A flexible battery prepared by volume additive manufacturing using orthogonal light

Abstract

The application discloses a flexible battery prepared by volume additive manufacturing based on orthogonal light. The technology is applied to 3D printing based on orthogonal light, and the solidification of a 3D printing liquid slurry is carried out by two light beams with different wavelengths and an angle difference of 90 degrees. The flexible battery prepared according to the technology has a core-shell structure, the shell layer is a spherical network structure formed by carbon fibers doped with positive active materials, the inner core is negative active materials loaded on a titanium net, and the shell layer and the inner core are filled with a gel-like electrolyte. The 3D printing technology based on orthogonal light has the advantages of high printing speed and high resolution, and is beneficial to the popularization and application of 3D printed batteries (including zinc ion batteries, lithium ion batteries and other secondary battery systems); the 3D printed battery based on the gel electrolyte has the characteristics of high structural strength, easy bending and deformation resistance, and can be used as a structural battery, and by being appropriately modified, the 3D printed battery can be directly applied to small intelligent devices without additional structural components.

Description

Technical Field

[0001] This invention relates to the field of structural batteries, and more specifically to a flexible battery prepared by volumetric additive manufacturing using orthogonal light. Background Technology

[0002] Rechargeable batteries are electrochemical batteries that can repeatedly convert chemical energy into electrical energy through charging and discharging. After more than a century of development, they are now widely used in human production and daily life. However, current industrially common continuous production processes for rechargeable batteries can only produce specific battery models, offering poor customization. Furthermore, most commercially available rechargeable batteries are non-flexible, making them difficult to apply under special conditions (bending, stretching, and torsional deformation), thus failing to meet the demands of wearable devices, distributed energy storage, and other applications.

[0003] Structural batteries are electrochemical batteries that can function as structural devices. Because they combine load-bearing and energy storage functions, they do not require extensive structural component design, thus improving the overall energy storage capacity of the device. Structural batteries are generally embedded or laminated structures. Laminated structural batteries, in particular, utilize carbon fiber reinforced polymer technology, significantly enhancing the strength of the battery structure. Simultaneously, the carbon fiber composite also improves the material's toughness, allowing the battery to possess both load-bearing capacity and a degree of flexibility. This facilitates implantation in wearable devices, implantable devices, and soft electronic devices, finding applications in specific fields such as healthcare, microelectronics communications, intelligent robots, unmanned systems, wearable combat equipment, and disaster relief equipment.

[0004] Additive manufacturing, also known as 3D printing, is a manufacturing technology that uses computer-aided design (CAD) to create solid parts by adding materials layer by layer. It is advantageous for designing and manufacturing high-precision, complex three-dimensional structures, saving materials while enhancing their structural performance. The advanced development of additive manufacturing technology has opened up new avenues for the design of structural batteries. Using additive manufacturing to produce structural battery devices allows for optimization of battery structure design based on early computer-aided design and simulation of actual operating conditions, enabling mass production with personalized customization. This improves the diversity, flexibility, integration, and safety of designs, facilitating the deeper application of structural batteries. However, increasing the rate of volumetric additive manufacturing at high resolution remains a challenge for the design and production of structural batteries using additive manufacturing technology. Summary of the Invention

[0005] In view of this, the technical problem to be solved by the present invention is to overcome the technical problems of microscale control and high resolution in the production of structural batteries by existing 3D printing, so as to provide a flexible battery prepared by volumetric additive manufacturing using orthogonal light.

[0006] In a first aspect, the present invention provides a flexible battery prepared by volumetric additive manufacturing using orthogonal light, characterized in that the flexible battery is a common secondary battery system and its structure is a core-shell structure.

[0007] Furthermore, the secondary battery system is characterized in that it includes at least one of zinc-ion batteries, lithium-ion batteries, sodium-ion batteries, aluminum-ion batteries, and magnesium-ion batteries.

[0008] Preferably, the secondary battery system is a zinc-ion battery and a lithium-ion battery.

[0009] More preferably, the secondary battery system is a zinc-ion battery.

[0010] Furthermore, the flexible battery shell is a 3D-printed carbon fiber spherical network structure loaded with positive electrode active material, the core layer is a 3D-printed titanium mesh spherical structure loaded with negative electrode active material, and the space between the shell and the core layer is a post-filled gel electrolyte.

