Geopolymer battery building block, preparation method thereof and building wall

Abstract

The invention discloses a geopolymer battery building block, a preparation method thereof and a building wall, and relates to the technical field of battery preparation, the geopolymer battery building block comprises: a geopolymer matrix, the geopolymer matrix contains a lithium salt and an alkaline substance; the two electrodes penetrate through two ends of the geopolymer substrate, the two electrodes comprise a positive electrode and a negative electrode, and the positive electrode and the negative electrode are arranged at an interval. Wherein lithium ions of the lithium salt in the geopolymer matrix have relatively small ion radius and relatively high mobility, so that rapid migration of ions in the electrolyte between the positive electrode and the negative electrode can be promoted, and the charge-discharge efficiency of the battery is improved; besides, the geopolymer base body is good in mechanical performance and high in fire resistance and acid corrosion resistance and can be used in the building industry, and due to the fact that the two electrodes penetrate through the two ends of the geopolymer base body, when a plurality of geopolymer battery building blocks are stacked, the geopolymer battery building blocks can be well connected in series, and therefore different electricity utilization requirements are met.

Description

Technical Field

[0001] The invention relates to the technical field of battery preparation, and in particular to a geopolymer battery building block and a preparation method thereof and a building wall. Background Art

[0002] Building Integrated Photovoltaics (BIPV) refers to the integration of solar photovoltaic modules into the structure of a building as part of the building materials to achieve the function of power generation while also serving as the building envelope. BIPV modules can replace traditional building materials such as roof tiles, curtain wall glass, sunshades, etc.

[0003] In the existing building photovoltaic integrated system, the battery energy storage system has many defects. On the one hand, it usually requires a separate space for setting up, which not only occupies valuable building space and increases space costs, but may also affect the overall layout and design flexibility of the building. On the other hand, traditional energy storage components often use commercial energy storage devices such as lithium batteries and supercapacitors. These devices have safety hazards. For example, lithium batteries may have the risk of overheating, combustion or even explosion. At the same time, their equipment procurement costs and installation and maintenance costs are high. Summary of the invention

[0004] The main purpose of the present invention is to propose a geopolymer battery building block and a preparation method thereof and a building wall, aiming to solve the problem of high space cost of battery energy storage system in existing building photovoltaic integrated system.

[0005] To achieve the above object, the present invention provides a geopolymer battery building block, comprising:

[0006] A geopolymer matrix containing a lithium salt and an alkaline substance; and

[0007] Two electrodes are provided at both ends of the geopolymer matrix, wherein the two electrodes include a positive electrode and a negative electrode, and the positive electrode and the negative electrode are spaced apart.

[0008] In one embodiment, the positive electrode comprises a carbon-based fiber web coated with a first metal oxide, wherein the first metal oxide comprises nickel oxide;

[0009] The negative electrode material includes a carbon-based fiber mesh coated with a second metal oxide, wherein the second metal oxide includes iron oxide or zinc oxide;

[0010] The standard electrode potential of the first metal oxide is greater than the standard electrode potential of the second metal oxide.

[0011] In one embodiment, the material of the carbon-based fiber web includes at least one of carbon, graphite and carbon nanotubes; and / or,

[0012] The thickness of the first metal oxide is 0.3 mm to 0.5 mm; and / or,

[0013] The thickness of the second metal oxide is 0.3 mm to 0.5 mm; and / or,

[0014] The alkaline substance includes at least one of sodium hydroxide, potassium hydroxide, sodium silicate and potassium silicate; and / or,

[0015] The lithium salt comprises lithium hydroxide and / or lithium sulfate; and / or,

[0016] The mass percentage of the lithium salt in the geopolymer matrix is ​​1% to 5%.

[0017] The present invention also provides a method for preparing a geopolymer battery building block, comprising the following steps:

[0018] S10, providing a positive electrode, a negative electrode and a cube mold, wherein the upper end of the cube mold is opened;

[0019] S20, placing the positive electrode and the negative electrode materials in sequence and fixing them in the cube mold at intervals and supporting them on the bottom of the cube mold;

[0020] S30, mixing an alkaline solution containing lithium salt with industrial waste containing aluminum silicate, and performing a polymerization reaction to obtain a geopolymer; and mixing the geopolymer with sand to obtain a mixture;

[0021] S40, filling the cube mold with the mixture to obtain a geopolymer battery building block.

