A fluorine-containing zwitterionic polymer electrolyte for solid-state batteries and solid-state batteries

Abstract

The present invention discloses a fluorinated zwitterionic polymer electrolyte for solid-state batteries and a solid-state battery. The present invention relates to the field of battery technology. The fluorinated zwitterionic polymer electrolyte is composed of a polymer skeleton and an ion-conducting matrix, wherein the polymer skeleton is prepared by copolymerization of a monomer and an initiator, and the ion-conducting matrix is ​​prepared by mixing a plasticizer with a lithium salt or a sodium salt. The preparation method and application of the fluorinated zwitterionic polymer electrolyte in the present invention innovatively introduce a new idea of ​​synergistic regulation of fluorinated monomers and zwitterionic monomers, and are applied to solid-state batteries. The improvement of the conductivity and electrochemical stability of the polymer electrolyte is achieved by constructing a sodium ion transmission channel through polyzwitterionic segments and improving the electrolyte stability through a synergistic strategy of using fluorinated segments.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a fluorine-containing zwitterionic polymer electrolyte for a solid-state battery and a solid-state battery. Background Art

[0002] The secondary battery market holds promising prospects, with lithium batteries, a prominent example, enjoying widespread application. Furthermore, sodium, due to its abundant resources, high specific capacity (1165 mAh g−1), low redox potential (−2.71 V), and low cost, is expected to complement lithium batteries and has become a current research hotspot and focus. However, electrolyte-based secondary batteries present serious safety risks, significantly limiting their development.

[0003] The development of solid-state electrolytes is expected to achieve high safety and increase the energy density of secondary batteries. Polymer electrolytes, due to their advantages such as flexibility and ease of processing, have become a research hotspot and focus in the field of solid-state batteries. However, current solid polymer electrolytes suffer from poor ion transport and electrochemical stability, which seriously restrict the development of solid-state batteries.

[0004] Zwitterionic polymers are a class of specialized polymers characterized by the presence of equal amounts of anionic and cationic groups on a single monomer chain, resulting in an overall neutral charge. Their unique characteristic is their ability to conduct both anions and cations. In electrolytes, these polymer chains dissolve or disperse in the solvent, enabling high targeted ion transport and thus improving ionic conductivity. While applications of zwitterionic polymer-based electrolytes have been reported (ACS Cent. Sci. 2022, 8, 169−175), these polyzwitterionic electrolytes do not address the issue of polymer electrolyte interfacial instability. Furthermore, the zwitterionic segments are relatively rigid, resulting in poor film-forming properties.

[0005] The introduction of fluorine atoms can increase the electron affinity and solvent affinity of the polymer, thereby improving its ion solubility and enhancing film-forming properties. The weak solvating ability and excellent stability of fluorinated polymers also contribute to their enhanced electrochemical stability. The synergistic regulation of these two monomers is expected to achieve polymer electrolytes with both high conductivity and high electrochemical stability.

[0006] Therefore, the present invention solves the problems of poor ion transport capability and poor electrochemical stability of solid polymer electrolytes through the synergistic effect of zwitterionic segments and fluorinated segments. Summary of the Invention

[0007] The object of the present invention is to provide a fluorine-containing zwitterionic polymer electrolyte for solid-state batteries and a solid-state battery to address the above-mentioned deficiencies in the prior art.

[0008] In order to achieve the above-mentioned object, the present invention provides the following technical solution: a fluorinated zwitterionic polymer electrolyte for solid-state batteries, wherein the fluorinated zwitterionic polymer electrolyte is composed of a polymer skeleton and an ion-conducting matrix, wherein the polymer skeleton is prepared by copolymerization of a monomer and an initiator, and the ion-conducting matrix is ​​prepared by mixing a plasticizer with a lithium salt or a sodium salt.

[0009] As a further description of the above technical solution:

[0010] The zwitterionic monomers include but are not limited to 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, [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfonic acid propyl)ammonium hydroxide; the fluorine-containing monomers include but are not limited to 2,2,3,4,4,4-hexafluorobutyl acrylate, 2,2,3,4,4,4-hexafluoromethylacrylate, octafluoropentyl acrylate, and heptafluorobutyl acrylate.

