Intrinsic stretchable polymer electrolyte and preparation method and application thereof

Abstract

This application discloses an intrinsically stretchable polymer electrolyte, its preparation method, and its applications. The intrinsically stretchable polymer electrolyte is self-polymerized at room temperature in a system containing an electrolyte salt from a zwitterionic monomer, without the need for heating or the introduction of an additional initiator. The electrolyte obtained in this application possesses advantages such as stretchability, excellent adhesion, good resilience, and high room temperature ionic conductivity. As a key component of stretchable energy storage devices, this electrolyte can be applied to flexible energy storage devices such as zinc-ion batteries, lithium-ion batteries, and supercapacitors, effectively improving the reliability and maintainability of energy storage devices against mechanical damage and suppressing short circuits caused by dendrite punctures in the battery, thereby enhancing the long-term cycle stability and safety of the energy storage device. The simple and efficient preparation method of this application can also effectively reduce process costs, providing more possibilities for the further integration of flexibility and stretchability into electronic devices and power supplies.

Description

Technical Field

[0001] This invention belongs to the field of flexible electronics, specifically relating to an intrinsically stretchable polymer electrolyte, its preparation method, and its application. Background Technology

[0002] In recent years, with the booming development of flexible electronic products, such as foldable displays / touchscreens, artificial electronic skin, soft robots, remote monitoring, artificial intelligence, implantable medical devices and wearable devices have permeated all aspects of people's lives.

[0003] However, for flexible electronic products to operate normally, matching flexible energy storage devices are required to maximize their effectiveness. To meet comprehensive requirements for bending deformation, flexibility, and safety, the development of hydrogel electrolytes with excellent elasticity, adhesion, self-healing properties, and high ionic conductivity has attracted increasing attention. Compared to traditional batteries, hydrogel materials, due to their inherent self-healing properties, can improve the reliable maintenance of energy storage devices against mechanical damage, enabling damaged batteries to effectively and autonomously recover their energy storage characteristics. Furthermore, their inherent mechanical flexibility and electrode-electrolyte interface stability give energy storage devices long-term cycle stability. Therefore, this provides a new solution to the problem of improving device lifespan.

[0004] However, traditional hydrogels (PAA, PVA, PAAS) suffer from structural defects, providing only a physical framework to support ion transport. They cannot withstand significant stretching and compression, resulting in poor mechanical properties and self-healing capabilities, limiting their application in flexible electronics. Zwitterionic polymers, with their positively and negatively charged polymer backbones and unique zwitterionic groups within repeating units, typically exhibit high water retention and toughness. The dipole-dipole physical interaction between the zwitterionic groups and chemical double bonds facilitates the formation of the zwitterionic hydrogel matrix. In electrolytes composed of zwitterionic polymer matrices, the strong electrostatic interaction between the charged zwitterionic groups and electrolyte ions can establish separate cation and anion migration channels, thereby promoting ion migration. Furthermore, the polar and charged groups of zwitterions can enhance the interfacial adhesion between the electrode and the gel electrolyte, reducing the electrode-electrolyte interfacial impedance and thus enhancing the long-term cycling stability of energy storage devices. Despite these advantages, the preparation process of tough hydrogel electrolytes derived from zwitterionic monomers typically involves monomers, chemical crosslinking agents, and toxic additives. In existing technologies, a precursor solution containing acrylamide (AM) and [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (SBMA) monomers, N,N-methylenebisacrylamide (MBAA), and the photoinitiator 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone is photopolymerized to form a crosslinked P(AM-co-SBMA) hydrogel. Then, the P(AM-co-SBMA) hydrogel is immersed in a Zn(OTf)2 aqueous solution for solvent displacement to prepare a hydrogel electrolyte. While related patents have reported the synthesis of zwitterionic polymer-based gel electrolytes, the incompletely polymerized monomers, crosslinking agents, and initiators in these zwitterionic electrolytes are harmful to the environment and human health. Furthermore, the gelation process of hydrogels is cumbersome and dependent on external stimuli, such as ultraviolet radiation or thermal initiation, significantly increasing time, manpower, and material resources. In addition, although existing technologies have prepared gel electrolytes containing acrylamide (AM) and N,N-methylenebisacrylamide through in-situ polymerization strategies, simplifying the preparation process, an initiator still needs to be introduced to promote the smooth progress of the reaction. Therefore, developing novel stretchable, self-healing, and highly conductive hydrogel electrolytes without external stimulation and the introduction of additional initiators remains a significant challenge. Summary of the Invention

[0005] This application overcomes the shortcomings of the prior art and provides an intrinsically stretchable polymer electrolyte, its preparation method and application. The high ionic conductivity, flexibility and excellent self-healing properties of this hydrogel make it a promising candidate for use as a flexible electrolyte in the development and application of flexible energy storage devices.

[0006] The objective of this application is achieved through the following technical solution.

