulverized by air jet milling to D50=50±5μm, then fluidized and dried at 120℃ for 2 hours until the moisture content was <0.5%, and then passed through a 100-mesh sieve to remove coarse particles, thus obtaining pretreated flake graphite. 500 parts by weight of pretreated flake graphite were added to a fluidized bed and fluidized for 30 minutes using hot air at 80°C to ensure uniform preheating of the material. Then, the material was spray-coated with the mGO coating liquid. During the spray coating process: bed temperature: 70°C (outlet); inlet temperature: 130°C; spray pressure: 0.35 MPa; spray rate: 18 L / min; atomizing air pressure: 0.5 MPa; fluidizing air volume: 1800 m³ / h; spray method: bottom spray. After coating, the material was fluidized and dried with hot air at 100°C for 1 hour, cooled to below 40°C with room temperature air, and passed through an 80-mesh sieve to obtain core-shell structured graphite@mGO. 4) Mix 10 parts by weight of hydrophobic silica (Evonik Degussa, AEROSIL R972), 2 parts by weight of antistatic agent (bis(octadecyldimethylammonium chloride)) and 20 parts by weight of ethanol evenly to form a uniform slurry; spray the obtained slurry onto 50 parts by weight of graphite@mGO, dry to remove ethanol, and obtain SiO2 masterbatch. The carbon fiber (Jiangsu Hengshen Co., Ltd., nickel-plated CF) was opened using a needle roller opener. The spacing of the needle roller opener was 2.5 times the diameter of the carbon fiber. At the same time, 10% of the total carbon fiber was sprayed with a wetting agent (5% polyvinylpyrrolidone aqueous solution) to wet the carbon fiber. Then, it was dried with hot air at 80°C until the moisture content was <2% to obtain the pretreated carbon fiber. 800 parts by mass of graphite@mGO were added to a mixer, and the SiO2 masterbatch was added to mix them evenly. Then, 180 parts by mass of pretreated carbon fiber were added and mixed for 50 minutes. The resulting mixture was passed through an 80-mesh sieve and homogenized in a homogenization chamber for 10 minutes to obtain a composite conductive carbon material with a three-level composite structure of "graphite core-mGO shell-CF bridge".

[0024] (ii) Preparation of Lanthanum Cobalt Oxide 2.166 g of lanthanum nitrate hexahydrate and 1.746 g of cobalt nitrate hexahydrate were dissolved in 20 mL of water to obtain a metal ion solution. The molar ratio of La to Co in the solution was 1:1, and the total metal ion concentration was approximately 0.2 mol / L. Add 4.202g of citric acid to 10mL of deionized water and stir until completely dissolved. Then add 3.0mL of ethylene glycol and stir to mix evenly to obtain a complexing agent solution. The metal ion solution is slowly added dropwise to the complexing agent solution, while stirring continuously and heating to 80°C. The temperature is maintained and the water is evaporated until a dark blue, transparent, viscous sol is formed. Stirring continues to form a wet gel. The wet gel was redispersed with 15 mL of deionized water to form a homogeneous solution, which was then transferred to the liner of the reaction vessel. The reaction vessel was placed in a microwave synthesizer and subjected to hydrothermal reaction at 180 °C for 60 minutes, and then allowed to cool naturally to room temperature. The microwave hydrothermal product was centrifuged, and the resulting solid was washed (washed three times alternately with deionized water and ethanol) and dried at 80°C for 12 hours to obtain the precursor powder. The precursor powder was placed in a crucible and placed in a muffle furnace. It was calcined at 580°C for 3 hours in air atmosphere, cooled to room temperature with the furnace, and then ground to obtain lanthanum cobalt oxide nanopowder.