[0011] Furthermore, the positive electrode active material is selected from at least one of manganese-based compounds, vanadium-based compounds, layered transition metal oxides, polyanionic compounds, Prussian blue analogs, and organic positive electrode materials; the gel-like electrolyte comprises a polymer matrix, an electrolyte salt, and a solvent.

[0012] Furthermore, the positive electrode active material accounts for 10-25 mg / cm³ of the carbon fiber mass concentration. -2 .

[0013] Further, the polymer matrix includes at least one of chitosan, hyaluronic acid, alginate, sodium carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, agarose, dextran, gelatin, hyaluronic acid gel, polyethylene oxide, polypropylene oxide, poly-L-lysine, poly-L-glutamic acid, fibrin, polyethylene glycol, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylonitrile, polyacrylic acid, polyoxyethylene, polyoxypropylene, polyvinyl chloride, polyvinylidene fluoride, polyacrylamide, polyhydroxyethyl methacrylate, polymethacrylic acid, polyethylene oxide-propylene oxide-ethylene oxide, polyisoacrylamide-acrylamide, polyvinylidene fluoride-hexafluoropropylene, and polyacrylonitrile-methyl methacrylate.

[0014] Furthermore, the electrolyte salt has cations that are at least one of zinc ions, lithium ions, sodium ions, aluminum ions, and magnesium ions, and are the same as the cations participating in the reaction in the battery reaction system; and anions that include at least one of sulfate ions, chloride ions, nitrate ions, acetate ions, methanesulfonate ions, trifluoromethanesulfonate ions, difluorosulfonylimide ions, ditrifluoromethanesulfonylimide ions, hexafluorophosphate ions, tetrafluoroborate ions, difluorooxalateborate ions, and perchlorate ions.

[0015] Further, the solvent includes at least one selected from water, acetonitrile (ACN), tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-MeTHF), 1,3-dioxolane (DOL), 4-methyl-1,3-dioxolane (4-MeDOL), dimethoxymethane (DMM), 1,2-dimethoxyethylene (DME), 1,2-dimethoxypropane (DMP), diethylene glycol dimethyl ether (Diglyme), N-methylpyrrolidone (NMP), propylene carbonate (PC), ethylene carbonate (EC), butenyl carbonate (BC), diethyl carbonate (DEC), dimethyl carbonate (DMC), methyl ethyl carbonate (EMC), methyl propyl carbonate (MPC), fluoroethylene carbonate (FEC), dimethylformamide (DMF), γ-butyrolactone (BL), methyl acetate (MA), and ethyl acetate (EA).

[0016] Furthermore, the concentration of the polymer matrix is ​​the concentration at which the polymer reaches swelling equilibrium.

[0017] Furthermore, the concentration of the electrolyte is 0.1-3 mol / L.

[0018] Preferably, the polymer matrix is ​​sodium alginate or sodium carboxymethyl cellulose; the electrolyte salt is 2 mol / L zinc sulfate or 3 mol / L zinc trifluoromethanesulfonate or 1 mol / L lithium hexafluorophosphate or 1 mol / L lithium bis(trifluoromethanesulfonyl)imide; and the solvent is water or acetonitrile.

[0019] More preferably, the electrolyte salt is 2 mol / L zinc sulfate or 3 mol / L zinc trifluoromethanesulfonate; and the solvent is water.

[0020] Secondly, the present invention provides a flexible battery fabrication technology using orthogonal light for volumetric additive manufacturing, characterized in that 3D printing liquid slurry is solidified by using two orthogonal light beams of different wavelengths with an angle difference of 90°.

[0021] Furthermore, the orthogonal beams of different wavelengths are characterized in that the irradiation time of the orthogonal beams spans the entire additive manufacturing process; their wavelengths are respectively located at the absorption peaks of the initial and latent states of the two-color photoinitiator molecules, so that the photoinitiator molecules absorb the light of the first wavelength and are activated to enter the latent state, and continue to absorb the light of the second wavelength to initiate photopolymerization.

[0022] Preferably, the photoinitiator is benzophenone-spiropyran, and the wavelengths of the orthogonal beams are 375 nm and 600 nm, respectively.

[0023] Furthermore, the 3D printing liquid slurry includes a positive electrode slurry and a negative electrode slurry.

[0024] Furthermore, the positive electrode slurry includes a positive electrode active material, a conductive agent, a binder, and water; the negative electrode slurry includes a negative electrode active material, titanium powder, a conductive agent, a binder, and water.