[0007] This application provides an intrinsically stretchable polymer electrolyte, wherein the intrinsically stretchable electrolyte is composed of zwitterionic polymer monomers in an electrolyte salt system; wherein:

[0008] Based on deionized water, the amount of deionized water is 2 mL, the mass concentration of zwitterionic polymer monomers ranges from 0.1 to 1.0 g / mL, and the molar concentration of electrolyte salts ranges from 1 to 5 mol / L.

[0009] This application also provides a method for preparing the intrinsically stretchable polymer electrolyte, characterized by comprising the following steps:

[0010] Step 1: Prepare an electrolyte salt solution with a concentration range of 1-5 mol / L;

[0011] Step 2: Add different masses of zwitterionic monomers to the electrolyte salt solution described in Step 1. The concentration of the zwitterionic monomers is based on deionized water, the amount of deionized water is controlled at 2 mL, and the mass concentration range of the zwitterionic monomers is 0.1-1.0 g / mL to prepare a mixed solution.

[0012] Step 3: Place the mixture obtained in Step 2 at room temperature to obtain a gel sample, thus obtaining the intrinsically stretchable polymer electrolyte.

[0013] This application also provides the application of the intrinsically stretchable polymer electrolyte in the preparation of energy storage devices, wherein the energy storage devices are zinc-ion batteries, lithium-ion batteries or supercapacitors.

[0014] Beneficial effects:

[0015] Compared with the prior art, the present invention provides an intrinsically stretchable polymer electrolyte, its preparation method and application. The intrinsically stretchable polymer electrolyte prepared in this application has excellent flexibility, self-healing properties, high ionic conductivity of 2.2 ms / cm, and a wide electrochemical stability window of 0-1.8V, which can meet the practical application window of aqueous zinc batteries and lithium-ion batteries.

[0016] When the intrinsically stretchable polymer electrolyte is applied to zinc-based batteries, the symmetrical zinc-based battery achieves a current density of 0.5 mA / cm². 2After 7000 hours of cycling under these conditions, the polymer electrolyte still maintains an overpotential of 60 mV, indicating that it effectively achieves uniformity of the metal anode during deposition and stripping, thereby effectively suppressing the formation of byproducts on the metal electrode. From the performance of the assembled vanadium-based full cell, the intrinsically stretchable polymer electrolyte prepared in this application exhibits excellent cycling stability at different rates without a significant degradation trend, demonstrating a high specific capacity of 340 mAh / g at a current density of 0.1 A / g.

[0017] Furthermore, this intrinsically stretchable polymer electrolyte exhibits superior electrochemical performance when used in supercapacitors. The present invention features a simple preparation process, uses inexpensive raw materials, and is suitable for large-scale production. It provides new ideas for the design, fabrication, and multifunctional applications of flexible energy storage devices, and is conducive to promoting the development of the flexible electronics industry. Attached Figure Description

[0018] Figure 1 This is a physical image of the intrinsically stretchable polymer electrolyte used in zinc-ion batteries in Example 1;

[0019] Figure 2 This is a physical image of the intrinsically stretchable polymer electrolyte used in zinc-ion batteries in Example 2;

[0020] Figure 3 This is a physical image of the intrinsically stretchable polymer electrolyte used in zinc-ion batteries in Example 3;

[0021] Figure 4 The impedance spectra of the intrinsic stretchable polymer electrolyte used in zinc-ion batteries in Examples 1-5 and the electrolyte in Comparative Example 1 are compared.

[0022] Figure 5 A comparison of the electrochemical stability windows of the intrinsically stretchable polymer electrolytes used in zinc-ion batteries in Examples 1-5;

[0023] Figure 6 Comparison of the cycle performance of zinc metal symmetric batteries corresponding to Examples 6-7 at different rates;

[0024] Figure 7 Comparison of rate performance test graphs for zinc-ion full cells corresponding to Examples 8-9;

[0025] Figure 8 This is a morphology image of the zinc anode surface of the zinc metal symmetric battery in Example 6 after 7000 hours of cycling.

[0026] Figure 9 This is a morphology image of the zinc anode surface of the zinc metal symmetric battery in Example 7 after 2000 hours of cycling.

[0027] Figure 10 This is a morphology diagram of the cathode material—sodium vanadate composite carbon nanotubes (CNT@V) in Example 8;

[0028] Figure 11 This is a photograph of the intrinsically stretchable polymer electrolyte used in an aqueous lithium-ion battery in Example 12;

[0029] Figure 12 This is a schematic diagram of the intrinsically stretchable polymer electrolyte used in an aqueous lithium-ion battery in Example 12 after cutting / healing.

[0030] Figure 13 The charge-discharge curve of the aqueous lithium-ion full battery in Example 15 at 0.1C is shown.

