A cement-based structural battery with integrated load-bearing and energy storage function and its preparation method

Abstract

The present invention belongs to the technical field of cement-based batteries for construction, and discloses a cement-based structural battery with integrated load-bearing and energy storage, and its preparation method. Method: 1) Mixing a polymer solution, cement, and fine sand to obtain a polymer-cement slurry electrolyte; the polymer solution is obtained by dissolving a polymer and a strong base in water, or by dissolving a polymer, a strong base, and a sulfide in water, or by dissolving a polymer, a strong base, an inorganic sulfide, and a chemical cross-linking agent in water; the polymer is one or more of PVA or PAA; 2) Preparation of a positive electrode sheet; 3) Preparation of a negative electrode sheet; 4) Placing the polymer-cement slurry electrolyte on the surface of the positive electrode sheet and the surface of the negative electrode sheet, respectively, and then stacking the positive electrode sheet and the negative electrode sheet in sequence, placing them in a mold for curing, and allowing them to stand to obtain a cement-based structural battery with integrated load-bearing and energy storage. The cement-based structural battery of the present invention has high mechanical bearing strength, high capacity, stable power retention, and excellent cycle performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of cement-based batteries for construction, and specifically relates to a cement-based structural battery integrating load bearing and energy storage, and a preparation method thereof. Background Art

[0002] To address the depletion and pollution of traditional energy sources, the application of renewable energy sources such as solar and wind power has increased dramatically. However, the intermittent and volatile nature of renewable energy sources has led to a mismatch between energy supply and demand. This has necessitated the use of energy storage materials and devices to store the electricity generated by these renewable energy sources. Future advanced building materials should possess multifunctional and intelligent properties, such as the ability to harvest and store renewable energy sources like solar and wind. Using structures and buildings as energy and storage devices holds immense innovative significance. Given the large size of buildings, even with a lower energy storage density per unit volume, the energy storage potential of new-generation building materials is considerable. However, due to the low ionic conductivity and high electrical resistance of conventional cement, as well as the lack of electrodes suitable for cement environments, the current development of cement-based structural energy storage materials favors cement-based supercapacitors. However, the low energy density and poor charge retention of capacitors severely limit their application in buildings. Developing cement-based structural batteries that combine high mechanical strength, high capacity, stable charge retention, and excellent cycling performance remains a challenge.

[0003] Therefore, cement-based structural batteries need to be developed. Summary of the Invention

[0004] Given the current lack of cement-based structural battery technology, the present invention aims to provide a cement-based structural battery that integrates load bearing and energy storage, and its preparation method. The cement-based structural battery of the present invention combines high mechanical load-bearing strength, high capacity, stable charge retention, and excellent cycle performance.

[0005] The technical solutions of the present invention are as follows:

[0006] A method for preparing a cement-based structural battery with integrated load-bearing and energy storage, comprising the steps of:

[0007] 1) mixing a polymer solution, cement and fine sand to obtain a polymer-cement slurry electrolyte;

[0008] The polymer solution is obtained by dissolving a polymer and a strong base in water, or by dissolving a polymer, a strong base and a sulfide in water, or by dissolving a polymer, a strong base, an inorganic sulfide and a chemical cross-linking agent in water;

[0009] The polymer is one or more of PVA and PAA; the strong base is one or more of KOH and NaOH; the sulfide is one or more of Na2S and K2S; the chemical crosslinking agent is one or more of TEAC (tetraethylammonium chloride) and PEGDGE (polyethylene glycol diglycidyl ether);

[0010] 2) Preparation of positive electrode sheet;

[0011] 3) Preparation of negative electrode sheet;

[0012] 4) placing a polymer-cement slurry electrolyte on the surface of the positive electrode sheet and the surface of the negative electrode sheet respectively, then stacking the positive electrode sheet and the negative electrode sheet in sequence, placing them in a mold for curing, and letting them stand to obtain a cement-based structural battery with integrated load-bearing and energy storage.

[0013] The amount of each substance in the polymer solution in step 1) is calculated by weight:

[0014] 8-10 parts of polymer

[0015] 30-40 parts of strong base

[0016] 190-210 parts water;

[0017] When inorganic sulfide is present, the amount of sulfide is 0.5-1 part;

[0018] When a chemical cross-linking agent is included, the amount of the chemical cross-linking agent is 0.1-0.5 parts.

[0019] The mixing in step 1) is specifically to mix the solution of polymer and strong base, cement and fine sand at 90-95°C, then cool to 2-5°C, and slowly add cold water during the cooling process to obtain a cement slurry containing a liquid-solid mixed phase.

[0020] When the polymer solution contains inorganic sulfide, the inorganic sulfide is added together with the cold water; when the polymer solution contains a chemical cross-linking agent, the chemical cross-linking agent is added together with the cold water.

[0021] The cement slurry containing the liquid-solid mixed phase is prepared under stirring conditions at a stirring speed of 135-165 r / min.

[0022] The mixing time at 90-95° C. is 1 min-2 min; the cooling to 2-5° C. means cooling to 2-5° C. within 5-10 min; after adding cold water and cooling to 2-5° C., stirring and mixing is performed, and the stirring and mixing time is 15-20 min.

[0023] The mixing of a solution prepared by polymer and strong alkali, cement and fine sand at 90-95° C. refers to stirring the polymer, strong alkali and water at 85-95° C. at a rotation speed of 240-260 r / min for 1.5-2 hours to prepare a solution; dry mixing cement and fine sand at 90-95° C. at a rotation speed of 60-70 r / min for 5-10 minutes to obtain a cement-fine sand mixture; and mixing the above solution and cement-fine sand mixture at 90-95° C.

[0024] The solution prepared by polymer and strong base refers to stirring the polymer and a part of water at 85-95° C. and a rotation speed of 240-260 r / min for 40-50 minutes to obtain an aqueous solution of the polymer; dissolving the strong base in another part of water to obtain a strong base solution; and mixing the strong base solution with the aqueous solution of the polymer for 50-70 minutes while keeping the temperature and rotation speed unchanged to obtain the desired solution.

[0025] The mass ratio of the cold water to the polymer is (60-80):(8-10).

[0026] The amounts of polymer, cement and fine sand in the polymer solution in step 1) are calculated by weight as follows: polymer: 8-10 parts; cement: 490-510 parts; fine sand: 140-160 parts.