[0011] A solid-state battery comprises a bracket and a cover matched with the bracket, a locking mechanism and a trigger assembly, both of which are arranged on the cover; and multiple sets of clamping mechanisms, both of which are arranged on the bracket. During installation, the trigger assembly drives the locking mechanism to move downward and then rotate, and in the process of self-locking the cover and the bracket, the locking mechanism drives the clamping mechanism to move to synchronously lock and seal multiple battery cells on the bracket.

[0012] As a further description of the above technical solution:

[0013] The locking mechanism includes a movable frame vertically slidably connected to the cover, the bottom end of the movable frame is rotatably connected to a plurality of connecting rods; the bottom end of the connecting rod is fixedly connected to a limit block, a plurality of supporting springs are provided between the movable frame and the cover, each of the connecting rods is fixedly connected to a cross bar, a plurality of track grooves are opened in the cover, the track grooves are composed of a vertical groove part and a spiral part, and the cross bar is slidably connected to the track grooves.

[0014] As a further description of the above technical solution:

[0015] The bracket is provided with a clamping groove, which is composed of a vertical groove part and a horizontal groove part. The limit block is driven to be clamped in the clamping groove during the movement of the connecting rod.

[0016] As a further description of the above technical solution:

[0017] The sealing mechanism includes a sealing ring fixedly connected to the bracket, and two arc-shaped opposing blocks are slidably connected to the bracket, and the two arc-shaped opposing blocks are fixedly connected to the two sides of the sealing ring; wedge-shaped grooves are provided on the two arc-shaped opposing blocks, and tension springs are provided between the sides of the two arc-shaped blocks that are away from each other and the bracket, and lateral expansion components are also provided on the two arc-shaped opposing blocks.

[0018] As a further description of the above technical solution:

[0019] A plurality of wedge rods are fixedly connected to the movable frame, and the wedge rods are driven to engage with the wedge-shaped grooves during the movement of the movable frame.

[0020] As a further description of the above technical solution:

[0021] The lateral expansion component includes a movable rod movably connected on both sides of the two arc-shaped opposing blocks, each of the movable rods is fixedly connected to a side arc block, and each of the side arc blocks is fixedly connected to a support rod; a plurality of inclined grooves are provided on the bracket, each of the support rods is slidably connected to the corresponding inclined groove, and each side arc block is connected to a sealing strip ring.

[0022] As a further description of the above technical solution:

[0023] The trigger assembly includes a rotating shaft rotatably connected to the cover, a positioning handle and a deflection plate are fixedly connected to the rotating shaft, and a linkage bar is fixedly connected to the deflection plate; a translation plate is slidably connected to the cover, the translation plate is rotatably connected to the linkage bar, and both ends of the translation plate are fixedly connected to multi-grooved wedges.

[0024] As a further description of the above technical solution:

[0025] A plurality of synchronization rods are fixedly connected to the movable frame, and each synchronization rod is fixedly connected to a wedge top block. The elastic force of the support spring drives each wedge top block to engage with the corresponding groove wedge block.

[0026] In the above technical solution, the present invention provides a fluorine-containing zwitterionic polymer electrolyte for solid-state batteries and a solid-state battery with the following beneficial effects:

[0027] The preparation method and application of the fluorinated zwitterionic polymer electrolyte disclosed in this invention innovatively introduces a new approach to the synergistic regulation of fluorinated and zwitterionic monomers for application in solid-state batteries. This synergistic strategy, which utilizes polyzwitterionic segments to construct sodium ion transport channels and fluorinated segments to enhance electrolyte stability, achieves enhanced conductivity and electrochemical stability in the polymer electrolyte.