[0031] Figure 14 Comparison of cycle count and capacitance retention of the supercapacitors corresponding to Examples 16 and 17 at a current density of 0.5 A / g;

[0032] Figure 15 This shows the original and stretched states of the intrinsic stretchable polymer electrolyte in one embodiment of this application. Detailed Implementation

[0033] The present application is further illustrated below with reference to specific embodiments. It should be understood that these embodiments are only used to illustrate the present application and are not intended to limit the scope of the present application. After reading the present application, any modifications of the present application in various equivalent forms by those skilled in the art fall within the scope defined by the appended claims.

[0034] In one embodiment, the intrinsically stretchable electrolyte is composed of zwitterionic polymer monomers in an electrolyte salt system; wherein:

[0035] Based on deionized water, the amount of deionized water is 2 mL, the mass concentration of zwitterionic polymer monomers ranges from 0.1 to 1.0 g / mL, and the molar concentration of electrolyte salts ranges from 1 to 5 mol / L.

[0036] In one embodiment, the zwitterionic polymer monomer includes 3-[(3-acrylamidopropyl)dimethylammonium]propionate, 2-(methacryloyloxy)ethyl-2-(trimethylamino)ethyl phosphate, (3-(methacryloylamino)propyldimethyl(3-thiopropyl)ammonium hydroxide inner salt), 3-[[2-(methacryloyloxy)ethyl]dimethylammonium]propionate, and [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfonylpropyl)ammonium hydroxide.

[0037] In one embodiment, the inorganic salt includes zinc trifluoromethanesulfonate, lithium trifluoromethanesulfonate, zinc perchlorate, lithium perchlorate, zinc chloride, lithium chloride, zinc sulfate, lithium sulfate, zinc fluoride, lithium fluoride, zinc nitrate, and lithium nitrate.

[0038] In one embodiment, the method for preparing the intrinsically stretchable polymer electrolyte is characterized by comprising the following steps:

[0039] Step 1: Prepare an electrolyte salt solution with a concentration range of 1-5 mol / L;

[0040] Step 2: Add different masses of zwitterionic monomers to the electrolyte salt solution described in Step 1. The concentration of the zwitterionic monomers is based on deionized water, the amount of deionized water is controlled at 2 mL, and the mass concentration range of the zwitterionic monomers is 0.1-1.0 g / mL to prepare a mixed solution.

[0041] Step 3: Place the mixture obtained in Step 2 at room temperature to obtain a gel sample, thus obtaining the intrinsically stretchable polymer electrolyte.

[0042] In one embodiment, the mass of the zwitterionic monomer is 10%-90% of the mass of the electrolyte salt.

[0043] In one embodiment, the intrinsically stretchable polymer electrolyte is used in the fabrication of an energy storage device, which is a zinc-ion battery, a lithium-ion battery, or a supercapacitor.

[0044] In one embodiment, the intrinsically stretchable polymer electrolyte is a component of a zinc-ion battery, the zinc-ion battery comprising: a positive electrode, a negative electrode, and the intrinsically stretchable polymer electrolyte situated between the positive electrode and the negative electrode; wherein, the positive electrode material is obtained by vacuum filtration of electrode slurry, and the positive electrode further comprises a positive electrode active material, wherein the positive electrode active material is one of sodium vanadate, manganese dioxide, and vanadium pentoxide, preferably sodium vanadate; the negative electrode comprises a negative electrode active material, which is a zinc sheet; the intrinsically stretchable polymer electrolyte and the electrode are bonded together in a sandwich structure, specifically a positive electrode / electrolyte / negative electrode bonding, to obtain the zinc-ion battery.

[0045] In one embodiment, the intrinsically stretchable polymer electrolyte is used as a component of a lithium-ion battery. The lithium-ion battery includes: a positive electrode, a negative electrode, and the intrinsically stretchable polymer electrolyte located between the positive electrode and the negative electrode. The electrode material is composed of an active material, a polymer binder, and conductive carbon black. The active material is either a positive electrode active material or a negative electrode active material, and the polymer binder is polyvinylidene fluoride or the zwitterionic material described herein. The positive electrode active material includes, but is not limited to, lithium iron phosphate, lithium cobalt oxide, and lithium manganese oxide, and the negative electrode active material includes, but is not limited to, graphite, lithium titanate, and vanadium pentoxide. The intrinsically stretchable polymer electrolyte is used as the electrolyte, and the electrodes are bonded together in a sandwich structure, specifically a positive electrode / electrolyte / negative electrode bonding, to obtain the lithium-ion battery.

[0046] In one embodiment, the intrinsically stretchable polymer electrolyte is used as a component of a supercapacitor, the supercapacitor comprising: a positive electrode, a negative electrode, and the intrinsically stretchable polymer electrolyte situated between the positive electrode and the negative electrode; wherein the intrinsically stretchable polymer electrolyte is bonded to the positive electrode and the negative electrode in a sandwich structure, specifically a bonding of positive electrode / electrolyte / negative electrode, to obtain the supercapacitor.

