Cement-based energy storage device and preparation method and application thereof

Abstract

The invention relates to a cement-based energy storage device and a preparation method and application thereof. The preparation method comprises the following steps: preparing cement-based printing slurry; filling the cement-based printing slurry into a 3D printing device, and stacking layer by layer to form a printing body; curing, maintaining, trimming and drying the printing body, and immersing the printing body into a soluble alkali / salt solution to obtain a cement-based electrolyte; a soluble alkali / salt solution is dropwise added to the surface of the electrode, then the electrode and the cement-based electrolyte are stacked and assembled, and an assembly is obtained; and sealing and packaging the assembly to obtain the cement-based energy storage device. The plane where the electrodes are located is perpendicular to the printing interlayer interface of the cement-based electrolyte. The parameters of 3D printing are as follows: the interlayer interval time is 20-60 min, the layer height is 10-20 mm, the diameter of a nozzle is 7-18 mm, the printing speed is 10-50 mm / s, and the extrusion speed is 0.2-0.5 rad / s. The prepared cement-based energy storage device is high in ion migration efficiency, good in energy storage performance and more practical.

Description

Technical Field

[0001] This invention relates to the field of energy storage technology, and in particular to a cement-based energy storage device, its preparation method, and its application. Background Technology

[0002] Against the backdrop of the ongoing "dual-carbon" strategy, building a new power system with new energy sources as the mainstay has become an important direction for energy transformation. However, new energy sources such as wind power and photovoltaics are characterized by high volatility and intermittency, posing challenges to grid stability. Energy storage technology has therefore become a key support for achieving a high proportion of new energy integration. Compared to traditional energy storage solutions such as lithium batteries and flow batteries, structural energy storage devices have the ability to integrate with building structures, serving both load-bearing and energy storage functions. They possess significant advantages in material saving, land saving, and functional integration, demonstrating promising application prospects.

[0003] Cement-based energy storage devices (CSSCs), as an emerging type of structural energy storage, utilize hardened cement slurry as a solid electrolyte and combine it with the energy storage mechanism of traditional supercapacitors to form a composite system integrating structure and function. The energy storage performance of cement-based energy storage devices mainly depends on electrode activity, the ion conductivity of the electrolyte, and interfacial reaction efficiency. Among these, the ion migration efficiency within the electrolyte is the core factor affecting the device's surface capacitance and energy density. Currently, conventional cement-based materials, due to their dense structure and disordered pores, have limited ion migration paths and low conductivity, severely restricting device performance. To address this bottleneck, existing solutions optimize the electrolyte structure through salt doping, polymer introduction, and pore control, but the improvement is limited and the cost is high, still failing to meet the practical requirements of high-performance, engineered CSSCs.

[0004] Therefore, it is of great significance to effectively improve the ion migration efficiency inside the electrolyte of cement-based energy storage devices. Summary of the Invention

[0005] The main objective of this invention is to provide a cement-based energy storage device, its preparation method, and its application. The technical problem to be solved is how to improve the ion migration efficiency inside the electrolyte of the cement-based energy storage device, thereby improving its energy storage performance and making it more suitable for practical use.

[0006] The objective of this invention and the technical problem it solves are achieved through the following technical solution. A method for preparing a cement-based energy storage device according to this invention includes the following steps:

[0007] S1: Preparation of cement-based printing paste;

[0008] S2: The aforementioned cement-based printing paste is loaded into a 3D printing device and deposited layer by layer to form a printed body;

[0009] S3: After curing, trimming, and drying the aforementioned printed body, immerse it in a soluble alkali / salt solution to obtain a cement-based electrolyte.

[0010] S4: A soluble alkali / salt solution is dropped onto the electrode surface, and then the aforementioned electrode is stacked and assembled with the aforementioned cement-based electrolyte to obtain an assembly; the aforementioned assembly is sealed and packaged to obtain a cement-based energy storage device; the plane where the aforementioned electrode is located is perpendicular to the interlayer interface of the aforementioned cement-based electrolyte.

[0011] In step S2, the 3D printing parameters are set as follows: interlayer interval time is 20-60 min, layer height is 10-20 mm, nozzle diameter is 7-18 mm, printing speed is 10-50 mm / s, and extrusion speed is 0.2-0.5 rad / s.

[0012] The objectives of this invention and the technical problems it addresses can be further achieved by the following technical measures.

[0013] Preferably, in the aforementioned method for preparing a cement-based energy storage device, the cement-based printing paste comprises the following components in parts by weight:

[0014] Cementitious material: 80-120 parts;

[0015] Polymer: 2-25 parts;

[0016] Water-reducing agent: 0.1–2 parts;

[0017] Accelerator: 0.5–10 parts;

[0018] Air-entraining agent: 0.002–0.1 parts;

[0019] Water: 28–65 parts.

