Tubular battery heterogeneous electrolyte and preparation method thereof

Abstract

The invention relates to the technical field of storage batteries, and particularly provides a tubular battery non-uniform electrolyte which comprises a first colloidal electrolyte, a second colloidal electrolyte and a third colloidal electrolyte which are sequentially distributed in a plate group of a tubular battery, between the periphery of the plate group and a busbar and in an area above the busbar respectively, each of the first colloidal electrolyte, the second colloidal electrolyte and the third colloidal electrolyte comprises mother liquor, and the mother liquor comprises the following components in parts by weight: 10 parts of water, 1.5-2.5 parts of mesoporous SiO2 nanoparticles, 0.8-1.2 parts of polystyrene-b-poly (2-vinylpyridine) micelles, 0.01-0.05 part of a photoinitiator, 0.01-0.05 part of an antioxidant and 0.3 part of a dispersing agent. And the first colloidal electrolyte and the second colloidal electrolyte further comprise a sulfuric acid solution. And by adopting a gradient electrolyte design and a synergistic effect of a mesoporous SiO2 / micelle composite system, the comprehensive performance of the tubular gel battery is remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of storage batteries, and in particular to a tubular battery non-uniform electrolyte and a preparation method thereof. Background Art

[0002] As an important innovation direction of lead-acid batteries, colloidal lead-acid batteries are widely used in electric vehicles, energy storage systems and other fields due to their characteristics such as electrolyte solidification, no acid mist leakage, and excellent low-temperature performance. However, traditional colloidal electrolytes generally have technical bottlenecks such as poor gel network stability, easy hydration stratification, and uncontrolled microcracks. For example, the electrolyte system using fumed silica or silica sol as a gelling agent can fix sulfuric acid through a three-dimensional silicon-oxygen network, but the gel has poor thixotropy and insufficient mechanical strength. During the charge and discharge cycle, the plate expansion stress can easily cause the colloid to shrink and the microcracks to expand, which in turn causes problems such as electrolyte stratification and active material shedding. In addition, although the existing technology can partially improve the gel strength by adding modified glass fibers or increasing the concentration of silica, it brings new contradictions such as decreased ionic conductivity and increased costs.

[0003] The current patented technologies for improving colloidal electrolytes mostly focus on optimizing a single performance, lacking a systematic design for the coordinated regulation of mechanics and electrochemistry. For example, by chemically grafting quaternary ammonium salts to modify the glass fiber reinforced gel network, the gel strength is increased to an insertion depth of 1.42 mm, but the poor compatibility between the rigid inorganic fiber and the organic colloidal matrix interface leads to obstruction of the ion migration channel; the nano-high-speed slitting process is used to prepare a highly dispersed colloidal mother liquor, which achieves particle size control and Zeta potential optimization, but still relies on the traditional staged gel addition process, which cannot suppress the gradient stress mismatch during the colloidal solidification process.

[0004] In response to the above problems, it is urgent to develop an innovative colloidal electrolyte solution that takes into account mechanical stability, electrochemical performance and process compatibility. Summary of the invention

[0005] In view of this, the present invention proposes a tubular battery non-uniform electrolyte and a preparation method thereof, aiming to improve the cycle performance of the colloidal battery.

[0006] The technical solution of the present invention is implemented as follows: The present invention provides a tubular battery non-uniform electrolyte, the non-uniform electrolyte includes a first colloidal electrolyte, a second colloidal electrolyte and a third colloidal electrolyte, the three electrolytes are respectively distributed in the interior of the pole group of the tubular battery, between the outer periphery of the pole group and the bus bar, and the area above the bus bar, the first colloidal electrolyte, the second colloidal electrolyte and the third colloidal electrolyte all include a mother liquid, the mother liquid is calculated by weight and includes 10 parts of water, mesoporous SiO 21.5-2.5 parts of nanoparticles, 0.8-1.2 parts of polystyrene-b-poly(2-vinylpyridine) micelles, 0.01-0.05 parts of photoinitiator, 0.01-0.05 parts of antioxidant and 0.3 parts of dispersant. The first colloidal electrolyte and the second colloidal electrolyte also include sulfuric acid solution.