[0028] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

[0029] This application document provides an overview of various implementations or examples of the technology described in this disclosure, and is not a comprehensive disclosure of the full scope or all features of the disclosed technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments described in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0031] Figure 1 This is a physical picture of a fluorinated zwitterionic polymer electrolyte membrane;

[0032] Figure 2 The ionic conductivity of fluorinated zwitterionic polymer electrolytes prepared based on different ratios of zwitterionic monomers and fluorinated monomers is compared.

[0033] Figure 3 Comparison of ionic conductivity of fluorinated zwitterionic polymer electrolytes with different plasticizer contents;

[0034] Figure 4 is the temperature-dependent ionic conductivity of the polymer electrolyte;

[0035] Figure 5 is the rate performance of the corresponding solid-state battery;

[0036] Figure 6 is the long cycle performance of the corresponding solid-state symmetric battery;

[0037] Figure 7 is the ion migration number and impedance of the corresponding polymer electrolyte;

[0038] Figure 8 is the ion migration number and impedance of the control group;

[0039] Figure 9 A schematic diagram of an exploded structure of a fixed battery provided by an embodiment of the present invention;

[0040] Figure 10 A schematic diagram of a cover structure provided by an embodiment of the present invention;

[0041] Figure 11 A schematic diagram of the support structure provided by an embodiment of the present invention;

[0042] Figure 12 A schematic diagram of the connection between the trigger assembly and the locking mechanism provided in an embodiment of the present invention;

[0043] Figure 13A schematic diagram of the locking mechanism structure provided by an embodiment of the present invention;

[0044] Figure 14 A schematic longitudinal section diagram of the overall structure provided by an embodiment of the present invention;

[0045] Figure 15 A schematic structural diagram of a clamping mechanism provided in an embodiment of the present invention;

[0046] Figure 16 A schematic diagram of the structure of the card slot provided in an embodiment of the present invention;

[0047] Figure 17 for Figure 9 Enlarged view of point A in the middle;

[0048] Figure 18 for Figure 12 Enlarged view of point B in the middle;

[0049] Figure 19 for Figure 14 Enlarged view of point C in the middle.

[0050] Description of reference numerals:

[0051] 1. Bracket; 11. Cover; 21. Moving frame; 22. Connecting rod; 23. Limit block; 24. Support spring; 25. Cross bar; 26. Track groove; 3. Snap-in groove; 41. Sealing strip; 42. Arc-shaped opposing block; 43. Wedge groove; 44. Tension spring; 5. Wedge rod; 61. Movable rod; 62. Side arc block; 63. Support rod; 64. Inclined groove; 71. Positioning handle; 72. Deflection plate; 73. Linkage bar; 74. Translation plate; 75. Groove wedge block; 76. Synchronous rod; 77. Wedge top block. DETAILED DESCRIPTION

[0052] To make the purpose, technical solutions, and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0053] See also Figure 1-19 This embodiment provides a fluorinated zwitterionic polymer electrolyte for solid-state batteries. The fluorinated zwitterionic polymer electrolyte is composed of a polymer skeleton and an ion-conducting matrix, wherein the polymer skeleton is prepared by copolymerization of a monomer and an initiator, and the ion-conducting matrix is ​​prepared by mixing a plasticizer with a lithium salt or a sodium salt.

[0054] In the embodiments further provided by the present invention, the zwitterionic monomers include but are not limited to 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, [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfonic acid propyl)ammonium hydroxide; the fluorine-containing monomers include but are not limited to 2,2,3,4,4,4-hexafluorobutyl acrylate, 2,2,3,4,4,4-hexafluoromethylacrylate, octafluoropentyl acrylate, and heptafluorobutyl acrylate.