[0025] Furthermore, the positive electrode active material is selected from at least one of manganese-based compounds, vanadium-based compounds, layered transition metal oxides, polyanionic compounds, Prussian blue analogs, and organic positive electrode materials.

[0026] Preferably, the positive electrode active material is at least one of manganese dioxide, manganese trioxide, lithium manganese oxide, vanadium dioxide, vanadium monoxide, vanadium pentoxide, sodium vanadium phosphate, lithium cobalt oxide, lithium iron phosphate, lithium nickel cobalt manganese oxide, and lithium nickel cobalt aluminum oxide.

[0027] Furthermore, the negative electrode active material is at least one of zinc powder, lithium titanate, graphite, hard carbon, soft carbon, titanium dioxide, molybdenum disulfide, aluminum powder, and magnesium powder.

[0028] Beneficial effects

[0029] The technical solution of this invention has the following advantages:

[0030] 1. This invention provides a flexible battery fabricated using orthogonal light in volumetric additive manufacturing, characterized in that the flexible battery has a core-shell structure. The spherical latitude and longitude structure of the shell layer helps to disperse external forces, enabling the battery to function as a self-supporting structural battery without the need for external structural components; simultaneously, the outer shell layer also helps to protect the negative electrode active species deposited on the titanium current collector, preventing stress accumulation during flexible deformation.

[0031] 2. The flexible battery provided by this invention comprises a shell layer of a 3D-printed carbon fiber reinforced spherical network structure loaded with positive electrode active material, a core layer of a 3D-printed titanium mesh loaded with negative electrode active material forming a spherical structure, and a gel-like electrolyte filled between the shell and core layers. The carbon fiber reinforced spherical network shell layer serves as both the positive electrode current collector and the structural support for the battery. Simultaneously, the carbon fiber also provides auxiliary toughening, significantly improving the flexibility of the battery structure. The spherical structure formed by the layered encapsulation and combination of the titanium layers loaded with active material possesses the dual characteristics of an "onion" structure with layered encapsulation and a "house of cards" structure with interlayered combinations, facilitating reversible deposition-stripping or insertion-extraction of conductive cations using it as a current collector. The gel electrolyte serves to isolate the positive and negative electrode active materials from the conductive ions and provides stress buffering for the flexible battery, enhancing its flexibility.

[0032] 3. This invention provides a flexible battery fabrication technology using orthogonal light for volumetric additive manufacturing. The key feature is the solidification of the 3D-printed liquid slurry using two beams of different wavelengths with a 90° angle difference. Additive manufacturing technology can optimize the surface morphology of the electrodes, avoiding the rapid degradation of battery performance caused by large-scale inhomogeneities in the initial morphology (e.g., scratches on the surface of large-scale zinc foil or titanium current collectors), thus improving the battery's electrochemical performance. Using additive manufacturing technology for carbon fiber-assisted toughening allows the printed battery to possess both structural load-bearing capacity and a certain degree of flexibility, enriching the applications of the manufactured batteries in healthcare, microelectronics communications, and intelligent robotics. Furthermore, using additive manufacturing for battery design and assembly can yield electrochemical energy storage devices with resolutions ranging from hundreds of nanometers to several millimeters, providing a convenient pathway for producing micro / miniaturized batteries. It also optimizes production lines, eliminating the calendering and clamping steps typically involved in current commercial lithium-ion battery production. Meanwhile, the technology provided by this invention uses two beams of light of different wavelengths for dual-color photopolymerization. The transparent photoinitiator molecules absorb the light of the first wavelength and are activated by it, and absorb the light of the second wavelength to start photopolymerization, thereby greatly improving the volumetric generation rate of additive manufacturing, so that the additive manufacturing technology has a faster 3D printing rate even at high resolution. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the specific embodiments of the present invention, the drawings used in the description of the specific embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0034] Figure 1This is a schematic diagram of Embodiment 1 of the flexible zinc-ion battery provided by the present invention;

[0035] Figure 2 A schematic diagram of Embodiment 2 of the flexible zinc-ion battery provided by the present invention;

[0036] Figure 3 A schematic diagram of Embodiment 3 of the flexible zinc-ion battery provided by the present invention;

[0037] Figure 4 A schematic diagram of Embodiment 4 of the flexible lithium-ion battery provided by the present invention;