[0007] In this application, by introducing mesoporous SiO 2 Nanoparticles and polystyrene-b-poly(2-vinylpyridine) micelles overcome the traditional gas-phase SiO 2 Due to the lack of docking and the strong hydrogen bonding that causes stress concentration during infusion, the hydrophobic PS core of polystyrene-b-poly(2-vinylpyridine) micelles is adsorbed on the mesoporous SiO 2 The surface of the P2VP shell is connected to the SiO 2 Hydroxyl hydrogen bonds form a steric hindrance layer, making SiO 2 The dispersed particle size D90 is less than 200 nm, and the hydrophilic segment of the micelle shell P2VP is closely related to the mesoporous SiO 2 The mesopores synergistically construct graded wetting channels, which greatly improves the penetration rate of sulfuric acid solution.

[0008] Traditional gas phase SiO 2 The gel shrinkage rate is high due to the physical adsorption of sulfuric acid, which leads to microcracks in the later stage. The polystyrene-b-poly(2-vinylpyridine) micelles of the present application can cause the pyridine groups therein to transition under the excitation of ultraviolet light, triggering the activation of the CH bonds of adjacent micelles to form a covalent cross-linked network. SiO 2 The silanol groups on the inner wall of the mesopores form a hydrogen bond network with the P2VP segments of the micelles, which makes the gel storage modulus higher than that of pure SiO 2 The gel is higher, so the cross-linked network dissipates mechanical energy synergistically through entropic elastic deformation of micelles and plastic deformation of the mesoporous structure under the plate expansion stress.

[0009] The highly mesoporous SiO 2 Acid storage combined with high micelle toughening to match the plate expansion stress, medium concentration of mesoporous SiO 2 With high acid concentration, ion conduction and mechanical support are enhanced; low acid concentration and low SiO2 are used in the bus area. 2 , inhibiting acid mist escape and corrosion.

[0010] In some embodiments, the first colloidal electrolyte is composed of a mother liquid and a sulfuric acid solution in a volume ratio of 1:1.2, wherein the concentration of the sulfuric acid solution is 38%, and the mother liquid, calculated by weight, includes 10 parts of water, mesoporous SiO 22-2.5 parts of nanoparticles, 1-1.2 parts of polystyrene-b-poly(2-vinylpyridine) micelles, 0.01-0.05 parts of photoinitiator, 0.01-0.05 parts of antioxidant and 0.3 parts of dispersant.

[0011] Higher concentration of mesoporous SiO 2 Nanoparticles help form a rigid skeleton network with a higher storage modulus, which effectively inhibits the propagation of microcracks caused by basic expansion stress.

[0012] In some embodiments, the second colloidal electrolyte is composed of a mother liquid and a sulfuric acid solution in a volume ratio of 1:1.5, wherein the concentration of the sulfuric acid solution is 45%, and the mother liquid, calculated by weight, includes 10 parts of water, mesoporous SiO 2 1.5-2 parts of nanoparticles, 0.8-1 parts of polystyrene-b-poly(2-vinylpyridine) micelles, 0.01-0.05 parts of photoinitiator, 0.01-0.05 parts of antioxidant and 0.3 parts of dispersant.

[0013] By reducing the mesoporous SiO 2 The amount of nanoparticles used enables the micelles to form a dynamic network through hydrophobic association, triggering the shear thickening effect under high stress, inhibiting the expansion of micro-attendants, and high concentration of sulfuric acid to increase the oxygen evolution overpotential and inhibit water decomposition; at the same time, the mesoporous SiO 2 The adsorption effect reduces the precipitation of free acid and lowers the interface impedance.

[0014] In some embodiments, the third colloidal electrolyte is composed of a mother solution, which includes 10 parts of water, mesoporous SiO 2 1 part of nanoparticles, 0.8 parts of polystyrene-b-poly(2-vinylpyridine) micelles, 0.01-0.05 parts of photoinitiator, 0.01-0.05 parts of antioxidant and 0.3 parts of dispersant.