[0027] The molecular weight of the polymer PVA is 1,000-10,000, and the molecular weight of PAA is 10,000-500,000.

[0028] The positive electrode sheet in step 2) is prepared by the following method:

[0029] S1: The positive electrode material, conductive agent, adhesive and solvent are uniformly mixed to obtain positive electrode active material slurry; S2: The positive electrode active material slurry is coated on the surface of the conductive substrate, and after film formation, it is dried to obtain a positive electrode sheet.

[0030] The positive electrode material is one or more of nickel hydroxide, transition metal (eg, cobalt), transition metal oxide (cobalt oxide), and transition metal hydroxide.

[0031] The conductive agent is one or more of graphite and carbon nanotubes.

[0032] The adhesive is potassium water glass or sodium water glass, and the modulus of the water glass is 2.0-3.3.

[0033] The solvent is water.

[0034] The mass ratio of the positive electrode material, the conductive agent and the binder is (8-9.5): (0.5-1): (3-6).

[0035] The mass ratio of the positive electrode material to the solvent is (8-9.5): (0.4-0.8). The coating amount of the positive electrode active material slurry is 0.3-0.4 g / cm 2 The positive electrode active material slurry is coated on both surfaces of the conductive substrate.

[0036] The conductive agent is divided into two parts, one part is mixed with the positive electrode material, and the other part is mixed with the adhesive and the solvent.

[0037] The conductive substrate is a metal sheet such as foamed nickel, copper foil, or aluminum foil.

[0038] The negative electrode sheet in step 3) is prepared by the following method: uniformly mixing the negative electrode active material, the conductive agent, and the binder to obtain a negative electrode active material slurry; coating the negative electrode active material slurry on the surface of the conductive substrate, forming a film, and drying to obtain a negative electrode sheet.

[0039] The negative electrode active material is one or more of iron, iron oxide, ferroferric oxide, carbonyl iron, ferrous sulfide, bismuth sulfide, zinc, zinc oxide, zinc-containing alloy, and iron-containing alloy;

[0040] The conductive agent is one or more of carbon nanotubes and graphite.

[0041] The binder is one or more of potassium water glass and sodium water glass.

[0042] The coating amount of the negative electrode active material slurry is 0.35-0.45 g / cm 2 .

[0043] The mass ratio of the negative electrode active material, the conductive agent and the binder is (7.5-10): (0-0.5): (3-5.5).

[0044] The conductive substrate is a metal sheet such as foamed nickel, copper foil, or aluminum foil.

[0045] The curing in step 4) refers to sealed curing at 0°C-3°C for 6-24 hours. The standing refers to room temperature for 12-24 hours.

[0046] A load-bearing and energy-storage integrated cement-based structural battery is prepared by the above preparation method.

[0047] Application of the battery of the present invention in construction.

[0048] Beneficial effects:

[0049] 1) The present invention uses controlled phase separation technology to enable the elastic phase separation of the polymer-strong base network (such as PVA-KOH) to proceed earlier than cement hydration. During the hydration process, the cement adaptively becomes the skeleton of the polymer-strong base network, and the interface between the two is good, forming a continuous high-conductivity ion channel.

[0050] 2) The positive and negative electrodes of the present invention use water glass as a binder. Due to its good compatibility, it can form a strong electrolyte-electrode interface, greatly improving the conductivity of ions at the interface.

[0051] 3) The preparation process of the present invention is simple to operate, highly repeatable, and the raw materials used are environmentally friendly and inexpensive.

[0052] In summary, the cement-based structural battery of the present invention has high mechanical bearing strength, high capacity, stable power retention and excellent cycle performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 Schematic diagram of the structure of the cement-based structural battery of the present invention; 1-positive electrode sheet, 2-negative electrode sheet, 3-electrolyte, 4-lead portion of the matrix (current collector); the upper two figures are schematic cross-sectional views, and the lower figure is a top view;

[0054] Figure 2 Schematic diagram of the present invention using a circular component mold to prepare a cement-based structural battery; 5- circular mold component No. 1, 6- semicircular mold component No. 2, 7- positive electrode sheet, 8- negative electrode sheet;

[0055] Figure 3 Schematic diagram of the present invention using a square component mold to prepare a cement-based structural battery; 9-mold square component No. 1, 10-mold right-angled triangle component No. 2, 11-positive electrode sheet, 12-negative electrode sheet;

[0056] Figure 4 EIS (Nyquist plot) of the battery prepared in Example 1;

[0057] Figure 5 EIS of the battery prepared in Example 2;

[0058] Figure 6 EIS of the battery prepared in Example 3;

[0059] Figure 7 EIS of the battery prepared in Comparative Example 1;

[0060] Figure 8 EIS of the battery prepared in Comparative Example 2;

[0061] Figure 9 EIS of the battery prepared in Comparative Example 3;

[0062] Figure 10 LSV curves of batteries prepared in Example 1, Comparative Examples 1 and 3;

[0063] Figure 11CV curves of the batteries prepared in Example 1, Comparative Examples 1 and 3;

[0064] Figure 12 XRD pattern of the positive electrode prepared in Example 1;

[0065] Figure 13 XRD pattern of the negative electrode prepared in Example 1;

[0066] Figure 14 The voltage-discharge capacity curves of the batteries prepared in Examples 1 to 3 are as follows;

[0067] Figure 15 This is a voltage-discharge capacity curve of the battery prepared in Example 4;

[0068] Figure 16 The voltage-discharge capacity curves of the batteries prepared in Comparative Examples 1 to 3 are shown;

[0069] Figure 17 This is a charge and discharge cycle performance test diagram of the battery prepared in Example 1;

[0070] Figure 18 The power retention performance test curves of Examples 1 and 2 and commercial nickel-iron batteries;

[0071] Figure 19 This is a picture of a light-emitting LED after the batteries prepared in Examples 5 and 6 are connected in series. DETAILED DESCRIPTION

[0072] The present invention will be further described in detail below with reference to specific examples, but the embodiments of the present invention are not limited thereto.

[0073] Figure 1 The diagrams below are schematic diagrams of the cement-based structural battery of the present invention; the top two figures are schematic cross-sectional views, and the bottom figure is a top view. The cement-based structural battery of the present invention includes positive and negative electrode sheets, and an electrolyte covering the positive and negative electrode sheets. The positive and negative electrode sheets are stacked in sequence, with the electrolyte disposed between them. The positive and negative electrode sheets are each provided with a substrate lead portion, i.e., a current collector.