[0025] III) Preparation of Cement-Based Batteries The cement-based battery, such as Figure 1 As shown, the cement-based battery includes a cement matrix, an electrolyte 1, a positive electrode 2, an insulating diaphragm 3, a negative electrode 4, a positive current collector 5, and a negative current collector 6. The insulating diaphragm 3 is embedded inside the cement matrix, dividing the cement matrix into two independent regions, one region containing the positive electrode 2 and the other region containing the negative electrode 4. The positive current collector 5 is in close contact with the positive electrode 2, and the negative current collector 6 is in close contact with the negative electrode 4. Both the positive current collector 5 and the negative current collector 6 extend to the outer end of the cement matrix. The electrolyte 1 fills the internal pores of the cement matrix and the gaps between the positive and negative electrodes 2 and 4 and the insulating diaphragm 3. The preparation of the cement-based battery includes the following steps: a) Preparation of conductive concrete grout: 100 parts by weight of cement, 70 parts by weight of granular filler (quartz sand + copper ore tailings, mass ratio 1:1), 1.2 parts by weight of nano-silica, 2.5 parts by weight of lanthanum cobalt oxide, 3 parts by weight of manganese dioxide and 4 parts by weight of porous material (zeolite) are stirred and mixed evenly to obtain a dry powder mixture. 25 parts by weight of deionized water, 0.8 parts by weight of nonionic dispersant (PVP), 0.8 parts by weight of sulfonate dispersant (Point-S), 0.8 parts by weight of hydrating agent (lithium carbonate + calcium nitrate, mass ratio 1:1), 0.8 parts by weight of lithium nitrate and 0.8 parts by weight of corrosion inhibitor (sodium phosphate) are stirred and mixed evenly to obtain a liquid base material. 10.5 parts by weight of deionized water, 4 parts by weight of composite conductive carbon material and 0.8 parts by weight of interface modifier (KH550) were stirred and mixed evenly to obtain nano-slurry; The liquid base material is slowly added to the dry powder mixture and stirred until it is evenly mixed. Then, the nano slurry is added and stirred until it is evenly mixed. Then, 0.03 parts by weight of air-entraining agent (rosin thermal polymer, Jiangsu Subote New Material Co., Ltd., PCA®-1) is added and stirred until it is evenly mixed without particle agglomeration, thus obtaining conductive concrete slurry. b) Casting and Curing: The conductive concrete slurry was poured into the pre-set mold, and the positive electrode cement matrix lower unit and the negative electrode cement matrix lower unit with the specifications of "thickness 2.5cm × width 40cm × length 40cm" were poured respectively. Then, carbon fiber cloth (Jiangsu Hengshen, HFW300T) is laid on the top surface of the positive electrode cement matrix unit and the negative electrode cement matrix unit respectively. The size of the carbon fiber cloth is slightly smaller than the mold. One side of the carbon fiber cloth is fixed with aluminum strips (5A06 anti-rust aluminum strips, thickness 1.5mm × width 30mm × length 450mm). Wires are welded on the aluminum strips and led out of the mold. Continue pouring conductive concrete slurry into the mold. Positive and negative cement matrix upper units, each with dimensions of 2.5cm thickness × 40cm width × 40cm length, are poured on top of the lower positive and negative cement matrix units, respectively. These units together form the cement matrix. After pouring, the concrete is vibrated to ensure compaction and eliminate internal air bubbles. The formed concrete specimens are then placed in a constant temperature and humidity environment (temperature 25℃, humidity >90%RH) for 6 days to ensure full hardening, resulting in positive and negative cement matrix-electrode-current collector assemblies. c) Soaking in potassium hydroxide solution: The cured positive electrode cement matrix-electrode-current collector assembly and negative electrode cement matrix-electrode-current collector assembly were respectively immersed in a 25wt% potassium hydroxide aqueous solution at room temperature for 3 days. After immersion, they were taken out and air-dried. d) Electrolyte coating and infiltration: Add 2 parts by weight of polyvinyl alcohol (PVA 1788) to 33 parts by weight of deionized water, stir at 88°C until completely dissolved, then cool to 72°C, add 4.5 parts by weight of sodium carboxymethyl cellulose (CMC), stir until completely dissolved, then cool to below 40°C, add 8.5 parts by weight of glycerol, 4 parts by weight of polyethylene glycol (PEG-400) and 0.6 parts by weight of silane coupling agent (KH550) in sequence, stir evenly to obtain the main polymer solution; Dissolve 12 parts by mass of potassium hydroxide in 22 parts by mass of deionized water to obtain a potassium hydroxide solution; Add potassium hydroxide solution to the main polymer solution and stir to mix evenly. Then add 8 parts by mass of potassium silicate and 1 part by mass of lithium nitrate and stir to dissolve them to obtain a gel solution. Then slowly add 0.6 parts by mass of boric acid to the gel solution and stir to mix evenly to obtain a gel-like electrolyte. The gel-like electrolyte is evenly applied to the surface of the positive and negative electrode cement matrix in the assembly, with a coating thickness of 1 mm. Then, the coated assembly is placed in a constant temperature and humidity environment (temperature 25℃, humidity >90%RH) and left to stand for 36 hours to allow the electrolyte to fully penetrate and solidify. e) Battery Molding: When the electrolyte gel coated on the surfaces of the positive and negative electrode cement substrates has cured to a touch-dry state, an insulating diaphragm (polypropylene film, 0.2 mm thick) is inserted between the positive and negative electrode cement substrates, and the insulating diaphragm is pressed into the assembly to form a single unit, resulting in... Figure 1 The cement-based battery shown. Example 2