[0038] Figure 5 A schematic diagram of Example 5 of the flexible zinc-ion battery provided by the present invention;

[0039] Figure 6 A schematic diagram of Embodiment 6 of the flexible zinc-ion battery provided by the present invention;

[0040] Figure 7 A schematic diagram of Embodiment 7 of the flexible zinc-ion battery provided by the present invention;

[0041] Figure 8 This is a graph showing the cycle test results of the Zn||LiMn2O4 full cell in Test Example 1 of this invention;

[0042] Figure 9 This is a charge-discharge curve of the Zn||LiMn2O4 full cell in Test Example 1 of this invention at weeks 10, 30, and 50. Detailed Implementation

[0043] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0044] Where specific experimental steps or conditions are not specified in the examples, they can be performed according to the conventional experimental steps or conditions described in the literature in this field. Raw materials whose manufacturers are not specified are all commercially available reagent products or prepared according to literature.

[0045] Example 1

[0046] A flexible zinc-ion battery is prepared by the following method:

[0047] (1) Weigh 700 mg of MnO2 and 200 mg of acetylene black, mix them, add them to a mortar, grind for 30 min, and then measure 200 μL of 500 mg / mL. -1A polyvinylidene fluoride (PVDF) solution was mixed with 1 mL of N-methylpyrrolidone and ground for 15 minutes until the mixture was slightly fluid and free of large particles when the mortar was tilted. This mixture was then added to a photocuring system containing short carbon fibers (the photoinitiator was benzophenone-spiropyran), and further supplemented with an appropriate amount of N-methylpyrrolidone. A high-speed rotating mixer was used to prepare the 3D printing cathode ink. The ink was then vacuum filtered to remove larger particles, allowed to stand at room temperature for 24 hours, and then loaded into the first 3D printing syringe.

[0048] (2) Mix nano-active zinc with titanium powder at a ratio of 1:1 (m. / m.), weigh 700 mg of the mixture and 200 mg of acetylene black, mix them together, add them to a mortar, grind for 30 min, and then measure 200 μL of 500 mg / mL. -1 A polyvinylidene fluoride (PVDF) solution was mixed with 1 mL of N-methylpyrrolidone and ground for 15 minutes until the mixture was slightly fluid and free of large particles when the mortar was tilted. This mixture was then added to a photocuring system (using benzophenone-spiropyran as a dual-color photoinitiator), and further supplemented with an appropriate amount of N-methylpyrrolidone. A high-speed rotating mixer was used to prepare the 3D printing negative electrode ink. The ink was then vacuum filtered to remove larger particles, allowed to stand at room temperature for 24 hours, and then loaded into a second 3D printing syringe.

[0049] (3) Develop a printing program based on the designed core-shell structure and input the program into the multi-needle 3D printer. Turn on the air compressor and adjust the pressure to 0.7MPa. Fix the needles to be used in the corresponding positions on the 3D printer. Set the printing speed to 120μm / s, the substrate temperature to 25℃, and the wavelengths of the two orthogonal beams to 375nm and 600nm, respectively. Place the cleaned glass plate on the printing stage and start 3D printing.

[0050] (4) After the electrode paste is printed, the printed core-shell structure is immersed in deionized water for 12 hours, then taken out, the surface moisture is dried, and it is pre-frozen in a refrigerator for 2 hours. Then it is immediately transferred to a freeze dryer and freeze-dried at -50 to -20°C for 8 hours.

[0051] (5) Prepare 50mL of 2MZnSO4+1MnSO4 solution, add 3.5g of alginic acid to it, stir evenly, and slowly add 2mL of 50% sodium hydroxide aqueous solution with constant pressure dropping funnel while stirring continuously. Cast the solution into the printed core-shell structure (the core-shell structure is covered with a polytetrafluoroethylene mold), dry at room temperature for 24h to allow the solvent to evaporate naturally, and then place it in a 50℃ oven to continue drying for 48h to allow the solvent to evaporate completely. After drying, the finished zinc-ion battery with core-shell structure is obtained.