[0047] Example 1

[0048] Weigh 0.7448 g of zinc perchlorate, add 2 ml of deionized water, stir to dissolve and prepare a 1 M zinc perchlorate solution, add 0.30 g of zwitterionic monomer 3-[(3-acrylamidopropyl)dimethylammonium]propionate (based on deionized water, the mass concentration of zwitterionic monomer is 0.15 g / mL), label it MZ0.15, and let it stand at room temperature for 2 h.

[0049] Example 2

[0050] Weigh 0.5452 g of zinc chloride salt, add 2 ml of deionized water, stir to dissolve and prepare a 2 M zinc chloride salt solution, add 0.70 g of zwitterionic monomer 2-(methacryloyloxy)ethyl-2-(trimethylamino)ethyl phosphate (based on deionized water, the mass concentration of zwitterionic monomer is 0.35 g / mL), label it MZ0.35, and let it stand at room temperature for 2 h.

[0051] Example 3

[0052] Weigh 2.1812 g of zinc trifluoromethanesulfonate salt, add 2 ml of deionized water, stir to dissolve and prepare a 3M zinc trifluoromethanesulfonate solution. Transfer 1 ml of the zinc trifluoromethanesulfonate solution to a sample vial, add 1.0 g of the zwitterionic monomer 3-(methacryloylamino)propyldimethyl(3-thiopropyl)ammonium hydroxide inner salt (based on deionized water, the mass concentration of the zwitterionic monomer is 0.5 g / mL), label it MZ0.5, and let it stand at room temperature for 2 h.

[0053] The zinc-based battery assembled with the intrinsically stretchable polymer electrolyte corresponding to Example 3 showed excellent cycle stability and excellent capacity performance compared with the zinc-based battery assembled in Comparative Example 1.

[0054] Example 4

[0055] Weigh 1.2916 g of zinc sulfate salt, add 2 ml of deionized water, stir to dissolve and prepare a 4 M zinc sulfate solution, add 1.50 g of zwitterionic monomer 3-[[2-(methacryloyloxy)ethyl]dimethylammonium]propionate (based on deionized water, the mass concentration of zwitterionic monomer is 0.75 g / mL), labeled as MZ0.75, and let stand at room temperature for 2 h.

[0056] Example 5

[0057] Weigh 0.8271 g of zinc fluoride salt, add 2 ml of deionized water, stir to dissolve and prepare a 4 M zinc fluoride solution, add 2.0 g of zwitterionic monomer [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfonic acid propionic)ammonium hydroxide (based on deionized water, the mass concentration of zwitterionic monomer is 1.0 g / mL), label it MZ1.0, and let it stand at room temperature for 2 h.

[0058] Example 6

[0059] Weigh 1.5152 g of zinc nitrate salt, add 2 ml of deionized water, stir to dissolve and prepare a 4 M zinc nitrate solution, add 2.0 g of zwitterionic monomer 3-(methacryloylamino)propyldimethyl(3-thiopropyl)ammonium hydroxide inner salt (based on deionized water, the mass concentration of zwitterionic monomer is 1.0 g / mL), label it as XMZ1.0, and let it stand at room temperature for 2 h.

[0060] Comparative Example 1

[0061] This comparative example provides an aqueous electrolyte solution, and the specific preparation steps of this electrolyte solution are as follows:

[0062] Weigh 2.1812 g of zinc trifluoromethanesulfonate salt, add 2 ml of deionized water, stir to dissolve, and obtain a 3 M electrolyte solution of zinc trifluoromethanesulfonate. The sample is labeled as 3 M Zn(OTF)2.

[0063] Figure 1 The intrinsically stretchable polymer electrolyte used in Example 1 for zinc-ion batteries shows that MZ0.15 is still in solution after 2 hours, as can be seen from the figure. Figure 2 The intrinsically stretchable polymer electrolyte used in Example 2 for zinc-ion batteries shows that MZ0.35 gelled significantly after 2 hours, as can be seen from the figure. Figure 3 Example 3 shows the intrinsically stretchable polymer electrolyte applied to zinc-ion batteries. As can be seen from the figure, MZ0.5 exhibits a gel state after 2 hours. Figure 15 The images show the original and stretched states of the intrinsically stretchable polymer electrolyte of Example 3 of this application. It is evident that it possesses excellent flexibility.

[0064] Figure 4 The impedance comparison spectra of different proportions of zwitterionic electrolytes in Examples 1-5 and the electrolyte of Comparative Example 1 are shown. The conductivity was calculated using the formula... Where d is the thickness of the electrolyte membrane, S is the area of ​​the electrolyte membrane, and R is the ohmic resistance obtained from impedance spectroscopy, when the mass concentration of the zwitterionic monomer is 0.5 g / mL, the conductivity of the polyzwitterionic electrolyte can reach 2.2 ms / cm, exhibiting high conductivity performance.