[0074] Figure 2 This is a schematic diagram of the present invention's use of a circular mold to prepare a cement-based structural battery. The mold comprises two components (No. 1) and four semicircular components (No. 2). The two semicircular components (No. 2) can be assembled into a circular component (No. 3). Circular component (No. 3) is hollow, while component (No. 1) is a solid circular structure. The two circular components (No. 3) are stacked, forming a hollow center. Components (No. 1) are positioned at both ends of the stacked components (No. 3), sealing the terminals. The positive electrode is located in one circular component (No. 3), and the negative electrode in the other. Electrolyte is located in the cavities of the circular components (No. 3) between the negative and positive electrodes.

[0075] Figure 3 This is a schematic diagram of a square-shaped mold used to prepare a cement-based structural battery. The mold comprises two square-shaped components (No. 1) and four right-angled triangular components (No. 2). The two right-angled triangular components (No. 2) can be assembled into a square component (No. 3). The square component (No. 3) is hollow, while the component (No. 1) is a solid square. The two square components (No. 3) are stacked, forming a hollow center. Components (No. 1) are positioned at both ends of the stacked two square components (No. 3), sealing the terminals. The positive electrode is located in one square component (No. 3), and the negative electrode is located in another square component (No. 3). Electrolyte is located between the negative and positive electrodes and in the cavities of the square components (No. 3).

[0076] Example 1: (Polymer solution is PVA-KOH)

[0077] Dissolve 10g of PVA1799 in 90g of deionized water, heat in a 95°C waterbath, and stir at 250 rpm for 50 minutes to obtain a PVA solution. Dissolve 30g of KOH solid in 110g of water to obtain a KOH solution. When the PVA solution turns light milky white, slowly add the KOH solution dropwise to the PVA solution and continue heating and stirring for 50 minutes until the mixed solution turns transparent and light yellow to obtain a PK solution. Premix 490g of cement (PO42.5R) and 140g of fine sand at 90°C for 10 minutes at 70 rpm to obtain a cement-fine sand mixture. Add the cement-fine sand mixture to the PK solution while maintaining 90°C and stirring at 145 rpm for 2 minutes. After this process, start the cooler and slowly add 60g of 2°C deionized water to reduce the slurry temperature to 2°C. Stir at 145 rpm for 16 minutes to obtain a polymer-cement slurry.

[0078] The positive electrode was prepared as follows: 0.36g Co, 8.7g Ni(OH )2 Grind for 15 minutes until the powder turns dark green, add 0.43g 100 mesh graphite and continue grinding for 13 minutes until the powder turns gray-green to obtain a mixed powder. Weigh 4.3g of low-temperature potassium water glass with a modulus of 3.3, add 0.7g deionized water and 0.28g 100 mesh graphite, stir evenly, and obtain a water glass dispersion. Add the mixed powder to the potassium water glass dispersion twice, stir until it becomes a uniform slurry, and evenly apply it on a 2mm*2mm square clean foam nickel substrate (0.35g / cm 2 After the electrode is formed into a film, place it under a 320W drying light source for 30 minutes until the electrode surface turns dark green and the center of the area hardens, then seal and bag it.

[0079] The negative electrode sheet was prepared as follows: 0.6g FeS and 6.8g iron powder were ground for 10 minutes until the powder was uniform, 2.1g Fe3O4 was added and ground for 20 minutes until the powder turned dark orange to obtain a mixed powder. The mixed powder was added twice to 4.55g low-temperature potassium water glass with a modulus of 3.3, stirred to a uniform slurry, and evenly coated on a 2mm*2mm square clean nickel foam substrate (0.4g / cm 2 After the electrode is coated, let it stand for 13 minutes. After the film is formed on the electrode surface, place it under a 320W drying light source for 27 minutes until the center of the electrode area hardens, and then seal it in a bag.

[0080] The positive and negative electrodes were assembled using polymer-cement slurry (i.e., the polymer-cement slurry was coated on the surface of the positive electrode and the negative electrode respectively), placed in a mold, sealed and cured at 2°C for 24 hours, and left to stand at room temperature for 24 hours to obtain a cement-based structural battery.

[0081] Example 2: (Polymer solution is PVA-PAA-KOH)

[0082] 7.8g of PVA1799 and 0.2g of PAA (polyacrylic acid, molecular weight 450,000) were dissolved in 90g of deionized water, heated in an 85°C waterbath, and stirred at 260 rpm for 50 minutes to obtain a polymer solution. 40g of KOH solid was dissolved in 115g of water to obtain a KOH solution. After the polymer solution turned light milky white, the KOH solution was slowly added dropwise to the polymer solution while heating and stirring for 70 minutes to obtain a PKA solution. 510g of cement (PO42.5R) and 160g of fine sand were premixed at 65 rpm at 95°C for 8 minutes to obtain a cement-fine sand mixture. The cement-fine sand mixture was added to the PKA solution while maintaining 95°C and stirring at 140 rpm for 1 minute and 30 seconds. After this process, a cooler was turned on and 80g of 5°C deionized water was slowly added to reduce the slurry temperature to 5°C. The mixture was stirred at 140 rpm for 20 minutes to obtain a polymer-cement slurry.

[0083] The preparation method of the positive electrode sheet is as follows: grind 0.40g Co and 8.0g Ni(OH)2 for 15min until the powder turns dark green, add 0.43g 100-mesh graphite and continue grinding for 13min until the powder turns gray-green to obtain a mixed powder. Weigh 4.3g of low-temperature potassium water glass with a modulus of 3.3, add 0.7g deionized water and 0.25g 100-mesh graphite, stir evenly, and obtain a potassium water glass mixture. Add the mixed powder to the potassium water glass mixture twice, stir until it becomes a uniform slurry, and evenly apply it on a 2mm*2mm square clean foam nickel substrate (0.35g / cm 2After the electrode is formed into a film, place it under a 320W drying light source for 28 minutes until the electrode surface turns dark green and the center of the area hardens, then seal and bag it.

[0084] The negative electrode sheet was prepared as follows: 0.6g FeS and 6.8g iron powder were ground for 10 minutes until the powder was uniform, 2.1g Fe3O4 was added and ground for another 20 minutes to obtain a mixed powder. The mixed powder was added twice to 4.55g low-temperature potassium water glass with a modulus of 3.3, stirred until a uniform slurry was obtained, and evenly coated on a 2mm*2mm square clean nickel foam substrate (0.4g / cm 2 After the electrode is coated, let it stand for 15 minutes. After the film is formed on the electrode surface, place it under a 320W drying light source for 27 minutes until the center of the electrode area hardens, and then seal it in a bag.