[0026] 1) Preparation of composite conductive carbon materials: Same as Example 1; (ii) Preparation of Lanthanum Cobalt Oxide Same as Example 1; III) Preparation of Cement-Based Batteries a) Preparation of conductive concrete grout: 100 parts by weight of cement, 75 parts by weight of granular filler (quartz sand + manganese tailings, mass ratio 3:1), 1.3 parts by weight of nano-silica, 2.8 parts by weight of lanthanum cobalt oxide, 3.2 parts by weight of manganese dioxide and 4.5 parts by weight of porous material (diatomite + montmorillonite, mass ratio 4:1) are stirred and mixed evenly to obtain a dry powder mixture. 28 parts by weight of deionized water, 0.9 parts by weight of nonionic dispersant (Tween 80), 0.7 parts by weight of sulfonate dispersant (Point-S), 0.9 parts by weight of hydrating agent (calcium nitrate + calcium formate, mass ratio 2:1), 0.9 parts by weight of lithium nitrate and 0.9 parts by weight of corrosion inhibitor (sodium silicate + hexadecylamine, mass ratio 1:1) were stirred and mixed evenly to obtain a liquid base material. 11 parts by mass of deionized water, 4 parts by mass of composite conductive carbon material and 0.9 parts by mass of interface modifier (KH560) were stirred and mixed evenly to obtain nano-slurry. The liquid base material is slowly added to the dry powder mixture and stirred until it is evenly mixed. Then the nano slurry is added and stirred until it is evenly mixed. Then 0.025 parts by weight of air-entraining agent (tea saponin) is added and stirred until it is evenly mixed without particle agglomeration, thus obtaining conductive concrete slurry. b) Casting and Curing: The conductive concrete slurry was poured into the pre-set mold, and the positive electrode cement matrix lower unit and the negative electrode cement matrix lower unit with the specifications of "thickness 2.5cm × width 40cm × length 40cm" were poured respectively. Then, carbon fiber cloth (Jiangsu Hengshen, HFW300T) is laid on the top surface of the positive electrode cement matrix unit and the negative electrode cement matrix unit respectively. The size of the carbon fiber cloth is slightly smaller than the mold. One side of the carbon fiber cloth is fixed with aluminum strips (5A06 anti-rust aluminum strips, thickness 1.5mm × width 30mm × length 450mm). Wires are welded on the aluminum strips and led out of the mold. Continue pouring conductive concrete slurry into the mold. Positive and negative cement matrix upper units, each with dimensions of 2.5cm thickness × 40cm width × 40cm length, are poured on top of the lower positive and negative cement matrix units, respectively. These units together form the cement matrix. After pouring, the concrete is vibrated to ensure compaction and eliminate internal air bubbles. The formed concrete specimens are then placed in a constant temperature and humidity environment (temperature 30℃, humidity >95% RH) for 7 days to ensure full hardening, resulting in positive and negative cement matrix-electrode-current collector assemblies. c) Soaking in potassium hydroxide solution: The cured positive electrode cement matrix-electrode-current collector assembly and negative electrode cement matrix-electrode-current collector assembly were respectively immersed in a 25wt% potassium hydroxide aqueous solution at room temperature for 3 days. After immersion, they were taken out and air-dried. d) Electrolyte coating and infiltration: 2.2 parts by weight of polyvinyl alcohol (PVA 1788) were added to 34 parts by weight of deionized water and stirred at 88°C until completely dissolved. The temperature was then lowered to 72°C, and 4.8 parts by weight of sodium carboxymethyl cellulose (CMC) were added and stirred until completely dissolved. The temperature was then lowered to below 40°C, and 9 parts by weight of glycerol, 4.5 parts by weight of polyethylene glycol (PEG-400), and 0.7 parts by weight of silane coupling agent (KH550) were added sequentially and stirred until homogeneous to obtain the main polymer solution. Dissolve 13 parts by mass of potassium hydroxide in 23 parts by mass of deionized water to obtain a potassium hydroxide solution; Add potassium hydroxide solution to the main polymer solution and stir to mix evenly. Then add 9 parts by mass of potassium silicate and 1.2 parts by mass of lithium nitrate and stir to dissolve them to obtain a gel solution. Then slowly add 0.7 parts by mass of boric acid to the gel solution and stir to mix evenly to obtain a gel-like electrolyte. The gel-like electrolyte is evenly applied to the surface of the positive and negative electrode cement matrix in the assembly, with a coating thickness of 1 mm. Then, the coated assembly is placed in a constant temperature and humidity environment (temperature 25℃, humidity >90% RH) and left to stand for 48 hours to allow the electrolyte to fully penetrate and solidify. e) Battery Molding: When the electrolyte gel coated on the surfaces of the positive and negative electrode cement substrates has cured to a touch-dry state, an insulating diaphragm (polyethylene film, 0.2 mm thick) is inserted between the positive and negative electrode cement substrates, and the insulating diaphragm is pressed into the assembly to form a single unit, resulting in the following: Figure 1 The cement-based battery shown. Example 3

