A shaped ring heterogeneous gel electrolyte, a preparation method thereof and an energy storage application thereof

Abstract

The application discloses a kind of polyenergizing ring heterogeneous gel electrolyte and its preparation method and energy storage application, preparation of polyenergizing ring heterogeneous gel electrolyte is carried out using step-by-step method, first preparation and adsorption of inner core gel are carried out, then inner core gel is placed in mould center, and solution for preparing outer ring is added dropwise in its periphery, finally polymerization is initiated, the preparation of outer ring gel and inner core and outer ring method composite are realized.The polyenergizing ring heterogeneous gel electrolyte of the application is used for zinc ion battery, and excellent electrochemical performance is shown, with significant application prospect and other functionalization potential.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of preparation of gel electrolyte, more particularly, relates to the preparation method and application of zinc ion battery electrode material and hydrogel electrolyte material. BACKGROUND

[0002] Zinc ion battery has the advantages of high safety, low cost, environmental friendliness, high charge / discharge rate and energy density, etc. With the rapid development of wearable and portable electronic devices in recent years, there is a greater demand for stable and efficient energy storage devices. However, the stability and reversibility of the commonly used zinc ion battery are poor, and the space utilization rate of the button cell is low, which needs to be further developed.

[0003] Hydrogel is a kind of gel-like substance with three-dimensional network structure, which is absorbed by water solution condensation. It has diverse crosslinking methods and special network structure. By designing the structure components, the hydrogel electrolyte shows the characteristics of quasi-solid-state electrolyte between liquid and solid, including: high ionic conductivity, excellent electrochemical performance, good adhesion, light texture with mechanical flexibility and tensile resistance. These advantages make hydrogel can be used as the electrolyte material of zinc ion battery. SUMMARY

[0004] The purpose of the present application is to overcome the shortcomings of the prior art, provide a poly-energy ring heterogeneous gel electrolyte and its preparation method and application in energy storage, realize its long cycle stability, high capacity and high rate recovery performance.

[0005] The technical purpose of the present application is realized by the following technical scheme.

[0006] A poly-energy ring heterogeneous gel electrolyte and its preparation method are carried out according to the following steps:

[0007] Step 1, preparing the inner core gel and soaking in the prepolymer solution of acrylamide monomer to adsorb acrylamide monomer in the inner core gel

[0008] The inner core gel is prepared by one of the following schemes: (1) polyethylene glycol monomethyl ether acrylate, an initiator and a cross-linking agent are uniformly dispersed in water and polymerization is initiated, wherein the molar ratio of polyethylene glycol monomethyl ether acrylate, the cross-linking agent and the initiator is 1: (0.01-0.02): (0.03-0.05); (2) acrylamide monomer, an initiator and a cross-linking agent are uniformly dispersed in water and polymerization is initiated, wherein the molar ratio of acrylamide monomer, the cross-linking agent and the initiator is 1: (0.004-0.00 6): (0.005-0.006); (3) uniformly dispersing excess basic zinc carbonate, 2-acrylamido-2-methyl-1-propane sulfonic acid, an initiator and a cross-linking agent in water, filtering after the basic zinc carbonate and 2-acrylamido-2-methyl-1-propane sulfonic acid react, and initiating polymerization on the filtrate, wherein the molar ratio of 2-acrylamido-2-methyl-1-propane sulfonic acid, the initiator and the cross-linking agent is 1: (0.004-0.005): (0.01-0.02);

[0009] The prepared inner core gel is then immersed in a prepolymer solution of acrylamide monomer, wherein the molar ratio of acrylamide monomer, N,N-methylenebisacrylamide and 2-ketoglutaric acid is 1:(0.004-0.006):(0.005-0.006);

[0010] In step 1, the initiator is 2-ketoglutaric acid and the cross-linking agent is N,N-methylenebisacrylamide.

[0011] In step 1, a square mold is used for polymerization, and 365 nm ultraviolet light is used for 10-30 minutes to carry out the polymerization reaction.

[0012] In step 1, basic zinc carbonate and 2-acrylamido-2-methyl-1-propanesulfonic acid are reacted and filtered. Since the 2-acrylamido-2-methyl-1-propanesulfonic acid needs to be completely converted into the corresponding zinc salt, the amount of basic zinc carbonate used is excessive relative to the 2-acrylamido-2-methyl-1-propanesulfonic acid.

[0013] In step 1, the number average molecular weight of polyethylene glycol monomethyl ether acrylate is 480-800.

[0014] In step 1, the soaking time is 20-24 hours, and the soaking temperature is 20-25 degrees Celsius.

[0015] In step 1, the soaked inner core gel is cut into discs with a diameter of 10 mm and used as the inner core.

[0016] Step 2, preparation of the outer ring reaction solution

[0017] The 1-vinyl-3-butyl imidazole chloride, initiator and catalyst are uniformly dispersed in water to form a yellow solution; the acrylamide monomer, N,N-methylene bisacrylamide and 2-ketoglutaric acid are uniformly dispersed in water, and the obtained solution and the yellow solution are uniformly mixed to obtain an outer ring reaction solution, wherein the molar ratio of the 1-vinyl-3-butyl imidazole chloride, initiator and catalyst in the yellow solution is 1:(0.004-0.006):(0.008-0.03); the acrylamide monomer, N,N-methylene bisacrylamide and 2-ketoglutaric acid are uniformly dispersed in water, and the molar ratio of the acrylamide monomer, N,N-methylene bisacrylamide and 2-ketoglutaric acid is 1:(0.005-0.01):(0.005-0.01); the molar ratio of the 1-vinyl-3-butyl imidazole chloride and acrylamide monomer is 1:(2-8), preferably 1:(2-6);

[0018] In step 2, the initiator is a photoinitiator such as ammonium persulfate; and the catalyst is tetramethyl ethylenediamine.

[0019] In step 2, the molar ratio of the 1-vinyl-3-butyl imidazole chloride, initiator and catalyst in the yellow solution is 1:(0.0043-0.005):(0.0085-0.025).

[0020] In step 2, the acrylamide monomer, N,N-methylene bisacrylamide and 2-ketoglutaric acid are uniformly dispersed in water, and the molar ratio of the acrylamide monomer, N,N-methylene bisacrylamide and 2-ketoglutaric acid is 1:

[0021] (0.005-0.008):(0.005-0.008).