[0085] The positive and negative electrodes were assembled using polymer-cement slurry, placed in a special mold, sealed and cured at 0°C for 6 hours, and left to stand at room temperature for 12 hours to obtain a cement-based structural battery.

[0086] Example 3: (Polymer solution is PVA-KOH-K2S)

[0087] Dissolve 9.8g of PVA1799 in 90g of deionized water, heat in a 92°C waterbath, and stir at 255 rpm for 4 minutes to obtain a polymer solution. Dissolve 33.6g of KOH solid in 110g of water to obtain a KOH solution. When the PVA solution turns light milky white, slowly add the KOH solution dropwise to the PVA solution while heating and stirring for 50 minutes to obtain a PK solution. Premix 500g of cement (PO42.5R) and 150g of fine sand at 92°C for 5 minutes at 60 rpm to obtain a cement-fine sand mixture. Add the cement-fine sand mixture to the PK solution while maintaining 92°C and stirring at 135 rpm for 1 minute and 45 seconds. After this process, start the cooler and slowly add 65g of 3°C deionized water and 0.8g of K2S to lower the slurry temperature to 3°C. Stir at 135 rpm for 18 minutes to obtain a polymer-cement slurry.

[0088] The preparation method of the positive electrode sheet is as follows: grind 0.36g Co and 8.7g Ni(OH)2 for 15min until the powder turns dark green, add 0.43g 100 mesh graphite and continue grinding for 13min until the powder turns gray-green to obtain a mixed powder. Weigh 4.3g low-temperature potassium water glass with a modulus of 3.3, add 0.7g deionized water and 0.28g 100 mesh graphite, stir evenly, and obtain a potassium water glass mixture. Add the mixed powder to the potassium water glass mixture twice, stir until it becomes a uniform slurry, and evenly apply it on a 2mm*2mm square clean foam nickel substrate (0.35g / cm 2After the electrode is formed into a film, place it under a 320W drying light source for 30 minutes until the electrode surface turns dark green and the center of the area hardens, then seal and bag it.

[0089] The negative electrode sheet was prepared as follows: 0.6g FeS and 6.8g iron powder were ground for 10 minutes until the powder was uniform, 2.1g Fe3O4 was added and ground for another 20 minutes to obtain a mixed powder. The mixed powder was added twice to 4.55g low-temperature potassium water glass with a modulus of 3.3, stirred until a uniform slurry was obtained, and evenly coated on a 2mm*2mm square clean nickel foam substrate (0.4g / cm 2 After the electrode is coated, let it stand for 15 minutes. After the film is formed on the electrode surface, place it under a 320W drying light source for 29 minutes until the center of the electrode area hardens, and then seal it in a bag.

[0090] The positive and negative electrodes were assembled using polymer-cement slurry, placed in a special mold, sealed and cured at 1°C for 21 hours, and allowed to stand at room temperature for 18 hours to obtain a cement-based structural battery.

[0091] Example 4: (Polymer solution is PVA-KOH)

[0092] Dissolve 10g of PVA1799 in 90g of deionized water, heat in a 95°C waterbath, and stir at 250 rpm for 50 minutes to obtain a polymer solution. Dissolve 33.6g of KOH solid in 110g of water to obtain a KOH solution. When the PVA solution turns light milky white, slowly drip the KOH solution into the PVA solution and maintain heating and stirring for 50 minutes to obtain a PK solution. Premix 500g of cement (PO42.5R) and 150g of fine sand (0.25-0.35mm) at 90°C for 10 minutes at 70 rpm to obtain a cement-fine sand mixture. Add the cement-fine sand mixture to the PK solution while maintaining 95°C and stirring at 145 rpm for 2 minutes. After this process, turn on the cooler and slowly add 65g of 2°C deionized water to reduce the slurry temperature to 2°C. Maintain stirring at 145 rpm for 16 minutes to obtain a polymer-cement slurry.

[0093] The preparation method of the positive electrode sheet is as follows: grind 1.44g Co and 34.8g Ni(OH)2 for 15min until the powder is dark green, add 1.72g 100 mesh graphite (acting as an electron path to reduce the particle interface resistance) and continue grinding for 13min until the powder is gray-green to obtain a mixed powder. Weigh 17.2g of low-temperature potassium water glass with a modulus of 3.3, add 2.8g deionized water and 1.12g 100 mesh graphite, stir evenly, and obtain a potassium water glass mixture. Add the mixed powder to the potassium water glass mixture twice, stir until it becomes a uniform slurry, and evenly apply it on an 80mm*80mm square clean foam nickel substrate (0.32g / cm2 After the electrode is formed into a film, it is placed under a 320W drying light source for 33 minutes until the electrode surface turns dark green and the center of the area is hardened, and then sealed and bagged. The present invention pre-disperses a portion of graphite in the adhesive to reduce the film-forming effect of the adhesive and simultaneously reduce the resistance of the adhesive.

[0094] The negative electrode sheet was prepared as follows: 2.4g FeS and 27.2g iron powder were added to a mortar and ground for 12 minutes until the powder was uniform. 8.4g Fe3O4 was added and ground for 20 minutes until the powder turned dark orange to obtain a mixed powder. The mixed powder was added twice to 18.2g low-temperature potassium water glass with a modulus of 3.3, stirred until a uniform slurry was formed, and evenly coated on an 80mm*80mm square clean nickel foam substrate (0.36g / cm 2 ), note that the coating method is scraping. After coating, let the electrode stand for 13 minutes. After the electrode surface forms a film, place it under a 320W drying light source for 27 minutes until the center of the electrode area hardens, and then seal and bag it.

[0095] The positive and negative electrodes are assembled using polymer-cement slurry, placed in a special mold, sealed and cured at 2°C for 24 hours, and left to stand at room temperature for 24 hours to obtain a cement-based structural battery.