[0022] In one embodiment, in step S10, the positive electrode is obtained by the following method:

[0023] The carbon-based fiber web is mixed with a metal source aqueous solution of a first metal oxide and subjected to electrodeposition to obtain a carbon-based fiber web coated with the first oxide, namely, a positive electrode.

[0024] In one embodiment, the metal source of the first metal oxide comprises a nickel source, and the nickel source comprises: NiSO 4 7H 2 O and / or NiCl 2 6H 2 O, the current of the electrodeposition is 0.5-1.5A, and the time of the electrodeposition is 4-8h.

[0025] In one embodiment, in step S10, the negative electrode is obtained by the following method:

[0026] The carbon-based fiber web is mixed with a metal source aqueous solution of a second metal oxide and subjected to electrodeposition to obtain a carbon-based fiber web coated with the second metal oxide, namely, a negative electrode.

[0027] In one embodiment, the metal source of the second metal oxide comprises an iron source, wherein the iron source comprises FeSO 4 7H 2 O and / or FeCl 2 The current of the electrodeposition is 0.5 to 1.5 A, and the time of the electrodeposition is 4 to 8 hours.

[0028] In one embodiment, in step S20, the distance between the positive electrode and the negative electrode is ≥4 mm; and / or,

[0029] In step S30, the step of preparing the alkaline solution containing lithium salt comprises: mixing the alkaline solution and the lithium salt, wherein the alkaline solution comprises at least one of sodium hydroxide solution, potassium hydroxide solution, sodium silicate solution and potassium silicate solution, the molar concentration of the alkali in the alkaline solution is 2 to 12 mol / L, and the lithium salt comprises lithium hydroxide and / or lithium sulfate; and / or,

[0030] In step S30, the mass ratio of alkali to lithium salt in the alkaline solution is 100:(1-5); and / or,

[0031] In step S30, the industrial waste containing aluminosilicates includes fly ash and / or blast furnace slag; and / or,

[0032] In step S30, the mass ratio of the alkaline solution containing lithium salt to the industrial waste containing aluminosilicate is 0.3 to 0.5; and / or,

[0033] In step S30, the mass ratio of the geopolymer to the sand is 0.3 to 0.5; and / or,

[0034] In step S30, the polymerization reaction time is 4 to 6 hours, and the polymerization reaction temperature is 20 to 25°C.

[0035] The present invention also provides a building wall, wherein the geopolymer battery block group comprises a plurality of geopolymer battery blocks stacked and connected in series along a first direction and a photovoltaic module connected in series with electrodes of the geopolymer battery blocks at the ends;

[0036] The geopolymer battery building block comprises the aforementioned geopolymer battery building block.

[0037] In the technical solution of the present invention, the lithium ions of the lithium salt in the geopolymer matrix have a small ion radius and a high mobility, which can promote the rapid migration of ions in the electrolyte between the positive electrode and the negative electrode, and improve the charging and discharging efficiency of the battery; in addition, the geopolymer matrix has good mechanical properties, strong fire resistance and acid corrosion resistance, and can be used in the construction industry. Since the two electrodes are through the two ends of the geopolymer matrix, when multiple geopolymer battery blocks are stacked, they can be well connected in series, and the current can flow smoothly from the electrode of one battery block to the electrode of the adjacent battery block to form a continuous circuit. This series connection method can increase the total voltage of the battery pack, thereby meeting different power requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0039] Figure 1 A schematic structural diagram of a geopolymer battery building block 100 provided in Example 1 of the present invention;

[0040] Figure 2 A schematic diagram of the structure of a building wall composed of geopolymer battery blocks provided in one embodiment of the present invention;

[0041] Figure 3 A top view of a geopolymer battery building block 100 provided in yet another embodiment of the present invention;

[0042] Figure 4 This is a graph showing the cyclic voltammetry test results of the geopolymer battery building block 100 provided in Example 1 of the present invention.

[0043] Description of Figure Numbers:

[0044] 100. Geopolymer battery building block; 1. Geopolymer matrix; 2. Positive electrode; 3. Negative electrode; 4. Photovoltaic module.

[0045] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0046] To make the purpose, technical scheme and advantages of the embodiment of the present invention clearer, the technical scheme in the embodiment of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiment, it is carried out according to the normal conditions or the conditions recommended by the manufacturer. If the reagents or instruments used do not specify the manufacturer, they are all conventional products that can be purchased commercially. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes, taking "A and / or B" as an example, including scheme A, or scheme B, or schemes that A and B meet at the same time. In addition, the technical schemes between the various embodiments can be combined with each other, but must be based on the ability of ordinary technicians in the field to achieve. When the combination of technical solutions is contradictory or cannot be achieved, it should be considered that the combination of such technical solutions does not exist, and is not within the scope of protection required by the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present invention.