[0052] Example 2

[0053] A flexible zinc-ion battery is prepared by the following method:

[0054] (1) Weigh 700 mg of VO2 and 200 mg of acetylene black, mix them, add them to a mortar, grind for 30 min, and then measure 200 μL of 500 mg / mL. -1 A polyvinylidene fluoride (PVDF) solution was mixed with 1 mL of N-methylpyrrolidone and ground for 15 minutes until the mixture was slightly fluid and free of large particles when the mortar was tilted. This mixture was then added to a photocuring system containing short carbon fibers (the photoinitiator was benzophenone-spiropyran), and further supplemented with an appropriate amount of N-methylpyrrolidone. A high-speed rotating mixer was used to prepare the 3D printing cathode ink. The ink was then vacuum filtered to remove larger particles, allowed to stand at room temperature for 24 hours, and then loaded into the first 3D printing syringe.

[0055] (2) Mix nano-active zinc with titanium powder at a ratio of 1:1 (m. / m.), weigh 700 mg of the mixture and 200 mg of acetylene black, mix them together, add them to a mortar, grind for 30 min, and then measure 200 μL of 500 mg / mL. -1 A polyvinylidene fluoride (PVDF) solution was mixed with 1 mL of N-methylpyrrolidone and ground for 15 minutes until the mixture was slightly fluid and free of large particles when the mortar was tilted. This mixture was then added to a photocuring system (using benzophenone-spiropyran as a dual-color photoinitiator), and further supplemented with an appropriate amount of N-methylpyrrolidone. A high-speed rotating mixer was used to prepare the 3D printing negative electrode ink. The ink was then vacuum filtered to remove larger particles, allowed to stand at room temperature for 24 hours, and then loaded into a second 3D printing syringe.

[0056] (3) Develop a printing program based on the designed core-shell structure and input the program into the multi-needle 3D printer. Turn on the air compressor and adjust the pressure to 0.7MPa. Fix the needles to be used in the corresponding positions on the 3D printer. Set the printing speed to 120μm / s, the substrate temperature to 25℃, and the wavelengths of the two orthogonal beams to 375nm and 600nm, respectively. Place the cleaned glass plate on the printing stage and start 3D printing.

[0057] (4) After the electrode paste is printed, the printed core-shell structure is immersed in deionized water for 12 hours, then taken out, the surface moisture is dried, and it is pre-frozen in a refrigerator for 2 hours. Then it is immediately transferred to a freeze dryer and freeze-dried at -50 to -20°C for 8 hours.

[0058] (5) Prepare 50 mL of 2 M ZnSO4 solution, add 3.5 g of alginic acid to it, stir evenly, and slowly add 2 mL of 50% sodium hydroxide aqueous solution with constant pressure using a dropping funnel while stirring continuously. Cast the solution into the printed core-shell structure (the core-shell structure is covered with a polytetrafluoroethylene mold), dry at room temperature for 24 h to allow the solvent to evaporate naturally, and then place it in a 50℃ oven to continue drying for 48 h to allow the solvent to evaporate completely. After drying, the finished zinc-ion battery with a core-shell structure is obtained.

[0059] Example 3

[0060] A flexible zinc-ion battery is prepared by the following method:

[0061] (1) Weigh 700 mg of LiMn2O4 and 200 mg of acetylene black, mix them, add them to a mortar, grind for 30 min, and then measure 200 μL of 500 mg / mL. -1 A polyvinylidene fluoride (PVDF) solution was mixed with 1 mL of N-methylpyrrolidone and ground for 15 minutes until the mixture was slightly fluid and free of large particles when the mortar was tilted. This mixture was then added to a photocuring system containing short carbon fibers (the photoinitiator was benzophenone-spiropyran), and further supplemented with an appropriate amount of N-methylpyrrolidone. A high-speed rotating mixer was used to prepare the 3D printing cathode ink. The ink was then vacuum filtered to remove larger particles, allowed to stand at room temperature for 24 hours, and then loaded into the first 3D printing syringe.

[0062] (2) Mix nano-active zinc with titanium powder at a ratio of 1:1 (m. / m.), weigh 700 mg of the mixture and 200 mg of acetylene black, mix them together, add them to a mortar, grind for 30 min, and then measure 200 μL of 500 mg / mL. -1 A polyvinylidene fluoride (PVDF) solution was mixed with 1 mL of N-methylpyrrolidone and ground for 15 minutes until the mixture was slightly fluid and free of large particles when the mortar was tilted. This mixture was then added to a photocuring system (using benzophenone-spiropyran as a dual-color photoinitiator), and further supplemented with an appropriate amount of N-methylpyrrolidone. A high-speed rotating mixer was used to prepare the 3D printing negative electrode ink. The ink was then vacuum filtered to remove larger particles, allowed to stand at room temperature for 24 hours, and then loaded into a second 3D printing syringe.

