Gel positive plate and processing method thereof

Abstract

The invention discloses a gel positive plate capable of normally discharging under high load, solving the problem of interface interaction and improving the utilization rate of active substances, which comprises a current collector and slurry formed on the surface of the current collector, the paste comprises the following components in percentage by mass: 1-2% of a thickening agent, 58-60% of deionized water, 21-24% of zinc salt, 0-2% of manganese salt, 0.5-1% of a conductive agent, 5-6% of a gel monomer, 7-9% of an active substance, 0.05-0.1% of a cross-linking agent, 2-3% of an additive and 0.03-0.04% of an initiator. The invention also discloses a method for processing the gel positive plate, which comprises the following steps: preparing slurry which comprises the following components in percentage by mass: 1-2% of a thickening agent, 58-60% of deionized water, 21-24% of zinc salt, 0-2% of manganese salt, 0.5-1% of a conductive agent, 5-6% of a gel monomer, 7-9% of an active substance, 0.05-0.1% of a cross-linking agent, 2-3% of an additive and 0.03-0.04% of an initiator; and introducing the slurry into a mold provided with a current collector, shaping and cutting to obtain the gel positive plate.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and particularly to a gel positive electrode sheet and a processing method thereof. Background Art

[0002] Aqueous zinc-ion batteries are new energy storage devices that utilize the migration of zinc ions between the positive and negative electrodes for energy storage and release. During discharge, while the negative electrode releases electrons into the external circuit, zinc ions on its surface also dissolve into the electrolyte and migrate to the positive electrode to complete the insertion process; the charging process is the opposite of discharge, where zinc ions are de-inserted from the positive electrode material into the electrolyte under the action of an external power source and finally migrate to the surface of the negative electrode to undergo a reduction reaction to form zinc metal and deposit on the surface of the negative electrode. Currently, conventional aqueous zinc-ion batteries generally use manganese dioxide as the main positive electrode material. However, all materials in conventional manganese dioxide positive electrode materials are not hydrophilic, and there is an interfacial interaction between manganese dioxide and the electrolyte, which leads to an increase in interfacial resistance and hindered ion transport, affecting the electrochemical performance and cycle life of the battery. Secondly, when the loading of manganese dioxide is forcibly increased, its specific capacity decreases instead, reducing the utilization rate of positive electrode manganese dioxide. In addition, affected by the processing technology, the uniformity of the dispersion of manganese dioxide in the manganese dioxide positive electrode material is insufficient, resulting in an increase in local resistance inside the battery, hindered electron and ion migration, and causing the battery to be unstable and capacity decay. Summary of the Invention

[0003] Based on this, in view of the above deficiencies, it is necessary to provide a gel positive electrode sheet and a processing method thereof that can discharge normally under high load, solve the interfacial interaction problem, and improve the uniformity and utilization rate of active substances.

[0004] A gel positive electrode sheet includes a current collector and a slurry formed on the surface of the current collector. The slurry includes the following components in mass percentages: 1-2% thickener, 58-60% deionized water, 21-24% zinc salt, 0-2% manganese salt, 0.5-1% conductive agent, 5-6% gel monomer, 7-9% active substance, 0.05-0.1% crosslinking agent, 2-3% additive, and 0.03-0.04% initiator.

[0005] In one embodiment, the current collector is carbon cloth or nickel foam.

[0006] In one embodiment, the thickener is carboxymethyl cellulose, the conductive agent is conductive carbon black, the gel monomer is acrylamide, and the crosslinking agent is methylene bisacrylamide; the additive is a mixture of 1-methyl-2-propanol and 2-methyl-1-methacrylate 1,2-dimethylacrylate, and the mass ratio of 1-methyl-2-propanol to 2-methyl-1-methacrylate 1,2-dimethylacrylate is 13:5.

[0007] In one embodiment, the zinc salt is zinc sulfate or zinc nitrate or zinc trifluoromethanesulfonate, the manganese salt is manganese sulfate or manganese nitrate, the initiator is ammonium persulfate or potassium persulfate, and the active material is manganese dioxide or vanadium pentoxide.

[0008] The present invention also discloses a method for processing the above gel positive electrode sheet, comprising the following steps:

[0009] S1. Prepare a slurry, which comprises the following components in mass percentages: 1-2% of a thickener, 58-60% of deionized water, 21-24% of a zinc salt, 0-2% of a manganese salt, 0.5-1% of a conductive agent, 5-6% of a gel monomer, 7-9% of an active material, 0.05-0.1% of a crosslinking agent, 2-3% of an additive, and 0.03-0.04% of an initiator;

[0010] S2. Introduce the slurry into a mold provided with a current collector for shaping and cutting to obtain the gel positive electrode sheet.

[0011] In one embodiment, step S1 includes:

[0012] S11. Stir and mix the thickener and deionized water to obtain glue;

[0013] S12. Continuously stir the glue, and add the zinc salt, manganese salt, conductive agent, gel monomer, active material, crosslinking agent, additive, and initiator into the glue and mix them evenly to obtain the slurry.

[0014] In one embodiment, step S11 includes:

[0015] S111. Stir the mixture of the thickener and deionized water at a first speed for sizing;

[0016] S112. Stir the sized mixture at a second speed until the bubbles in the mixture are eliminated to obtain glue, and the second speed is less than the first speed.

[0017] In one embodiment, step S12 includes:

[0018] S121. Stir the glue at a uniform speed, and sequentially add the zinc salt, manganese salt, and conductive agent into the glue and mix them evenly;

[0019] S122. Add the gel monomer and the active material into the glue and stir and mix them evenly;

[0020] S123. Add the crosslinking agent and the additive into the glue and stir and mix them evenly;

[0021] S124. Add the initiator into the colloid and stir evenly to obtain the slurry.