[0047] Building Integrated Photovoltaics (BIPV) refers to the integration of solar photovoltaic modules into the structure of a building as part of the building materials to achieve the function of power generation while also serving as the building envelope. BIPV modules can replace traditional building materials such as roof tiles, curtain wall glass, sunshades, etc.

[0048] In the existing building photovoltaic integrated system, the battery energy storage system has many defects. On the one hand, it usually requires a separate space for setting up, which not only occupies valuable building space and increases space costs, but may also affect the overall layout and design flexibility of the building. On the other hand, traditional energy storage components often use commercial energy storage devices such as lithium batteries and supercapacitors. These devices have safety hazards. For example, lithium batteries may have the risk of overheating, combustion or even explosion. At the same time, their equipment procurement costs and installation and maintenance costs are high.

[0049] In view of this, if Figure 1 As shown, the present invention provides a geopolymer battery building block 100, comprising: a geopolymer matrix 1, wherein the geopolymer matrix 1 contains lithium salt and alkaline substances; and two electrodes running through both ends of the geopolymer matrix 1, wherein the two electrodes include a positive electrode 2 and a negative electrode 3, and the positive electrode 2 and the negative electrode 3 are arranged at intervals.

[0050] In the technical solution of the present invention, the lithium ions of the lithium salt in the geopolymer matrix 1 have a smaller ion radius and a higher mobility, which can promote the rapid migration of ions in the electrolyte between the positive electrode 2 and the negative electrode 3, thereby improving the charging and discharging efficiency of the battery; in addition, the geopolymer matrix 1 has good mechanical properties, strong fire resistance and acid corrosion resistance, and can be used in the construction industry. Since the two electrodes run through both ends of the geopolymer matrix 1, when multiple geopolymer battery blocks 100 are stacked, they can be well connected in series, and the current can flow smoothly from the electrode of one battery block to the electrode of the adjacent battery block to form a continuous circuit. This series connection method can increase the total voltage of the battery pack, thereby meeting different power requirements. The top view of the geopolymer battery block 100 is shown in FIG. Figure 3 shown.

[0051] It should be noted that the geopolymer matrix 1 in the present invention has a very low moisture content, and is therefore a solid electrolyte. The geopolymer matrix 1 in the present invention is a three-dimensional network structure, which has a large number of oxygen bridge bonds (Si-O-Si, Al-O-Al), and lithium ions tend to fill the oxygen vacancies in the oxygen bridge bonds to form a more stable coordination environment, so these oxygen vacancies can serve as migration points for lithium ions. In addition, the micropores and nanochannels in the three-dimensional network of the geopolymer matrix 1 provide a path for lithium ions to migrate rapidly, so at least including a path for lithium ions to migrate rapidly between the positive and negative electrodes through the three-dimensional network.

[0052] It should be noted that the geopolymer matrix 1 may also include components such as sand and cement to improve the compression resistance and flexural resistance of the geopolymer matrix 1 .

[0053] In some embodiments of the present invention, the positive electrode 2 includes a carbon-based fiber mesh coated with a first metal oxide, wherein the first metal oxide includes nickel oxide; the negative electrode material includes a carbon-based fiber mesh coated with a second metal oxide, wherein the second metal oxide includes iron oxide or zinc oxide; and the standard electrode potential of the first metal oxide is greater than the standard electrode potential of the second metal oxide.

[0054] In the technical solution of the present invention, the carbon-based fiber mesh coated with the first metal oxide and the carbon-based fiber mesh coated with the second metal oxide have good conductivity, high mechanical strength, and good force bearing capacity, and are suitable for the construction industry. In addition, the standard electrode potential of the first metal oxide is greater than the standard electrode potential of the second metal oxide. This potential difference can promote charge transfer inside the battery and help form an effective electrochemical reaction path to ensure the normal operation of the battery.

[0055] In some embodiments of the present invention, the material of the carbon-based fiber mesh includes at least one of carbon, graphite and carbon nanotubes. That is, the carbon-based fiber mesh can be any one of carbon, graphite and carbon nanotubes, or two or three of carbon, graphite and carbon nanotubes, all within the scope of protection of the present invention. The material of the above-mentioned carbon-based fiber mesh can ensure good conductivity and mechanical strength of the electrode.