[0022] Step 3, the inner core gel prepared in step 1 is arranged in the center of a circular mold, and the outer ring reaction solution obtained in step 2 is added to the gap between the inner core gel and the mold until the liquid surface is flush with the surface of the gel inner core; polymerization is initiated by light irradiation to perform the reaction; after the reaction is completed, the product is soaked in an electrolyte containing zinc sulfate and manganese sulfate to obtain a poly-energy ring heterogeneous gel electrolyte.

[0023] In step 3, the concentration of ZnSO4 in the electrolyte is 2 mol / L, the concentration of MnSO4 is 0.2 mol / L, the soaking temperature is room temperature 20-25 degrees Celsius, and the soaking time is 20-24 hours.

[0024] In step 3, the gel swells, and the inner core diameter increases from 10 mm to 12 mm, and a "poly-energy ring" heterogeneous gel electrolyte disc with a diameter of 16 mm is cut off for standby use.

[0025] In step 3, the ratio of the gel inner core to the outer ring in the radial direction is 3:1.

[0026] In step 3, 365 nm ultraviolet light was used for 15 min to carry out the reaction.

[0027] The energy-polymerizing ring heterogeneous gel electrolyte of the present invention is used in energy storage, such as zinc ion batteries.

[0028] α-MnO2, the active material, was mixed with conductive carbon black and a binder (PVDF) in a mass ratio of 7:2:1. The mixture was ground evenly in an agate mortar. After adding the dispersant NMP, the grinding continued until a viscous, uniform positive electrode slurry was formed. The slurry was then evenly applied to a carbon cloth fixed to a glass plate using a spatula. The mixture was dried at 60°C for 12 hours and cut into small discs with a diameter of 10 mm to serve as the battery cathode material. A 12 mm diameter piece of zinc foil was cut and the surface polished to remove the oxide layer to serve as the anode material.

[0029] An anode material, the energy-gathering ring heterogeneous gel electrolyte of the present invention, and a cathode material are assembled into a sandwich structure in a CR 2032 button battery to prepare a zinc ion gel battery.

[0030] Polyethylene glycol monomethyl ether acrylate (PEGMEA) is a water-soluble multifunctional active monomer, 1-vinyl-3-butylimidazolium chloride (VBIMCl) is a multifunctional water-soluble cationic active monomer, and acrylamide (AM) is also a water-soluble multifunctional active monomer. Carbon cloth is a flexible material with excellent chemical stability, water solubility, and good mechanical strength, making it an important material for the cathode substrate of zinc-ion batteries. The technical solution of the present invention builds on this foundation by enabling the preparation and application of a "polycyclic" gel electrolyte with an ionic conductivity of up to 37.0 mS / cm. The method is simple and uses inexpensive raw materials. The prepared "polycyclic" gel zinc-ion battery exhibits excellent electrochemical performance, with a discharge capacity of up to 253 mAh / g. After 200 cycles at 0.1C, the discharge capacity reaches 205 mAh / g, demonstrating highly stable and reversible battery chemistry. At a rate recovery of 0.1C, the discharge capacity returns to its initial level and gradually increases, demonstrating excellent resistance to high currents. The prepared "energy ring" gel symmetrical battery has a long cycle stability of 800h. The cationic chain segment can anchor sulfate groups, improving the stability of zinc ion deposition / stripping. The prepared device has significant application prospects and other functional potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the energy-gathering ring heterogeneous gel electrolyte and assembled button battery in the present invention.

[0032] Figure 2CV and full cell cycling performance of the polyenergized ring heterogel electrolyte-zinc ion battery of Example 1 of the present application at a scan rate of 1 mV / s.

[0033] Figure 3 SEM photo of the polyenergized ring heterogel electrolyte of Example 1 of the present application.

[0034] Figure 4 Current cycling performance of the gel Zn||Zn symmetric battery of Example 1 and Comparative Example 1 of the present application.

[0035] Figure 5 Mechanical tensile sample fracture and tensile curve of the polyenergized ring heterogel of the present application.

[0036] Figure 6 EIS spectrum and corresponding I-t curve of the Zn||Zn symmetric battery of Example 3 and Comparative Example 2 of the present application before and after polarization at an applied voltage of 10 mV.

[0037] Figure 7 Impedance and conductivity test results of the polyenergized ring heterogel electrolyte of the present application.

[0038] Figure 8 Electrochemical impedance spectrum of the polyenergized ring heterogel zinc ion battery of the present application.

[0039] Figure 9 Rate cycling performance of the polyenergized ring heterogel full battery of the present application. DETAILED DESCRIPTION

[0040] The present application will be further described below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are merely used to explain the present application and are not used to limit the present application.

[0041] Experimental raw materials used and manufacturers

[0042]

[0043]

[0044] Example 1 (inner core is PEGMEA-AM; outer ring is VBIM: AM = 1:6 molar ratio)

[0045] (1) 2.5 g of PEGMEA monomer, 0.025 g of initiator 2-ketoglutaric acid, and 0.008 g of crosslinking agent Bis were weighed using a balance and added to a beaker. 5 mL of deionized water was added to the beaker, and a magnetic stirrer was used to mix uniformly. The solution was injected into a square mold, and 365 nm ultraviolet light was used for irradiation for 15 min to obtain a square gel.

[0046] (2) Weigh 5.68 g of AM, 0.055 g of 2-ketoglutaric acid, and 0.0533 g of Bis on a balance, pour into a beaker, and inject 40 mL of deionized water, and stir uniformly with a magnetic stirrer. Put the square gel prepared in step (1) into the 2M AM solution, soak for 20 h, cut into a round piece with a diameter of 10 mm, and use as an inner core.

[0047] (3) Weigh 0.2489 g of VBIMCl monomer, 2 mL of water, 0.0013 g of APS initiator, and 5 μL of catalyst TEMED on a balance, mix uniformly, and heat at 75°C for 3 h to obtain a yellow solution.

[0048] (4) Weigh 0.568 g of AM monomer, 0.0057 g of 2-ketoglutaric acid, and 0.0062 g of Bis on a balance, pour into a beaker, and inject 2 mL of water, and stir uniformly with a magnetic stirrer. Mix the obtained solution with the yellow solution prepared in step (3) to obtain the solution prepared in step (4).