[0027] 1) Preparation of composite conductive carbon materials: Same as Example 1; (ii) Preparation of Lanthanum Cobalt Oxide Same as Example 1; III) Preparation of Cement-Based Batteries a) Preparation of conductive concrete grout: 100 parts by weight of cement, 68 parts by weight of granular filler (quartz sand + iron ore tailings, mass ratio 1:1), 1.4 parts by weight of nano-silica, 2.6 parts by weight of lanthanum cobalt oxide, 2.8 parts by weight of manganese dioxide and 3.5 parts by weight of porous material (zeolite) are stirred and mixed evenly to obtain a dry powder mixture. 26 parts by weight of deionized water, 0.7 parts by weight of nonionic dispersant (PVP), 0.9 parts by weight of sulfonate dispersant (Point-S), 0.7 parts by weight of hydrating agent (lithium carbonate), 0.7 parts by weight of lithium nitrate and 1.0 parts by weight of corrosion inhibitor (sodium phosphate + benzimidazole, mass ratio 3:1) were stirred and mixed evenly to obtain a liquid base material. Ten parts by mass of deionized water, four parts by mass of composite conductive carbon material, and one part by mass of interface modification material (KH570 and TiN nanopowder, mass ratio 1:1) were stirred and mixed evenly to obtain a nano slurry. The liquid base material is slowly added to the dry powder mixture and stirred until it is evenly mixed. Then, the nano slurry is added and stirred until it is evenly mixed. Then, 0.035 parts by weight of air-entraining agent (rosin thermal polymer, Jiangsu Subote New Material Co., Ltd., PCA®-1) is added and stirred until it is evenly mixed without particle agglomeration, thus obtaining conductive concrete slurry. b) Casting and Curing: The conductive concrete slurry was poured into the pre-set mold, and the positive electrode cement matrix lower unit and the negative electrode cement matrix lower unit with the specifications of "thickness 2.5cm × width 40cm × length 40cm" were poured respectively. Then, carbon fiber cloth (Jiangsu Hengshen, HFW300T) is laid on the top surface of the positive electrode cement matrix unit and the negative electrode cement matrix unit respectively. The size of the carbon fiber cloth is slightly smaller than the mold. One side of the carbon fiber cloth is fixed with aluminum strips (5A06 anti-rust aluminum strips, thickness 1.5mm × width 30mm × length 450mm). Wires are welded on the aluminum strips and led out of the mold. Continue pouring conductive concrete slurry into the mold. Positive and negative cement matrix upper units, each with dimensions of 2.5cm thickness × 40cm width × 40cm length, are poured on top of the lower positive and negative cement matrix units, respectively. These units together form the cement matrix. After pouring, the concrete is vibrated to compact it and eliminate internal air bubbles. The formed concrete specimens are then placed in a constant temperature and humidity environment (25℃, >90% RH) for 6 days to ensure full hardening, resulting in positive and negative cement matrix-electrode-current collector assemblies. c) Soaking in potassium hydroxide solution: The cured positive electrode cement matrix-electrode-current collector assembly and negative electrode cement matrix-electrode-current collector assembly were respectively immersed in a 25wt% potassium hydroxide aqueous solution at room temperature for 3 days. After immersion, they were taken out and air-dried. d) Electrolyte coating and infiltration: 1.8 parts by weight of polyvinyl alcohol (PVA 1788) were added to 32 parts by weight of deionized water and stirred at 88°C until completely dissolved. The temperature was then lowered to 72°C, and 4.2 parts by weight of sodium carboxymethyl cellulose (CMC) were added and stirred until completely dissolved. The temperature was then lowered to below 40°C, and 8 parts by weight of glycerol, 3.5 parts by weight of polyethylene glycol (PEG-400), and 0.65 parts by weight of silane coupling agent (KH550) were added sequentially and stirred until homogeneous to obtain the main polymer solution. Dissolve 11 parts by mass of potassium hydroxide in 21 parts by mass of deionized water to obtain a potassium hydroxide solution; Add potassium hydroxide solution to the main polymer solution and stir to mix evenly. Then add 7 parts by mass of potassium silicate and 0.8 parts by mass of lithium nitrate and stir to dissolve them to obtain a gel solution. Then slowly add 0.5 parts by mass of boric acid to the gel solution and stir to mix evenly to obtain a gel-like electrolyte. The gel-like electrolyte is evenly applied to the surface of the positive and negative electrode cement matrix in the assembly, with a coating thickness of 1 mm. Then, the coated assembly is placed in a constant temperature and humidity environment (temperature 25℃, humidity >90% RH) and left to stand for 40 hours to allow the electrolyte to fully penetrate and solidify. e) Battery Molding: When the electrolyte gel coated on the surfaces of the positive and negative electrode cement substrates has cured to a touch-dry state, an insulating diaphragm (polypropylene film, 0.2 mm thick) is inserted between the positive and negative electrode cement substrates, and the insulating diaphragm is pressed into the assembly to form a single unit, resulting in the following: Figure 1 The cement-based battery shown.