[0096] Example 5: (Polymer solution is PVA-KOH)

[0097] 9.5g of PVA1799 was dissolved in 90g of deionized water, heated in a 95°C waterbath, and stirred at 250 rpm for 50 minutes to obtain a PVA solution. 30g of KOH solid was dissolved in 110g of water to obtain a KOH solution. When the PVA solution turned light milky white, the KOH solution was slowly added dropwise to the PVA solution while heating and stirring for 50 minutes until the mixed solution turned transparent and light yellow, obtaining a PK solution. 490g of cement (PO42.5R) and 140g of fine sand were premixed at 70 rpm for 10 minutes at 90°C to obtain a cement-fine sand mixture. The cement-fine sand mixture was added to the PK solution while maintaining 90°C and stirring at 145 rpm for 2 minutes. After this process, a cooler was turned on and 60g of 2°C deionized water was slowly added to reduce the slurry temperature to 2°C. The mixture was stirred at 145 rpm for 16 minutes to obtain a polymer-cement slurry.

[0098] The positive electrode was prepared as follows: 0.36g Co, 8.7g Ni(OH )2Grind for 15 minutes until the powder turns dark green, add 0.43g 100 mesh graphite and continue grinding for 13 minutes until the powder turns gray-green to obtain a mixed powder. Weigh 4.3g of low-temperature potassium water glass with a modulus of 3.3, add 0.7g deionized water and 0.28g 100 mesh graphite, stir evenly, and obtain a water glass dispersion. Add the mixed powder to the potassium water glass dispersion twice, stir until it becomes a uniform slurry, and evenly apply it on a 2mm*2mm square clean foam nickel substrate (0.35g / cm 2 After the electrode is formed into a film, place it under a 320W drying light source for 30 minutes until the electrode surface turns dark green and the center of the area hardens, then seal and bag it.

[0099] The negative electrode sheet was prepared as follows: 0.6g FeS and 6.8g iron powder were ground for 10 minutes until the powder was uniform, 2.1g Fe3O4 was added and ground for 20 minutes until the powder turned dark orange to obtain a mixed powder. The mixed powder was added twice to 4.55g low-temperature potassium water glass with a modulus of 3.3, stirred to a uniform slurry, and evenly coated on a 2mm*2mm square clean nickel foam substrate (0.4g / cm 2 After the electrode is coated, let it stand for 13 minutes. After the film is formed on the electrode surface, place it under a 320W drying light source for 27 minutes until the center of the electrode area hardens, and then seal it in a bag.

[0100] The positive and negative electrodes were assembled using polymer-cement slurry (i.e., the polymer-cement slurry was coated on the surface of the positive electrode and the negative electrode respectively), placed in a mold, sealed and cured at 2°C for 24 hours, and left to stand at room temperature for 24 hours to obtain a cement-based structural battery.

[0101] Example 6: (Polymer solution is PVA-KOH)

[0102] 9.7g of PVA1799 was dissolved in 90g of deionized water, heated in a 95°C waterbath, and stirred at 250 rpm for 50 minutes to obtain a PVA solution. 30g of KOH solid was dissolved in 110g of water to obtain a KOH solution. When the PVA solution turned light milky white, the KOH solution was slowly added dropwise to the PVA solution while heating and stirring for 50 minutes until the mixed solution turned transparent and light yellow, obtaining a PK solution. 490g of cement (PO42.5R) and 140g of fine sand were premixed at 70 rpm for 10 minutes at 90°C to obtain a cement-fine sand mixture. The cement-fine sand mixture was added to the PK solution while maintaining 90°C and stirring at 145 rpm for 2 minutes. After this process, a cooler was turned on and 60g of 2°C deionized water was slowly added to reduce the slurry temperature to 2°C. The mixture was stirred at 145 rpm for 16 minutes to obtain a polymer-cement slurry.

[0103] The positive electrode was prepared as follows: 0.36g Co, 8.7g Ni(OH )2 Grind for 15 minutes until the powder turns dark green, add 0.43g 100 mesh graphite and continue grinding for 13 minutes until the powder turns gray-green to obtain a mixed powder. Weigh 4.3g of low-temperature potassium water glass with a modulus of 3.3, add 0.7g deionized water and 0.28g 100 mesh graphite, stir evenly, and obtain a water glass dispersion. Add the mixed powder to the potassium water glass dispersion twice, stir until it becomes a uniform slurry, and evenly apply it on a 2mm*2mm square clean foam nickel substrate (0.35g / cm 2 After the electrode is formed into a film, place it under a 320W drying light source for 30 minutes until the electrode surface turns dark green and the center of the area hardens, and then seal it in a bag.

[0104] The negative electrode sheet was prepared as follows: 0.6g FeS and 6.8g iron powder were ground for 10 minutes until the powder was uniform, 2.1g Fe3O4 was added and ground for 20 minutes until the powder turned dark orange to obtain a mixed powder. The mixed powder was added twice to 4.55g low-temperature potassium water glass with a modulus of 3.3, stirred to a uniform slurry, and evenly coated on a 2mm*2mm square clean nickel foam substrate (0.4g / cm 2 After the electrode is coated, let it stand for 13 minutes. After the film is formed on the electrode surface, place it under a 320W drying light source for 27 minutes until the center of the electrode area hardens, and then seal it in a bag.

[0105] The positive and negative electrodes were assembled using polymer-cement slurry (i.e., the polymer-cement slurry was coated on the surface of the positive electrode and the negative electrode respectively), placed in a mold, sealed and cured at 2°C for 24 hours, and left to stand at room temperature for 24 hours to obtain a cement-based structural battery.

[0106] Comparative Example 1: (The polymer solution is PVA-KOH, there is no cooling process, it is directly mixed and stirred, and then placed in a 2°C environment for curing)

[0107] Dissolve 10g of PVA1799 in 90g of deionized water, heat in a 95°C waterbath, and stir at 250 rpm for 50 minutes to obtain a polymer solution. Dissolve 33.6g of KOH solid in 110g of water to obtain a KOH solution. When the PVA solution turns light milky white, slowly drip the KOH solution into the PVA solution while heating and stirring for 50 minutes to obtain a PK solution. Premix 500g of cement (PO42.5R) with 150g of fine sand at 70 rpm for 10 minutes at 90°C to obtain a cement-fine sand mixture. Add the cement-fine sand mixture and 65g of room-temperature deionized water to the PK solution at room temperature and stir at 145 rpm for 18 minutes to obtain a polymer-cement slurry.