[0020] Preferably, in the aforementioned method for preparing a cement-based energy storage device, the cement-based printing paste comprises the following components in parts by weight:

[0021] Cementitious material: 95-105 parts;

[0022] Polymer: 5-20 parts;

[0023] Water-reducing agent: 0.3–0.6 parts;

[0024] Thickener: 0.08–0.25 parts;

[0025] Accelerator: 2-4 parts;

[0026] Air-entraining agent: 0.008–0.05 parts;

[0027] Water: 36-44 parts.

[0028] Preferably, in the aforementioned method for preparing cement-based energy storage devices, the cementing material is silicate cement;

[0029] The aforementioned polymer is polyacrylamide;

[0030] The aforementioned water-reducing agent is a polycarboxylate-based water-reducing agent;

[0031] The aforementioned quick-setting agent is an aluminate quick-setting agent;

[0032] The aforementioned air-entraining agent is an alkyl sulfate-based air-entraining agent.

[0033] Preferably, in the aforementioned method for preparing cement-based energy storage devices, during step S2, during the interlayer deposition interval in the 3D printing process, a soluble alkali / salt solution and / or polyacrylamide are applied to the interlayer interface.

[0034] Preferably, in the aforementioned method for preparing the cement-based energy storage device, during the interlayer deposition interval, a 5-7 mol / L potassium hydroxide solution is sprayed onto the interlayer interface at a spraying rate of 0.5-2 g / cm³. 2 ; and a polyacrylamide aqueous solution with a solid content of 25-35%, with a spraying amount of 1-3 g / cm³. 2 .

[0035] Preferably, in the aforementioned method for preparing cement-based energy storage devices, in steps S3 and S4, the soluble alkali / salt solution is a 5-7 mol / L potassium hydroxide solution.

[0036] Preferably, in the aforementioned method for preparing the cement-based energy storage device, the positive electrode is a magnesium cobalt layered double hydroxide / nickel foam electrode, and the negative electrode is an activated carbon / nickel foam electrode.

[0037] The objective of this invention and the solution to its technical problem are also achieved by the following technical solution. A cement-based energy storage device according to this invention is prepared by any of the aforementioned methods. The aforementioned cement-based electrolyte has a directionally arranged pore structure with a pore size of 0.5–20 μm and a porosity of 10–50%.

[0038] The objectives of this invention and the solutions to its technical problems are also achieved through the following technical solutions. This invention proposes the application of the aforementioned cement-based energy storage devices in buildings or infrastructure.

[0039] By employing the above technical solution, the cement-based energy storage device, its preparation method, and its application of the present invention have at least the following advantages:

[0040] (1) In the traditional view, weak interlayer interfaces in 3D printed components are considered structural defects that may cause a decrease in material strength or durability. However, this invention is the first to reverse the trend by utilizing the low density and high porosity of the interface region to construct a directionally arranged pore structure as an efficient ion migration channel, which significantly improves the ionic conductivity of cement-based electrolytes and provides a new approach to the structural optimization of cement-based electrolytes.

[0041] (2) The cement-based energy storage device prepared by the present invention can control the size of the directional hole structure by adjusting parameters such as interlayer interval time, printing speed and layer height during the printing process. It has the advantages of low cost, simple operation process and easy large-scale preparation.

[0042] (3) The present invention has good scalability. Using this method, not only can the internal directional pore structure of cement-based electrolyte be constructed, but also subsequent optimization measures such as interface functionalization can be combined to further improve the ion conduction performance of the directional pore structure and the overall performance of the device.

[0043] (4) This invention has strong adaptability and is applicable to all types of cement-based electrolyte materials and common electrode materials, which can meet the construction needs of various energy storage systems such as cement-based batteries and cement-based supercapacitors. The printing equipment and raw materials used are widely available and cost-controllable, and can be easily integrated into existing building 3D printing platforms, which has great potential for widespread application.

[0044] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the assembly of a cement-based energy storage device in some embodiments of the present invention;

[0046] Figure 2 The AC impedance spectral curves of the cement-based energy storage devices prepared in Examples 1-3 and Comparative Example 1 of this invention are shown.