[0022] In one embodiment, the thickener is carboxymethyl cellulose, the conductive agent is conductive carbon black, the gel monomer is acrylamide, and the crosslinking agent is methylene bisacrylamide; the additive is a mixture of 1-methyl-2-propanol and 2-methyl-1-acrylate 1,2-dimethylacrylate, and the mass ratio of 1-methyl-2-propanol to 2-methyl-1-acrylate 1,2-dimethylacrylate is 13:5.

[0023] In one embodiment, the zinc salt is zinc sulfate or zinc nitrate or zinc trifluoromethanesulfonate, the manganese salt is manganese sulfate or manganese nitrate, the initiator is ammonium persulfate or potassium persulfate, the current collector is carbon cloth or nickel foam, and the active material is manganese dioxide or vanadium pentoxide.

[0024] Implementing the gel cathode sheet of the present invention and its processing method, by adding glue (gel) formed by a thickener and deionized water and a salt bridge composed of a zinc salt to the cathode sheet, the utilization rate of the active material in the cathode sheet can be improved, so that the cathode sheet can be normally discharged under high load; due to the setting of the salt bridge, when assembling the battery, only a layer of ultra-thin hydrogel needs to be separated between the positive and negative electrodes to prevent short circuit, and there is no need to add electrolyte between the positive and negative electrodes, solving the problems of increased interfacial resistance and blocked ion transport caused by the interaction between the solid-liquid interface, ensuring the electrochemical performance of the battery and being beneficial to extending the cycle life of the battery; using the glue as the carrier for the distribution of the active material is beneficial to the uniform dispersion of the active material during the preparation process, so as to reduce the local resistance in the battery, prevent the hindrance of electron and ion migration, improve the stability of the battery and delay the attenuation of the battery capacity. Description of the Drawings

[0025] Figure 1 It is a process flow diagram of the processing method of the gel cathode sheet in an embodiment of the present invention;

[0026] Figure 2 It is the first-cycle charge-discharge curve of the battery made of the gel cathode sheet in an embodiment of the present invention;

[0027] Figure 3 It is the discharge capacity diagram of the batteries respectively using the gel cathode sheet and the conventional manganese dioxide cathode sheet in an embodiment of the present invention;

[0028] Figure 4 It is the external shape structure diagram of the gel cathode sheet in an embodiment of the present invention. Detailed Embodiments

[0029] To make the above objects, features, and advantages of the present invention more apparent and understandable, the following will provide a detailed description of the specific embodiments of the present invention with reference to the accompanying drawings. Many specific details are set forth in the following description to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the spirit of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0030] The present invention discloses a gel positive electrode sheet that can be normally discharged under high load, solve the problem of interfacial interaction, and improve the uniformity of active materials. The gel positive electrode sheet includes a current collector and a slurry formed on the surface of the current collector. The slurry includes the following components in mass percentages: 1-2% of a thickener, 58-60% of deionized water, 21-24% of a zinc salt, 0-2% of a manganese salt, 0.5-1% of a conductive agent, 5-6% of a gel monomer, 7-9% of active materials, 0.05-0.1% of a crosslinking agent, 2-3% of an additive, and 0.03-0.04% of an initiator. In this embodiment, the active materials are the substances participating in the charge-discharge reaction in the positive and negative electrodes of the battery. They release electrical energy through chemical changes to enable the battery to discharge, and are the source of the battery capacity in the gel positive electrode sheet. The current collector serves as a carrier for the slurry and as an element for collecting current in the gel positive electrode sheet, so as to collect the current generated by the active materials in the battery, thereby forming a larger current for external output. The zinc salt serves as the main component of the salt bridge in the gel positive electrode sheet. It forms a connection through the electrostatic interaction between ions and is used to improve the utilization rate of the active materials in the gel positive electrode sheet. In addition, the setting of the salt bridge replaces the addition of the electrolyte and can reduce the impedance of the battery interface. The thickener and deionized water together form a glue (gel) that is used to form a unified whole of the components in the slurry and facilitate the full mixing of the components; it is also used to improve the stability of the zinc salt bridge to further enhance the utilization rate of the active materials. In addition, the setting of the gel can also improve the flexibility of the gel positive electrode sheet to expand the applicable scenarios of the gel positive electrode sheet. The manganese salt is used to inhibit the dissolution of the active materials to improve the cycle stability of the battery. The conductive agent is used to provide an electron channel between the active materials and the current collector to enable the electrons generated by the active materials to be transmitted to the current collector. The gel monomer is used to generate a binder under the co-catalysis of the crosslinking agent and the initiator to bond the salt bridge, the conductive agent, the gel, and the current collector together and shape them, ensuring the stability of the structure of the gel positive electrode sheet.