[0108] The positive electrode sheet is prepared as follows: Grind 0.36g Co and 8.7g Ni(OH)2 for 15 minutes until the powder turns dark green. Add 0.43g 100-mesh graphite and continue grinding for 13 minutes until the powder turns gray-green to obtain a mixed powder. Weigh 4.3g of low-temperature potassium water glass with a modulus of 3.3, add 0.7g deionized water and 0.28g 100-mesh graphite, and stir evenly to obtain a potassium water glass mixture. Add the mixed powder to the potassium water glass mixture in two batches, stir until a uniform slurry is formed, and evenly apply it to a 2mm*2mm square clean nickel foam substrate. After the electrode sheet is formed into a film, place it under a 320W drying light source for 30 minutes until the electrode surface turns dark green and the center of the area hardens. Then seal and bag it.

[0109] The negative electrode sheet was prepared as follows: 0.6g FeS and 6.8g iron powder were ground for 10 minutes until a uniform powder was obtained. 2.1g Fe₃O₄ was added and ground for another 20 minutes to obtain a mixed powder. The mixed powder was then added twice to 4.55g of low-temperature potassium water glass with a modulus of 3.3, stirred until a homogeneous slurry was formed, and evenly coated onto a 2mm x 2mm square clean nickel foam substrate. After coating, the electrode sheet was allowed to stand for 13 minutes. Once a film formed on the electrode surface, the sheet was placed under a 320W drying light source for 27 minutes until the center of the electrode area hardened. The sheet was then sealed and bagged.

[0110] The positive and negative electrodes were assembled using polymer-cement slurry, placed in a mold, sealed and cured at 2°C for 24 hours, and left standing at room temperature for 24 hours to obtain a cement-based structural battery.

[0111] Comparative Example 2: (The polymer solution is PVA-KOH, with a cooling process and room temperature curing)

[0112] Dissolve 10g of PVA1799 in 90g of deionized water, heat in a 95°C waterbath, and stir at 250 rpm for 50 minutes to obtain a polymer solution. Dissolve 33.6g of KOH solid in 110g of water to obtain a KOH solution. When the PVA solution turns light milky white, slowly drip the KOH solution into the PVA solution and maintain heating and stirring for 50 minutes to obtain a PK solution. Premix 500g of cement (PO42.5R) and 150g of fine sand at 70 rpm at 90°C for 10 minutes to obtain a cement-fine sand mixture. Add the cement-fine sand mixture to the PK solution while maintaining 95°C and stirring at 145 rpm for 2 minutes. After this process, turn on the cooler and slowly add 65g of 2°C deionized water to reduce the slurry temperature to 2°C. Maintain stirring at 145 rpm for 16 minutes to obtain a polymer-cement slurry.

[0113] The positive electrode sheet is prepared as follows: Grind 0.36g Co and 8.7g Ni(OH)2 for 15 minutes, add 0.43g 100-mesh graphite, and continue grinding for 13 minutes until the powder turns gray-green to obtain a mixed powder. Weigh 4.3g of low-temperature potassium water glass with a modulus of 3.3, add 0.7g deionized water and 0.28g 100-mesh graphite, and stir evenly to obtain a potassium water glass mixture. Add the mixed powder to the potassium water glass mixture in two batches, stir until a uniform slurry is formed, and evenly apply it to a 2mm*2mm square clean nickel foam substrate. After the electrode sheet is formed into a film, place it under a 320W drying light source for 30 minutes until the electrode surface turns dark green and the center of the area hardens, then seal and bag it.

[0114] The negative electrode sheet was prepared as follows: 0.6g FeS and 6.8g iron powder were ground for 10 minutes, 2.1g Fe₃O₄ was added, and grinding continued for 20 minutes to obtain a mixed powder. The mixed powder was added twice to 4.55g of low-temperature potassium water glass with a modulus of 3.3, stirred until a homogeneous slurry was formed, and evenly coated onto a 2mm x 2mm square clean nickel foam substrate. After coating, the electrode sheet was allowed to stand for 13 minutes. Once a film formed on the electrode surface, it was placed under a 320W drying light source for 27 minutes until the center of the electrode area hardened, and then sealed and bagged.

[0115] The positive and negative electrodes were assembled using polymer-cement slurry, placed in a mold, and allowed to stand at room temperature for 48 hours to obtain a cement-based structural battery.

[0116] Comparative Example 3: (Polymer solution is PVA-KOH, no cooling process, room temperature curing)

[0117] Dissolve 10g of PVA1799 in 90g of deionized water, heat in a 95°C waterbath, and stir at 250 rpm for 50 minutes to obtain a polymer solution. Dissolve 33.6g of KOH solid in 110g of water to obtain a KOH solution. When the PVA solution turns light milky white, slowly drip the KOH solution into the PVA solution while heating and stirring for 50 minutes to obtain a PK solution. Premix 500g of cement (PO42.5R) with 150g of fine sand at 70 rpm for 10 minutes at 90°C to obtain a cement-fine sand mixture. Add the cement-fine sand mixture and 65g of room-temperature deionized water to the PK solution and stir at 145 rpm for 18 minutes to obtain a polymer-cement slurry.

[0118] The positive electrode sheet was prepared as follows: 0.36g Co and 8.7g Ni(OH)2 were ground for 15 minutes, 0.43g 100-mesh graphite was added, and grinding continued for 13 minutes to obtain a mixed powder. 4.3g of low-temperature potassium water glass with a modulus of 3.3 was weighed, 0.7g deionized water and 0.28g 100-mesh graphite were added, and stirred to obtain a potassium water glass mixture. The mixed powder was added to the potassium water glass mixture in two portions, stirred until a homogeneous slurry was formed, and evenly spread on a 2mm*2mm square clean nickel foam substrate. After the electrode sheet formed into a film, it was placed under a 320W drying light source for 30 minutes until the electrode surface turned dark green and the center of the area hardened. It was then sealed and bagged.

[0119] The negative electrode sheet was prepared as follows: 0.6g FeS and 6.8g iron powder were added to a mortar and ground for 10 minutes. 2.1g Fe₃O₄ was then added and ground for another 20 minutes to obtain a mixed powder. The mixed powder was then added to 4.55g of low-temperature potassium water glass (modulus 3.3) in two portions, stirred until a homogeneous slurry was formed, and evenly coated onto a 2mm x 2mm square clean nickel foam substrate. After coating, the electrode was allowed to stand for 13 minutes. Once a film formed on the electrode surface, the electrode was placed under a 320W drying light source for 27 minutes until the center of the electrode area hardened. The mixture was then sealed and bagged.