[0055] The preparation method of the above-mentioned fluorine-containing zwitterionic polymer electrolyte comprises the following steps:

[0056] S1: Control the ratio of zwitterions and fluorinated monomers, adjust the ratio of lithium salt or sodium salt and ionic liquid to obtain the optimal ratio, and add photoinitiator and crosslinker;

[0057] S2: UV-polymerizing the precursor solution prepared in step S1 for six hours to obtain a fluorinated zwitterionic polymer electrolyte;

[0058] The plasticizer used in step S1 is one or more of tributylphosphine bis(trifluoromethanesulfonyl)imide, tri-n-butylmethylammonium bis(trifluoromethanesulfonyl)imide, tributyl(2-methoxyethyl)phosphine bis(trifluoromethanesulfonyl)imide, 1-butyl-3-methylimidazole bis(trifluoromethanesulfonyl)imide, 1-methyl-1-propylpyrrolidine bis(trifluoromethanesulfonyl)imide, or cyclohexyltrimethylammonium bis(trifluoromethanesulfonyl)imide; the lithium salt or sodium salt used is one or more of lithium perchlorate / sodium, lithium difluorooxalatoborate / sodium, lithium dioxalatoborate / sodium, lithium / sodium bistrifluoromethanesulfonyl imide, lithium / sodium trifluoromethanesulfonate, lithium / sodium tetrafluoroborate, and lithium / sodium hexafluorophosphate;

[0059] In step S2, the photoinitiator is one of 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-methylphenylpropane-1-one, benzoin dimethyl ether, or ethyl 4-(N,N-dimethylamino)benzoate. The zwitterionic monomer is present in an amount of 0.5% to 20% by mole of the fluorinated monomer, and the mass of the salt is present in an amount of 10% to 50% by mass of the plasticizer. The amount of the photoinitiator is 0.1% to 5% by mole of the total monomer mass. The amount of the crosslinker is 0.5% to 1% by mole of the monomer mass.

[0060] A solid-state battery comprises a bracket 1 and a cover 11 matched with the bracket 1, a locking mechanism and a trigger assembly, both of which are arranged on the cover 11; and multiple sets of clamping mechanisms, both of which are arranged on the bracket 1; during installation, the trigger assembly drives the locking mechanism to move downward and then rotate, and in the process of self-locking the cover 11 and the bracket 1, the locking mechanism drives the clamping mechanism to move to synchronously lock and seal multiple battery cells on the bracket 1. The device drives the locking mechanism to move by operating the trigger assembly to lock the cover 11 and the bracket 1, so that a closed space can be formed between the two, providing a good and stable working environment for the battery cells, and the movement of the locking mechanism synchronously triggers the movement of the clamping mechanism to further seal and fix the battery cells on the bracket 1. Compared with traditional screw clamping and locking, it is more convenient and sufficiently sealed, and prevents dust, water and other contaminants from entering the interior of the bracket 1 and contaminating the connection area, thereby ensuring the reliability of the connection of the battery cells on the bracket 1.

[0061] Furthermore, the locking mechanism includes a movable frame 21 vertically slidably connected to the cover 11, and the bottom end of the movable frame 21 is rotatably connected to a plurality of connecting rods 22; the bottom end of the connecting rod 22 is fixedly connected to a limit block 23, and a plurality of supporting springs 24 are provided between the movable frame 21 and the cover 11. A cross bar 25 is fixedly connected to each connecting rod 22, and a plurality of track grooves 26 are provided in the cover 11. The track groove 26 consists of a vertical groove part and a spiral part. The cross bar 25 is slidably connected to the track groove 26, and a clamping groove 3 is provided on the bracket 1. The clamping groove 3 consists of a vertical groove part and a horizontal groove part. The limit block 23 is driven to be clamped in the clamping groove 3 during the movement of the connecting rod 22, and a clamping groove for moving is provided on the cover 11. The movable frame 21 moves in the groove, and the movable frame 21 is affected by the groove and can only move vertically in the cover 11. When the cross bar 25 moves downward, it will first move in the vertical groove part of the track groove 26. At this time, the limit block 23 connected to the bottom end of the connecting rod 22 will enter the vertical groove part of the clamping groove 3. When the cross bar 25 enters the spiral part of the track groove 26, the limit block 23 enters the horizontal groove part of the clamping groove 3. Since the horizontal groove part of the clamping groove 3 is set to an inclined shape, when the limit block 23 is rotated, it can be clamped with the inclined part of the horizontal groove part of the clamping groove 3, thereby realizing rapid installation and fixation between the cover 11 and the bracket 1, and the connecting rods 22 are arranged to be equidistantly distributed, and the connection is strong and easy to operate.