[0031] In one embodiment, the current collector is carbon cloth or nickel foam. Carbon cloth, short for carbon fiber cloth, can serve as a current conductor to collect the current generated by the active material and output it externally. Nickel foam, as the current collector, is used to achieve the collection and external output of current and fix the other components. The thickener is carboxymethyl cellulose (CMC). The aqueous solution of carboxymethyl cellulose has functions such as thickening, film-forming, adhesion, water retention, colloid protection, emulsification, and suspension, so that the thickener and deionized water are processed to form a gel. The conductive agent is conductive carbon black. As a semiconductor material, conductive carbon black is used as an electron transport channel between the active material and the current collector to transport the electrons generated by the active material to the current collector. The gel monomer is acrylamide, the initiator is ammonium persulfate or potassium persulfate, and the crosslinking agent is methylene bisacrylamide. In this solution, acrylamide can be polymerized into high-viscosity polyacrylamide under the catalytic action of the initiator and the crosslinking agent. Polyacrylamide has thickening and adhesiveness, which can increase the overall viscosity of the slurry in the gel cathode sheet, so that the slurry can firmly adhere to the current collector. The additive is a mixture of 1-methyl-2-propanol and 2-methyl-1-acrylate 1,2-dimethylacrylate. The mass ratio of 1-methyl-2-propanol to 2-methyl-1-acrylate 1,2-dimethylacrylate is 13:5. Among them, the alcohol hydroxyl group in 1-methyl-2-propanol can be connected to free water molecules through hydrogen bonds, reducing the activity of free water, thereby improving the cycle performance of the battery; 2-methyl-1-acrylate 1,2-dimethylacrylate is also a gel monomer, which is used to adjust the viscosity of the binder formed by the gel monomer.

[0032] The zinc salt is zinc sulfate or zinc nitrate or zinc trifluoromethanesulfonate, and the manganese salt is manganese sulfate or manganese nitrate. It should be noted that in this solution, when the manganese salt content in the gel cathode sheet is greater than 0, the zinc salt and the manganese salt need to be sulfates or nitrates at the same time. For example, when the zinc salt is zinc sulfate, the manganese salt is manganese sulfate; when the zinc salt is zinc nitrate, the manganese salt is manganese nitrate. In this way, the types of acid radicals in the gel cathode sheet can be reduced, which is beneficial to controlling the acidity and alkalinity of the slurry. The active material is manganese dioxide or vanadium pentoxide.

[0033] Please combine Figure 1 with Figure 4 , the present invention also discloses a method for processing the above gel cathode sheet, and the method includes the following steps:

[0034] S1. Prepare a slurry, and the slurry includes the following components in mass percentages: thickener 1-2%, deionized water 58-60%, zinc salt 21-24%, manganese salt 0-2%, conductive agent 0.5-1%, gel monomer 5-6%, active material 7-9%, crosslinking agent 0.05-0.1%, additive 2-3%, initiator 0.03-0.04%.

[0035] Specifically, step S1 includes:

[0036] S11. Stir and mix the thickener and deionized water to obtain glue. The thickener is carboxymethyl cellulose. The aqueous solution of carboxymethyl cellulose has functions such as thickening, film-forming, adhesion, moisture retention, colloid protection, emulsification, and suspension. After carboxymethyl cellulose is stirred and mixed with deionized water, a viscous gel substance is produced to provide a matrix for the dispersion of each component in the slurry. It should be noted that during the stirring and mixing of the thickener, air will enter the gel, causing bubbles to form in the glue, thereby interfering with the dispersion of each component in the glue (gel). Therefore, step S11 includes:

[0037] S111. Stir the mixture of the thickener and deionized water at a first speed for gluing. This step is used to fully dissolve the thickener in deionized water to form a colloid. Using deionized water as the solvent can avoid the interference of ions in the water on the reaction between the gel positive electrode and the negative electrode in the battery, ensuring the reliability of the gel positive electrode and the battery. In this embodiment, the first speed is 800 - 1200 r / min, and the temperature of the deionized water during gluing is 20 - 40 °C to accelerate the dissolution rate of the thickener.

[0038] S112. Stir the glued mixture at a second speed until the bubbles in the mixture are eliminated to obtain glue, and the second speed is less than the first speed. It can be understood that in this step, by stirring the colloid at a speed lower than the stirring speed for thickener dissolution, the bubbles in the colloid can be broken by the impact of the colloid, removing the air in the colloid, avoiding the interference of the air in the colloid on the subsequent homogenization of each component, enabling each component, especially the active substance, to be fully and evenly dispersed in the gel, and reducing the internal resistance of the battery. In this embodiment, the second speed is 300 - 500 r / min.

[0039] S12. Continuously stir the glue, and add zinc salt, manganese salt, conductive agent, gel monomer, active substance, crosslinking agent, additive, and initiator into the glue and mix them evenly to obtain the slurry.

[0040] Step S12 includes:

[0041] S121. Stir the glue at a constant speed, and sequentially add zinc salt, manganese salt, and conductive agent into the glue and mix them evenly;

[0042] S122. Add the gel monomer and active substance into the glue and stir and mix them evenly;

[0043] S123. Add the crosslinking agent and additive into the glue and stir and mix them evenly;

[0044] S124. Add the initiator into the colloid and stir evenly to obtain the slurry.

[0045] In this solution, zinc salt is used as the main component of the salt bridge in the gel positive electrode sheet. As a connection formed by electrostatic interaction between ions, it is used to improve the utilization rate of the active material in the gel positive electrode sheet. In addition, the setting of the salt bridge replaces the filling of the electrolyte, which can reduce the impedance of the battery interface. Manganese salt is used to inhibit the dissolution of the active material to improve the cycle stability of the battery. Preferably, the zinc salt is zinc sulfate or zinc nitrate or zinc trifluoromethanesulfonate, and the manganese salt is manganese sulfate or manganese nitrate. When the content of manganese salt in the gel positive electrode sheet is greater than 0, the zinc salt and the manganese salt need to be sulfates or nitrates at the same time. For example, when the zinc salt is zinc sulfate, the manganese salt is manganese sulfate; when the zinc salt is zinc nitrate, the manganese salt is manganese nitrate. In this way, the types of acid radical ions in the gel positive electrode sheet can be reduced to facilitate the control of the acidity and alkalinity of the slurry. The active material is manganese dioxide or vanadium pentoxide.