[0120] The positive and negative electrodes were assembled using polymer-cement slurry, placed in a mold, and allowed to stand at room temperature for 48 hours to obtain a cement-based structural battery.

[0121] Performance testing:

[0122] Figures 4 to 9 The EIS (Nyquist plots) of the batteries prepared in Examples 1 to 3 and Comparative Examples 1 to 3 are shown respectively.

[0123] EIS (Nyquist plot) reflects the ionic conductivity of the electrolyte and the electrolyte-electrode interface resistance. The higher the ionic conductivity and the lower the electrolyte-electrode interface resistance, the better the performance of the electrolyte.

[0124] From the EIS results, it can be seen that the conductivity of Example 1 is 108 mS / cm, the conductivity of Example 2 is 303 mS / cm, the conductivity of Example 3 is 165.6 mS / cm, the conductivity of Comparative Example 1 is 63.3 mS / cm, the conductivity of Comparative Example 2 is 1.926 mS / cm, and the conductivity of Comparative Example 3 is 0.166 mS / cm.

[0125] From Examples 1-3, it can be seen that the ionic conductivity of the cement-based structured electrolyte with cooling stirring and low temperature curing is 10 2 On the order of mS / cm.

[0126] From the comparison between Example 1 and Comparative Example 1, it can be seen that the ion conductivity decreased by 41.4% due to the lack of cooling and stirring.

[0127] From the comparison between Example 1 and Comparative Example 2, it can be seen that the ion conductivity decreases by 98.2% due to the lack of low-temperature curing.

[0128] Comparison of Example 1 with Comparative Example 3 shows that the ion conductivity decreased by 99.8% due to the lack of both cooling, stirring, and low-temperature curing. This means that the product formed by directly mixing the polymer solution and cement is not capable of serving as an electrolyte.

[0129] From the analysis of the interface resistance of Examples 1-3 and Comparative Examples 1-3, most of the values ​​are around 1 ohm, which confirms the enhancement effect of water glass at the electrolyte-electrode interface.

[0130] Figure 10 The LSV curves of the batteries prepared in Example 1 and Comparative Examples 1 and 3 are shown. The longer the LSV window, the more stable the electrolyte. The electrolyte with cooling, stirring and low-temperature curing (Example 1) is the most stable.

[0131] Figure 11 The CV curves of the batteries prepared in Example 1, Comparative Example 1 and Comparative Example 3 are as follows. The CV test is conducted by applying a linearly varying potential (voltage) and monitoring the corresponding current response. Comparative Example 1 (without cooling and stirring, and with curing at 2-5°C) and Comparative Example 3 (without cooling and stirring, and without curing at 2-5°C) do not have the reaction peaks shown in Example 1. The reaction peaks of 0.74V and 1.00V correspond to the reduction reaction of the iron pole, and 1.65V corresponds to the oxidation reaction of the nickel pole. Only in Example 1 (with both cooling and constant-speed stirring, and with curing of the electrolyte at 2-5°C) is there a complete reaction peak, which proves the feasibility of applying this electrolyte to all-solid-state alkaline batteries. This illustrates the superiority of the temperature-controlled, originally phase-separated, cement-based structured electrolyte proposed in the present invention in supporting the electrical reaction of all-solid-state batteries.

[0132] Figure 12 XRD pattern of the positive electrode prepared in Example 1; Figure 13 This is the XRD pattern of the negative electrode prepared in Example 1.

[0133] Figure 14 The voltage-discharge capacity curves of the batteries prepared in Examples 1 to 3 are shown. Figure 15 This is a voltage-discharge capacity curve of the battery prepared in Example 4. Figure 16 The voltage-discharge capacity curves of the batteries prepared in Comparative Examples 1 to 3 are shown.

[0134] Discharge capacity: The battery with cooling and stirring + low temperature curing (Examples 1-3) can reach a capacity of 50mAh and an area energy density of 12.5mAh / cm2 , 175Wh / m 2 , that is, a 6m*6m cement wall can store 6.3KWh of electricity. Keeping the electrolyte unchanged and increasing the electrode area (Example 4), the capacity can reach 550mAh. Lack of cooling and stirring (temperature-controlled second step) (Comparative Example 1), the capacity is only 24mAh; lack of low-temperature maintenance (temperature-controlled third step) (Comparative Example 2), the capacity is only 10mAh; lack of both (direct mixing of PK and cement, Comparative Example 3) is only 7mAh. It shows that the temperature-controlled phase separation technology in the present invention plays a very important role in the capacity of all-solid-state cement batteries.

[0135] Figure 17 This is a test diagram of the charge and discharge cycle performance of the battery prepared in Example 1.

[0136] For Example 1 alone, 2 mA / cm 2 The charge and discharge cycles of the present invention are carried out, each cycle involves charging for 1320s and discharging for 1200s, and the above cycle test results are obtained. The all-solid-state cement-based structural battery of the present invention has no obvious attenuation in the first 500 cycles. After 3000 cycles, the polarization voltage is only 0.3V. The cement battery of the present invention has excellent cycle characteristics and is particularly suitable as a structured energy storage device.

[0137] Figure 18 The graphs are the power retention performance test curves of Examples 1 and 2 and a commercial nickel-iron battery.

[0138] For Examples 1-2, the cells were charged at 15 mA for 3 hours, then left to rest. The open-circuit voltage of the cells was measured every hour and compared with the publicly available data on the retention of commercial alkaline nickel-iron batteries. It was found that the voltage retention of the unsealed cement-based structured battery of the present invention in air conditions was close to that of the commercial battery. Since stable retention is a primary requirement for energy storage devices (a significant feature that distinguishes them from capacitors), the cement-based structured battery of the present invention is fully capable of being used as an energy storage device.

[0139] Figure 19 The figure shows the LEDs lit after the batteries prepared in Examples 5 and 6 were connected in series. For Examples 5-6, after charging at 15 mA for 5 minutes, the red LEDs were lit in series.

[0140] The mechanical strengths of the cement-based batteries of Examples 1 to 3 are shown in Table 1.

[0141] Table 1 Mechanical strength

[0142]

[0143] As can be seen from Table 1, Examples 1-3 have high and stable compressive and flexural strengths and are capable of serving as structures. Therefore, the cement-based batteries of the present invention can actually be used as cement-based structural batteries and directly serve as part of a building (walls, columns, and panels). They not only participate in bearing stress, but can also serve as energy storage devices to collect clean energy such as solar energy.