[0062] In an embodiment further provided by the present invention, the sealing mechanism includes a sealing ring 41 fixedly connected to the bracket 1, and two arc-shaped opposing blocks 42 are slidably connected to the bracket 1, and the two arc-shaped opposing blocks 42 are fixedly connected to both sides of the sealing ring 41; wedge-shaped grooves 43 are provided on the two arc-shaped opposing blocks 42, and tension springs 44 are provided between the sides of the two arc-shaped blocks away from each other and the bracket 1, and lateral expansion components are also provided on the two arc-shaped opposing blocks 42, and a plurality of wedge rods 5 are fixedly connected to the mobile frame 21, and the wedge rods 5 and the wedge grooves 43 are driven during the movement of the mobile frame 21. 3 snap fit, when the wedge rod 5 is not snap fit with the wedge groove 43, the elastic force of the tension spring 44 drives the two arc-shaped opposing blocks 42 to move synchronously towards each other, and pulls the sealing ring 41 set on the battery groove of the bracket 1 towards each other, so that the battery on the bracket 1 can be disassembled later. When the wedge rod 5 moves down with the mobile frame 21 and enters the wedge groove in the arc-shaped opposing block 42, the arc-shaped opposing blocks 42 on both sides are driven to move closer, and the stretched sealing ring 41 is reset and squeezed, and the battery unit is wrapped and sealed, so as to improve the sealing and firmness when the bracket 1 is connected to the battery unit.

[0063] Specifically, the lateral expansion component includes a movable rod 61 movably connected to the two sides of the two arc-shaped opposing blocks 42, each movable rod 61 is fixedly connected to a side arc block 62, and each side arc block 62 is fixedly connected to a support rod 63; a plurality of inclined grooves 64 are provided on the bracket 1, each support rod 63 is slidably connected in the corresponding inclined groove 64, and each side arc block 62 is connected to the sealing ring 41. The lateral expansion component is provided so that when the arc-shaped opposing blocks 42 on both sides are synchronously moved away from and the two sides of the sealing ring 41 are pulled apart, the other two sides of the sealing ring 41 can be synchronously expanded, thereby facilitating the installation and disassembly of the battery.

[0064] In the solution further provided by the present invention, the trigger assembly includes a rotating shaft rotatably connected to the cover 11, a positioning handle 71 and a deflection plate 72 are fixedly connected to the rotating shaft, and a linkage bar 73 is fixedly connected to the deflection plate 72; a translation plate 74 is slidably connected to the cover 11, the translation plate 74 is rotatably connected to the linkage bar 73, and both ends of the translation plate 74 are fixedly connected to multi-grooved wedge blocks 75, and a clamping piece is provided on the positioning handle 71 to facilitate clamping and fixing the positioning handle 71 after movement, and by providing this trigger assembly, the installation space of the solid-state battery can be reduced to a certain extent, and it is not easily triggered by other mechanisms after installation.

[0065] A plurality of synchronization rods 76 are fixedly connected to the movable frame 21 , and a wedge top block 77 is fixedly connected to each synchronization rod 76 . The elastic force of the support spring 24 drives each wedge top block 77 to engage with the corresponding groove wedge block 75 .

[0066] Example 1

[0067] Take 0.6 g of sodium bis(trifluoromethylsulfonyl)imide and 2 g of 1-butyl-3-methylimidazole bis(trifluoromethylsulfonyl)imide and stir at room temperature until a clear solution is obtained, which is used as an ion conductive matrix. Add 170 μL of hexafluorobutyl acrylate, 0.00118 g of (3-(methacrylamido)propyl)dimethyl(3-thiopropyl)ammonium hydroxide inner salt, 0.2 mg of photoinitiator 1-hydroxycyclohexylphenyl ketone, and 0.77 mg of cross-linking agent to the sample bottle, stir at room temperature for 1 hour, then add 0.3 ml of conductive matrix and stir at room temperature until a clear solution is obtained. Add the precursor solution in the sample bottle to the mold and obtain a polymer electrolyte by UV polymerization for 6 hours. (As shown in the figure) Figure 1 )

[0068] In the above reaction, sodium salt / plasticizer (mass ratio) = 30%, zwitterionic monomer / fluorinated monomer (mass ratio) = 0.5%, photoinitiator / corresponding monomer (molar ratio) = 0.1%.