[0046] The conductive agent is used to provide an electron channel between the active material and the current collector, so that the electrons generated by the active material are transmitted to the current collector. In this solution, the conductive agent is conductive carbon black. As a semiconductor material, conductive carbon black is used as an electron transmission channel between the active material and the current collector to transmit the electrons generated by the active material to the current collector. The gel monomer is used to generate a binder under the co-catalysis of the cross-linking agent and the initiator, so that the salt bridge, the conductive agent, the gel and the current collector are bonded together and shaped to ensure the stability of the structure of the gel positive electrode sheet. The gel monomer is acrylamide, the cross-linking agent is methylene bisacrylamide, and the initiator is ammonium persulfate or potassium persulfate. The additive is a mixture of 1-methyl-2-propanol and 2-methyl-1-acrylate 1,2-dimethylacrylate. The mass ratio of 1-methyl-2-propanol to 2-methyl-1-acrylate 1,2-dimethylacrylate is 13:5. Among them, the alcohol hydroxyl group in 1-methyl-2-propanol can be connected to the free water form molecules through hydrogen bonds, reducing the activity of the free water, thereby improving the cycle performance of the battery; 2-methyl-1-acrylate 1,2-dimethylacrylate is also a gel monomer, which is used to adjust the viscosity of the binder generated by the gel monomer.

[0047] S2. Pour the slurry into a mold provided with a current collector for shaping and cutting to obtain a gel positive electrode sheet.

[0048] Specifically, pour the mixed slurry into the mold, so that the slurry is formed under the constraint of the mold and adhered to the surface of the current collector. After the slurry is consolidated and firmly attached to the current collector, cut it according to the preset size to obtain the finished gel positive electrode sheet. In this solution, the current collector is used as the carrier of the slurry and as the element for collecting current in the gel positive electrode sheet, so as to collect the current generated by the active material in the battery, thereby forming a larger current for external output. Preferably, the current collector is carbon cloth or nickel foam.

[0049] The processing process of the gel positive electrode sheet is described below with specific examples.

[0050] Example 1

[0051] Weigh 4 g of carboxymethyl cellulose and 200 g of deionized water, and put the two into a stirrer for sizing. When the carboxymethyl cellulose is completely dissolved in the deionized water, it is judged that the sizing is completed. During sizing, the rotation speed of the stirrer is 800 r / min, and the temperature of the deionized water is 40 °C. After sizing, reduce the rotation speed of the stirrer so that the stirrer stirs the colloid at a speed of 400 r / min to remove the bubbles in the colloid. When the bubbles in the colloid are completely eliminated, increase the rotation speed of the stirrer so that the stirrer rotates at a speed of 800 r / min, and slowly add 78 g of zinc sulfate, 4.5 g of manganese sulfate, and 3 g of conductive carbon black in sequence. After adding the above materials, continue to stir at a speed of 800 r / min for 30 min to ensure the uniformity of the slurry. Then slowly add 19 g of acrylamide and 24 g of manganese dioxide powder, and then add 0.3 g of methylene bisacrylamide (BIS), 5.2 g of 1-methyl-2-propanol, and 2 g of 2-methyl-1-acrylate 1,2-dimethylacrylate in sequence. Finally, add 0.13 g of initiator ammonium persulfate and continue to stir for 10 min to allow acrylamide to fully react and form a polyacrylamide colloid, and to make manganese dioxide and other materials fully mixed in the gel to obtain a slurry. After the slurry is mixed evenly, pour the slurry into a mold with carbon cloth for pole piece plasticity. After the plasticity is completed and the slurry is solidified, cut the gel positive electrode sheet to the required size.

[0052] Example 2

[0053] Weigh 3.5 g of carboxymethyl cellulose and 200.5 g of deionized water. Put the two into a stirrer for sizing. When the carboxymethyl cellulose is completely dissolved in the deionized water, it is judged that the sizing is completed. During sizing, the rotation speed of the stirrer is 1000 r / min, and the temperature of the deionized water is 35 °C. After sizing, reduce the rotation speed of the stirrer, and let the stirrer stir the colloid at a rotation speed of 300 r / min to remove the bubbles in the colloid. When the bubbles in the colloid are completely eliminated, increase the rotation speed of the stirrer, and let the stirrer rotate at a rotation speed of 800 r / min, and slowly add 79 g of zinc acetate, 3.5 g of manganese acetate, and 3 g of conductive carbon black in sequence. After adding the above materials, continuously stir at a rotation speed of 800 r / min for 30 min to ensure the uniformity of the slurry. Then slowly add 17 g of acrylamide and 26 g of manganese dioxide powder, and then add 0.3 g of methylene bisacrylamide (BIS), 5.2 g of 1-methyl-2-propanol, and 2 g of 2-methyl-1-acrylate 1,2-dimethylacrylate in sequence. Finally, add 0.13 g of initiator ammonium persulfate, and continuously stir for 10 min to make acrylamide fully react to form a polyacrylamide colloid, and make manganese dioxide and other materials fully mixed in the gel to obtain a slurry. After the slurry is mixed evenly, pour the slurry into a mold with carbon cloth for pole piece plasticity. After the plasticity is completed and the slurry is solidified, cut the gel positive electrode sheet with the required size.