[0049] (5) Put the gel inner core obtained in step (2) into a circular mold with a diameter of 14 mm, and drop the solution obtained in step (4) into the gap between the gel and the mold until the liquid surface is flush with the gel surface, use 365 nm ultraviolet light for 15 min to carry out the reaction, and then soak the product in 60 mL of electrolyte containing 2M (2 mol / L) ZnSO4 and 0.2M (0.2 mol / L) MnSO4 for 20 h to obtain a hydrogel electrolyte. At this time, the gel swells, the inner core diameter increases from 10 mm to 12 mm, and a "poly-energetic ring" heterogeneous gel electrolyte round piece with a diameter of 16 mm is cut off using a cutter for standby.

[0050] (6) Mix α-MnO2 as an active material, conductive carbon black, and a binder (PVDF) in a mass ratio of 7:2:1 in a agate mortar, continue to grind after adding a dispersant NMP until a viscous and uniform positive electrode slurry is formed. Then, the slurry is uniformly coated on the carbon cloth fixed on a glass plate using a spatula, and dried at 60°C for 12 h. A small round piece with a diameter of 10 mm is cut off using a cutter as a battery cathode material.

[0051] (7) Cut off zinc foil with a diameter of 12 mm, polish the surface to remove the oxide layer as an anode material.

[0052] (8) Assemble the anode material, hydrogel electrolyte, and cathode material in a CR 2032 button cell in a sandwiched structure to prepare a zinc ion gel battery.

[0053] As Figure 1The prepared polyenergized ring heterogeneous gel electrolyte physical photos are shown, wherein a is Example 1, b is Example 3, c is Example 6, and d is a "polyenergized ring" heterogeneous gel zinc ion button cell assembly structure. The current zinc ion gel battery assembly method is to assemble the electrode material and hydrogel electrolyte into a sandwich structure, and coat the positive and negative electrode shells. The available space range in the positive and negative electrode shells is a circular range with a diameter of 16.5 mm, the zinc negative electrode used has a diameter of 12 mm, and the manganese dioxide positive electrode has a diameter of 10 mm. Therefore, a "polyenergized ring" heterogeneous gel electrolyte with an inner ring of 12-13 mm and an outer ring plus inner core diameter of 16 mm is prepared, which fully utilizes the internal space of the battery, and the gel inner core has a diameter of 12 mm (the same as the diameter of the zinc negative electrode), the outer ring has a diameter of 16 mm, and the ratio of the two in the radial direction is 3 (the gel inner core radius is 6 mm): 1 (the width of the outer ring in the radial direction is 2 mm). At the same time, the cationic monomer of the outer ring can anchor sulfate ions, improve the zinc ion migration rate, and increase the battery capacity.

[0054] As shown in Figure 2 , Figure 2 is the CV graph and full cell cycle characteristic graph of the polyenergized ring heterogeneous gel electrolyte-zinc ion battery of Example 1 of the present application at a scan rate of 1 mV / s, wherein a is the CV graph and b is the full cell cycle characteristic graph. Using the instrument Shanghai Chenhua CHI660E electrochemical workstation, the cyclic voltammetry curve of the "polyenergized ring" heterogeneous gel zinc ion battery of Example 1 was tested at a scan rate of 1 mV / s in a potential range of 1.0-1.8 V, and two pairs of redox peaks in the image can be clearly observed, corresponding to two-step reactions. In addition, the two CV curves remain basically unchanged, indicating that the "polyenergized ring" gel zinc ion battery has good reversibility. The "polyenergized ring" heterogeneous gel zinc ion full cell of Example 1 was tested for cyclic charge and discharge using a Shenzhen Xinwei CT-4008Tn-5 V10 / 20 / 50mA-164 high-performance battery detection system. Within 80 cycles, the battery capacity gradually increased and then remained stable, which can be attributed to the activation of the positive electrode and the gradual release of manganese elements from the carbon cloth. After 200 cycles, the specific capacity of the battery was 205 mAh / g, indicating its high reversibility in charge and discharge cycles.

[0055] As shown in Figure 3As shown, the SEM image of the "energy-gathering ring" heterogeneous gel electrolyte prepared in Example 1. The micromorphology of the "energy-gathering ring" heterogeneous gel was observed under 3.0kV conditions using a Japanese Hitachi field emission scanning electron microscope (S4800). Through the SEM image, a clear boundary line between the outer ring and the inner core of the energy-gathering ring can be observed. The inner core gel has a high cross-linking density, dense voids, a pore size of about 2μm, greater mechanical strength, and fibrous stripes at the cross section; the outer ring gel has a low cross-linking density, loose voids, a pore size of about 4μm, low mechanical strength, and a relatively flat cross section. This proves that the outer ring cationic segment is in close contact with the inner core, and the acrylamide contained in the two is cross-linked to form a penetrating network structure. There is no structural separation, forming an "energy-gathering ring" that can anchor sulfate anions, thereby improving the migration efficiency of zinc ions in the inner ring gel.

[0056] like Figure 4 As shown in the figure, the current cycling characteristics of the Zn||Zn symmetrical battery of Example 1 of the present invention and Comparative Example 1. Using Shenzhen Xinwei CT-4008Tn-5 V10 / 20 / 50mA-164 high-performance battery testing system, the "energy ring" heterogeneous gel Zn||Zn symmetrical battery was tested at 1.0mA / cm 2 Constant current cycling characteristics were tested under a fixed 1-hour discharge / charge cycle. Image analysis revealed that the symmetrical gel battery with the "energy-gathering ring" exhibited long-term cycling stability of 800 hours. However, the control battery without the "energy-gathering ring" deteriorated due to irregular Zn deposition on the negative electrode surface, remaining unstable for a long time during the test and completely losing stability after 450 hours. The cationic segments that make up the "energy-gathering ring" can anchor sulfate groups, improving the stability of zinc ion deposition and stripping, which has practical significance for practical applications.

[0057] Example 2 (the inner core is PEGMEA-AM; the outer ring is VBIM:AM with a molar ratio of 1:2)

[0058] (1) Weigh 2.5 g of PEG-MEA monomer, 0.025 g of 2-ketoglutaric acid, and 0.008 g of Bis using a balance and add them to a beaker. Pour 5 mL of deionized water into the beaker and mix thoroughly using a magnetic stirrer. Pour the solution into a square mold and irradiate with 365 nm UV light for 15 min to obtain a square gel.