[0069] The solid polymer electrolyte was obtained by injection molding and photopolymerization for 6 hours. The room temperature ionic conductivity of the electrolyte was 2.58×10-4 S·cm-1 (such as Figure 2 ), the electrochemical window can reach 4.1 V, and the stretching ratio is about 1000%.

[0070] An electrode was prepared by scraping 20 μm sodium phosphate slurry on aluminum foil, and a button sodium battery was prepared with a structure of sodium phosphate electrode / electrolyte / sodium electrode. The battery capacity reached 112 mAh / g at 2C and the number of cycles could reach 1000.

[0071] Example 2

[0072] Separately, 0.8 g of lithium bis(trifluoromethylsulfonyl)imide and 2 g of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide were stirred at room temperature until a clear solution was obtained. This solution was then used as the ion-conductive matrix. To a sample vial, 170 μL of hexafluorobutyl acrylate, 0.00236 g of (3-(methacrylamido)propyl)dimethyl(3-thiopropyl)ammonium hydroxide inner salt, 0.2 mg of the photoinitiator 1-hydroxycyclohexylphenyl ketone, and 0.77 mg of the crosslinker were added. Stirring was continued at room temperature for 1 hour, followed by the addition of 0.3 ml of the conductive matrix and stirring at room temperature until a clear solution was obtained. The precursor solution in the sample vial was then added to a mold and subjected to UV photopolymerization for 6 hours to obtain a polymer electrolyte.

[0073] In the above reaction, lithium salt / plasticizer (mass ratio) = 40%, zwitterionic monomer / fluorinated monomer (mass ratio) = 1%, photoinitiator / corresponding monomer (molar ratio) = 0.1%.

[0074] The electrode was prepared by scraping 20μm LiNi0.8Co0.1Mn0.1O2 slurry on aluminum foil, and a button sodium battery was prepared with a structure of sodium phosphate electrode / electrolyte / lithium electrode. The battery capacity reached 100mAh / g at 2C. (As Figure 5 )

[0075] Example 3

[0076] Separately, 1 g of sodium bis(trifluoromethylsulfonyl)imide and 2 g of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide were stirred at room temperature until a clear solution was obtained. This solution was then used as the ion-conductive matrix. To a sample vial, 170 μL of hexafluorobutyl acrylate, 0.0118 g of (3-(methacrylamido)propyl)dimethyl(3-thiopropyl)ammonium hydroxide inner salt, 0.2 mg of the photoinitiator 1-hydroxycyclohexylphenyl ketone, and 0.77 mg of the crosslinker were added. Stirring was continued at room temperature for 1 hour, followed by the addition of 0.3 ml of the conductive matrix and stirring at room temperature until a clear solution was obtained. The precursor solution in the sample vial was then added to a mold and subjected to UV photopolymerization for 6 hours to obtain a polymer electrolyte.

[0077] In the above reaction, sodium salt / plasticizer (mass ratio) = 50%, zwitterionic monomer / fluorinated monomer (mass ratio) = 5%, photoinitiator / corresponding monomer (molar ratio) = 0.1%.

[0078] A symmetric sodium-ion battery was prepared with a sodium electrode / electrolyte / sodium electrode structure, and the battery cycle number exceeded 500 cycles at a current density of 0.1 mA / cm2.