[0065] Figure 5 The figure shows the electrochemical stability windows of different proportions of zwitterionic electrolytes in Examples 1-5. As shown in the figure, the electrochemical stability window of the zwitterionic electrolyte corresponding to Example 3 can reach 0-1.8V, which meets the practical application window of aqueous zinc-ion batteries and lithium-ion batteries.

[0066] In conjunction with Examples 1-5 and Comparative Example 1, the electrolyte described in this application is used in a power supply device, namely a zinc-based battery, which will be further explained below.

[0067] Example 6

[0068] Example 6 is a zinc metal symmetric battery, using the zwitterionic hydrogel corresponding to Example 3 (selected based on optimal conductivity performance and electrolyte membrane strength) as the electrolyte layer. The preparation process of the zinc metal symmetric battery corresponding to Example 6 includes the following steps:

[0069] A zwitterionic material with a diameter of 16 mm was selected as the electrolyte layer, and a zinc sheet with a diameter of 12 mm was selected as the positive electrode and negative electrode. The positive electrode (12 mm zinc sheet), electrolyte layer, separator and negative electrode (12 mm zinc sheet) were sequentially encapsulated with a battery case CR2016 to obtain a zinc metal symmetric battery.

[0070] Example 7

[0071] Example 7 is a zinc metal symmetric battery, using the zinc trifluoromethanesulfonate aqueous solution corresponding to Comparative Example 1 as the electrolyte layer. The preparation process of the zinc metal symmetric battery corresponding to Example 7 includes the following steps:

[0072] A zinc sheet with a diameter of 12 mm was selected as the positive and negative electrodes. 100 μL of zinc trifluoromethanesulfonate solution was added as the electrolyte. The positive electrode (zinc sheet with a diameter of 12 mm), electrolyte, GF / D glass fiber separator and negative electrode (zinc sheet with a diameter of 12 mm) were sequentially encapsulated with a battery case CR2016 to obtain a zinc metal symmetric battery.

[0073] Example 8

[0074] Example 8 is a zinc-ion full battery, using the zwitterionic hydrogel corresponding to Example 3 (selected based on optimal conductivity performance and electrolyte membrane strength) as the electrolyte layer. The preparation process of the zinc-ion full battery corresponding to Example 8 includes the following steps:

[0075] 1) Positive electrode-carbon nanotube composite sodium vanadate material

[0076] Preparation of carbon nanotube dispersion

[0077] Weigh 1g of sodium dodecyl sulfate, add 100mL of deionized water, stir to dissolve, add 50mg of carbon nanotubes, and sonicate for 15min to obtain a carbon nanotube dispersion of 0.5mg / mL.

[0078] Preparation of sodium vanadate slurry

[0079] Weigh 2g of vanadium oxide, add 30mL of 2M sodium chloride solution, stir at room temperature for 96h, wash several times by centrifugation with ethanol, and vacuum dry at 80℃ for 12h to obtain a dark brown solid powder. Add deionized water to quantitatively prepare a sodium vanadate solution with a concentration of 0.0102g / mL.

[0080] Preparation of electrode paste for sodium vanadate composite carbon nanotubes (CNT@V)

[0081] 20 mL of a 0.5 mg / mL carbon nanotube dispersion was transferred, and 2.5 mL of a 0.0102 g / mL sodium vanadate solution was slowly added dropwise. The mixture was stirred for 2 h, then vacuum filtered and dried at 45 °C for 2 h to obtain the sodium vanadate composite carbon nanotube electrode film. The morphology of the cathode material—sodium vanadate composite carbon nanotubes (CNT@V)—is shown in the figure. Figure 10 .

[0082] The prepared electrode film was perforated into small circular pieces with a diameter of 12 mm, which were then used as the positive electrode material for zinc-ion full cells. The average loading of the electrode pieces was 2 mg / cm³. 2 .

[0083] 2) Negative electrode – a zinc sheet with a diameter of 12mm

[0084] 3) Electrolyte—The zwitterionic hydrogel material described in Example 3 is sequentially encapsulated with the above-mentioned positive electrode (CNT@V electrode sheet), electrolyte, separator, negative electrode (12mm diameter zinc sheet), gasket, and spring sheet using a battery case CR2025 to obtain a zinc metal full battery.

[0085] Example 9

[0086] Example 9 is a zinc-ion full battery, serving as a standard device for zinc-ion batteries. It uses the zinc trifluoromethanesulfonate solution corresponding to Comparative Example 1 as the electrolyte, and the preparation methods for other materials and the battery assembly process are consistent.

[0087] The battery capacity, cycle performance, and rate performance of the zinc metal symmetric battery and zinc-ion full battery tested in Examples 6-9 are as follows: Figure 6-7 As shown.