[0056] In some embodiments of the present invention, the thickness of the first metal oxide is 0.3 mm to 0.5 mm; and / or, the thickness of the second metal oxide is 0.3 mm to 0.5 mm. The thickness within the above range can balance the mechanical stability of the electrode and the utilization rate of the metal oxide. Too thick metal oxides may crack or delaminate during multiple charge and discharge cycles, affecting the long-term stability of the battery; while too thin metal oxides may be gradually consumed during use.

[0057] In some embodiments of the present invention, the alkaline substance includes at least one of sodium hydroxide, potassium hydroxide, sodium silicate, and potassium silicate. That is, the alkaline substance can be any one of sodium hydroxide, potassium hydroxide, sodium silicate, and potassium silicate, or two or more of sodium hydroxide, potassium hydroxide, sodium silicate, and potassium silicate, all within the protection scope of the present invention. The above alkaline substance can reduce the interaction between the three-dimensional network polymer segments in the geopolymer matrix 1, making the network looser, which is conducive to the movement of lithium ions.

[0058] In some embodiments of the present invention, the lithium salt includes lithium hydroxide and / or lithium sulfate. The above lithium salts are widely available and can dissociate into lithium ions relatively quickly.

[0059] In some embodiments of the present invention, the lithium salt accounts for 1% to 5% by mass of the geopolymer matrix 1. The mass percentage within the above range can ensure that there are sufficient lithium ions in the geopolymer matrix 1, which can better migrate between the positive and negative electrodes 3, thereby improving the charging and discharging efficiency of the battery.

[0060] The present invention also provides a method for preparing a geopolymer battery building block 100, comprising the following steps:

[0061] S10, providing a positive electrode 2, a negative electrode 3 and a cube mold, wherein the upper end of the cube mold is opened;

[0062] S20, placing the positive electrode 2 and the negative electrode 3 materials in sequence and fixing them in the cube mold and supporting them at the bottom of the cube mold;

[0063] S30, mixing an alkaline solution containing lithium salt with industrial waste containing aluminum silicate, and performing a polymerization reaction to obtain a geopolymer; and mixing the geopolymer with sand to obtain a mixture;

[0064] S40, filling the cube mold with the mixture to obtain a geopolymer battery building block 100.

[0065] In the technical solution of the present invention, the geopolymer battery building block 100 is prepared by a square mold with an opening at the upper end. In step S20, the positive electrode 2 and the negative electrode 3 are first placed and fixed in the square mold in sequence, so that one end of the positive electrode and the negative electrode 3 are supported at the bottom of the square mold, and the other end is flush with the square mold or exceeds the square mold, and at the same time, the positive electrode 2 and the negative electrode 3 are ensured to be placed at intervals. In step S30, after the alkaline solution containing lithium salts is mixed with the industrial waste containing aluminosilicates, the alkaline solution will have an alkalization effect on the industrial waste, that is, the alkaline solution can effectively destroy the Si-O-Al bond in the aluminosilicates in the industrial waste to form soluble silicates and aluminates. The dissolved silicates and aluminates repolymerize in an alkaline environment to form a three-dimensional network structure with high stability and high strength, that is, the three-dimensional network structure is composed of [SiO 4 ] 4- With [AlO 4 ] 5- The amorphous to semi-crystalline three-dimensional spatial network structure is linked by covalent bonds formed by shared vertex oxygen atoms, and has a large number of oxygen bridging bonds (Si-O-Si, Al-O-Al); the initial lithium salt dissociates into lithium ions in an alkaline solution, and the lithium ions form a relatively stable coordination structure with the oxygen vacancies in the three-dimensional network structure, and can also make up for the defects in the geopolymer matrix 1; in addition, the alkaline substance can also reduce the interaction between the polymer segments in the three-dimensional network structure, making the network looser and conducive to the movement of lithium ions; the obtained geopolymer is further mixed with sand, and the obtained mixture has a large mechanical strength and can be used as a substitute for traditional cement concrete. In step S40, the mixture is filled into a cube mold to obtain a cube geopolymer battery block 100, in which the mixture is in close contact with the positive and negative electrodes.

[0066] In some embodiments of the present invention, in step S10, the positive electrode 2 is obtained by the following method: a carbon-based fiber web is mixed with a metal source aqueous solution of a first metal oxide, and electrodeposited to obtain a carbon-based fiber web coated with the first oxide, i.e., the positive electrode 2. The carbon-based fiber web coated with the first metal oxide is obtained by electrodeposition, which has a faster speed, better coating effect, larger coating area, and more uniform coating.