[0079] Example 4

[0080] 0.6g of sodium difluorooxalatoborate and 2g of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide were stirred at room temperature until a clear solution was obtained. This was used as the ion-conductive matrix. To a sample vial, 170μL of hexafluorobutyl acrylate, 0.0236g of (3-(methacrylamido)propyl)dimethyl(3-thiopropyl)ammonium hydroxide inner salt, 0.2mg of the photoinitiator 1-hydroxycyclohexylphenyl ketone, and 0.77mg of the crosslinker were added. After stirring at room temperature for 1 hour, 0.3ml of the conductive matrix was added and stirred at room temperature until a clear solution was obtained. The precursor solution in the sample vial was added to a mold and UV-polymerized for 6 hours to obtain a polymer electrolyte.

[0081] In the above reaction, sodium salt / plasticizer (mass ratio) = 30%, zwitterionic monomer / fluorinated monomer (mass ratio) = 10%, photoinitiator / corresponding monomer (molar ratio) = 0.1%.

[0082] The solid polymer electrolyte was obtained by injection molding and photopolymerization for 6 hours. The room temperature ionic conductivity of the electrolyte was 0.58×10-4 S·cm-1 (such as Figure 3), the electrochemical window can reach 3.8 V, and the stretching ratio is about 1000%.

[0083] Electrodes were prepared by scraping 20μm sodium vanadium phosphate slurry on aluminum foil, and solid-state batteries were prepared with a sodium vanadium phosphate / electrolyte / sodium structure. The battery capacity reached 105mAh / g at 2C and the number of cycles could reach 800.

[0084] Example 5

[0085] Separately, 0.8 g of sodium bis(trifluorodifluorooxalatoborate) and 2 g of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide were stirred at room temperature until a clear solution was obtained. This solution was then used as the ion-conductive matrix. To a sample vial, 170 μL of hexafluorobutyl acrylate, 0.0472 g of (3-(methacrylamido)propyl)dimethyl(3-thiopropyl)ammonium hydroxide inner salt, 0.2 mg of the photoinitiator 1-hydroxycyclohexylphenyl ketone, and 0.77 mg of the crosslinker were added. Stirring was continued at room temperature for 1 hour, followed by the addition of 0.3 ml of the conductive matrix and stirring at room temperature until a clear solution was obtained. The precursor solution in the sample vial was then added to a mold and subjected to UV photopolymerization for 6 hours to obtain a polymer electrolyte.

[0086] In the above reaction, sodium salt / plasticizer (mass ratio) = 40%, zwitterionic monomer / fluorinated monomer (mass ratio) = 20%, photoinitiator / corresponding monomer (molar ratio) = 0.1%.

[0087] The solid polymer electrolyte was obtained by injection molding and photopolymerization for 6 hours. The room temperature ionic conductivity of the electrolyte was 4.3×10-4 S·cm-1 (such as Figure 4 ), the electrochemical window can reach 4.2V, and the stretching ratio is about 1000%.

[0088] An electrode was prepared by scraping 20 μm sodium phosphate slurry on aluminum foil, and a button sodium battery was prepared with a structure of sodium phosphate electrode / electrolyte / sodium electrode. The battery capacity reached 120 mAh / g at 1C and the number of cycles could reach 900.

[0089] Example 6

[0090] Separately, 0.6 g of lithium perchlorate and 2 g of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide were stirred at room temperature until a clear solution was obtained. This solution was then used as the ion-conductive matrix. To a sample vial, 170 μL of hexafluorobutyl acrylate, 0.00236 g of (3-(methacrylamido)propyl)dimethyl(3-thiopropyl)ammonium hydroxide inner salt, 0.2 mg of the photoinitiator 1-hydroxycyclohexylphenyl ketone, and 0.77 mg of the crosslinker were added. Stirring was continued at room temperature for 1 hour, followed by the addition of 0.5 ml of the conductive matrix and stirring at room temperature until a clear solution was obtained. The precursor solution in the sample vial was then added to a mold and subjected to UV photopolymerization for 6 hours to obtain a polymer electrolyte.