[0047] Figure 3 The ionic conductivity of the cement-based energy storage devices prepared in Examples 1-3 and Comparative Example 1 of this invention;

[0048] Figure 4 The cyclic voltammetry curve of the cement-based energy storage device prepared in Example 1 of this invention;

[0049] Figure 5 The constant current charge-discharge curve of the cement-based energy storage device prepared in Example 1 of this invention;

[0050] Figure 6This is a pore structure morphology diagram of the cross-section of the cement-based electrolyte in Embodiment 1 of the present invention. Detailed Implementation

[0051] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, provides a detailed description of the specific implementation methods, structures, features, and effects of a cement-based energy storage device, its preparation method, and its application based on the present invention. In the following description, different "embodiments" or "embodiments" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable manner.

[0052] This invention proposes a method for preparing a cement-based energy storage device, such as... Figure 1 As shown, the steps include:

[0053] S1: Preparation of cement-based printing paste;

[0054] S2: The aforementioned cement-based printing paste is loaded into a 3D printing device and deposited layer by layer to form a printed body;

[0055] S3: After curing, trimming, and drying the aforementioned printed body, immerse it in a soluble alkali / salt solution to obtain a cement-based electrolyte.

[0056] S4: A soluble alkali / salt solution is dropped onto the electrode surface, and then the aforementioned electrode is stacked and assembled with the aforementioned cement-based electrolyte to obtain an assembly; the aforementioned assembly is sealed and packaged to obtain a cement-based energy storage device; the plane where the aforementioned electrode is located is perpendicular to the interlayer interface of the aforementioned cement-based electrolyte.

[0057] In step S2, the 3D printing parameters are set as follows: interlayer interval time is 20-60 min, layer height is 10-20 mm, nozzle diameter is 7-18 mm, printing speed is 10-50 mm / s, and extrusion speed is 0.2-0.5 rad / s.

[0058] Specifically, in step S1, the raw materials are mixed and stirred to prepare a cement-based printing paste. Preferably, the cement-based printing paste comprises the following components in parts by weight: cementitious material: 80-120 parts; polymer: 2-25 parts; water-reducing agent: 0.1-2 parts; accelerator: 0.5-10 parts; air-entraining agent: 0.002-0.1 parts; water: 28-65 parts. More preferably, the cement-based printing paste comprises the following components in parts by weight: cementitious material: 95-105 parts; polymer: 5-20 parts; water-reducing agent: 0.3-0.6 parts; thickener: 0.08-0.25 parts; accelerator: 2-4 parts; air-entraining agent: 0.008-0.05 parts; water: 36-44 parts. Preferably, the stirring is performed by first stirring at 140 r / min for 120 s, stopping for 15 s, and then stirring at 285 r / min for 120 s.

[0059] Cementing materials include, but are not limited to, ordinary Portland cement, sulfoaluminate cement, aluminate cement, magnesium cement, and geopolymer cementing materials. Cementing materials prepared mainly from solid waste, such as fly ash, granulated blast furnace slag powder, steel slag, red mud, coal gangue, construction demolition waste, and urban solid waste incineration fly ash, can also be selected as cementing systems after mechanical activation, heat treatment, or chemical activation. Alternatively, mineral admixtures such as limestone powder, silica fume, and metakaolin can be compounded with the above-mentioned cementing materials to form a composite cementing system, with ordinary Portland cement being the preferred choice.

[0060] The polymers include, but are not limited to, polyvinyl alcohol (PVA), polyacrylamide (PAM), polyacrylic acid (PAA), polyvinylpyrrolidone (PVP), hydroxypropyl methylcellulose (HPMC), and polyurethane (PU), with polyacrylamide (PAM) being preferred.

[0061] Water-reducing agents include, but are not limited to, polycarboxylate-based water-reducing agents, naphthalene-based water-reducing agents, sulfonated melamine-formaldehyde condensate water-reducing agents, lignin sulfonate water-reducing agents, and combinations thereof, with polycarboxylate-based water-reducing agents being preferred.

[0062] Accelerators include, but are not limited to, aluminate accelerators, sulfoaluminate accelerators, nitrate accelerators, sulfate accelerators, and mixtures thereof, with aluminate accelerators being preferred.

[0063] Air-entraining agents include, but are not limited to, alkyl sulfate air-entraining agents, rosin soap air-entraining agents, alkyl hydrocarbon sulfonate air-entraining agents, fluorocarbon surfactants and combinations thereof, with alkyl sulfate air-entraining agents being preferred.

[0064] Preferably, the water is tap water that meets the requirements of GB 5749-2022 "Standards for Drinking Water Quality".