[0144] 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 method for preparing a cement-based structural battery with integrated load-bearing and energy storage, characterized in that: Including steps: 1) mixing a polymer solution, cement and fine sand to obtain a polymer-cement slurry electrolyte; The polymer solution is obtained by dissolving a polymer and a strong base in water, or by dissolving a polymer, a strong base and a sulfide in water, or by dissolving a polymer, a strong base, an inorganic sulfide and a chemical cross-linking agent in water; the polymer is one or more of PVA and PAA; 2) Preparation of positive electrode sheet; 3) Preparation of negative electrode sheet; 4) placing a polymer-cement slurry electrolyte on the surface of the positive electrode sheet and the surface of the negative electrode sheet respectively, then stacking the positive electrode sheet and the negative electrode sheet in sequence, placing them in a mold for curing, and allowing them to stand to obtain a cement-based structural battery with integrated load-bearing and energy storage capabilities; The mixing in step 1) is specifically to mix the solution of polymer and strong base, cement and fine sand at 90-95°C, then cool to 2-5°C, and add cold water to obtain a cement slurry containing a liquid-solid mixed phase.

2. The method for preparing the cement-based structural battery with integrated load-bearing and energy storage according to claim 1, characterized in that: When the polymer solution contains inorganic sulfide, the inorganic sulfide is added together with the cold water; when the polymer solution contains a chemical cross-linking agent, the chemical cross-linking agent is added together with the cold water; The amount of each substance in the polymer solution in step 1) is calculated by weight: 8-10 parts of polymer 30-40 parts of strong base 190-210 parts water; When inorganic sulfide is present, the amount of sulfide is 0.5-1 part; When a chemical cross-linking agent is contained, the amount of the chemical cross-linking agent is 0.1-0.5 parts; The amounts of polymer, cement and fine sand in the polymer solution in step 1) are calculated by weight: 8-10 parts of polymer; 490-510 parts of cement; and 140-160 parts of fine sand. The curing in step 4) refers to closed curing at 0°C to 3°C.

3. The method for preparing the cement-based structural battery with integrated load-bearing and energy storage according to claim 1, characterized in that: The positive electrode sheet in step 2) is prepared by the following method: S1: uniformly mixing the positive electrode material, conductive agent, binder and solvent to obtain positive electrode active material slurry; S2: coating the positive electrode active material slurry on the surface of the conductive substrate, forming a film, and drying to obtain a positive electrode sheet; the binder is potassium water glass or sodium water glass.

4. The method for preparing the cement-based structural battery with integrated load-bearing and energy storage according to claim 3, characterized in that: The positive electrode material is one or more of nickel hydroxide, transition metal, transition metal oxide, and transition metal hydroxide; the conductive agent is one or more of graphite and carbon nanotube; The modulus of water glass is 2.0-3.3; the solvent is water; The mass ratio of the positive electrode material, the conductive agent and the binder is (8-9.5): (0.5-1): (3-6).

5. The method for preparing the cement-based structural battery with integrated load-bearing and energy storage according to claim 3, characterized in that: The mass ratio of the positive electrode material to the solvent is (8-9.5): (0.4-0.8); The coating amount of the positive electrode active material slurry is 0.3-0.4 g / cm 2 ; The positive electrode active material slurry is coated on both surfaces of the conductive substrate; The conductive agent is divided into two parts, one part is mixed with the positive electrode material, and the other part is mixed with the binder and the solvent; The conductive substrate is foamed nickel, copper foil or aluminum foil.

6. The method for preparing the cement-based structural battery with integrated load-bearing and energy storage according to claim 1, characterized in that: The negative electrode sheet in step 3) is prepared by the following method: uniformly mixing a negative electrode active material, a conductive agent, and a binder to obtain a negative electrode active material slurry; coating the negative electrode active material slurry on the surface of a conductive substrate, forming a film, and drying to obtain a negative electrode sheet; the binder is one or more of potassium water glass and sodium water glass.

7. The method for preparing the cement-based structural battery with integrated load-bearing and energy storage according to claim 6, characterized in that: The negative electrode active material is one or more of iron, iron oxide, ferroferric oxide, carbonyl iron, ferrous sulfide, bismuth sulfide, zinc, zinc oxide, zinc-containing alloy, and iron-containing alloy; The conductive agent is one or more of carbon nanotubes and graphite; The coating amount of the negative electrode active material slurry is 0.35-0.45 g / cm 2 ; The mass ratio of the negative electrode active material, the conductive agent, and the binder is (7.5-10): (0-0.5): (3-5.5); The conductive substrate is foamed nickel, copper foil or aluminum foil.

8. The method for preparing the cement-based structural battery with integrated load-bearing and energy storage according to claim 1, characterized in that: The cement slurry containing the liquid-solid mixed phase is prepared under stirring conditions at a stirring speed of 135 to 165 r / min; The mixing time at 90-95°C in step 1) is 1-2 minutes; the cooling to 2-5°C means cooling to 2-5°C within 5-10 minutes; after adding cold water and cooling to 2-5°C, stirring and mixing are performed for 15-20 minutes; Mixing the solution of the polymer and the strong base, cement and fine sand at 90-95°C in step 1) refers to stirring the polymer, the strong base and water at 85-95°C at a speed of 250-260r / min for 1.5-2h to prepare a solution; dry mixing the cement and fine sand at 90-95°C at a speed of 60-70r / min for 5-10min to obtain a cement-fine sand mixture; and mixing the above solution and cement-fine sand mixture at 90-95°C; The mass ratio of the cold water to the polymer is (60-80):(8-10).

9. The method for preparing the cement-based structural battery with integrated load-bearing and energy storage according to claim 1, characterized in that: In step 1), the strong base is one or more of KOH and NaOH; the sulfide is one or more of Na2S and K2S; the chemical cross-linking agent is one or more of tetraethylammonium chloride and polyethylene glycol diglycidyl ether; The molecular weight of the polymer PVA is 1000-10000, and the molecular weight of PAA is 10000-500000; The curing in step 4) refers to closed curing at 0°C to 3°C for 6-24 hours; the standing in step 4) refers to room temperature for 12 hours to 24 hours.

10. A cement-based structural battery with integrated load-bearing and energy storage capabilities prepared by the method according to any one of claims 1 to 9.

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