[0088] Figure 6 The graph shows a comparison of the cycle performance of the symmetrical zinc metal batteries in Examples 6 and 7, as shown in the figure. Figure 6 As shown, a symmetrical zinc metal battery using zinc trifluoromethanesulfonate solution as the electrolyte exhibits an overpotential of 400 mV after 300 hours of cycling at different rates. This indicates that the rampant growth of zinc dendrites leads to an internal short circuit in the battery. In contrast, a symmetrical zinc metal battery using zwitterionic electrolyte shows a similar overpotential at a current density of 5 mA / cm². 2 Under these conditions, the battery overpotential remains at 180mV, at 0.5mA / cm. 2 When cycling at the current density, after 7000 hours of cycling, the overpotential still remained at around 60 mV, indicating that the polyzwitterionic electrolyte can effectively inhibit dendrite growth, and the -SO3 groups on the side of the polyzwitterionic chain can react with Zn. 2+ Through electrostatic interactions, Zn can be induced 2+ The uniform deposition and stripping results in excellent cycle stability and long lifespan.

[0089] Figure 7 The graph shows a comparison of the rate performance of zinc-ion full cells in Examples 8 and 9, as shown in the figure. Figure 7 As shown, when the zinc-ion full cell using zinc trifluoromethanesulfonate solution as electrolyte is cycled at different rate levels of 0.1, 0.2, 0.3, 0.4, 0.5, and 1 A / g, the capacity decay of the zinc-ion full cell using zinc trifluoromethanesulfonate solution as electrolyte is more severe. In contrast, the capacity of the zinc-ion full cell using zwitterionic hydrogel as electrolyte in Example 8 remains more stable. Under a current density of 1 A / g, the specific capacity of the full cell remains at 260 mAh / g, and it exhibits good cycle stability.

[0090] Therefore, whether considering the cycle performance and rate performance of the zinc metal symmetric batteries corresponding to Examples 6-7, or the cycle performance, battery capacity, and rate performance of the zinc-ion full batteries corresponding to Examples 8-9, the battery performance using the zwitterionic hydrogel corresponding to Example 3 as the electrolyte is superior to that using the zinc trifluoromethanesulfonate solution corresponding to Comparative Example 1 as the electrolyte. This indicates that the zwitterionic electrolyte described in this application can effectively suppress dendrite growth and byproduct formation during battery cycling, resulting in excellent cycle stability and a longer lifespan for the battery.

[0091] Furthermore, the -SO3 groups on the side chains of the zwitterionic hydrogel react with Zn... 2+ There is electrostatic interaction, which can induce Zn during the charging and discharging process of the battery. 2+ The homogenized deposition and stripping effectively suppress the formation of byproducts on the metal electrode. Figure 8 As shown, the zinc metal symmetric cell with a zwitterionic electrolyte exhibits a relatively dense hexagonal deposit on the electrode surface after 7000 hours of cycling. In contrast, the zinc metal symmetric cell using zinc trifluoromethanesulfonate as the electrolyte shows a similar deposit after 300 hours of cycling. Figure 9 As shown, the zinc anode surface has blocky zinc dendrites, and the dendrite growth is quite severe, which greatly shortens the battery life. This indicates that the zwitterionic electrolyte described in this application can effectively suppress the generation of by-products, so that the battery exhibits excellent cycle stability and a long life.

[0092] Example 10

[0093] Weigh 0.2128 g of lithium perchlorate salt, add 2 ml of deionized water, stir to dissolve and prepare a 1 M lithium perchlorate solution, and add 0.30 g of zwitterionic monomer 3-[(3-acrylamidopropyl)dimethylammonium]propionate (based on deionized water, the mass concentration of zwitterionic monomer is 0.15 g / mL).

[0094] Example 11

[0095] Weigh 0.1696 g of lithium chloride salt, add 2 ml of deionized water, stir to dissolve and prepare a 2 M lithium chloride solution. Transfer 1 ml of the lithium chloride solution to a sample vial and add 0.70 g of the zwitterionic monomer 2-(methacryloyloxy)ethyl-2-(trimethylamino)ethyl phosphate (based on deionized water, the mass concentration of the zwitterionic monomer is 0.35 g / mL).

[0096] Example 12

[0097] Weigh 0.9361 g of lithium trifluoromethanesulfonate, add 2 ml of deionized water, stir to dissolve and prepare a 3 M lithium trifluoromethanesulfonate solution, and add 1.0 g of zwitterionic monomer 3-(methacryloylamino)propyldimethyl(3-thiopropyl)ammonium hydroxide inner salt (based on deionized water, the mass concentration of zwitterionic monomer is 0.5 g / mL).

[0098] The solid-state supercapacitor assembled with the intrinsically stretchable polymer electrolyte corresponding to Example 12 exhibits higher electrochemical performance compared to the liquid supercapacitor assembled in Comparative Example 2.

[0099] Example 13

[0100] Weigh 0.8796 g of lithium sulfate, add 2 ml of deionized water, stir to dissolve and prepare a 4 M lithium sulfate solution, and add 1.5 g of zwitterionic monomer [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfonic acid propionic)ammonium hydroxide (based on deionized water, the mass concentration of zwitterionic monomer is 0.75 g / mL).