[0065] In step S2, the aforementioned cement-based printing slurry is loaded into a 3D printing device and deposited layer by layer to form a printed body. By adjusting the 3D printing process parameters, an ordered pore structure is formed in the interlayer / strip interface region using the 3D printing process. This pore structure serves as a rapid ion migration channel, effectively improving the ion transport efficiency within the electrolyte. The 3D printing parameters are set as follows: interlayer interval time of 20–60 min, layer height of 10–20 mm, nozzle diameter of 7–18 mm, printing speed of 10–50 mm / s, and extrusion speed of 0.2–0.5 rad / s. More preferably, the 3D printing parameters are set as follows: interlayer interval time of 30 min, layer height of 10 mm, nozzle diameter of 10 mm, printing speed of 30 mm / s, and extrusion speed of 0.4 rad / s.

[0066] The oriented pore structure can be functionalized to enhance its ion conductivity. Functionalization includes, but is not limited to:

[0067] During the interlayer deposition interval, an aqueous solution containing a soluble alkali / salt is sprayed at the interlayer interface; the soluble alkali / salt includes, but is not limited to, alkaline compounds, sulfates, chlorides, nitrates, carbonates, acetates, and lithium salts, with potassium hydroxide being preferred.

[0068] During the interlayer deposition interval, a polymer material, preferably polyacrylamide, is applied to the interlayer interface.

[0069] Preferably, during the interlayer deposition interval, a 5–7 mol / L potassium hydroxide solution is sprayed at the interlayer interface, with a spraying amount of 0.5–2 g / cm³. 2 ; and a polyacrylamide aqueous solution with a solid content of 25-35%, with a spraying amount of 1-3 g / cm³. 2 More preferably, during the printing deposition interval, a 6 mol / L potassium hydroxide solution is sprayed at the interlayer interface at a spraying rate of 1 g / cm³. 2 And a 30% solids content polyacrylamide aqueous solution, with a spraying amount of 2 g / cm³. 2 .

[0070] In step S3, the printed body is placed in a standard curing chamber for curing. After curing, the printed grooves on the surface of the printed body are removed to make the surface smooth; then it is placed in a vacuum drying oven to dry to constant weight; the dried printed body is then transferred to a vacuum water retention machine, and a soluble alkali / salt solution is introduced to fully penetrate into the pores of the printed body. After the treatment, a cement-based electrolyte is obtained. Preferably, the curing period is 28 days; the printed grooves on the surface of the printed body are removed using a wire cutting machine; the temperature of the vacuum drying oven is 45°C; the vacuum degree of the vacuum water retention machine is set to 2 kPa; the soluble alkali / salt solution is a 5-7 mol / L potassium hydroxide solution, more preferably a 6 mol / L potassium hydroxide solution.

[0071] In S4, the electrodes include a positive electrode and a negative electrode. The positive and negative electrodes include single-material electrodes and composite material electrodes. The single-material electrode is one of the following: a metal electrode (iron, nickel, copper, aluminum, etc.), a carbon material electrode (graphite, carbon fiber, graphene, etc.), or a lithium compound electrode (lithium iron phosphate electrode, lithium manganese oxide electrode, lithium cobalt oxide electrode, lithium nickel cobalt oxide electrode, ternary lithium electrode, etc.). The composite electrode is one or more of the following: a metal oxide and carbon material composite electrode, a conductive polymer and metal composite electrode, a multi-metal composite electrode, a carbon material and metal compound composite electrode, and a cement-based composite electrode. Preferably, the positive electrode is a magnesium cobalt layered double hydroxide / foamed nickel electrode, and the negative electrode is an activated carbon / foamed nickel electrode.

[0072] Before assembly, equal amounts of soluble alkali / salt solution are dropped onto the surfaces of the positive and negative electrodes, respectively. Then, the positive electrode, cement-based electrolyte, and negative electrode are sequentially stacked in a sandwich structure to obtain the assembly. The pore orientation of the oriented pore structure of the cement-based electrolyte is consistent with the ion migration direction between the positive and negative electrodes; therefore, the plane of the electrode is perpendicular to the interlayer interface of the cement-based electrolyte. Preferably, the soluble alkali / salt solution is a 5–7 mol / L potassium hydroxide solution, more preferably a 6 mol / L potassium hydroxide solution. Preferably, the amount of soluble alkali / salt solution added is 30 μL / cm³. 2 The assembly is sealed and packaged using a vacuum heat sealer to obtain the cement-based energy storage device.

[0073] This invention proposes a cement-based energy storage device, which is prepared by any of the aforementioned methods. The aforementioned cement-based electrolyte has a directionally arranged pore structure with a pore size of 0.5 to 20 μm and a porosity of 10 to 50%.