[0091] In the above reaction, lithium salt / plasticizer (mass ratio) = 30%, zwitterionic monomer / fluorinated monomer (mass ratio) = 1%, photoinitiator / corresponding monomer (molar ratio) = 0.1%.

[0092] An electrode was prepared by scraping 20μm LiFePO4 slurry on aluminum foil, and a solid-state battery was prepared with a LiFePO4 electrode / electrolyte / Li electrode structure. The battery capacity reached 110mAh / g at 2C and the number of cycles could reach 2000.

[0093] Example 7

[0094] Separately, 0.8 g of sodium perchlorate and 2 g of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide were stirred at room temperature until a clear solution was obtained. This solution was then used as the ion-conductive matrix. To a sample vial, 170 μL of hexafluorobutyl acrylate, 0.00236 g of (3-(methacrylamido)propyl)dimethyl(3-thiopropyl)ammonium hydroxide inner salt, 0.2 mg of the photoinitiator 1-hydroxycyclohexylphenyl ketone, and 0.77 mg of the crosslinker were added. Stirring was continued at room temperature for 1 hour, followed by the addition of 0.7 ml of the conductive matrix and stirring at room temperature until a clear solution was obtained. The precursor solution in the sample vial was then added to a mold and subjected to UV photopolymerization for 6 hours to obtain a polymer electrolyte.

[0095] In the above reaction, sodium salt / plasticizer (mass ratio) = 40%, zwitterionic monomer / fluorinated monomer (mass ratio) = 1%, photoinitiator / corresponding monomer (molar ratio) = 0.1%.

[0096] An electrode was prepared by scraping 20 μm sodium phosphate slurry on aluminum foil, and a button sodium battery was prepared with a sodium phosphate electrode / electrolyte / sodium electrode structure. The battery capacity reached 104 mAh / g at 2C.

[0097] Example 8

[0098] Separately, 1 g of sodium perchlorate and 2 g of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide were stirred at room temperature until a clear solution was obtained. This solution was then used as the ion-conductive matrix. To a sample vial, 170 μL of hexafluorobutyl acrylate, 0.00236 g of (3-(methacrylamido)propyl)dimethyl(3-thiopropyl)ammonium hydroxide inner salt, 0.2 mg of the photoinitiator 1-hydroxycyclohexylphenyl ketone, and 0.77 mg of the crosslinker were added. Stirring was continued at room temperature for 1 hour, followed by the addition of 0.9 ml of the conductive matrix and stirring at room temperature until a clear solution was obtained. The precursor solution in the sample vial was then added to a mold and subjected to UV photopolymerization for 6 hours to obtain a polymer electrolyte.

[0099] In the above reaction, sodium salt / plasticizer (mass ratio) = 50%, zwitterionic monomer / fluorinated monomer (mass ratio) = 1%, photoinitiator / corresponding monomer (molar ratio) = 0.1%.

[0100] An electrode was prepared by scraping 20 μm sodium phosphate slurry on aluminum foil, and a button sodium battery was prepared with a sodium phosphate electrode / electrolyte / sodium electrode structure. The battery capacity reached 90 mAh / g at 2C.

[0101] The above description is merely illustrative of certain exemplary embodiments of the present invention. It goes without saying that those skilled in the art will be able to modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims.

Claims

1. A fluorinated zwitterionic polymer electrolyte for solid-state batteries, characterized in that: The fluorinated zwitterionic polymer electrolyte is composed of a polymer skeleton and an ion-conducting matrix, wherein the polymer skeleton is prepared by copolymerizing a zwitterionic monomer, a fluorinated monomer, and an initiator, and the ion-conducting matrix is ​​prepared by mixing a plasticizer with a lithium salt or a sodium salt; The zwitterionic monomers include but are not limited to 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, [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfonic acid propyl)ammonium hydroxide; the fluorine-containing monomers include but are not limited to 2,2,3,4,4,4-hexafluorobutyl acrylate, 2,2,3,4,4,4-hexafluoromethylacrylate, octafluoropentyl acrylate, and heptafluorobutyl acrylate.

Images