[0015] A dense protective layer is constructed by the hydrophobic core (PS) of the PS-b-P2VP micelle, which has a lower water vapor permeability and solves the problem of late drying and cracking of traditional colloids.

[0016] In some embodiments, mesoporous SiO 2 The method for preparing nanoparticles includes: Step 1: Mix the template agent hexadecyltrimethylammonium p-toluenesulfonate with deionized water and triethanolamine, adjust the pH to 9-10, heat to 75-85°C and stir until clear; Step 2: Add tetraethyl orthosilicate dropwise at a rate of 0.5 ml / min, with a molar ratio of hexadecyltrimethylammonium p-toluenesulfonate to tetraethyl orthosilicate of 1:5, and stir at 300 rpm for 1.5-2.5 hours to obtain a white precipitate; Step 3: Filter and wash, then heat at a rate of 2 °C / min to 500 - 600 °C and calcine for 1 - 2 h to obtain mesoporous SiO 2 nanoparticles; The obtained mesoporous SiO 2 nanoparticles have a particle size of 50 - 200 nm and a pore diameter of 3.2 - 7.6 nm.

[0017] In some embodiments, in Step 3, after filtering and washing, before calcining at 500 - 600 °C for 1 - 2 h, it further includes dispersing the precipitate in an ethanol - aqueous solution, adding resorcinol and formaldehyde, stirring for 8 - 12 h, and then filtering and washing again, where the mass ratio of resorcinol to the precipitate is (0.5 - 0.8):1, and the molar ratio of resorcinol to formaldehyde is 1:2.

[0018] A uniform coating layer is formed on the surface of the SiO 2 particles by resorcinol and formaldehyde. When calcining at 500 - 600 °C subsequently, the coating layer is carbonized to form an amorphous carbon layer. This carbon layer and the SiO 2 skeleton form a core - shell heterostructure, which improves the ion transport efficiency. This composite structure enhances the compressive strength and helps reduce the cyclic shrinkage rate.

[0019] In some embodiments, the preparation method of the polystyrene - b - poly(2 - vinylpyridine) micelles includes: Dissolve 1 g of polystyrene - b - poly(2 - vinylpyridine) powder in 50 ml of a solvent with a THF:methanol volume ratio of 95:5 (v:v). After ultrasonic treatment at 150 W for 20 min, perform evaporation treatment at 20 - 30 °C and a humidity ≤ 30% for 12 h to form a micelle film. After vacuum drying, polystyrene - b - poly(2 - vinylpyridine) micelles are obtained, where the molecular weight of the polystyrene - b - poly(2 - vinylpyridine) powder is 25000 - 30000 g / mol.

[0020] In some embodiments, the dispersant is PEG - 4000, the photo - initiator is Irgacure 2959, and the antioxidant is benzotriazole.

[0021] In a second aspect, the present invention also provides a preparation method of the non - uniform electrolyte for the above - mentioned tubular battery, including the following steps: Step 1: Mix the mother liquor of the first colloidal electrolyte raw material and the sulfuric acid solution, then disperse ultrasonically, and then pour it into the battery not exceeding the top of the electrode group. Place it in a water bath at 15 - 20 °C and perform a primary charge formation under ultraviolet light irradiation. When the state of charge (SOC) reaches 95%, vacuum - negative - pressure extract the free acid to obtain the first colloidal electrolyte; Step 2: Mix the mother liquor of the second colloidal electrolyte raw material and the sulfuric acid solution, ultrasonically disperse it, then pour it into the battery and cover the top of the electrode group, not exceeding the bus bar, place it in a water bath at 15-20 °C, and perform a primary charge formation. During the charge and discharge process, pulsed ultraviolet irradiation is carried out. When the state of charge (SOC) reaches 95%, free acid is extracted under vacuum negative pressure to obtain the second colloidal electrolyte; Step 3: Ultrasonically disperse the mother liquor of the third colloidal electrolyte raw material, then pour it into the battery and cover the bus bar, place it in a water bath at 45-60 °C, and perform a primary charge formation to obtain the third colloidal electrolyte.