[0063] (3) Develop a printing program based on the designed core-shell structure and input the program into the multi-needle 3D printer. Turn on the air compressor and adjust the pressure to 0.7MPa. Fix the needles to be used in the corresponding positions on the 3D printer. Set the printing speed to 120μm / s, the substrate temperature to 25℃, and the wavelengths of the two orthogonal beams to 375nm and 600nm, respectively. Place the cleaned glass plate on the printing stage and start 3D printing.

[0064] (4) After the electrode paste is printed, the printed core-shell structure is immersed in deionized water for 12 hours, then taken out, the surface moisture is dried, and it is pre-frozen in a refrigerator for 2 hours. Then it is immediately transferred to a freeze dryer and freeze-dried at -50 to -20°C for 8 hours.

[0065] (5) Prepare 50 mL of 2 M ZnSO4 + 1 M Li2SO4 solution, add 3.5 g of alginic acid to it, stir evenly, and slowly add 2 mL of 50% sodium hydroxide aqueous solution with constant pressure dropping funnel while stirring continuously. Cast the solution into the printed core-shell structure (the core-shell structure is covered with a polytetrafluoroethylene mold), dry at room temperature for 24 h to allow the solvent to evaporate naturally, and then place it in a 50℃ oven to continue drying for 48 h to allow the solvent to evaporate completely. After drying, the finished zinc-ion battery with core-shell structure is obtained.

[0066] Example 4

[0067] A flexible lithium-ion battery is prepared by the following method:

[0068] (1) Weigh 700 mg of LiCoO2 and 200 mg of acetylene black, mix them, add them to a mortar, grind for 30 min, and then measure 200 μL of 500 mg / mL. -1 A polyvinylidene fluoride (PVDF) solution was mixed with 1 mL of N-methylpyrrolidone and ground for 15 minutes until the mixture was slightly fluid and free of large particles when the mortar was tilted. This mixture was then added to a photocuring system containing short carbon fibers (the photoinitiator was benzophenone-spiropyran), and further supplemented with an appropriate amount of N-methylpyrrolidone. A high-speed rotating mixer was used to prepare the 3D printing cathode ink. The ink was then vacuum filtered to remove larger particles, allowed to stand at room temperature for 24 hours, and then loaded into the first 3D printing syringe.

[0069] (2) Mix artificial graphite and titanium powder in a 1:1 ratio (m. / m.), weigh 700 mg of the mixture and 200 mg of acetylene black, mix them together, add them to a mortar, grind for 30 min, and then measure 200 μL of 500 mg / mL. -1 A polyvinylidene fluoride (PVDF) solution was mixed with 1 mL of N-methylpyrrolidone and ground for 15 minutes until the mixture was slightly fluid and free of large particles when the mortar was tilted. This mixture was then added to a photocuring system (using benzophenone-spiropyran as a dual-color photoinitiator), and further supplemented with an appropriate amount of N-methylpyrrolidone. A high-speed rotating mixer was used to prepare the 3D printing negative electrode ink. The ink was then vacuum filtered to remove larger particles, allowed to stand at room temperature for 24 hours, and then loaded into a second 3D printing syringe.

[0070] (3) Develop a printing program based on the designed core-shell structure and input the program into the multi-needle 3D printer. Turn on the air compressor and adjust the pressure to 0.7MPa. Fix the needles to be used in the corresponding positions on the 3D printer. Set the printing speed to 120μm / s, the substrate temperature to 25℃, and the wavelengths of the two orthogonal beams to 375nm and 600nm, respectively. Place the cleaned glass plate on the printing stage and start 3D printing.

[0071] (4) After the electrode paste is printed, the printed core-shell structure is immersed in deionized water for 12 hours, then taken out, the surface moisture is dried, and it is pre-frozen in a refrigerator for 2 hours. Then it is immediately transferred to a freeze dryer and freeze-dried at -50 to -20°C for 8 hours.