[0028] Comparative Example 1 The difference between this comparative example and Example 1 is that the conductive carbon material used in the conductive concrete slurry is a simple blend of flake graphite, reduced graphene oxide, and carbon fiber; that is, the preparation of the nano-slurry in the conductive concrete slurry is as follows: 10.5 parts by mass of deionized water, 2 parts by mass of flake graphite, 1 part by mass of reduced graphene oxide, 1 part by mass of carbon fiber and 0.8 parts by mass of interface modification material (KH550) were stirred and mixed evenly to obtain nano-slurry.

[0029] Comparative Example 2 The difference between this comparative example and Example 1 is that lanthanum cobalt oxide, manganese dioxide, and nano-silica were not added to the conductive concrete slurry.

[0030] Comparative Example 3 The difference between this comparative example and Example 1 is as follows: 1) The conductive carbon material used in the conductive concrete slurry is a simple blend of flake graphite, reduced graphene oxide, and carbon fiber. 2) No lanthanum cobalt oxide or nano-silica was added to the conductive concrete slurry; 3) The electrolyte is a gel-like electrolyte composed of potassium hydroxide, sodium carboxymethyl cellulose and water. Specifically: potassium hydroxide is dissolved in water to obtain a 25wt% KOH aqueous solution. Then, 6 parts by mass of sodium carboxymethyl cellulose are slowly added to 94 parts by mass of the 25wt% KOH aqueous solution. The mixture is stirred continuously at room temperature until a uniform gel is formed, thus obtaining a gel-like electrolyte.

[0031] Performance testing: The performance of the cement-based batteries prepared in Examples 1-3 and Comparative Examples 1-3 was tested, specifically: 1) Mechanical property testing: The flexural and compressive strengths of the cement matrix were tested according to GB / T 17671-2021 "Test Method for Strength of Cement Mortar"; 2) Electrochemical performance testing: The DC conductivity of the cement matrix was tested using the four-electrode method (ASTM D257); the initial specific capacity and coulombic efficiency of the cement-based cell were tested under the conditions of a current density of 0.5 A / g and a voltage window of 0-1.2 V; and the electrochemical impedance spectroscopy (EIS) of the cement-based cell was tested in the frequency range of 0.01 Hz-100 kHz. 3) Electrochemical stability test: The cement-based battery was tested for long-cycle performance by constant current charge-discharge cycles of 1000 times; and its self-discharge rate was tested by measuring voltage decay after 7 days of open-circuit storage. The test results are shown in Table 1.