[0059] (2) Weigh 5.68 g AM, 0.055 g 2-ketoglutaric acid, and 0.0533 g Bis using a balance and place them in a beaker. Add 40 mL of deionized water and stir evenly with a magnetic stirrer. Place the square gel prepared in step (1) in the 2 M AM solution and soak for 20 h. Cut it into 10 mm diameter discs to serve as the inner core.

[0060] (3) 0.7467 g of VBIMCl monomer, 2 ml of water, 0.0037 g of APS initiator, and 5 μL of TEMED catalyst were weighed on a balance, mixed well, and heated at 75°C for 3 h to obtain a yellow solution.

[0061] (4) Using a balance, weigh 0.568 g of AM monomer, 0.0057 g of 2-ketoglutaric acid, and 0.0062 g of Bis(II) into a beaker. Add 2 ml of water and stir evenly with a magnetic stirrer. The resulting solution is mixed evenly with the yellow solution prepared in step (3) to obtain the solution prepared in step (4).

[0062] (5) The gel core obtained in step (2) was placed in the center of a circular mold with a diameter of 14 mm. The solution obtained in step (4) was added dropwise to the gap between the gel and the mold until the liquid level was flush with the gel surface. The product was irradiated with 365 nm ultraviolet light for 15 minutes to react. The product was then immersed in 60 mL of an electrolyte solution containing 2 M ZnSO4 and 0.2 M MnSO4 for 20 hours to obtain a hydrogel electrolyte. At this time, the gel swelled and the diameter of the core increased from 10 mm to 12 mm. A cutter was used to cut a 16 mm diameter "energy-gathering ring" heterogeneous gel electrolyte disc for use.

[0063] (6) α-MnO2 as the active material was mixed with conductive carbon black and a binder (PVDF) in a mass ratio of 7:2:1. The mixture was ground evenly in an agate mortar. After adding the dispersant NMP, the grinding was continued until a viscous and uniform positive electrode slurry was formed. The slurry was then evenly applied to a carbon cloth fixed to a glass plate using a spatula, dried at 60°C for 12 hours, and cut into small discs with a diameter of 10 mm using a cutter to serve as the battery cathode material.

[0064] (7) Cut a zinc foil with a diameter of 12 mm and polish the surface to remove the oxide layer to use as the anode material.

[0065] (8) The anode material, hydrogel electrolyte, and cathode material are assembled into a sandwich structure in a CR 2032 button battery to prepare a zinc ion gel battery.

[0066] This example attempts to further enhance electrochemical performance by increasing the amount of VBIMCl added during the preparation of the "energy-gathering ring" outer ring hydrogel electrolyte, thereby increasing the concentration of cationic monomers in the electrolyte. However, the actual electrochemical performance did not change much, and even slightly decreased.

[0067] Example 3 (Inner core is AM-AM; outer ring is VBIM:AM=1:4 molar ratio)

[0068] (1) A balance was used to weigh 0.426 g of AM monomer, 0.004 g of 2-ketoglutaric acid, and 0.0037 g of Bis into a beaker, 3 mL of deionized water was injected into the beaker, and the mixture was mixed uniformly using a magnetic stirrer. The solution was injected into a square mold, and square gel was obtained by irradiating with ultraviolet light for 15 min.

[0069] (2) A balance was used to weigh 5.33 g of AM, 0.055 g of 2-ketoglutaric acid, and 0.0533 g of Bis into a beaker, 40 mL of deionized water was injected into the beaker, and the mixture was mixed uniformly using a magnetic stirrer. The square gel prepared in step (1) was placed in the prepared solution, and after soaking for 20 h, it was cut into a circular piece with a diameter of 10 mm as an inner core for later use.

[0070] (3) A balance was used to weigh 0.2489 g of VBIMCl monomer, 2 mL of water, 0.0013 g of APS initiator, and 5 μL of catalyst TEMED, and the mixture was heated at 75°C for 3 h to obtain a yellow solution.

[0071] (4) A balance was used to weigh 0.568 g of AM monomer, 0.0057 g of 2-ketoglutaric acid, and 0.0062 g of Bis into a beaker, 2 mL of water was injected into the beaker, and the mixture was mixed uniformly using a magnetic stirrer. The resulting solution was mixed uniformly with the yellow solution prepared in step (3) to obtain the solution prepared in step (4).

[0072] (5) The gel inner core obtained in step (2) was placed in the center of a circular mold with a diameter of 14 mm, and the solution obtained in step (4) was added dropwise to the gap between the gel and the mold until the liquid surface was flush with the gel surface, and 365 nm ultraviolet light was used for 15 min to react, after which the product was soaked in 60 mL of electrolyte containing 2M ZnSO4 and 0.2M MnSO4 for 20 h to obtain a hydrogel electrolyte. At this time, the gel swelled, and the inner core diameter increased from 10 mm to 12 mm, and a "poly-energetic ring" heterogeneous gel electrolyte circular piece with a diameter of 16 mm was cut off using a cutter for later use.

[0073] (6) α-MnO2 was mixed with conductive carbon black and binder (PVDF) in a mass ratio of 7:2:1 as an active material, and the mixture was ground uniformly in an agate mortar. After adding the dispersant NMP, the mixture was ground until a thick and uniform positive electrode slurry was formed. The slurry was then evenly spread on the carbon cloth fixed on a glass plate using a spatula, and dried at 60°C for 12 h. The cathode material was cut into small circular pieces with a diameter of 10 mm using a cutter.

[0074] (7) Zinc foil with a diameter of 12 mm was cut and polished to remove the oxide layer as an anode material.

[0075] (8) The anode material, hydrogel electrolyte, and cathode material were assembled into a sandwich structure in a CR 2032 button cell to prepare a zinc ion gel battery.

[0076] Example 4 (Inner core: AM-AM; outer ring: VBIM: AM = 1:6 molar ratio)

[0077] (1) A balance was used to weigh 0.426 g of AM monomer, 0.004 g of 2-ketoglutaric acid, and 0.0037 g of Bis into a beaker, 3 mL of deionized water was injected into the beaker, and the mixture was mixed uniformly using a magnetic stirrer. The solution was injected into a square mold, and UV light was used for 15 min to obtain a square gel.