[0067] In some embodiments of the present invention, the metal source of the first metal oxide includes a nickel source, and the nickel source includes: NiSO4 7H 2 O and / or NiCl 2 6H 2 O, the current of the electrodeposition is 0.5-1.5A, and the time of the electrodeposition is 4-8h. The above nickel source can form a good nickel oxide coating layer on the carbon-based fiber mesh during the electrodeposition process. The current and time of the electrodeposition within the above range can ensure that more nickel oxide is deposited on the carbon-based fiber mesh.

[0068] In some embodiments of the present invention, in step S10, the negative electrode 3 is obtained by the following method: a carbon-based fiber web is mixed with a metal source aqueous solution of a second metal oxide, and electrodeposited to obtain a carbon-based fiber web coated with the second metal oxide, i.e., the negative electrode 3. The carbon-based fiber web coated with the second metal oxide is obtained by electrodeposition, which is fast and has a more uniform coating.

[0069] In some embodiments of the present invention, the metal source of the second metal oxide includes an iron source, and the iron source includes FeSO 4 7H 2 O and / or FeCl 2 The current of the electrodeposition is 0.5-1.5A, and the time of the electrodeposition is 4-8h. The iron source can form a good iron oxide coating layer on the carbon-based fiber web during the electrodeposition process. The current and time of the electrodeposition within the above range can ensure that more iron oxide is deposited on the carbon-based fiber web.

[0070] In some embodiments of the present invention, in step S20, the distance between the positive electrode 2 and the negative electrode 3 is ≥4 mm. The distance between the positive electrode 2 and the negative electrode 3 can be 4 mm, 5 cm, 10 cm or 15 cm, or even larger, and the distance within the above range can ensure high charging and discharging efficiency.

[0071] In some embodiments of the present invention, in step S30, the step of preparing the alkaline solution containing a lithium salt comprises: mixing an alkaline solution and a lithium salt, wherein the alkaline solution comprises at least one of a sodium hydroxide solution, a potassium hydroxide solution, a sodium silicate solution, and a potassium silicate solution, the molar concentration of the alkali in the alkaline solution is 2 to 12 mol / L, and the lithium salt comprises lithium hydroxide and / or lithium sulfate.

[0072] In the technical solution of the present invention, after the alkaline solution and the lithium salt are mixed, the lithium salt dissociates into lithium ions in the alkaline solution for migration between the positive electrode and the negative electrode 3. Among them, the alkaline solution can make the aluminosilicate decompose well to form silicate and aluminate, and can promote the polymerization reaction of silicate and aluminate to form a three-dimensional network quickly. The mass concentration of alkali in the alkaline solution within the above range can ensure that the decomposition and repolymerization efficiency of aluminosilicate is high. The lithium salt is easy to dissociate into lithium ions.

[0073] In some embodiments of the present invention, in step S30, the mass ratio of alkali to lithium salt in the alkaline solution is 100:(1-5). The mass ratio of alkali to lithium salt within the above range can ensure that more lithium ions migrate in the geopolymer battery building block 100.

[0074] In some embodiments of the present invention, in step S30, the industrial waste containing aluminosilicates includes fly ash and / or blast furnace slag. Fly ash and blast furnace slag have a high content of aluminosilicates, and the three-dimensional polymer network formed by the activation of alkaline solution has good compression and flexural properties, and is suitable for the construction industry.

[0075] In some embodiments of the present invention, in step S30, the mass ratio of the alkaline solution containing lithium salt to the industrial waste containing aluminosilicate is 0.3 to 0.5. The mass ratio within the above range can ensure that the aluminosilicate can be fully cracked and the cracked products can be fully repolymerized into a three-dimensional network structure, so that the obtained geopolymer battery building block 100 has better compression and flexural properties.

[0076] In some embodiments of the present invention, in step S30, the mass ratio of the geopolymer to the sand is 0.3 to 0.5. The mass ratio within the above range can ensure that the obtained geopolymer battery building block 100 has good compression and flexural properties.

[0077] In some embodiments of the present invention, in step S30, the polymerization reaction time is 4 to 6 hours, and the polymerization reaction temperature is 20 to 25° C. The polymerization reaction time and temperature within the above range can ensure that the alkaline solution acts more fully on the aluminosilicate, so that the Si-O-Al bonds in the aluminosilicate are more fully broken, forming more soluble silicates and aluminates, and ensuring that the silicates and aluminates are cross-linked as much as possible under the action of the alkaline solution to form a more stable three-dimensional network structure with better mechanical properties.