[0032] Table 1 Performance test data of cement-based batteries in Examples 1-3 and Comparative Examples 1-3

[0033] As shown in Table 1, the cement-based batteries prepared in Examples 1-3 of this invention exhibit better compressive strength, flexural strength, conductivity, initial specific capacity, coulombic efficiency, capacity retention after 1000 cycles, and self-discharge rate compared to the cement-based batteries in Comparative Examples 1-3. This indicates that the cement-based batteries prepared in these examples, compared to the cement-based batteries in the comparative examples, possess better mechanical and electrochemical performance, as well as better chemical stability and a longer service life. This is because: 1) The composite conductive carbon material used in Examples 1-3 has a three-level structure of graphite core-mGO shell-CF bridge, compared to the conductive carbon material system formed by simply blending graphite, graphene, and carbon fiber in the comparative examples: The mGO coating improves the interfacial compatibility between graphite and cement matrix, and the carbon fiber bridging forms a three-dimensional conductive network, which enhances the overall conductivity and mechanical strength of the battery, thereby effectively improving the mechanical and electrochemical performance of cement-based batteries. In composite conductive carbon materials, the mGO shell is modified by silanization and amino-containing water-reducing agents. On the one hand, it tightly coats the hydrophobic flake graphite surface through π-π stacking and van der Waals forces to form a stable "shell". On the other hand, it can interact strongly with calcium ions and other substances in cement hydration products, and even chemically bond with them. CF can connect and bridge isolated graphite@mGO core-shell particles in series, forming a macroscopic conductive framework that runs through the entire cement matrix. This makes the overall structure of the composite conductive carbon material stable, providing a stable electronic pathway and a uniform current / potential distribution. It can effectively prevent the initiation and propagation of microcracks in the cement matrix, better withstand electrochemical strain during charging and discharging, and physical stress caused by changes in environmental temperature and humidity, maintain structural integrity, effectively slow down interface corrosion, and thus effectively improve the service life of cement-based batteries. 2) In Examples 1-3, lanthanum cobalt oxide, manganese dioxide, and nano-silica were added simultaneously. Lanthanum cobalt oxide and manganese dioxide have a synergistic effect. Lanthanum cobalt oxide acts as a catalyst to enhance the electrochemical reaction activity of the battery, manganese dioxide provides pseudocapacitance to enhance the specific capacity of the battery, and nano-silica can fill the pores to improve the density and durability of the battery, thereby effectively improving the mechanical properties, electrochemical properties and service life of cement-based batteries. 3) The electrolyte used in Examples 1-3 is composed of "PVA, CMC, KOH, potassium silicate, coupling agent, boric acid, lithium nitrate, and water". Compared with the electrolyte composed of "CMC / KOH and water" in the comparative example, the PVA / CMC / KOH / potassium silicate system can form a stable ion channel, the coupling agent can enhance the binding between the electrolyte and the electrode interface, and the boric acid and lithium nitrate can improve the ion mobility and stability, thereby effectively improving the mechanical properties, electrochemical performance and service life of cement-based batteries.

[0034] Finally, it should be noted that the above are only some preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A long-life cement-based battery, characterized in that, The system includes a cement matrix, an electrolyte, a positive electrode, an insulating diaphragm, a negative electrode, a positive current collector, and a negative current collector. The insulating diaphragm is embedded inside the cement matrix, dividing it into two independent regions, one containing the positive electrode and the other containing the negative electrode. The positive current collector is in close contact with the positive electrode, and the negative current collector is in close contact with the negative electrode. Both the positive and negative current collectors extend to the outer end of the cement matrix and are led out. The electrolyte fills the internal pores of the cement matrix and the gaps between the positive and negative electrodes and the insulating diaphragm. The cementitious matrix is ​​obtained by pouring and curing conductive concrete slurry, which has the following composition and proportions: Cement: 100 parts by weight; Particulate filler: 60-80 parts by weight; Deionized water: 30-40 parts by weight; Nano-silica: 1.0-1.5 parts by weight; Lanthanum cobalt oxide: 2-3 parts by weight; Manganese dioxide: 2-4 parts by weight; Composite conductive carbon material: 3-5 parts by weight; Nonionic dispersant: 0.5-1 parts by weight; Sulfonate dispersant: 0.5-1 parts by weight; Hydration agent: 0.5-1 parts by weight; Lithium nitrate: 0.5-1 parts by weight; Corrosion inhibitor: 0.5-1 parts by weight; Interface modification material: 0.5-1 parts by weight; Air-entraining agent: 0.01-0.05 parts by weight; Porous material: 3-5 parts by weight; The aforementioned composite conductive carbon material is obtained by first modifying reduced graphene oxide by silanization and then by modifying it with a water-reducing agent containing amino terminals to obtain modified reduced graphene oxide mGO. Then, with graphite as the core, mGO is coated on the surface of graphite to obtain a core-shell structured graphite@mGO. Finally, graphite@mGO is composited with carbon fiber.