[0072] (5) Measure 50 mL of anhydrous acetonitrile, add 0.3 g of lithium hexafluorophosphate and 3.0 g of polyethylene oxide, stir evenly, and then cast the solution into the printed core-shell structure (the core-shell structure is covered with a polytetrafluoroethylene mold) in a glove box where the concentration of water and oxygen is less than 0.1 ppm. Dry at room temperature for 24 h to allow the solvent to evaporate naturally. Then heat the glove box to 50 °C and continue drying for 48 h to allow the solvent to evaporate completely. After drying, immerse the resulting gel in a 1 M LiPF6 EC / DMC (v. / v. 1:1) solution in an inert atmosphere to obtain the finished lithium-ion battery with a core-shell structure.

[0073] Example 5

[0074] A flexible zinc-ion battery is prepared by the following method:

[0075] (1) Weigh 700 mg of MnO2 and 200 mg of acetylene black, mix them, add them to a mortar, grind for 30 min, and then measure 200 μL of 500 mg / mL. -1 A polyvinylidene fluoride (PVDF) solution was mixed with 1 mL of N-methylpyrrolidone and ground for 15 minutes until the mixture was slightly fluid and free of large particles when the mortar was tilted. This mixture was then added to a photocuring system containing short carbon fibers (the photoinitiator was benzophenone-spiropyran), and further supplemented with an appropriate amount of N-methylpyrrolidone. A high-speed rotating mixer was used to prepare the 3D printing cathode ink. The ink was then vacuum filtered to remove larger particles, allowed to stand at room temperature for 24 hours, and then loaded into the first 3D printing syringe.

[0076] (2) Mix nano-active zinc with titanium powder at a ratio of 1:1 (m. / m.), weigh 700 mg of the mixture and 200 mg of acetylene black, mix them together, add them to a mortar, grind for 30 min, and then measure 200 μL of 500 mg / mL. -1A polyvinylidene fluoride (PVDF) solution was mixed with 1 mL of N-methylpyrrolidone and ground for 15 minutes until the mixture was slightly fluid and free of large particles when the mortar was tilted. This mixture was then added to a photocuring system (using benzophenone-spiropyran as a dual-color photoinitiator), and further supplemented with an appropriate amount of N-methylpyrrolidone. A high-speed rotating mixer was used to prepare the 3D printing negative electrode ink. The ink was then vacuum filtered to remove larger particles, allowed to stand at room temperature for 24 hours, and then loaded into a second 3D printing syringe.

[0077] (3) Develop a printing program based on the designed core-shell structure and input the program into the multi-needle 3D printer. Turn on the air compressor and adjust the pressure to 0.7MPa. Fix the needles to be used in the corresponding positions on the 3D printer. Set the printing speed to 120μm / s, the substrate temperature to 25℃, and the wavelengths of the two orthogonal beams to 375nm and 600nm, respectively. Place the cleaned glass plate on the printing stage and start 3D printing.

[0078] (4) After the electrode paste is printed, the printed core-shell structure is immersed in deionized water for 12 hours, then taken out, the surface moisture is dried, and it is pre-frozen in a refrigerator for 2 hours. Then it is immediately transferred to a freeze dryer and freeze-dried at -50 to -20°C for 8 hours.

[0079] (5) Prepare 50 mL of 1 M ZnSO4 + 1 M N SO4 solution, add 3.5 g of alginic acid to it, stir evenly, and slowly add 2 mL of 50% sodium hydroxide aqueous solution with constant pressure dropping funnel while stirring continuously. Cast the solution into the printed core-shell structure (the core-shell structure is covered with a polytetrafluoroethylene mold), dry at room temperature for 24 h to allow the solvent to evaporate naturally, and then place it in a 50℃ oven to continue drying for 48 h to allow the solvent to evaporate completely. After drying, the finished zinc-ion battery with core-shell structure is obtained.

[0080] Example 6

[0081] A flexible zinc-ion battery is prepared by the following method:

[0082] (1) Weigh 700 mg of MnO2 and 200 mg of acetylene black, mix them, add them to a mortar, grind for 30 min, and then measure 200 μL of 500 mg / mL. -1A polyvinylidene fluoride (PVDF) solution was mixed with 1 mL of N-methylpyrrolidone and ground for 15 minutes until the mixture was slightly fluid and free of large particles when the mortar was tilted. This mixture was then added to a photocuring system containing short carbon fibers (the photoinitiator was benzophenone-spiropyran), and further supplemented with an appropriate amount of N-methylpyrrolidone. A high-speed rotating mixer was used to prepare the 3D printing cathode ink. The ink was then vacuum filtered to remove larger particles, allowed to stand at room temperature for 24 hours, and then loaded into the first 3D printing syringe.