[0078] (2) A balance was used to weigh 5.33 g of AM, 0.055 g of 2-ketoglutaric acid, and 0.0533 g of Bis into a beaker, 40 mL of deionized water was injected into the beaker, and the mixture was mixed uniformly using a magnetic stirrer. The square gel prepared in step (1) was placed into the prepared solution, soaked for 20 h, and then cut into a circular piece with a diameter of 10 mm as an inner core for later use.

[0079] (3) A balance was used to weigh 0.3737 g of VBIMCl monomer, 2 mL of water, 0.0018 g of APS initiator, and 5 μL of catalyst TEMED, and the mixture was heated at 75°C for 3 h to obtain a yellow solution.

[0080] (4) A balance was used to weigh 0.568 g of AM monomer, 0.0057 g of 2-ketoglutaric acid, and 0.0062 g of Bis into a beaker, 2 mL of water was injected into the beaker, and the mixture was mixed uniformly using a magnetic stirrer. The resulting solution was mixed uniformly with the yellow solution prepared in step (3) to obtain the solution prepared in step (4).

[0081] (5) The gel inner core obtained in step (2) was placed in the center of a circular mold with a diameter of 14 mm, and the solution obtained in step (4) was added dropwise to the gap between the gel and the mold until the liquid surface was flush with the gel surface, and UV light was used for 15 min to perform the reaction. Then the product was soaked in 60 mL of electrolyte containing 2M ZnSO4 and 0.2M MnSO4 for 20 h to obtain a hydrogel electrolyte. At this time, the gel swelled, and the inner core diameter increased from 10 mm to 12 mm. A "poly-energetic ring" heterogeneous gel electrolyte circular piece with a diameter of 16 mm was cut using a cutter for later use.

[0082] (6) α-MnO2 was mixed with conductive carbon black and binder (PVDF) in a mass ratio of 7:2:1 as an active material, and the mixture was ground uniformly in an agate mortar. After adding a dispersant NMP, the mixture was further ground until a viscous and uniform positive electrode slurry was formed. The slurry was then uniformly spread on a carbon cloth fixed on a glass plate using a spatula, and dried at 60°C for 12 h. The carbon cloth was cut into small circular pieces with a diameter of 10 mm as a cathode material for a battery.

[0083] (7) Zinc foil with a diameter of 12 mm was cut and polished to remove the oxide layer on the surface as an anode material.

[0084] (8) The anode material, hydrogel electrolyte, cathode material were assembled into a sandwich structure in CR 2032 button cell, and a zinc ion gel battery was prepared.

[0085] Example 5 (inner core: AMPS-AM; outer ring: VBIM: AM = 1:4 molar ratio)

[0086] (1) 3.0195 g (excess) basic zinc carbonate, 10.36 g AMPS (0.05 mol), 0.0365 g ketoglutaric acid (0.25 mmol), and 0.077 g Bis (0.5 mmol) were weighed with a balance and placed in a beaker, 25 ml of water was injected, and they were mixed uniformly with a magnetic stirrer. After 10 min of sufficient reaction, the filtrate was filtered and injected into a square mold, and a square gel was obtained by irradiating with ultraviolet light for 15 min.

[0087] (2) 10.65 g AM, 0.1065 g ketoglutaric acid, and 0.1155 g Bis were weighed with a balance and placed in a beaker, 50 mL of deionized water was injected, and they were stirred uniformly with a magnetic stirrer. The gel prepared in step (1) was taken out and immersed in the prepared solution for 20 h, and a circular piece with a diameter of 10 mm was cut as an inner ring for standby.

[0088] (3) 0.3737 g VBIMCl monomer, 2 ml water, 0.0018 g APS initiator, and 5 μL catalyst TEMED were weighed with a balance and mixed uniformly, and then heated at 75°C for 3 h to obtain a yellow solution.

[0089] (4) 0.568 g AM monomer, 0.0057 g 2-ketoglutaric acid, and 0.0062 g Bis were weighed with a balance and placed in a beaker, 2 ml of water was injected, and they were stirred uniformly with a magnetic stirrer. The solution prepared in step (4) was mixed uniformly with the yellow solution prepared in step (3).

[0090] (5) The inner core of the gel obtained in step (2) was placed in the center of a circular mold with a diameter of 16 mm, and the solution obtained in step (4) was added dropwise to the gap between the gel and the mold until the liquid surface was flush with the gel surface, and then irradiated with ultraviolet light for 15 min. The hydrogel electrolyte was obtained by soaking in 60 mL of electrolyte containing 2M ZnSO4 and 0.2M MnSO4 for 20 h. At this time, the gel swelled, the inner core diameter increased from 10 mm to 12 mm, and a "poly-energetic ring" heterogeneous gel electrolyte circular piece with a diameter of 16 mm was cut with a cutter for standby.

[0091] (6) α-MnO2 as the active material was mixed with conductive carbon black and a binder (PVDF) in a mass ratio of 7:2:1. The mixture was ground evenly in an agate mortar. After adding the dispersant NMP, the grinding was continued until a viscous and uniform positive electrode slurry was formed. The slurry was then evenly applied to a carbon cloth fixed to a glass plate using a spatula, dried at 60°C for 12 hours, and cut into small discs with a diameter of 10 mm using a cutter to serve as the battery cathode material.

[0092] (7) Cut a zinc foil with a diameter of 12 mm and polish the surface to remove the oxide layer to use as the anode material.

[0093] (8) The anode material, the "energy-gathering ring" heterogeneous gel electrolyte, and the cathode material were assembled into a sandwich structure in a CR 2032 button battery to prepare a zinc ion gel battery.

[0094] Example 6 (Inner core is AMPS-AM; outer ring is VBIM:AM=1:8 molar ratio)

[0095] (1) Use a balance to weigh 3.0195 g (excess) basic zinc carbonate, 10.36 g AMPS (0.05 mol), 0.0365 g ketoglutaric acid (0.25 mmol), and 0.077 g Bis (0.5 mmol) into a beaker. Pour in 25 ml of water and mix well using a magnetic stirrer. After fully reacting for 10 min, filter and inject the filtrate into a square mold. Irradiate with ultraviolet light for 15 min to obtain a square gel.