[0074] This invention proposes the application of the aforementioned cement-based energy storage devices in buildings or infrastructure. These devices can be integrated into walls or roofs, storing energy through photovoltaic power generation during the day and supplying power to building interior lighting, air conditioning, and other systems at night. Applying cement-based energy storage devices to roads can create "zero-carbon service areas," storing energy by collecting solar or mechanical energy (such as vehicle pressure) to power streetlights and traffic lights.

[0075] The present invention will be further described below with reference to specific embodiments, but this should not be construed as a limitation on the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above description of the present invention still fall within the scope of protection of the present invention.

[0076] Unless otherwise specified, all materials and reagents mentioned below are commercially available products well known to those skilled in the art; unless otherwise specified, all methods described are methods known in the art. Unless otherwise defined, the technical or scientific terms used should have the ordinary meaning understood by those skilled in the art to which this invention pertains.

[0077] Example 1

[0078] This embodiment provides a cement-based energy storage device and its preparation method, such as... Figure 1 As shown.

[0079] The cement-based energy storage device includes a magnesium cobalt layered double hydroxide / foamed nickel electrode (MgCo-LDHs@Ni), an activated carbon / foamed nickel electrode (AC@Ni), and a cement-based electrolyte. The cement-based electrolyte comprises the following components in parts by weight: cementitious material: 100 parts; polymer: 6 parts; water-reducing agent: 0.3 parts; thickener: 0.2 parts; accelerator: 2 parts; air-entraining agent: 0.01 parts; water: 40 parts. The cementitious material is ordinary Portland cement; the polymer is polyacrylamide (PAM); the water-reducing agent is polycarboxylate high-performance water-reducing agent with a solid content of 40%; the thickener is hydroxymethyl cellulose ether (HPMC); the accelerator comprises the following components in parts by weight: aluminate cement 50%, sodium carbonate 10%, aluminum sulfate 10%, sodium sulfate 15%, quicklime 15%; the air-entraining agent is hydrogen peroxide solution with a purity of 99%.

[0080] The preparation method of cement-based energy storage devices is as follows:

[0081] S1: Mix cement, polymer, water-reducing agent, air-entraining agent, quick-setting agent and water. First, stir at 140 r / min for 120 s, stop for 15 s, and then stir at 285 r / min for 120 s to prepare cement-based printing slurry.

[0082] S2: The prepared cement-based printing paste is loaded into a 3D printing device and deposited layer by layer to form a printed body. The printed body is 120cm long, 60mm wide, and 100mm high. The printing process is as follows: interlayer interval 30min, layer height 10mm, 10 layers, nozzle diameter 10mm, printing speed 30mm / s, and extrusion speed 0.4rad / s. During the printing deposition interval, a 6mol / L potassium hydroxide solution is sprayed at the interlayer interface at a spraying rate of 1g / cm³. 2 And a PAM aqueous solution with a solid content of 30%, with a spraying amount of 2 g / cm³. 2 .

[0083] S3: The printed body was placed in a standard curing room for 28 days for curing. After curing, the printed grooves on the surface of the printed body were removed to make the surface flat. The length of the printed body after removal was 100cm, the width was 50mm, and the height was 100mm. Then it was placed in a vacuum drying oven at 45℃ to dry to constant weight. The dried printed body was then transferred to a vacuum water retention machine with a vacuum degree of 2kPa and 6mol / L potassium hydroxide solution was introduced to allow it to fully penetrate into the pores of the printed body. After the treatment, cement-based electrolyte was obtained.

[0084] S4: Add 30 μL / cm³ of the solution to the surfaces of the magnesium cobalt layered double hydroxide / nickel foam electrode (MgCo-LDHs@Ni) and the activated carbon / nickel foam electrode (AC@Ni), respectively. 2 A 6 mol / L potassium hydroxide solution, with electrode areas of 100 cm². 2 Then, MgCo-LDHs@Ni, cement-based electrolyte, and AC@Ni are sequentially stacked and assembled in a sandwich structure, with the plane of the electrode perpendicular to the interlayer interface of the cement-based electrolyte, to obtain the assembly. The assembly is then sealed and packaged using a vacuum heat sealer to obtain the cement-based energy storage device.

[0085] Example 2

[0086] This embodiment provides a cement-based energy storage device and its preparation method, such as... Figure 1 As shown.