[0022] In some embodiments, in Step 2, after pouring it into the battery and covering the top of the electrode group, before performing the water bath heat preservation, it further includes centrifuging at 8000×g for 10 min at 15-20 °C, and then centrifuging at 12000×g for 20 min. The centrifugal force during the above centrifugation process is perpendicular to the axis of the tubular battery.

[0023] In the above embodiments, the colloidal particles are rapidly sedimented by high-speed centrifugal force to remove large-size pores and undispersed aggregates at the top of the electrode group, forming a preliminary dense layer; subsequent higher centrifugal force drives the colloid to penetrate into the micropores of the electrode plate and the fiber gaps of the separator, forming a multi-level pore structure with more nano-scale pores.

[0024] The present invention has the following beneficial effects compared with the prior art: This application adopts the gradient electrolyte design and the synergistic effect of the mesoporous SiO 2 / micelle composite system, which significantly improves the comprehensive performance of the tubular colloidal battery. The hierarchical structure precisely matches the functional requirements of the interior of the electrode group (high acid storage and anti-swelling), high ion conduction in the periphery, and acid mist sealing in the bus bar area. Combining the ordered pores of mesoporous SiO 2 and the dynamic cross-linked network of PS-b-P2VP micelles realizes the efficient adsorption and directional transmission of the electrolyte. The ultraviolet curing process and vertical centrifugation control further ensure the uniformity of the gel network and the interfacial bonding strength, improving the battery cycle life, increasing the high-temperature capacity retention rate, and effectively suppressing the microcracks and electrolyte stratification caused by the expansion of the electrode plate. Specific Embodiments

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative work shall fall within the protection scope of the present invention.

[0026] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the embodiments of the present invention belong. If the definitions set forth in this section are contrary to or otherwise inconsistent with the definitions set forth in the patents, patent applications, published patent applications, and other publications incorporated herein by reference, the definitions listed in this section take precedence over the definitions incorporated herein by reference.

[0028] Unless otherwise specified, the methods used in the following examples are all conventional methods. Unless otherwise specified, the materials, reagents and instruments used are all conventional materials, reagents and instruments in the art, and can be obtained by those skilled in the art through commercial channels.

[0029] When an amount, concentration or other value or parameter is expressed as a range, a preferred range or a range defined by a series of upper preferred values ​​and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is disclosed separately. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted as including the range "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described herein, unless otherwise stated, the range is intended to include its end values ​​and all integers and fractions within the range. In the present specification and claims, range definitions can be combined and / or interchanged, and if not otherwise stated, these ranges include all subranges contained therein.

[0030] Example 1 This embodiment provides a technical solution for a tubular battery with a non-uniform electrolyte, using carbon-coated mesoporous SiO 2 Nanoparticles and polystyrene-b-poly(2-vinylpyridine) micelles.

[0031] Its structure includes three layers of electrolyte, and the raw materials of the three layers of electrolyte are as follows: The first layer: The mother liquor and sulfuric acid solution are composed of a volume ratio of 1:1.2, wherein the mass concentration of the sulfuric acid solution is 38%, and the mother liquor is calculated by weight and consists of 10 kg of water, mesoporous SiO 2It is composed of 2.5 kg of nanoparticles, 1.2 kg of polystyrene-b-poly(2-vinylpyridine) micelles, 0.05 kg of photoinitiator Irgacure 2959, 0.05 kg of antioxidant benzotriazole, and 0.3 kg of dispersant PEG-4000.

[0032] The second layer: It is composed of a mother liquor and a sulfuric acid solution with a volume ratio of 1:1.5. The mass concentration of the sulfuric acid solution is 45%. The mother liquor, calculated by weight, consists of 10 kg of water and mesoporous SiO 2 It is composed of 2 kg of nanoparticles, 1 kg of polystyrene-b-poly(2-vinylpyridine) micelles, 0.03 kg of photoinitiator Irgacure 2959, 0.03 kg of antioxidant benzotriazole, and 0.3 kg of dispersant PEG-4000.