[0078] like Figure 2As shown, the present invention also provides a building wall, wherein the group of geopolymer battery blocks 100 includes a plurality of geopolymer battery blocks 100 stacked in series along a first direction and a photovoltaic module 4 connected in series with the electrode of the end geopolymer battery block 100; the geopolymer battery block 100 includes the aforementioned geopolymer battery block 100. Among them, the photovoltaic module 4 includes a perovskite photovoltaic module 4, a crystalline silicon photovoltaic module 4 or a thin film photovoltaic module 4. The photovoltaic module 4 can be arranged on the brick electrode at the top of the building wall to generate electricity for the building wall. At the same time, the positive electrode 2 of each geopolymer battery block 100 can be connected to the negative electrode 3 of the geopolymer battery stacked thereon to obtain a series circuit. The building wall includes the geopolymer battery block 100, and therefore has all the beneficial effects of the aforementioned geopolymer battery block 100, which will not be repeated here one by one.

[0079] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments and drawings. It should be understood that the following embodiments are only used to explain the present invention and are not used to limit the present invention.

[0080] Example 1

[0081] A method for preparing a geopolymer battery building block 100 comprises:

[0082] S10, a carbon fiber mesh is selected as the electrode substrate, the grid space size is 5mm×5mm, the longitudinal fiber bundle is composed of 6K filaments (each fiber bundle contains 6000 filaments), the vertical weft fiber bundle is 3K, and the mesh thickness is less than 1mm. The carbon fiber mesh is purchased from Ruibang Fiber Company and is a high-performance material for carbon fiber mesh building lining cloth. First, the surface of the carbon fiber mesh is treated to remove impurities such as oil stains brought in during the production process to ensure its purity. Then, the positive electrode 2 is prepared, that is, the carbon fiber mesh of the above size is immersed in a temperature of 48°C and containing 250g / L NiSO 4 7H 2 O, 20g / L NiCl 2 6H 2 O, 25g / LH 3 BO 3 The positive electrode 2 was prepared by electroplating the carbon fiber mesh of the above size in an aqueous solution of 1.0A for 6 hours. The negative electrode 3 was prepared by immersing the carbon fiber mesh of the above size in a solution containing 180g / L FeSO at a temperature of 28°C. 4 7H 2 O in an aqueous solution and electrodeposited at a current of 1.0 A for 6 h to obtain a negative electrode 3.

[0083] A cube mold with an opening at the upper end is selected, and its size is 50mm×50mm×20mm.

[0084] S20, place the positive electrode 2 and the negative electrode 3 in a cube mold with a spacing of 4 mm and fix them, with one end of the positive electrode 2 and the negative electrode 3 touching the bottom and the other end flush with the opening;

[0085] S30, adding 8.4 g of lithium hydroxide to an alkaline solution containing 82 g of potassium hydroxide, 168 g of a sodium silicate solution having a modulus of 3.2, and 40 g of deionized water to obtain an alkaline solution containing a lithium salt; mixing the solution with 500 g of fly ash, polymerizing at 20° C. for 5 h to obtain a geopolymer, and then mixing the geopolymer with 250 g of sand to obtain a mixture;

[0086] S40, filling the mixture into a cubic mold, and then curing it at 50° C. and 60% humidity for one day to obtain a geopolymer battery building block 100.

[0087] Example 2

[0088] Compared with Example 1, Example 2 is different in that:

[0089] In step S30, 8.4 g of lithium hydroxide is added to an alkaline solution containing 68 g of potassium hydroxide, 168 g of a sodium silicate solution with a modulus of 3.2, and 40 g of deionized water to obtain an alkaline solution containing a lithium salt; the solution is mixed with 500 g of fly ash, and polymerized at 20° C. for 5 hours to obtain a geopolymer, and then the geopolymer is mixed with 250 g of sand to obtain a mixture.

[0090] Example 3

[0091] Compared with Example 1, Example 3 is different in that:

[0092] In step S30, 8.4 g of lithium hydroxide is added to an alkaline solution containing 75 g of potassium hydroxide, 168 g of a sodium silicate solution having a modulus of 3.2, and 40 g of deionized water to obtain an alkaline solution containing a lithium salt; the solution is mixed with 500 g of fly ash, and polymerized at 20° C. for 5 hours to obtain a geopolymer, and the geopolymer is then mixed with 250 g of sand to obtain a mixture.