[0054] Example 3

[0055] Weigh 3.4 g of carboxymethyl cellulose and 200 g of deionized water. Put the two into a stirrer for sizing. When the carboxymethyl cellulose is completely dissolved in the deionized water, it is judged that the sizing is completed. During sizing, the rotation speed of the stirrer is 1200 r / min, and the temperature of the deionized water is 20 °C. After sizing, reduce the rotation speed of the stirrer, and let the stirrer stir the colloid at a rotation speed of 500 r / min to remove the bubbles in the colloid. When the bubbles in the colloid are completely eliminated, increase the rotation speed of the stirrer, and let the stirrer rotate at a rotation speed of 800 r / min, and slowly add 79.6 g of zinc sulfate, 3.5 g of manganese sulfate, and 6 g of conductive carbon black in sequence. After adding the above materials, continuously stir at a rotation speed of 800 r / min for 30 min to ensure the uniformity of the slurry. Then slowly add 17 g of acrylamide and 23 g of manganese dioxide powder, and then add 0.3 g of methylene bisacrylamide (BIS), 5.2 g of 1-methyl-2-propanol, and 2 g of 2-methyl-1-acrylate 1,2-dimethylacrylate in sequence. Finally, add 0.13 g of initiator ammonium persulfate, and continuously stir for 10 min to make acrylamide fully react to form a polyacrylamide colloid, and make manganese dioxide and other materials fully mixed in the gel to obtain a slurry. After the slurry is mixed evenly, pour the slurry into a mold with nickel foam for pole piece plasticity. After the plasticity is completed and the slurry is solidified, cut the gel positive electrode sheet with the required size.

[0056] Example 4

[0057] Weigh 6 g of carboxymethyl cellulose and 198 g of deionized water, and put the two into a stirrer for sizing. When the carboxymethyl cellulose is completely dissolved in the deionized water, it is judged that the sizing is completed. During sizing, the rotation speed of the stirrer is 800 r / min, and the temperature of the deionized water is 40 °C. After sizing, reduce the rotation speed of the stirrer, and make the stirrer stir the colloid at a rotation speed of 400 r / min to remove the bubbles in the colloid. When the bubbles in the colloid are completely eliminated, increase the rotation speed of the stirrer to make the stirrer rotate at a rotation speed of 800 r / min, and slowly add 76.5 g of zinc acetate, 6 g of manganese acetate, and 3 g of conductive carbon black in sequence. After adding the above materials, continue to stir at a rotation speed of 800 r / min for 30 min to ensure the uniformity of the slurry. Subsequently, slowly add 18 g of acrylamide and 25 g of manganese dioxide powder, and then add 0.3 g of methylene bisacrylamide (BIS), 5.2 g of 1-methyl-2-propanol, and 2 g of 2-methyl-1-acrylate 1,2-dimethylacrylate in sequence. Finally, add 0.13 g of initiator ammonium persulfate and continue to stir for 10 min to make acrylamide fully react to form a polyacrylamide colloid, and make manganese dioxide and other materials fully mixed in the gel to obtain a slurry. After the slurry is mixed evenly, pour the slurry into a mold with nickel foam for pole piece plasticity. After the plasticity is completed and the slurry is consolidated, cut the gel positive pole piece into the required size.

[0058] Example 5

[0059] Weigh 4 g of carboxymethyl cellulose and 200 g of deionized water, put the two into a stirrer for sizing. When the carboxymethyl cellulose is completely dissolved in the deionized water, it is judged that the sizing is completed. During sizing, the rotation speed of the stirrer is 1000 r / min, and the temperature of the deionized water is 30 °C. After sizing, reduce the rotation speed of the stirrer, so that the stirrer stirs the colloid at a rotation speed of 300 r / min to remove the bubbles in the colloid. When the bubbles in the colloid are completely eliminated, increase the rotation speed of the stirrer, so that the stirrer rotates at a rotation speed of 800 r / min, and sequentially and slowly add 78 g of zinc sulfate, 4.5 g of manganese sulfate, and 3 g of conductive carbon black. After adding the above materials, continuously stir at a rotation speed of 800 r / min for 30 min to ensure the uniformity of the slurry. Subsequently, slowly add 19 g of acrylamide and 24 g of manganese dioxide powder, and then sequentially add 0.3 g of methylene bisacrylamide (BIS), 5.2 g of 1-methyl-2-propanol, and 2 g of 2-methyl-1-acrylate 1,2-dimethylacrylate. Finally, add 0.13 g of initiator potassium persulfate, and continuously stir for 10 min to make acrylamide fully react to form a polyacrylamide colloid, and make manganese dioxide and other materials fully mixed in the gel to obtain a slurry. After the slurry is mixed evenly, pour the slurry into a mold with carbon cloth for pole piece plasticity. After the plasticity is completed and the slurry is solidified, cut the gel positive electrode sheet of the required size.

[0060] Example 6

[0061] Weigh 3.5 g of carboxymethyl cellulose and 200.5 g of deionized water, put the two into a stirrer for sizing. When the carboxymethyl cellulose is completely dissolved in the deionized water, it is judged that the sizing is completed. During sizing, the rotation speed of the stirrer is 1200 r / min, and the temperature of the deionized water is 25 °C. After sizing, reduce the rotation speed of the stirrer, so that the stirrer stirs the colloid at a rotation speed of 500 r / min to remove the bubbles in the colloid. When the bubbles in the colloid are completely eliminated, increase the rotation speed of the stirrer, so that the stirrer rotates at a rotation speed of 800 r / min, and sequentially and slowly add 79 g of zinc acetate, 3.5 g of manganese acetate, and 3 g of conductive carbon black. After adding the above materials, continuously stir at a rotation speed of 800 r / min for 30 min to ensure the uniformity of the slurry. Subsequently, slowly add 17 g of acrylamide and 26 g of manganese dioxide powder, and then sequentially add 0.3 g of methylene bisacrylamide (BIS), 5.2 g of 1-methyl-2-propanol, and 2 g of 2-methyl-1-acrylate 1,2-dimethylacrylate. Finally, add 0.13 g of initiator potassium persulfate, and continuously stir for 10 min to make acrylamide fully react to form a polyacrylamide colloid, and make manganese dioxide and other materials fully mixed in the gel to obtain a slurry. After the slurry is mixed evenly, pour the slurry into a mold with carbon cloth for pole piece plasticity. After the plasticity is completed and the slurry is solidified, cut the gel positive electrode sheet of the required size.