[0087] The cement-based energy storage device comprises two activated carbon / foamed nickel electrodes (AC@Ni) and a cement-based electrolyte. The cement-based electrolyte comprises the following components in parts by weight: cementitious material: 100 parts; polymer: 10 parts; water-reducing agent: 0.5 parts; thickener: 0.1 parts; accelerator: 3 parts; air-entraining agent: 0.02 parts; water: 43 parts. The cementitious material is ordinary Portland cement; the polymer is polyacrylamide (PAM); the water-reducing agent is polycarboxylate superplasticizer with a solid content of 40%; the thickener is hydroxymethyl cellulose ether (HPMC); the accelerator comprises the following components in parts by weight: aluminate cement 50%, sodium carbonate 10%, aluminum sulfate 10%, sodium sulfate 15%, quicklime 15%; and the air-entraining agent is hydrogen peroxide solution with a purity of 99%.

[0088] The preparation method of cement-based energy storage devices is as follows:

[0089] S1: Mix cement, polymer, water-reducing agent, air-entraining agent, quick-setting agent and water. First, stir at 140 r / min for 120 s, stop for 15 s, and then stir at 285 r / min for 120 s to prepare cement-based printing slurry.

[0090] S2: The prepared cement-based printing paste is loaded into a 3D printing device and deposited layer by layer to form a printed body. The printed body is 120cm long, 60mm wide, and 100mm high. The printing process is as follows: interlayer interval 30min, layer height 10mm, 10 layers, nozzle diameter 10mm, printing speed 40mm / s, and extrusion speed 0.4rad / s. During the printing deposition interval, a 6mol / L potassium hydroxide solution is sprayed at the interlayer interface at a spraying rate of 1g / cm³. 2 And a PAM aqueous solution with a solid content of 30%, with a spraying amount of 2 g / cm³. 2 .

[0091] S3: The printed body was placed in a standard curing room for 28 days for curing. After curing, the printed grooves on the surface of the printed body were removed to make the surface flat. The length of the printed body after removal was 100cm, the width was 50mm, and the height was 100mm. Then it was placed in a vacuum drying oven at 45℃ to dry to constant weight. The dried printed body was then transferred to a vacuum water retention machine with a vacuum degree of 2kPa and 6mol / L potassium hydroxide solution was introduced to allow it to fully penetrate into the pores of the printed body. After the treatment, cement-based electrolyte was obtained.

[0092] S4: Add 30 μL / cm² of solution to both activated carbon / nickel foam electrodes (AC@Ni). 2 A 6 mol / L potassium hydroxide solution, with electrode areas of 100 cm². 2 Then, AC@Ni, cement-based electrolyte, and AC@Ni are sequentially stacked in a sandwich structure, with the plane of the electrode perpendicular to the interlayer interface of the cement-based electrolyte, to obtain the assembly. The assembly is then sealed using a vacuum heat sealer to obtain the cement-based energy storage device.

[0093] Example 3

[0094] This embodiment provides a cement-based energy storage device and its preparation method, such as... Figure 1 As shown.

[0095] The cement-based energy storage device comprises two reduced graphene oxide / nickel foam electrodes (rGO@Ni) and a cement-based electrolyte. The cement-based electrolyte comprises the following components in parts by weight: cementitious material: 100 parts; polymer: 10 parts; water-reducing agent: 0.5 parts; thickener: 0.1 parts; accelerator: 3 parts; air-entraining agent: 0.02 parts; water: 43 parts. The cementitious material is ordinary Portland cement; the polymer is polyacrylamide (PAM); the water-reducing agent is polycarboxylate superplasticizer with a solid content of 40%; the thickener is hydroxymethyl cellulose ether (HPMC); the accelerator comprises the following components in parts by weight: aluminate cement 50%, sodium carbonate 10%, aluminum sulfate 10%, sodium sulfate 15%, quicklime 15%; and the air-entraining agent is hydrogen peroxide solution with a purity of 99%.

[0096] The preparation method of cement-based energy storage devices is as follows:

[0097] S1: Mix cement, polymer, water-reducing agent, air-entraining agent, quick-setting agent and water. First, stir at 140 r / min for 120 s, stop for 15 s, and then stir at 285 r / min for 120 s to prepare cement-based printing slurry.

[0098] S2: The prepared cement-based printing paste is loaded into a 3D printing device and deposited layer by layer to form a printed body. The printed body is 120cm long, 60mm wide, and 100mm high. The printing process is as follows: interlayer interval 40min, layer height 10mm, 10 layers, nozzle diameter 10mm, printing speed 30mm / s, and extrusion speed 0.4rad / s. During the printing deposition interval, a 6mol / L potassium hydroxide solution is sprayed at the interlayer interface at a spraying rate of 1g / cm³. 2 And a PAM aqueous solution with a solid content of 30%, with a spraying amount of 2 g / cm³. 2 .