[0093] Comparative Example 1

[0094] Compared with Example 1, Comparative Example 1 is different in that:

[0095] In step S30, lithium hydroxide is not added.

[0096] Comparative Example 2

[0097] Compared with Example 1, Comparative Example 2 is different in that:

[0098] In step S30, 8.4 g of lithium hydroxide is added to an alkaline solution containing 82 g of potassium hydroxide, 168 g of a sodium silicate solution having a modulus of 3.2, and 40 g of deionized water to obtain an alkaline solution containing lithium salt; the solution is mixed with 500 g of fly ash and 250 g of sand, and polymerized at 20° C. for 5 hours to obtain a mixture.

[0099] Performance Testing

[0100] The geopolymer battery building blocks 100 in Examples 1 to 3 and Comparative Examples 1 to 2 were tested for charge and discharge cycles, compressive strength, and electrochemical impedance spectroscopy (EIS). The specific testing methods are as follows:

[0101] Cyclic charge and discharge test: Use the Xinwei battery tester to perform cyclic charge and discharge test, set the charging current to 10mA, the discharging current to 3mA, and the cut-off voltage to 0.2V;

[0102] Compression strength test: The compression strength test was carried out in a universal testing machine, and the specimen block was 40 mm cubed;

[0103] EIS curve test: The electrochemical impedance spectroscopy test was performed using an electrochemical workstation with a scanning frequency of 0.1 Hz to 10000 Hz.

[0104] The test results are shown in Table 1.

[0105] Table 1 Performance test results of geopolymer battery blocks 100 of Examples 1 to 3 and Comparative Examples 1 to 2

[0106] Discharge capacity 28d compressive strength resistance Energy density Example 1 6.3mA 5.8MPa 4Ω <![CDATA[4.63mWh / m 2 ]]> Example 2 3.5mA 5.6MPa 7Ω <![CDATA[3.21mWh / m 2 ]]> Example 3 4.1mA 6.0MPa 6Ω <![CDATA[3.56mWh / m 2 ]]> Comparative Example 1 1.5mA 5.6MPa 9Ω <![CDATA[1.25mWh / m 2 ]]> Comparative Example 2 3.7mA 4.1MPa 5Ω <![CDATA[3.32mWh / m 2 ]]>

[0107] As shown in Table 1, adding lithium hydroxide can improve the ionic conductivity of geopolymer batteries and increase the battery discharge capacity. This is because lithium hydroxide, as a strong electrolyte, changes the double-layer structure of the electrode surface. For electrodes plated with iron oxide and nickel oxide, lithium ions may be adsorbed on the electrode surface, affecting the potential and kinetics of the electrode reaction.

[0108] By comparing Comparative Example 2 with the embodiment, it is found that the durability of the comparative example is worse than that of the embodiment, that is, the strength after 28 days is lower. This is because: the alkaline solution and fly ash are firstly alkali-activated, and then the sand is added, which is conducive to the use of the alkaline solution. If the fly ash and sand are mixed and then the alkaline activator is added, the alkaline solution will be wrapped on the sand, and the sand does not react with the alkaline solution, resulting in the excess alkaline solution reacting with the carbon dioxide in the air to form "flour", that is, potassium salt, sodium salt, etc., which affects the durability of the geopolymer battery.

[0109] The geopolymer battery building block 100 provided in Example 1 was subjected to a cyclic voltammetry test. The specific test method was as follows: a CV test was performed using an electrochemical workstation, a two-electrode system was used, and scanning was performed at 8mv / s and 10mv / s. The results were as follows: Figure 4 As shown (the red curve represents 8mv / s and the blue curve represents 10mv / s).

[0110] CV curve in a two-electrode system: The shape and symmetry of the curve reflect the reversibility of the electrode process. If the reaction is reversible, the oxidation wave and the reduction wave are symmetrical; if the reaction is irreversible, the curve is asymmetrical. All the examples show quasi-reversible phenomena, indicating that there is still room for further optimization of the battery.

[0111] The above are only preferred embodiments of the present invention, and do not limit the patent scope of the present invention. For those skilled in the art, the present invention may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the patent protection scope of the present invention.

Claims

1. A geopolymer battery building block, characterized in that: include: A geopolymer matrix containing a lithium salt and an alkaline substance; and Two electrodes are provided at both ends of the geopolymer matrix, wherein the two electrodes include a positive electrode and a negative electrode, and the positive electrode and the negative electrode are spaced apart.