2. The high-lifespan cement-based battery according to claim 1, characterized in that, The granular filler is selected from one or more of the following: quartz sand, river sand, aeolian sand, copper mine tailings, iron mine tailings, manganese mine tailings, tungsten mine tailings, zinc mine tailings, and red mud. The nonionic dispersant is selected from one or more of PVP, poloxamer, and Tween 80; The hydrating agent is selected from one or more of lithium carbonate, barium nitrate, calcium nitrate, sodium sulfate, and calcium formate; The air-entraining agent is selected from one or more of the following: rosin thermal polymer, sodium dodecylbenzene sulfonate, tea saponin, and fatty alcohol polyoxyethylene ether; The interface modification material is selected from one or more of KH550, KH560, KH570, and TiN / CrN; The corrosion inhibitor is selected from one or more of sodium phosphate, sodium silicate, benzimidazole, and hexadecylamine; The porous material is selected from one or more of zeolite, montmorillonite, and diatomite.

3. The high-lifespan cement-based battery according to claim 1, characterized in that, The preparation of the composite conductive carbon material includes the following steps: 1) Disperse 190-210 parts by weight of reduced graphene oxide (rGO) in an aqueous ethanol solution to obtain an rGO slurry with a solid content of 5%; add the rGO slurry to a reaction vessel, disperse at high speed, adjust the pH to 5.3-5.7 with hydrochloric acid, raise the temperature to 58-62℃, add 28-32 parts by weight of GPTMS dropwise, and after the addition is complete, keep the temperature for 1-3 hours. After the reaction is completed, cool down to below 40℃, separate the solid and liquid, and wash the separated solid with ethanol 1-3 times to obtain a silanized reduced graphene oxide (GO-EP) wet filter cake; 2) Redisperse the GO-EP wet filter cake in water, adjust the solid content to 15%, add NaOH aqueous solution to adjust the pH to 8.3-8.7, add 230-250 parts by weight of amino-terminated water-reducing agent on a dry basis, and then stir the reaction at 78-82℃ for 3-5 hours. After the reaction is completed, cool down to below 50℃, separate the solid and liquid, wash and dry the separated solid to obtain modified redox graphene mGO; 3) Mix 49-51 parts by weight of mGO, 0.4-0.6 parts by weight of sodium hexametaphosphate and 440-460 parts by weight of deionized water evenly to obtain an mGO coating solution; Add 490-510 parts by weight of graphite to a fluidized bed, use hot air at 78-82℃ to fluidize for 20-40 minutes to preheat the material evenly, and then spray the mGO coating liquid. After coating, dry, cool and sieve to obtain graphite@mGO with a core-shell structure. 4) Mix 9-11 parts by weight of hydrophobic silica, 1.8-2.2 parts by weight of antistatic agent and 19-21 parts by weight of ethanol evenly to form a uniform slurry; spray the obtained slurry onto 49-51 parts by weight of graphite@mGO, dry to remove ethanol, and obtain SiO2 masterbatch. Add 790-810 parts by weight of graphite@mGO to a mixer, add the SiO2 masterbatch, mix them evenly, then add 178-182 parts by weight of carbon fiber, mix for 45-60 minutes, sieve the resulting mixture, homogenize it, and obtain the composite conductive carbon material.

4. The high-lifespan cement-based battery according to claim 3, characterized in that: The antistatic agent is dioctadecyldimethylammonium chloride.

5. The high-lifespan cement-based battery according to claim 1, characterized in that: The preparation of the lanthanum cobalt oxide includes the following steps: Lanthanum nitrate hexahydrate and cobalt nitrate hexahydrate are dissolved in water to obtain a metal ion solution; Citric acid, ethylene glycol and water are stirred and mixed evenly to obtain a complexing agent solution; The metal ion solution is slowly added dropwise to the complexing agent solution, while stirring continuously and heating to 80°C. The temperature is maintained and the water is evaporated until a dark blue, transparent, viscous sol is formed. Stirring continues to form a wet gel. The wet gel was redispersed with an appropriate amount of deionized water to form a homogeneous solution, which was then transferred to the liner of the reaction vessel. The reaction vessel was placed in a microwave synthesizer and subjected to hydrothermal reaction at 175-185℃ for 50-70 minutes, and then allowed to cool naturally to room temperature. The microwave hydrothermal products were centrifuged, and the resulting solids were washed and dried to obtain precursor powder. The precursor powder was placed in a crucible and then placed in a muffle furnace. It was calcined at 550-600℃ for 2-3 hours in air atmosphere, cooled to room temperature with the furnace, and then ground to obtain lanthanum cobalt oxide nanopowder.