[0062] Example 7

[0063] Weigh 3.4 g of carboxymethyl cellulose and 200 g of deionized water, and put the two into a stirrer for sizing. When the carboxymethyl cellulose is completely dissolved in the deionized water, it is judged that the sizing is completed. During sizing, the rotation speed of the stirrer is 850 r / min, and the temperature of the deionized water is 20 °C. After sizing, reduce the rotation speed of the stirrer, so that the stirrer stirs the colloid at a rotation speed of 350 r / min to remove the bubbles in the colloid. When the bubbles in the colloid are completely eliminated, increase the rotation speed of the stirrer, so that the stirrer rotates at a rotation speed of 800 r / min, and sequentially and slowly add 79.6 g of zinc sulfate, 3.5 g of manganese sulfate, and 3 g of conductive carbon black. After adding the above materials, continuously stir at a rotation speed of 800 r / min for 30 min to ensure the uniformity of the slurry. Subsequently, slowly add 17 g of acrylamide and 23 g of manganese dioxide powder, and then sequentially add 0.3 g of methylene bisacrylamide (BIS), 5.2 g of 1-methyl-2-propanol, and 2 g of 2-methyl-1-acrylate 1,2-dimethylacrylate. Finally, add 0.13 g of initiator potassium persulfate and continuously stir for 10 min to make acrylamide fully react to form polyacrylamide colloid, and make manganese dioxide and other materials fully mixed in the gel to obtain the slurry. After the slurry is mixed evenly, pour the slurry into a mold with nickel foam for pole piece plasticity. After the plasticity is completed and the slurry is consolidated, cut the gel positive electrode sheet to the required size.

[0064] Example 8

[0065] Weigh 6 g of carboxymethyl cellulose and 198 g of deionized water, put the two into a stirrer for sizing. When the carboxymethyl cellulose is completely dissolved in the deionized water, it is judged that the sizing is completed. During sizing, the rotation speed of the stirrer is 800 r / min, and the temperature of the deionized water is 20 °C. After sizing, reduce the rotation speed of the stirrer, make the stirrer stir the colloid at a rotation speed of 450 r / min to remove the bubbles in the colloid. When the bubbles in the colloid are completely eliminated, increase the rotation speed of the stirrer to make the stirrer rotate at a speed of 800 r / min, and slowly add 76.5 g of zinc acetate, 6 g of manganese acetate, and 3 g of conductive carbon black in sequence. After adding the above materials, continuously stir at a speed of 800 r / min for 30 min to ensure the uniformity of the slurry. Then slowly add 18 g of acrylamide and 25 g of manganese dioxide powder, and then add 0.3 g of methylene bisacrylamide (BIS), 5.2 g of 1-methyl-2-propanol, and 2 g of 2-methyl-1-acrylate 1,2-dimethylacrylate in sequence. Finally, add 0.13 g of initiator potassium persulfate, continuously stir for 10 min to make acrylamide fully react to form a polyacrylamide colloid, and make manganese dioxide and other materials fully mixed in the gel to obtain a slurry. After the slurry is mixed evenly, pour the slurry into a mold with nickel foam for pole piece plasticity. After the plasticity is completed and the slurry is solidified, cut the gel positive electrode sheet with the required size.

[0066] Example 9

[0067] Weigh 4 g of carboxymethyl cellulose and 200 g of deionized water, put the two into a stirrer for sizing. When the carboxymethyl cellulose is completely dissolved in the deionized water, it is judged that the sizing is completed. During sizing, the rotation speed of the stirrer is 800 r / min, and the temperature of the deionized water is 40 °C. After sizing, reduce the rotation speed of the stirrer, make the stirrer stir the colloid at a rotation speed of 400 r / min to remove the bubbles in the colloid. When the bubbles in the colloid are completely eliminated, increase the rotation speed of the stirrer to make the stirrer rotate at a speed of 800 r / min, and slowly add 78 g of zinc trifluoromethanesulfonate and 3 g of conductive carbon black in sequence. After adding the above materials, continuously stir at a speed of 800 r / min for 30 min to ensure the uniformity of the slurry. Then slowly add 19 g of acrylamide and 29 g of vanadium pentoxide powder, and then add 0.3 g of methylene bisacrylamide (BIS), 5.2 g of 1-methyl-2-propanol, and 2 g of 2-methyl-1-acrylate 1,2-dimethylacrylate in sequence. Finally, add 0.13 g of initiator ammonium persulfate, continuously stir for 10 min to make acrylamide fully react to form a polyacrylamide colloid, and make manganese dioxide and other materials fully mixed in the gel to obtain a slurry. After the slurry is mixed evenly, pour the slurry into a mold with carbon cloth for pole piece plasticity. After the plasticity is completed and the slurry is solidified, cut the gel positive electrode sheet with the required size.