[0033] The third layer: It only contains the mother liquor, which consists of 10 kg of water and mesoporous SiO 2 It is composed of 1 kg of nanoparticles, 0.8 kg of polystyrene-b-poly(2-vinylpyridine) micelles, 0.01 kg of photoinitiator Irgacure 2959, 0.01 kg of antioxidant benzotriazole, and 0.3 kg of dispersant PEG-4000.

[0034] Among them, mesoporous SiO 2 The preparation method of the nanoparticles is as follows: Step 1: Mix 100 g of template agent cetyltrimethyl-p-toluenesulfonate with 5 L of deionized water, add triethanolamine to adjust the pH to 9.5, and heat to 78 °C and stir until clear. Step 2: Dropwise add 229 g of tetraethyl orthosilicate at a rate of 0.5 ml / min. The molar ratio of cetyltrimethyl-p-toluenesulfonate to tetraethyl orthosilicate is 1:5. Keep the temperature at 300 rpm and stir for 2 h to obtain a white precipitate. Step 3: After filtration, washing, drying, and weighing, disperse the precipitate in an ethanol aqueous solution, add resorcinol and formaldehyde, stir for 10 h, and then filter and wash again. The mass ratio of resorcinol to the precipitate is 0.6:1, and the molar ratio of resorcinol to formaldehyde is 1:2. Under nitrogen protection, heat at a heating rate of 2 °C / min to 550 °C and calcine for 1.5 h to obtain mesoporous SiO 2 Nanoparticles; The obtained mesoporous SiO 2 The nanoparticles are subjected to dynamic light scattering, and the detected hydrodynamic diameter conforms to 50 - 200 nm. By nitrogen adsorption-desorption detection, its BET specific surface area > 500 m 2 / g, and the pore size distribution conforms to 3.2 - 7.6 nm.

[0035] The preparation method of the polystyrene-b-poly(2-vinylpyridine) micelles is as follows: Dissolve 1 g of polystyrene-b-poly(2-vinylpyridine) powder in a mixed solvent of 50 ml of THF and methanol with a volume ratio of 95:5. After ultrasonic treatment at 150 W for 20 min, perform evaporation treatment at 25 °C and a humidity ≤ 30% environment for 12 h to form a micelle film. After vacuum drying, polystyrene-b-poly(2-vinylpyridine) micelles are obtained, where the molecular weight of the polystyrene-b-poly(2-vinylpyridine) powder is 28000 g / mol.

[0036] Electrolyte preparation: Mix the mother liquor of the first-layer colloidal electrolyte raw material and the sulfuric acid solution, then perform ultrasonic dispersion, and then pour it into the battery not exceeding the top of the electrode group. Place it in a 15 °C water bath and perform a primary charge formation under ultraviolet light irradiation at 365 nm and 10 mW / cm 2 When the SOC reaches 95%, vacuum negative pressure is used to extract the free acid to obtain the first colloidal electrolyte; Mix the mother liquor of the second-layer colloidal electrolyte raw material and the sulfuric acid solution, then perform ultrasonic dispersion, and then pour it into the battery to cover the top of the electrode group and not exceed the bus bar. First, perform centrifugation at 8000×g for 10 min at 15 °C, and then perform centrifugation at 12000×g for 20 min. The centrifugal force during the above centrifugation process is perpendicular to the axis of the tubular battery. Then place it in a 15 °C water bath and perform a primary charge formation. Pulse ultraviolet irradiation is performed during the charging process, irradiating for 5 s and stopping for 10 s. When the SOC reaches 95%, vacuum negative pressure is used to extract the free acid to obtain the second colloidal electrolyte; Ultrasonically disperse the mother liquor of the third-layer colloidal electrolyte raw material, then pour it into the battery to cover the bus bar, and place it in a 45 °C water bath to perform a primary charge formation to obtain the third colloidal electrolyte.