[0096] (2) Weigh 10.65 g AM, 0.1065 g ketoglutaric acid, and 0.1155 g Bis using a balance and place them in a beaker. Add 50 mL of deionized water and stir evenly with a magnetic stirrer. Remove the gel prepared in step (1) and place it in the prepared solution. Soak for 20 hours and cut into 10 mm diameter discs for use as inner cores.

[0097] (3) 0.1869 g of VBIMCl monomer, 2 ml of water, 0.0011 g of APS initiator, and 5 μL of TEMED catalyst were weighed on a balance, mixed well, and heated at 75°C for 3 h to obtain a yellow solution.

[0098] (4) Weigh 0.568 g of AM monomer, 0.0057 g of 2-ketoglutaric acid, and 0.0062 g of Bis using a balance and place them in a beaker. Add 2 ml of water and stir with a magnetic stirrer. Mix the solution obtained in step (4) with the yellow solution prepared in step (3) until uniform.

[0099] (5) The inner ring of gel obtained in step (2) was placed in the center of a circular mold with a diameter of 16 mm. The solution obtained in step (4) was added dropwise to the gap between the gel and the mold until the liquid level was flush with the gel surface. The gel was exposed to ultraviolet light for 15 minutes and then immersed in 60 mL of an electrolyte solution containing 2 M ZnSO4 and 0.2 M MnSO4 for 20 hours to obtain a hydrogel electrolyte. At this time, the gel swelled and the inner core diameter increased from 10 mm to 12 mm. A cutter was used to cut a 16 mm diameter "energy-gathering ring" heterogeneous gel electrolyte disc for later use.

[0100] (6) α-MnO2 as the active material was mixed with conductive carbon black and a binder (PVDF) in a mass ratio of 7:2:1. The mixture was ground evenly in an agate mortar. After adding the dispersant NMP, the grinding was continued until a viscous and uniform positive electrode slurry was formed. The slurry was then evenly applied to a carbon cloth fixed to a glass plate using a spatula, dried at 60°C for 12 hours, and cut into small discs with a diameter of 10 mm using a cutter to serve as the battery cathode material.

[0101] (7) Cut a zinc foil with a diameter of 12 mm and polish the surface to remove the oxide layer to use as the anode material.

[0102] (8) The anode material, the "energy-gathering ring" heterogeneous gel electrolyte, and the cathode material were assembled into a sandwich structure in a CR 2032 button battery to prepare a zinc ion gel battery.

[0103] Comparative Example 1 (PEGMEA-AM core)

[0104] (1) Weigh 2.5 g of PEGMEA monomer, 0.025 g of 2-ketoglutaric acid, and 0.008 g of Bis using a balance and add them to a beaker. Pour 5 mL of deionized water into the beaker and mix thoroughly using a magnetic stirrer. Pour the solution into a square mold and irradiate with 365 nm UV light for 15 min to obtain a square gel.

[0105] (2) Using a balance, weigh 5.68 g AM, 0.055 g 2-oxoglutaric acid, and 0.0125 g Bis into a beaker. Add 40 mL of deionized water and stir evenly with a magnetic stirrer. Remove the gel prepared in step (1) and place it in a 2 M AM solution. Soak for 20 h and cut into 14 mm diameter discs.

[0106] (3) The gel obtained in step (2) was irradiated with 365 nm ultraviolet light for 15 min to react, and then immersed in 60 mL of an electrolyte solution containing 2 M ZnSO4 and 0.2 M MnSO4 for 20 h to obtain a hydrogel electrolyte.

[0107] (4) α-MnO2 as the active material was mixed with conductive carbon black and a binder (PVDF) in a mass ratio of 7:2:1. The mixture was ground evenly in an agate mortar. After adding the dispersant NMP, the grinding was continued until a viscous and uniform positive electrode slurry was formed. The slurry was then evenly applied to a carbon cloth fixed to a glass plate using a spatula, dried at 60°C for 12 hours, and cut into small discs with a diameter of 10 mm using a cutter to serve as the battery cathode material.

[0108] (5) Cut a zinc foil with a diameter of 12 mm and grind the surface to remove the oxide layer to use as the anode material.

[0109] (6) The anode material, hydrogel electrolyte, and cathode material are assembled into a sandwich structure in a CR 2032 button battery to prepare a zinc ion gel battery.

[0110] In Comparative Example 1, the outer ring of the "energy-gathering ring" heterogeneous gel electrolyte is removed, which reduces its ionic conductivity by an order of magnitude, resulting in little practical application significance.

[0111] By adjusting the process parameters according to the content of the present invention, the "energy-gathering ring" heterogeneous gel electrolyte of the present invention can be prepared, and the performance is basically the same as that of Example 1.

[0112] Comparative Example 2 (AM-AM inner core)

[0113] (1) Weigh 0.426 g of AM monomer, 0.004 g of 2-ketoglutaric acid, and 0.0037 g of Bis using a balance and add them to a beaker. Pour 3 mL of deionized water into the beaker and mix thoroughly using a magnetic stirrer. Pour the solution into a square mold and irradiate with UV light for 15 min to obtain a square gel.

[0114] (2) Weigh 5.33 g AM, 0.055 g 2-oxoglutaric acid, and 0.0533 g Bis using a balance and place them in a beaker. Add 40 mL of deionized water and stir evenly with a magnetic stirrer. Remove the gel prepared in step (1) and place it in the prepared solution. Soak for 20 h and cut into 14 mm diameter discs.

[0115] (3) The gel obtained in step (2) was irradiated with 365 nm ultraviolet light for 15 min to react, and then immersed in 60 mL of an electrolyte solution containing 2 M ZnSO4 and 0.2 M MnSO4 for 20 h to obtain a hydrogel electrolyte.

[0116] (4) α-MnO2 as the active material was mixed with conductive carbon black and a binder (PVDF) in a mass ratio of 7:2:1. The mixture was ground evenly in an agate mortar. After adding the dispersant NMP, the grinding was continued until a viscous and uniform positive electrode slurry was formed. The slurry was then evenly applied to a carbon cloth fixed to a glass plate using a spatula, dried at 60°C for 12 hours, and cut into small discs with a diameter of 10 mm using a cutter to serve as the battery cathode material.

[0117] (5) Cut a zinc foil with a diameter of 12 mm and grind the surface to remove the oxide layer to use as the anode material.