[0068] Example 10

[0069] Weigh 3.5 g of carboxymethyl cellulose and 200.5 g of deionized water. Put the two into a stirrer for sizing. When the carboxymethyl cellulose is completely dissolved in the deionized water, it is judged that the sizing is completed. During sizing, the rotation speed of the stirrer is 1000 r / min, and the temperature of the deionized water is 35 °C. After sizing, reduce the rotation speed of the stirrer so that the stirrer stirs the colloid at a rotation speed of 300 r / min to remove the bubbles in the colloid. When the bubbles in the colloid are completely eliminated, increase the rotation speed of the stirrer so that the stirrer rotates at a rotation speed of 800 r / min, and sequentially and slowly add 80 g of zinc trifluoromethanesulfonate and 3 g of conductive carbon black. After adding the above materials, continuously stir at a rotation speed of 800 r / min for 30 min to ensure the uniformity of the slurry. Subsequently, slowly add 19 g of acrylamide and 27 g of vanadium pentoxide powder, and then sequentially add 0.3 g of methylene bisacrylamide (BIS), 5.2 g of 1-methyl-2-propanol, and 2 g of 2-methyl-1-acrylate 1,2-dimethylacrylate. Finally, add 0.13 g of initiator ammonium persulfate and continuously stir for 10 min to make acrylamide fully react to form a polyacrylamide colloid, and make manganese dioxide and other materials fully mixed in the gel to obtain a slurry. After the slurry is mixed evenly, pour the slurry into a mold with nickel foam for pole piece plasticity. After the plasticity is completed and the slurry is solidified, cut the gel positive electrode sheet with the required size.

[0070] Example 11

[0071] Weigh 6 g of carboxymethyl cellulose and 198 g of deionized water. Put the two into a stirrer for sizing. When the carboxymethyl cellulose is completely dissolved in the deionized water, it is judged that the sizing is completed. During sizing, the rotation speed of the stirrer is 1200 r / min, and the temperature of the deionized water is 20 °C. After sizing, reduce the rotation speed of the stirrer so that the stirrer stirs the colloid at a rotation speed of 500 r / min to remove the bubbles in the colloid. When the bubbles in the colloid are completely eliminated, increase the rotation speed of the stirrer so that the stirrer rotates at a rotation speed of 800 r / min, and sequentially and slowly add 75 g of zinc trifluoromethanesulfonate and 6 g of conductive carbon black. After adding the above materials, continuously stir at a rotation speed of 800 r / min for 30 min to ensure the uniformity of the slurry. Subsequently, slowly add 18 g of acrylamide and 30 g of vanadium pentoxide powder, and then sequentially add 0.3 g of methylene bisacrylamide (BIS), 5.2 g of 1-methyl-2-propanol, and 2 g of 2-methyl-1-acrylate 1,2-dimethylacrylate. Finally, add 0.13 g of initiator potassium persulfate and continuously stir for 10 min to make acrylamide fully react to form a polyacrylamide colloid, and make manganese dioxide and other materials fully mixed in the gel to obtain a slurry. After the slurry is mixed evenly, pour the slurry into a mold with carbon cloth for pole piece plasticity. After the plasticity is completed and the slurry is solidified, cut the gel positive electrode sheet with the required size.

[0072] Example 12

[0073] Weigh 4.5 g of carboxymethyl cellulose and 199.5 g of deionized water, put the two into a stirrer for sizing. When the carboxymethyl cellulose is completely dissolved in the deionized water, it is judged that the sizing is completed. During sizing, the rotation speed of the stirrer is 800 r / min, and the temperature of the deionized water is 25 °C. After sizing, reduce the rotation speed of the stirrer, and make the stirrer stir the colloid at a rotation speed of 350 r / min to remove the bubbles in the colloid. When the bubbles in the colloid are completely eliminated, increase the rotation speed of the stirrer to make the stirrer rotate at a speed of 800 r / min, and slowly add 75 g of zinc trifluoromethanesulfonate and 4 g of conductive carbon black in sequence. After adding the above materials, continuously stir at a speed of 800 r / min for 30 min to ensure the uniformity of the slurry. Then slowly add 20 g of acrylamide and 30 g of vanadium pentoxide powder, and then add 0.3 g of methylene bisacrylamide (BIS), 5.2 g of 1-methyl-2-propanol, and 2 g of 2-methyl-1-acrylate 1,2-dimethylacrylate in sequence. Finally, add 0.13 g of initiator potassium persulfate, and continuously stir for 10 min to make acrylamide fully react to form a polyacrylamide colloid, and make manganese dioxide and other materials fully mixed in the gel to obtain a slurry. After the slurry is mixed evenly, pour the slurry into a mold with nickel foam for pole piece plasticity. After the plasticity is completed and the slurry is consolidated, cut the gel positive pole piece with the required size.

[0074] On the basis of preparing the above gel positive pole piece, assemble the gel positive pole piece with the negative electrode to obtain a battery. A layer of ultra-thin hydrogel is separated between the gel positive pole piece and the negative electrode to prevent the positive and negative electrodes of the battery from short-circuiting. In this scheme, only take the gel positive pole piece prepared in Example 1 to assemble the battery and evaluate its performance. After the battery made of this gel positive pole piece is subjected to charge and discharge experiments, the first-cycle charge and discharge curve as shown in Figure 2 is obtained. It can be seen that the initial voltage platform of the battery is about 1.8 V, the voltage drop rate during its discharge is small, the capacity decay is slow, the cut-off voltage after discharge is about 0.8 V, and the discharge depth of the battery is large. The voltage platform of the battery during charging is stable at 1.8 V, and the chemical reaction stability inside the battery is good.