[0037] Example 2 In this example, based on Example 1, the mesoporous SiO 2 nanoparticles are not treated with carbon coating. Specifically, in step three, after filtration and washing, directly heat it to 550 °C at a rate of 2 °C / min under nitrogen protection and perform calcination treatment for 1.5 h to obtain mesoporous SiO 2 nanoparticles.

[0038] The obtained mesoporous SiO 2 nanoparticles are subjected to dynamic light scattering, and the detected hydrodynamic diameter meets 50 - 200 nm. Nitrogen adsorption-desorption detection shows that its BET specific surface area > 500 m 2 / g, and the pore size distribution meets 3.2 - 7.6 nm.

[0039] Other conditions remain unchanged.

[0040] Example 3 On the basis of Example 1, this example does not perform centrifugation after the second layer perfusion. The specific steps are as follows: After mixing the mother liquor of the second layer colloidal electrolyte raw material and the sulfuric acid solution, ultrasonically disperse it, then pour it into the battery and cover the top of the electrode group, not exceeding the bus bar, and then place it in a 15°C water bath for a primary charge formation. During the charging process, perform pulsed ultraviolet irradiation, irradiate for 5 s and stop for 10 s. When the SOC reaches 95%, vacuum negative pressure is used to extract free acid to obtain the second colloidal electrolyte.

[0041] Other conditions remain unchanged.

[0042] Example 4 On the basis of Example 3, the mesoporous SiO 2 nanoparticles used in this example are not carbon-coated. Specifically, in step three, after filtration and washing, directly heat it to 550°C at a rate of 2°C / min under nitrogen protection and calcine for 1.5 h to obtain mesoporous SiO 2 nanoparticles.

[0043] The obtained mesoporous SiO 2 nanoparticles are subjected to dynamic light scattering, and the detected hydrodynamic diameter meets 50 - 200 nm. Nitrogen adsorption - desorption detection shows that its BET specific surface area > 500 m 2 / g, and the pore size distribution meets 3.2 - 7.6 nm.

[0044] Other conditions remain unchanged.

[0045] Comparative Example 1 This comparative example does not adopt a multi-layer electrolyte structure It only adopts the formula of the second layer electrolyte in Example 1.

[0046] The preparation method includes: After mixing the mother liquor of the second layer colloidal electrolyte raw material and the sulfuric acid solution, ultrasonically disperse it, then pour it into the battery until it covers the bus bar, place it in a 15°C water bath, and perform a primary charge formation under ultraviolet light irradiation at 365 nm and 10 mW / cm 2 When the SOC reaches 95%, vacuum negative pressure is used to extract free acid to obtain the electrolyte.

[0047] Comparative Example 2 This comparative example uses conventional gas-phase SiO 2 nanoparticles (average particle size 20 nm, specific surface area 220 m 2 / g) and adopts a uniform electrolyte structure.

[0048] Specifically, the electrolyte raw material is composed of a mother liquor and a sulfuric acid solution in a volume ratio of 1:1.5, wherein the mass concentration of the sulfuric acid solution is 45%, and the mother liquor is calculated by weight and consists of 10 kg of water, gas-phase SiO 2 The nanoparticles consisted of 2 kg, antioxidant benzotriazole 0.03 kg and dispersant PEG-4000 0.3 kg.

[0049] The preparation method comprises: The electrolyte raw materials are mixed and dispersed by ultrasound, then poured into the battery and cover the bus, placed in a 15°C water bath, and charged once. When the SOC reaches 95%, the free acid is extracted by vacuum negative pressure to obtain the electrolyte.

[0050] Comparative Example 3 This comparative example is based on Example 1, but uses an electrolyte raw material system without polystyrene-b-poly(2-vinylpyridine) micelles, and the polystyrene-b-poly(2-vinylpyridine) micelles in each layer are replaced with PEG-4000 in equal weight, while other conditions remain unchanged.

[0051] The different tubular colloidal batteries prepared by the above scheme were subjected to cycle tests and ion conductivity tests, wherein the cycle test was carried out in accordance with the standard of GB / T 22473-2008, the cycle test was carried out at 25°C with 1C charge and discharge, the cut-off voltage was 2.0V-2.4V, and the ion conductivity was measured using a four-electrode method.