2. The geopolymer battery building block according to claim 1, characterized in that: The positive electrode comprises a carbon-based fiber web coated with a first metal oxide, wherein the first metal oxide comprises nickel oxide; The negative electrode material includes a carbon-based fiber mesh coated with a second metal oxide, wherein the second metal oxide includes iron oxide or zinc oxide; The standard electrode potential of the first metal oxide is greater than the standard electrode potential of the second metal oxide.

3. The geopolymer battery building block according to claim 2, characterized in that: The material of the carbon-based fiber web includes at least one of carbon, graphite and carbon nanotubes; and / or, The thickness of the first metal oxide is 0.3 mm to 0.5 mm; and / or, The thickness of the second metal oxide is 0.3 mm to 0.5 mm; and / or, The alkaline substance includes at least one of sodium hydroxide, potassium hydroxide, sodium silicate and potassium silicate; and / or, The lithium salt comprises lithium hydroxide and / or lithium sulfate; and / or, The mass percentage of the lithium salt in the geopolymer matrix is ​​1% to 5%.

4. A method for preparing a geopolymer battery building block, characterized in that: The following steps are involved: S10, providing a positive electrode, a negative electrode and a cube mold, wherein the upper end of the cube mold is opened; S20, placing the positive electrode and the negative electrode materials in sequence and fixing them in the cube mold at intervals and supporting them on the bottom of the cube mold; S30, mixing an alkaline solution containing lithium salt with industrial waste containing aluminosilicate, and performing a polymerization reaction to obtain a geopolymer; mixing the geopolymer and sand to obtain a mixture; S40, filling the cube mold with the mixture to obtain a geopolymer battery building block.

5. The method for preparing a geopolymer battery block according to claim 4, characterized in that: In step S10, the positive electrode is obtained by the following method: The carbon-based fiber web is mixed with a metal source aqueous solution of a first metal oxide and subjected to electrodeposition to obtain a carbon-based fiber web coated with the first oxide, namely, a positive electrode.

6. The method for preparing a geopolymer battery block according to claim 5, characterized in that: The metal source of the first metal oxide includes a nickel source, and the nickel source includes: NiSO4·7H2O and / or NiCl2·6H2O. The current of the electroplating is 0.5-1.5A, and the time of the electroplating is 4-8h.

7. The method for preparing a geopolymer battery block according to claim 4, characterized in that: In step S10, the negative electrode is obtained by the following method: The carbon-based fiber web is mixed with a metal source aqueous solution of a second metal oxide and subjected to electrodeposition to obtain a carbon-based fiber web coated with the second metal oxide, namely, a negative electrode.

8. The method for preparing a geopolymer battery block according to claim 7, characterized in that: The metal source of the second metal oxide includes an iron source, and the iron source includes FeSO4·7H2O and / or FeCl2. The current of the electrodeposition is 0.5 to 1.5 A, and the time of the electrodeposition is 4 to 8 hours.

9. The method for preparing a geopolymer battery block according to claim 4, characterized in that: In step S20, the distance between the positive electrode and the negative electrode is ≥4 mm; and / or, In step S30, the step of preparing the alkaline solution containing lithium salt comprises: mixing the alkaline solution and the lithium salt, wherein the alkaline solution comprises at least one of sodium hydroxide solution, potassium hydroxide solution, sodium silicate solution and potassium silicate solution, the molar concentration of the alkali in the alkaline solution is 2 to 12 mol / L, and the lithium salt comprises lithium hydroxide and / or lithium sulfate; and / or, In step S30, the mass ratio of alkali to lithium salt in the alkaline solution is 100:(1-5); and / or, In step S30, the industrial waste containing aluminosilicates includes fly ash and / or blast furnace slag; and / or, In step S30, the mass ratio of the alkaline solution containing lithium salt to the industrial waste containing aluminosilicate is 0.3 to 0.5; and / or, In step S30, the mass ratio of the geopolymer to the sand is 0.3 to 0.5; and / or, In step S30, the polymerization reaction time is 4 to 6 hours, and the polymerization reaction temperature is 20 to 25°C.

10. A building wall, characterized in that: It comprises a geopolymer battery block group, wherein the geopolymer battery block group comprises a plurality of geopolymer battery blocks stacked and connected in series along a first direction and a photovoltaic module connected in series with electrodes of the geopolymer battery blocks at the ends; The geopolymer battery building block comprises the geopolymer battery building block according to any one of claims 1 to 4.

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