[0099] S3: The printed body was placed in a standard curing room for 28 days for curing. After curing, the printed grooves on the surface of the printed body were removed to make the surface flat. The length of the printed body after removal was 100cm, the width was 50mm, and the height was 100mm. Then it was placed in a vacuum drying oven at 45℃ to dry to constant weight. The dried printed body was then transferred to a vacuum water retention machine with a vacuum degree of 2kPa and 6mol / L potassium hydroxide solution was introduced to allow it to fully penetrate into the pores of the printed body. After the treatment, cement-based electrolyte was obtained.

[0100] S4: 30 μL / cm² of solution was dropped onto both surfaces of the reduced graphene oxide / nickel foam electrode (rGO@Ni). 2 A 6 mol / L potassium hydroxide solution, with electrode areas of 100 cm². 2Then, rGO@Ni, cement-based electrolyte, and rGO@Ni are sequentially stacked in a sandwich structure, with the plane of the electrode perpendicular to the interlayer interface of the cement-based electrolyte, to obtain the assembly. The assembly is then sealed using a vacuum heat sealer to obtain the cement-based energy storage device.

[0101] Comparative Example 1

[0102] This comparative example provides a cast cement-based energy storage device and its preparation method.

[0103] The cast cement-based energy storage device includes a magnesium cobalt layered double hydroxide / foamed nickel electrode (MgCo-LDHs@Ni), an activated carbon / foamed nickel electrode (AC@Ni), and a cast cement-based electrolyte. The cast cement-based electrolyte comprises the following components in parts by weight: cementitious material: 100 parts; polymer: 6 parts; water-reducing agent: 0.3 parts; thickener: 0.2 parts; accelerator: 2 parts; air-entraining agent: 0.01 parts; water: 40 parts. The cementitious material is ordinary Portland cement; the polymer is polyacrylamide (PAM); the water-reducing agent is polycarboxylate high-performance water-reducing agent with a solid content of 40%; the thickener is hydroxymethyl cellulose ether (HPMC); the accelerator comprises the following components in parts by weight: aluminate cement 50%, sodium carbonate 10%, aluminum sulfate 10%, sodium sulfate 15%, quicklime 15%; and the air-entraining agent is hydrogen peroxide solution with a purity of 99%.

[0104] The preparation method of cast cement-based energy storage devices is as follows:

[0105] S1: Mix cement, polymer, water-reducing agent, air-entraining agent, quick-setting agent and water. First, stir at 140 r / min for 120 s, stop for 15 s, and then stir at 285 r / min for 120 s to prepare cement-based slurry.

[0106] S2: Pour the prepared cement-based slurry into a silicone mold with a length of 100cm, a width of 50mm, and a height of 100mm. Demold the mold one day later to obtain the casting.

[0107] S3: The cast body was transferred to a standard curing room for 28 days of curing. After curing, the cast body was then placed in a vacuum drying oven at 45°C to dry to constant weight. The dried cast body was then transferred to a vacuum water retention chamber with a vacuum degree of 2 kPa, and a 6 mol / L potassium hydroxide solution was introduced to allow it to fully penetrate into the pores of the cementitious material. After this treatment, the cast cement-based electrolyte was obtained.

[0108] S4: Add 30 μL / cm³ of the solution to the surfaces of the magnesium cobalt layered double hydroxide / nickel foam electrode (MgCo-LDHs@Ni) and the activated carbon / nickel foam electrode (AC@Ni), respectively. 2A 6 mol / L potassium hydroxide solution, with electrode areas of 100 cm². 2 Then, MgCo-LDHs@Ni, cast cement-based electrolyte and AC@Ni are stacked and assembled in a sandwich structure, and the assembly is sealed and packaged using a vacuum heat sealer to obtain the cast cement-based energy storage device.

[0109] Compressive strength and porosity tests were conducted on the cement-based electrolyte samples (cut into 40mm×40mm×160mm pieces) prepared in Examples 1-3 and the cast cement-based electrolyte sample (cut into 40mm×40mm×160mm pieces) prepared in Comparative Example 1, in accordance with the national standard "Test Method for Strength of Cement Mortar (ISO Method)" (GB / T17671-2021). A universal testing machine was used for the compressive strength test; an AutoPore IV 9510 fully automatic mercury porosimeter was used for the porosity test, with mercury intrusion pressures ranging from 1.4 kPa to 414 MPa. The results of the compressive strength and porosity tests are shown in Table 1.

[0110] Table 1. Physical and electrochemical properties of cement-based electrolyte samples from Examples 1-3 and the cast cement-based electrolyte sample from Comparative Example 1.