6. The high-lifespan cement-based battery according to claim 5, characterized in that, In the preparation of lanthanum cobaltate, the total concentration of metal ions in the metal ion solution is 0.1-0.3 mol / L; n(citric acid) : n(total metal ions) = (1-2) :

1.

7. The high-lifespan cement-based battery according to claim 1, characterized in that: In cement-based batteries, the electrolyte has the following composition and proportions: Potassium hydroxide: 10-15 parts by weight; Potassium silicate: 5-10 parts by weight; Lithium nitrate: 0.5-2 parts by weight; Deionized water: 52-58 parts by weight; Sodium carboxymethyl cellulose: 3.5-5 parts by weight; Polyvinyl alcohol: 1.5-2.5 parts by weight; Glycerin: 7-10 parts by weight; Polyethylene glycol: 3-5 parts by weight; Silane coupling agent: 0.3-0.8 parts by weight; Boric acid: 0.4-0.8 parts by weight.

8. The high-lifespan cement-based battery according to claim 7, characterized in that, The preparation of the electrolyte includes the following steps: Add the specified amount of polyvinyl alcohol to 60% of the specified amount of deionized water, stir at 85-90℃ until it is completely dissolved, then cool down to 70-75℃, add the specified amount of sodium carboxymethyl cellulose, stir until it is completely dissolved, then cool down to below 40℃, add the specified amounts of glycerol, polyethylene glycol and silane coupling agent in sequence, stir evenly to obtain the main polymer solution. Dissolve the specified amount of potassium hydroxide in 40% deionized water to obtain a potassium hydroxide solution. Add potassium hydroxide solution to the main polymer solution and stir to mix evenly. Then add the specified amounts of potassium silicate and lithium nitrate and stir to dissolve them to obtain a gel solution. Then slowly add the specified amount of boric acid to the gel solution and stir to mix evenly to obtain a gel-like electrolyte.

9. The high-lifespan cement-based battery according to claim 1, characterized in that: Both the positive and negative electrodes are made of carbon fiber cloth, both the positive and negative current collectors are made of aluminum strips, and the insulating diaphragm is made of polyethylene film or polypropylene film with a thickness of 0.1-0.3 mm.

10. A method for preparing a high-lifespan cement-based battery according to any one of claims 1-9, characterized in that, Includes the following steps: a) Preparation of conductive concrete grout: Mix all the components in the specified proportions evenly to ensure that all components are mixed uniformly and without particle agglomeration, thus obtaining conductive concrete slurry. b) Casting and Curing: The conductive concrete slurry is poured into the pre-set mold, and the lower unit of the positive electrode cement matrix and the lower unit of the negative electrode cement matrix are poured respectively. Then, positive electrode material and negative electrode material are laid on the top surface of the positive electrode cement matrix unit and the negative electrode cement matrix unit respectively. The size of the positive electrode material and the negative electrode material is slightly smaller than the mold. One side of the positive electrode material and the negative electrode material is fixed with positive current collector material and negative current collector material respectively. Wires are welded on the positive current collector material and the negative current collector material respectively and led out of the mold. Continue pouring conductive concrete slurry into the mold, and pour the upper positive and lower negative cement matrix units on top of the lower positive and lower negative cement matrix units respectively. The lower positive and lower negative cement matrix units, the upper positive and lower negative cement matrix units together form the cement matrix. After pouring, vibrate to compact and eliminate internal air bubbles. Then, place the formed concrete specimen in a constant temperature and humidity environment for 5-8 days to ensure that the concrete is fully hardened, and obtain the positive cement matrix-electrode-current collector assembly and the negative cement matrix-electrode-current collector assembly. c) Soaking in potassium hydroxide solution: The cured positive electrode cement matrix-electrode-current collector assembly and negative electrode cement matrix-electrode-current collector assembly were respectively immersed in a 20-30 wt% potassium hydroxide aqueous solution at room temperature for 2-3 days. After immersion, they were taken out and air-dried. d) Coating and penetration of electrolyte: The gel-like electrolyte is evenly coated on the surface of the positive and negative cement matrix in the assembly. Then the coated assembly is placed in a constant temperature and humidity environment and left to stand for 24-48 hours to allow the electrolyte to fully penetrate and solidify. e) Battery molding: When the electrolyte gel coated on the surface of the positive and negative electrode cement substrates has solidified to the touch-dry state, the insulating diaphragm is inserted between the positive and negative electrode cement substrates, and the insulating diaphragm and the assembly are pressed together to obtain a cement-based battery.

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