[0118] (6) The anode material, hydrogel electrolyte, and cathode material are assembled into a sandwich structure in a CR 2032 button battery to prepare a zinc ion gel battery.

[0119] In Comparative Example 2, the outer ring of the "energy-gathering ring" heterogeneous gel electrolyte is removed, which reduces its ionic conductivity by an order of magnitude, resulting in little practical application significance.

[0120] By adjusting the process parameters according to the content of the present invention, the "energy-gathering ring" gel electrolyte of the present invention can be prepared, and the performance is basically the same as that of Example 3.

[0121] Comparative Example 3 (AMPS-AM core)

[0122] (1) Use a balance to weigh 3.0195 g (excess) basic zinc carbonate, 10.36 g AMPS (0.05 mol), 0.0365 g ketoglutaric acid (0.25 mmol), and 0.077 g Bis (0.5 mmol) into a beaker. Pour in 25 ml of water and mix well using a magnetic stirrer. After fully reacting for 10 min, filter and inject the filtrate into a square mold. Irradiate with ultraviolet light for 15 min to obtain a square gel.

[0123] (2) Weigh 10.65 g AM, 0.1065 g ketoglutaric acid, and 0.1155 g Bis using a balance and place in a beaker. Add 50 mL of deionized water and stir evenly with a magnetic stirrer. Remove the gel prepared in step (1) and place in the prepared solution. Soak for 20 h and cut into 10 mm diameter discs for use as inner cores.

[0124] (3) The gel obtained in step (2) was irradiated with 365 nm ultraviolet light for 15 min and immersed in 60 mL of an electrolyte solution containing 2 M ZnSO4 and 0.2 M NSO4 for 20 h to obtain a hydrogel electrolyte.

[0125] (4) The α-MnO2 as active material was mixed with conductive carbon black and binder (PVDF) in a mass ratio of 7:2:1, and ground uniformly in a marble mortar. After adding the dispersing agent NMP, the grinding was continued until a thick and uniform positive electrode slurry was formed. The slurry was then uniformly coated on the carbon cloth fixed on a glass plate using a doctor blade, and dried at 60°C for 12h. The carbon cloth was cut into small discs with a diameter of 10mm using a cutter, and used as the cathode material of the battery.

[0126] (5) Zinc foil with a diameter of 12mm was cut and polished to remove the oxide layer on the surface as the anode material.

[0127] (6) The anode material, hydrogel electrolyte, and cathode material were assembled into a sandwich structure in a CR 2032 button cell to prepare a zinc ion gel battery.

[0128] The outer ring of the "poly-energy ring" heterogeneous gel electrolyte was removed in the comparative example 3, which reduced the ionic conductivity and made it less useful in practical applications.

[0129] The process parameters were adjusted according to the content of the application, and the "poly-energy ring" gel electrolyte of the application could be prepared, which showed basically the same performance as example 5.

[0130] The dumbbell-shaped "poly-energy ring" heterogeneous gel sample was tested by a microcomputer-controlled electronic universal testing machine. As shown in Figure 5 The gel fracture position was not at the junction of the inner core and the outer ring, and the gel elongation at break was about 100% according to the stress-strain curve. This showed that the acrylamide of the outer ring and the inner core was crosslinked, which connected the two networks and had good mechanical properties.

[0131] The EIS spectrum and the corresponding I-t curve of the Zn||Zn symmetric cell before and after polarization of the "poly-energy ring" heterogeneous gel electrolyte under an applied voltage of 10mV were tested using the instrument Shanghai Chenhua CHI660E electrochemical workstation, as shown in Figure 6 a corresponds to comparative example 2, and b corresponds to example 3. The Zn 2+ migration number of the "poly-energy ring" heterogeneous gel electrolyte of comparative example 2 and example 3 was calculated to be 0.51 and 0.76, respectively. The improvement of zinc ion mobility in example 3 could be attributed to the local swing of the polycation chain, which promoted the rapid migration of zinc ions by restricting the movement of sulfate radicals.

[0132] The impedance of the "poly-energy ring" heterogeneous gel electrolyte was tested using the instrument Shanghai Chenhua CHI660E electrochemical workstation, and the conductivity was calculated. The results are shown in Figure 7As shown, a corresponds to the impedance of Example 1 and Examples 1 and 2, b corresponds to the impedance of Example 2 and Examples 3 and 4, c corresponds to the impedance of Example 3 and Examples 5 and 6, and d corresponds to the conductivity of Examples 1-6 and Comparative Examples 1-3. By comparison, it can be seen that the ionic conductivity of the embodiments is higher than that of the comparative examples. In Examples 1 and 2 and Examples 3 and 4, when the outer ring VBIMCl:AM=1:6, the ionic conductivity of the polyenergetic ring heterogeneous gel electrolyte is higher. In Examples 5 and 6, when the outer ring VBIMCl:AM=1:8, the ionic conductivity of the polyenergetic ring heterogeneous gel electrolyte is higher. This shows that the polycation chain in the polyenergetic ring fully plays the role of anchoring anions, reducing the electrochemical impedance and improving the ionic conductivity.

[0133] The EIS electrochemical impedance spectroscopy test of the "energy ring" heterogeneous gel zinc ion full battery was performed using the Shanghai Chenhua CHI660E electrochemical workstation. Figure 8 As shown, a corresponds to the electrochemical impedance spectra of comparative example 1 and embodiment 1, b corresponds to the electrochemical impedance spectra of comparative example 2 and embodiment 3, and c corresponds to the electrochemical impedance spectra of comparative example 3 and embodiment 6. In the Nyquist plot of the "energy-gathering ring" gel zinc-ion battery, the semicircle in the high-frequency region is attributed to charge transfer, and the low-frequency region is approximately a straight line, which is controlled by diffusion behavior. Examples 1, 3, and 6 show smaller semicircle diameters, indicating that the electron transfer behavior in the "energy-gathering ring" gel and on the electrode is faster; the slope of the Warburg impedance corresponding to Example 3 is higher than that of comparative example 2, indicating that Zn 2+ The diffusion of Zn is very rapid, which can maintain a compatible electrode / electrolyte interface. The cationic segments in the energy-gathering ring anchor the sulfate in the electrolyte, promoting the 2+ The rapid diffusion and migration of the electrodes helps maintain the rate performance of the battery.