[0101] Example 14

[0102] Weigh 0.5516 g of lithium nitrate, add 2 ml of deionized water, stir to dissolve and prepare a 4 M lithium nitrate solution, and add 2.0 g of zwitterionic monomer 3-[[2-(methacryloyloxy)ethyl]dimethylammonium]propionate (based on deionized water, the mass concentration of zwitterionic monomer is 1.0 g / mL).

[0103] Comparative Example 2

[0104] This comparative example provides an aqueous electrolyte solution, and the specific preparation steps of this electrolyte solution are as follows:

[0105] Weigh 0.9361 g of lithium trifluoromethanesulfonate, add 2 ml of deionized water, stir to dissolve, and obtain a 3 M electrolyte solution of lithium trifluoromethanesulfonate. The sample is labeled as 3 M LiOTf.

[0106] Figure 11 This is a photograph of the intrinsically stretchable polymer electrolyte used in an aqueous lithium-ion battery in Example 12; Figure 12 This is a schematic diagram of the intrinsically stretchable polymer electrolyte of Example 12 after cutting / healing. It can be seen that the zwitterionic electrolyte in Example 12 can self-heal after 20 minutes following a single cutting. This is due to the physical cross-linking of dynamic bonds such as ion association and hydrogen bonds in the side chains of the zwitterionic copolymer. When subjected to external forces such as cutting, the dynamic bonds temporarily break, and the healing occurs after the external force is removed.

[0107] Over time, new dynamic bonds can be generated to achieve physical cross-linking, thus achieving the purpose of gel self-repair.

[0108] In conjunction with Examples 10-14 and Comparative Example 2, the electrolyte described in this application is used in a power supply device, namely an aqueous lithium-ion battery, which will be further explained below.

[0109] Example 15

[0110] Example 15 is an aqueous lithium-ion full battery. In Example 15, the lithium-ion full battery utilizes the intrinsically stretchable polymer electrolyte corresponding to Example 12 as the electrolyte layer. The assembly steps for the lithium-ion battery in Example 15 include: using a conventional coin cell assembly method, encapsulating the lithium manganese oxide positive electrode, electrolyte, and lithium titanate negative electrode with a battery case.

[0111] Figure 13 The figure shows the charge-discharge curves of the aqueous lithium-ion battery corresponding to Example 15 at 0.1C. As shown in the figure, the aqueous lithium-ion battery exhibits good electrochemical performance and has constant current charge-discharge curves with an average discharge voltage plateau of 1.8V at the 2nd, 20th, and 80th cycles.

[0112] In conjunction with Examples 10-14 and Comparative Example 2, the electrolyte described in this application is used in a power supply device, namely a supercapacitor, which will be further explained below.

[0113] Example 16

[0114] Example 16 is a solid-state supercapacitor. In Example 16, the supercapacitor utilizes the intrinsically stretchable polymer electrolyte corresponding to Example 12 as the electrolyte layer. The assembly steps of the supercapacitor corresponding to Example 16 include: using a conventional button-type supercapacitor assembly method, with graphene films as the dual electrodes, an intrinsically stretchable polymer electrolyte as the electrolyte, conductive graphite as the current collector, and encapsulation with a battery casing.

[0115] Example 17

[0116] Example 17 is a liquid supercapacitor. In Example 17, the supercapacitor uses the lithium trifluoromethanesulfonate solution corresponding to Comparative Example 2 as the electrolyte. The assembly steps of the supercapacitor in Example 17 include: using a traditional button-type supercapacitor assembly method, with graphene films as the dual electrodes, lithium trifluoromethanesulfonate solution as the electrolyte, conductive graphite as the current collector, and encapsulation with a battery casing.

[0117] Figure 14 This section compares the number of cycles and capacitance retention of the supercapacitors corresponding to Examples 16-17 at a current density of 0.5 A / g. Figure 13As shown, the solid supercapacitor with intrinsically stretchable polymer electrolyte corresponding to Example 12 has a capacity retention of 100.7% after 500 cycles at a current density of 0.5 A / g. In contrast, the liquid supercapacitor corresponding to Comparative Example 2 has a capacity that continuously decreases after 500 cycles at a current density of 0.5 A / g, with a capacity retention of 74.2%.

[0118] As demonstrated by the above embodiments, this application synthesizes an intrinsically stretchable polymer electrolyte using a simple and efficient one-step method. Compared to the preparation of traditional hydrogel electrolytes, this method reduces cumbersome processes and significantly saves cost and time. This intrinsically stretchable polymer electrolyte exhibits certain flexibility and self-healing properties, along with excellent conductivity of 2.2 mS / cm and a wide electrochemical stability window of 0–1.8 V, meeting the practical application requirements of aqueous zinc-ion batteries and lithium-ion batteries.