[0052] The test results are shown in the following table:

[0053] Comparing the data of Example 1 with that of Comparative Example 1, it can be seen that the layered structure design has better adaptability to the plate expansion stress than the single-layer structure, greatly improves the cycle life of the battery, and is conducive to reducing the expansion of cracks. The layered structure uses low-acid mother liquid to seal the confluence, which greatly inhibits the oxidation of acid mist.

[0054] Comparison of the data of Example 1 and Example 2 shows that the mesoporous structure of the mesoporous silica after carbon coating is better protected, the acid etching rate is greatly reduced, and the compressive strength is greatly improved after the carbon coating structure is set. This should be due to the introduction of the carbon interface to form a mechanical interlocking.

[0055] Comparison of the data of Example 1 and Example 3 shows that the centrifugal treatment significantly reduces the colloid packing density deviation and the basic crack rate. At the same time, a more uniform gel network is conducive to reducing the ion migration resistance, thereby significantly improving the ion conductivity.

[0056] From the data comparison between Example 1 and Example 4, it can be seen that through the carbon coating treatment on the surface of silica, not only the acid etching problem of silica is significantly reduced, but also the carbon coating and micelles play a certain composite toughening effect, thus improving the compressive effect.

[0057] From the data comparison between Example 1 and Comparative Example 2, it can be seen that compared with conventional fumed silica, the mesoporous channels are beneficial to provide a directional transmission path, resulting in a huge improvement in the performance of ionic conductivity, and the acid storage capacity is also larger than that of conventional fumed silica.

[0058] From the data comparison between Example 1 and Comparative Example 3, it can be seen that after the micelles are missing, the dynamic cross-linking network formed by mesoporous silica and micelles is missing, the compressive strength drops significantly, and the ionic conductivity also drops significantly. This shows that after the micelles are protonated, they play a certain auxiliary role in the migration of ions, and the crack rate of the electrode plate also increases significantly, indicating that after the micelles are missing, the gel network cannot adapt to the expansion of the electrode plate during the cyclic charging process, thus resulting in stress concentration.

[0059] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A tubular battery with a non-uniform electrolyte, characterized in that: The invention comprises a first colloidal electrolyte, a second colloidal electrolyte and a third colloidal electrolyte, which are respectively distributed in the interior of the pole group, between the periphery of the pole group and the bus, and the area above the bus of the tubular battery. The first colloidal electrolyte, the second colloidal electrolyte and the third colloidal electrolyte all comprise a mother liquor, which comprises, by weight, 10 parts of water, 1.5-2.5 parts of mesoporous SiO2 nanoparticles, 0.8-1.2 parts of polystyrene-b-poly(2-vinylpyridine) micelles, 0.01-0.05 parts of photoinitiator, 0.01-0.05 parts of antioxidant and 0.3 parts of dispersant. The first colloidal electrolyte and the second colloidal electrolyte also comprise a sulfuric acid solution.

2. The tubular battery non-uniform electrolyte according to claim 1, characterized in that: The first colloidal electrolyte is composed of a mother liquor and a sulfuric acid solution in a volume ratio of 1:1.2, wherein the mass concentration of the sulfuric acid solution is 38%, and the mother liquor, calculated by weight, includes: 10 parts of water, 2-2.5 parts of mesoporous SiO2 nanoparticles, 1-1.2 parts of polystyrene-b-poly(2-vinylpyridine) micelles, 0.01-0.05 parts of photoinitiator, 0.01-0.05 parts of antioxidant and 0.3 parts of dispersant.

3. The tubular battery non-uniform electrolyte according to claim 1, characterized in that: The second colloidal electrolyte is composed of a mother liquor and a sulfuric acid solution in a volume ratio of 1:1.5, wherein the mass concentration of the sulfuric acid solution is 45%, and the mother liquor, calculated by weight, includes: 10 parts of water, 1.5-2 parts of mesoporous SiO2 nanoparticles, 0.8-1 parts of polystyrene-b-poly(2-vinylpyridine) micelles, 0.01-0.05 parts of photoinitiator, 0.01-0.05 parts of antioxidant and 0.3 parts of dispersant.