[0134] Shenzhen Xinwei CT-4008Tn-5 V10 / 20 / 50mA-164 high-performance battery testing system was used to test the discharge / charge curves at different current densities and plot the battery's cycle performance at the rate. Figure 9 As shown, a corresponds to the rate characteristics of Example 1 and Examples 1 and 2, b corresponds to the rate characteristics of Example 2 and Examples 3 and 4, and c corresponds to the rate characteristics of Example 3 and Examples 5 and 6. The image comparison shows that the electrolyte of the embodiment "energy ring" has excellent rate cycling performance. In the energy ring, thanks to the polyVB1M chain segment to SO4 2- Good anchoring effect and unique structural design, Zn 2+The migration of the anode is more rapid, the reaction efficiency of the positive electrode is improved, the discharge specific capacity is larger, and the ability to resist large current is optimal. When returning to a low current density of 0.1C or 0.1A / g, the discharge specific capacity is again restored to the initial level or gradually increases, indicating that the "energy ring" gel zinc ion battery has highly stable and reversible battery chemical properties.

[0135] According to the adjustment of the process parameters according to the content of the present application, the preparation of the poly-energetic ring heterogeneous gel electrolyte in the present application can be realized, which shows basically consistent performance with the present application. The above has exemplarily described the present application, and it should be indicated that, without departing from the core of the present application, any simple transformation, modification or other equivalent replacement which can not cost the creative labor of the person skilled in the art falls into the protection scope of the present application.

Claims

1. A method for preparing a polycyclic heterogeneous gel electrolyte, characterized in that: Follow the steps below: Step 1: prepare the inner core gel and soak it in the prepolymer solution of acrylamide monomer to absorb the acrylamide monomer in the inner core gel The core gel was prepared by one of the following schemes: (1) polyethylene glycol monomethyl ether acrylate, initiator and cross-linking agent were uniformly dispersed in water and polymerization was initiated, and the molar ratio of polyethylene glycol monomethyl ether acrylate, cross-linking agent and initiator was 1: (0.01-0.02): (0.03-0.05); (2) acrylamide monomer, initiator and cross-linking agent were uniformly dispersed in water and polymerization was initiated, and the molar ratio of acrylamide monomer, cross-linking agent and initiator was 1: (0.004-0.00 6): (0.005-0.006); (3) uniformly dispersing excess basic zinc carbonate, 2-acrylamido-2-methyl-1-propane sulfonic acid, an initiator and a cross-linking agent in water, filtering after the basic zinc carbonate and 2-acrylamido-2-methyl-1-propane sulfonic acid react, and initiating polymerization of the filtrate, wherein the molar ratio of 2-acrylamido-2-methyl-1-propane sulfonic acid, the initiator and the cross-linking agent is 1: (0.004-0.005): (0.01-0.02); Then, the prepared inner core gel is placed in the prepolymer solution of acrylamide monomer for soaking. In the prepolymer solution of acrylamide monomer, acrylamide monomer, N , N -The molar ratio of methylenebisacrylamide and 2-ketoglutaric acid is 1:(0.004-0.006):(0.005-0.006); Step 2, preparation of the outer ring reaction solution 1-vinyl-3-butyl imidazole chloride, initiator and catalyst are uniformly dispersed in water to form a yellow solution; acrylamide monomer, N , N -methylenebisacrylamide and 2-ketoglutaric acid are uniformly dispersed in water, and the resulting solution is evenly mixed with the yellow solution to obtain an outer ring reaction solution, wherein in the yellow solution, the molar ratio of 1-vinyl-3-butylimidazole chloride, initiator and catalyst is 1: (0.004-0.006): (0.008-0.03); acrylamide monomer, N , N -Methylenebisacrylamide and 2-ketoglutaric acid are uniformly dispersed in water, acrylamide monomer, N , N -The molar ratio of methylenebisacrylamide and 2-ketoglutaric acid is 1:(0.005-0.01):(0.005-0.01); the molar ratio of 1-vinyl-3-butylimidazole chloride and acrylamide monomer is 1:(2-8); Step 3: Place the inner core gel prepared in step 1 at the center of a circular mold, and add the outer ring reaction liquid obtained in step 2 into the gap between the inner core gel and the mold until the liquid surface is flush with the surface of the gel inner core; initiate polymerization by light to carry out the reaction; after the reaction is completed, soak the product in an electrolyte containing zinc sulfate and manganese sulfate to obtain a poly-energy ring heterogeneous gel electrolyte.

2. The method for preparing a polycyclic heterogeneous gel electrolyte according to claim 1, characterized in that: In step 1, the initiator is 2-ketoglutaric acid and the cross-linking agent is N , N -Methylene bisacrylamide, polymerized using a square mold, irradiated with 365nm ultraviolet light for 10-30 minutes to carry out the polymerization reaction; the number average molecular weight of polyethylene glycol monomethyl ether acrylate is 480-800, the immersion time is 20-24 hours, and the immersion temperature is 20-25 degrees Celsius.

3. The method for preparing a polycyclic heterogeneous gel electrolyte according to claim 1, characterized in that: In step 2, the initiator is a photoinitiator, such as ammonium persulfate; the catalyst is tetramethylethylenediamine; in the yellow solution, the molar ratio of 1-vinyl-3-butylimidazole chloride, the initiator and the catalyst is 1: (0.0043-0.005): (0.0085-0.025); the acrylamide monomer, N , N -Methylenebisacrylamide and 2-ketoglutaric acid are uniformly dispersed in water, acrylamide monomer, N , N The molar ratio of methylenebisacrylamide and 2-ketoglutaric acid is 1:(0.005-0.008):(0.005-0.008).

4. The method for preparing a polycyclic heterogeneous gel electrolyte according to claim 1, characterized in that: In step 3, in the electrolyte, the concentration of ZnSO4 is 2 mol / L, the concentration of MnSO4 is 0.2 mol / L, the immersion temperature is room temperature 20-25 degrees Celsius, and the immersion time is 20-24 hours; 365 nm ultraviolet light is used for 15 minutes to carry out the reaction; the radial ratio of the gel inner core and the outer ring is 3:

1.

5. The poly-energy ring heterogeneous gel electrolyte obtained by the preparation method according to any one of claims 1 to 4.

6. Application of the energy-polymerizing ring heterogeneous gel electrolyte as claimed in claim 5 in energy storage.

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