[0075] In addition, this scheme also compares the discharge capacity of the battery using the gel positive pole piece of Example 1 with that of the battery using the conventional manganese dioxide positive pole piece. It can be seen that when the load is 10 mg·cm -2 and the current rate is 1.5 C, with the increase of the number of cycles, the discharge capacity of the battery prepared from the gel positive pole piece of this scheme always remains at 90 mAh·g -1, It can be seen that the gel cathode plate processed by the above method has a smaller capacity attenuation, which is beneficial to extending the service life of the battery and ensuring the stability of the battery.

[0076] By implementing the gel cathode plate and its processing method of the present invention, by adding glue (gel) formed by a thickening agent and deionized water and a salt bridge composed of a zinc salt in the cathode plate, the utilization rate of the active substance in the cathode plate can be improved, so that the cathode plate can normally discharge under high load; due to the setting of the salt bridge, when assembling the battery, only a layer of ultra-thin hydrogel is needed to separate the positive and negative electrodes to prevent short circuit, and there is no need to add electrolyte between the positive and negative electrodes, solving the problems of increased interfacial resistance and blocked ion transport caused by the interaction between the solid-liquid interface, ensuring the electrochemical performance of the battery and being beneficial to extending the cycle life of the battery; using the glue as the carrier for the distribution of the active substance is beneficial to the uniform dispersion of the active substance during the preparation process, so as to reduce the local resistance in the battery, prevent the hindrance of electron and ion migration, improve the stability of the battery and delay the attenuation of the battery capacity.

[0077] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0078] The above-described embodiments only represent several implementation manners of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the invention patent should be subject to the appended claims.

Claims

1. A gel positive electrode sheet, characterized in that: The invention comprises a current collector and a slurry formed on the surface of the current collector, wherein the slurry comprises the following components in percentage by mass: 1-2% thickener, 58-60% deionized water, 21-24% zinc salt, 0-2% manganese salt, 0.5-1% conductive agent, 5-6% gel monomer, 7-9% active substance, 0.05-0.1% crosslinking agent, 2-3% additive and 0.03-0.04% initiator.

2. The gel positive electrode sheet according to claim 1, characterized in that: The current collector is carbon cloth or nickel foam.

3. The gel positive electrode sheet according to claim 1, characterized in that: The thickener is carboxymethyl cellulose, the conductive agent is conductive carbon black, the gel monomer is acrylamide, and the crosslinking agent is methylene acrylamide; the additive is a mixture of 1-methyl-2-propanol and 1,2-dimethacrylate-2-methyl-1-methyl acrylate, and the mass ratio of 1-methyl-2-propanol to 1,2-dimethacrylate-2-methyl-1-methyl acrylate is 13:

5.

4. The gel positive electrode sheet according to claim 1, characterized in that: The zinc salt is zinc sulfate or zinc nitrate or zinc trifluoromethanebenzenesulfonate, the manganese salt is manganese sulfate or manganese nitrate, the initiator is ammonium persulfate or potassium persulfate, and the active substance is manganese dioxide or vanadium pentoxide.

5. A method for processing the gel cathode sheet according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1. Prepare slurry, which includes the following components in mass percentage: thickener 1-2%, deionized water 58-60%, zinc salt 21-24%, manganese salt 0-2%, conductive agent 0.5-1%, gel monomer 5-6%, active substance 7-9%, crosslinking agent 0.05-0.1%, additive 2-3%, initiator 0.03-0.04%; S2. The slurry is introduced into a mold provided with a current collector to shape and cut the slurry to obtain a gel positive electrode sheet.

6. The method according to claim 5, characterized in that Step S1 includes: S11, stirring and mixing the thickener and deionized water to obtain glue; S12, continuously stirring the glue, and adding the zinc salt, manganese salt, conductive agent, gel monomer, active substance, crosslinking agent, additive and initiator into the glue and mixing well to obtain the slurry.

7. The method according to claim 6, characterized in that Step S11 includes: S111, stirring the mixture of thickener and deionized water at a first speed to perform glue application; S112, stirring the glued mixture at a second speed until bubbles in the mixture are eliminated to obtain glue, wherein the second speed is lower than the first speed.

8. The method according to claim 6, characterized in that Step S12 includes: S121, stirring the glue at a uniform speed, and adding zinc salt, manganese salt and conductive agent to the glue in sequence and mixing them evenly; S122, adding gel monomer and active substance to the glue, and stirring to mix; S123, adding a cross-linking agent and an additive to the glue, and stirring and mixing; S124. Add an initiator to the colloid and stir evenly to obtain a slurry.

9. The method according to claim 5, characterized in that The thickener is carboxymethyl cellulose, the conductive agent is conductive carbon black, the gel monomer is acrylamide, and the crosslinking agent is methylene acrylamide; the additive is a mixture of 1-methyl-2-propanol and 1,2-dimethacrylate-2-methyl-1-methyl acrylate, and the mass ratio of 1-methyl-2-propanol to 1,2-dimethacrylate-2-methyl-1-methyl acrylate is 13:

5.

10. The method according to claim 5, characterized in that The zinc salt is zinc sulfate or zinc nitrate or zinc trifluoromethanebenzenesulfonate, the manganese salt is manganese sulfate or manganese nitrate, the initiator is ammonium persulfate or potassium persulfate, the current collector is carbon cloth or nickel foam, and the active material is manganese dioxide or vanadium pentoxide.

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