[0111]

[0112] AC impedance testing was performed on the cement-based electrolytes prepared in Examples 1-3 and the cast cement-based electrolyte prepared in Comparative Example 1. The results are shown in the figure. Figure 2 .

[0113] The ionic conductivity of the cement-based electrolytes prepared in Examples 1-3 and the cast cement-based electrolyte prepared in Comparative Example 1 was tested, and the results are shown in the figure. Figure 3 See Table 1.

[0114] Cyclic voltammetry tests were performed on the cement-based energy storage device prepared in Example 1 above, and the results are shown below. Figure 4 .

[0115] A constant current charge-discharge test was performed on the cement-based energy storage device prepared in Example 1 above, and the results are shown below. Figure 5 .

[0116] The electrochemical testing instrument used for AC impedance testing, cyclic voltammetry testing, and constant current charge-discharge testing is Shanghai Chenhua CHI 660F. The testing environment conditions are room temperature (20±2)℃ and relative humidity (above 95%).

[0117] The cross-section of the cement-based electrolyte sample prepared in Example 1 was subjected to fluorescence impregnation and then photographed under a microscope. The resulting pore structure morphology is shown in the figure. Figure 6 As shown.

[0118] The technical features in the claims and / or specification of this invention can be combined, and the combination is not limited to the combinations obtained through reference in the claims. Technical solutions obtained by combining the technical features in the claims and / or specification are also within the scope of protection of this invention.

[0119] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a cement-based energy storage device, characterized in that, The steps include: S1: Preparation of cement-based printing paste; S2: The cement-based printing paste is loaded into a 3D printing device and deposited layer by layer to form a printed body; S3: After curing, trimming, and drying the printed body, immerse it in a soluble alkali / salt solution to obtain a cement-based electrolyte; S4: A soluble alkali / salt solution is dropped onto the electrode surface, and then the electrode is stacked and assembled with the cement-based electrolyte to obtain an assembly; the assembly is sealed and packaged to obtain a cement-based energy storage device; the plane of the electrode is perpendicular to the interlayer interface of the printed cement-based electrolyte; In step S2, the 3D printing parameters are set as follows: interlayer interval time is 20-60 min, layer height is 10-20 mm, nozzle diameter is 7-18 mm, printing speed is 10-50 mm / s, and extrusion speed is 0.2-0.5 rad / s.

2. The preparation method according to claim 1, characterized in that, The cement-based printing paste comprises the following components in parts by weight: Cementitious material: 80-120 parts; Polymer: 2-25 parts; Water-reducing agent: 0.1–2 parts; Accelerator: 0.5–10 parts; Air-entraining agent: 0.002–0.1 parts; Water: 28–65 parts.

3. The preparation method according to claim 2, characterized in that, The cement-based printing paste comprises the following components in parts by weight: Cementitious material: 95-105 parts; Polymer: 5-20 parts; Water-reducing agent: 0.3–0.6 parts; Thickener: 0.08–0.25 parts; Accelerator: 2-4 parts; Air-entraining agent: 0.008–0.05 parts; Water: 36-44 parts.

4. The preparation method according to claim 2, characterized in that, The cementing material is silicate cement; The polymer is polyacrylamide; The water-reducing agent is a polycarboxylate-based water-reducing agent; The quick-setting agent is an aluminate quick-setting agent; The air-entraining agent is an alkyl sulfate-based air-entraining agent.

5. The preparation method according to claim 1, characterized in that, In step S2, during the 3D printing process, a soluble alkali / salt solution and / or polyacrylamide are applied to the interlayer interface during the interlayer deposition interval.

6. The preparation method according to claim 5, characterized in that, During the interlayer deposition interval, a 5–7 mol / L potassium hydroxide solution is sprayed at the interlayer interface at a spraying rate of 0.5–2 g / cm³. 2 ; and a polyacrylamide aqueous solution with a solid content of 25-35%, with a spraying amount of 1-3 g / cm³. 2 .

7. The preparation method according to claim 1, characterized in that, In steps S3 and S4, the soluble alkali / salt solution is a 5-7 mol / L potassium hydroxide solution.

8. The preparation method according to claim 1, characterized in that, In the electrodes, the positive electrode is a magnesium cobalt layered double hydroxide / foam nickel electrode, and the negative electrode is an activated carbon / foam nickel electrode.

9. A cement-based energy storage device, manufactured by the method described in any one of claims 1 to 8, characterized in that, The cement-based electrolyte has a directionally arranged pore structure with a pore size of 0.5–20 μm and a porosity of 10–50%.

10. The application of the cement-based energy storage device of claim 9 in buildings or infrastructure.

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