[0119] Without external stimuli or the introduction of additional initiators, the development of intrinsically stretchable polymer electrolytes that are stretchable, self-healing, and highly conductive promises to provide more possibilities for the further practicality and extended integration of electronic devices and power supplies.

[0120] The above are merely preferred embodiments of this application. It should be noted that, for those skilled in the art, numerous improvements and modifications can be made without departing from the principles of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. An intrinsically stretchable polymer electrolyte, characterized by: The intrinsic stretchable electrolyte is composed of zwitterionic polymer monomer in an electrolyte salt system; wherein: The intrinsic stretchable polymer electrolyte is composed of deionized water, zwitterionic polymer monomer and electrolyte salt; The amount of deionized water is 2 mL, the mass concentration of zwitterionic polymer monomer ranges from 0.1 to 1.0 g / mL, and the molar concentration of electrolyte salt ranges from 1 to 5 mol / L, based on deionized water; wherein the zwitterionic polymer monomer includes 3-[(3-acrylamidopropyl)dimethylammonium] propionate, 2-(methacryloyloxy)ethyl-2-(trimethylamino)ethyl phosphate, (3-(methacrylamido)propyl dimethyl(3-thiopropyl) ammonium inner salt, 3-[[2-(methacryloyloxy)ethyl]dimethylammonium] propionate, [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl) ammonium hydroxide; wherein the electrolyte salt is zinc trifluoromethanesulfonate, lithium trifluoromethanesulfonate, zinc perchlorate, lithium perchlorate, zinc chloride, lithium chloride, zinc sulfate, lithium sulfate, zinc fluoride, lithium fluoride, zinc nitrate or lithium nitrate.

2. The method of producing the intrinsically stretchable polymer electrolyte according to claim 1, characterized by, The method comprises the following steps: Step one, prepare an electrolyte salt solution with a concentration ranging from 1 to 5 mol / L; Step two, add different amounts of zwitterionic monomer to the electrolyte salt solution in step one, the concentration of the zwitterionic monomer is based on deionized water, the amount of deionized water is controlled at 2 mL, and the mass concentration of the zwitterionic monomer ranges from 0.1 to 1.0 g / mL, to prepare a mixed solution; Step three, place the mixed solution obtained in step two at room temperature to obtain a gel sample, thereby obtaining the intrinsic stretchable polymer electrolyte.

3. The method for preparing the intrinsically stretchable polymer electrolyte according to claim 2, characterized in that: The mass of the zwitterionic monomer is 10% to 90% of the mass of the electrolyte salt.

4. The intrinsic stretchable polymer electrolyte of claim 1 is used in the preparation of energy storage devices, which are zinc ion batteries, lithium ion batteries or supercapacitors.

5. Use according to claim 4, characterized in that, The intrinsic stretchable polymer electrolyte is used as a component of a zinc ion battery, which comprises a positive electrode, a negative electrode and the intrinsic stretchable polymer electrolyte between the positive electrode and the negative electrode; wherein the positive electrode material is prepared by vacuum suction filtration of electrode slurry, and the positive electrode further comprises a positive electrode active material, wherein the positive electrode active material is one of sodium vanadate, manganese dioxide and vanadium pentoxide, and the negative electrode comprises a negative electrode active material, which is zinc sheet; The intrinsic stretchable polymer electrolyte is used as an electrolyte and electrode in a sandwich structure, specifically a positive electrode / electrolyte / negative electrode structure, to obtain the zinc ion battery.

6. Use according to claim 4, characterized in that, The intrinsic stretchable polymer electrolyte is used as a component of a lithium ion battery, the lithium ion battery comprising: a positive electrode, a negative electrode, and the intrinsic stretchable polymer electrolyte between the positive electrode and the negative electrode; wherein the electrode material is composed of an active material, a polymer binder, and conductive carbon black, wherein the active material is a positive electrode active material or a negative electrode active material, and the polymer binder is polyvinylidene fluoride or a polyzwitterionic material; wherein the positive electrode active material includes but is not limited to lithium iron phosphate, lithium cobaltate, lithium manganate, and the negative electrode active material includes but is not limited to graphite, lithium titanate, and vanadium pentoxide; the intrinsic stretchable polymer electrolyte is used as an electrolyte and electrodes in a sandwich structure, specifically a positive electrode / electrolyte / negative electrode, to obtain the lithium ion battery.

7. Use according to claim 4, characterized in that, The intrinsic stretchable polymer electrolyte is used as a component of a supercapacitor, the supercapacitor comprising: a positive electrode, a negative electrode, and the intrinsic stretchable polymer electrolyte between the positive electrode and the negative electrode; wherein the intrinsic stretchable polymer electrolyte is used as an electrolyte and positive and negative electrodes in a sandwich structure, specifically a positive electrode / electrolyte / negative electrode, to obtain the supercapacitor.

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