4. The tubular battery non-uniform electrolyte according to claim 1, characterized in that: The third colloidal electrolyte is composed of a mother liquid, which, calculated by weight, includes: 10 parts of water, 1 part of mesoporous SiO2 nanoparticles, 0.8 parts of polystyrene-b-poly(2-vinylpyridine) micelles, 0.01-0.05 parts of photoinitiator, 0.01-0.05 parts of antioxidant and 0.3 parts of dispersant.

5. The tubular battery non-uniform electrolyte according to claim 1, characterized in that: The preparation method of mesoporous SiO2 nanoparticles comprises: Step 1: Mix the template agent hexadecyltrimethylammonium p-toluenesulfonate with deionized water, adjust the pH to 9-10 with triethanolamine, heat to 75-85°C and stir until clear; Step 2: Add ethyl orthosilicate, keep warm and stir for 1.5-2.5 hours to obtain a white precipitate; Step 3, filtering, washing, and calcining at 500-600°C for 1-2h to obtain mesoporous SiO2 nanoparticles; The particle size of the obtained mesoporous SiO2 nanoparticles is 50-200 nm, and the pore size is 3.2-7.6 nm.

6. The tubular battery non-uniform electrolyte according to claim 5, characterized in that: In step three, after filtering and washing, and before calcining at 500-600° C. for 1-2 hours, the precipitate is dispersed in an ethanol aqueous solution, resorcinol and formaldehyde are added, stirred for 8-12 hours, and then filtered and washed again.

7. The tubular battery non-uniform electrolyte according to claim 1, characterized in that: The preparation method of polystyrene-b-poly(2-vinylpyridine) micelles comprises: 1 g of polystyrene-b-poly(2-vinylpyridine) powder was dissolved in 50 ml of a mixed solvent of THF and methanol in a volume ratio of 95:5, and subjected to 150 W ultrasonic treatment for 20 min. The mixture was volatilized for 12 h at 20-30° C. and a humidity of ≤30% to form a micelle film. The polystyrene-b-poly(2-vinylpyridine) micelle was obtained after vacuum drying, wherein the molecular weight of the polystyrene-b-poly(2-vinylpyridine) powder was 25000-30000 g / mol.

8. The tubular battery non-uniform electrolyte according to claim 1, characterized in that: The dispersant is PEG-4000, the photoinitiator is Irgacure 2959, and the antioxidant is benzotriazole.

9. The method for preparing a tubular battery non-uniform electrolyte according to any one of claims 1 to 8, characterized in that: The steps include: Step 1: Mix the mother liquor of the first colloidal electrolyte raw material and the sulfuric acid solution, disperse them by ultrasonication, and then pour them into the battery without exceeding the top of the pole group, place them in a 15-20°C water bath, and perform the first charge formation under ultraviolet light. When the SOC reaches 95%, vacuum negative pressure is used to extract the free acid to obtain the first colloidal electrolyte; Step 2: Mix the mother liquor of the second colloidal electrolyte raw material and the sulfuric acid solution, disperse them by ultrasonication, and then pour them into the battery to cover the top of the pole group, not exceeding the bus bar, place them in a 15-20°C water bath, perform the first charge formation, perform pulsed ultraviolet irradiation during the charge and discharge process, and when the SOC reaches 95%, extract the free acid by vacuum negative pressure to obtain the second colloidal electrolyte; Step 3: Ultrasonic disperse the mother liquor of the third colloidal electrolyte raw material, then pour it into the battery and cover the bus, place it in a 45-60° C. water bath, perform the first charge formation, and obtain the third colloidal electrolyte.

10. The preparation method according to claim 9, characterized in that: In step 2, after pouring into the battery and covering the top of the pole group, before water bath insulation, it also includes centrifugation at 8000×g for 10 minutes at 15-20°C, and then centrifugation at 12000×g for 20 minutes.

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