[0083] (2) Mix nano-active zinc with titanium powder at a ratio of 1:1 (m. / m.), weigh 700 mg of the mixture and 200 mg of acetylene black, mix them together, add them to a mortar, grind for 30 min, and then measure 200 μL of 500 mg / mL. -1 A polyvinylidene fluoride (PVDF) solution was mixed with 1 mL of N-methylpyrrolidone and ground for 15 minutes until the mixture was slightly fluid and free of large particles when the mortar was tilted. This mixture was then added to a photocuring system (using benzophenone-spiropyran as a dual-color photoinitiator), and further supplemented with an appropriate amount of N-methylpyrrolidone. A high-speed rotating mixer was used to prepare the 3D printing negative electrode ink. The ink was then vacuum filtered to remove larger particles, allowed to stand at room temperature for 24 hours, and then loaded into a second 3D printing syringe.

[0084] (3) Develop a printing program based on the designed core-shell structure and input the program into the multi-needle 3D printer. Turn on the air compressor and adjust the pressure to 0.7MPa. Fix the needles to be used in the corresponding positions on the 3D printer. Set the printing speed to 120μm / s, the substrate temperature to 25℃, and the wavelengths of the two orthogonal beams to 375nm and 600nm, respectively. Place the cleaned glass plate on the printing stage and start 3D printing.

[0085] (4) After the electrode paste is printed, the printed core-shell structure is immersed in deionized water for 12 hours, then taken out, the surface moisture is dried, and it is pre-frozen in a refrigerator for 2 hours. Then it is immediately transferred to a freeze dryer and freeze-dried at -50 to -20°C for 8 hours.

[0086] (5) Prepare 50 mL of 2MZn(OTf)2 solution, add 3.5 g of alginic acid to it, stir evenly, and slowly add 2 mL of 50% sodium hydroxide aqueous solution with constant pressure dropping funnel while stirring continuously. Cast the solution into the printed core-shell structure (the core-shell structure is covered with a polytetrafluoroethylene mold), dry at room temperature for 24 h to allow the solvent to evaporate naturally, and then place it in a 50℃ oven to continue drying for 48 h to allow the solvent to evaporate completely. After drying, the finished zinc-ion battery with core-shell structure is obtained.

[0087] Example 7

[0088] A flexible zinc-ion battery is prepared by the following method:

[0089] (1) Weigh 700 mg of MnO2 and 200 mg of acetylene black, mix them, add them to a mortar, grind for 30 min, and then measure 200 μL of 500 mg / mL. -1 A polyvinylidene fluoride (PVDF) solution was mixed with 1 mL of N-methylpyrrolidone and ground for 15 minutes until the mixture was slightly fluid and free of large particles when the mortar was tilted. This mixture was then added to a photocuring system containing short carbon fibers (the photoinitiator was benzophenone-spiropyran), and further supplemented with an appropriate amount of N-methylpyrrolidone. A high-speed rotating mixer was used to prepare the 3D printing cathode ink. The ink was then vacuum filtered to remove larger particles, allowed to stand at room temperature for 24 hours, and then loaded into the first 3D printing syringe.

[0090] (2) Mix nano-active zinc with titanium powder at a ratio of 1:1 (m. / m.), weigh 700 mg of the mixture and 200 mg of acetylene black, mix them together, add them to a mortar, grind for 30 min, and then measure 200 μL of 500 mg / mL. -1 A polyvinylidene fluoride (PVDF) solution was mixed with 1 mL of N-methylpyrrolidone and ground for 15 minutes until the mixture was slightly fluid and free of large particles when the mortar was tilted. This mixture was then added to a photocuring system (using benzophenone-spiropyran as a dual-color photoinitiator), and further supplemented with an appropriate amount of N-methylpyrrolidone. A high-speed rotating mixer was used to prepare the 3D printing negative electrode ink. The ink was then vacuum filtered to remove larger particles, allowed to stand at room temperature for 24 hours, and then loaded into a second 3D printing syringe.

[0091] (3) Develop a printing program based on the designed core-shell structure and input the program into the multi-needle 3D printer. Turn on the air compressor and adjust the pressure to 0.7MPa. Fix the needles to be used in the corresponding positions on the 3D printer. Set the printing speed to 120μm / s, the substrate temperature to 25℃, and the wavelengths of the two orthogonal beams to 375nm and 600nm, respectively. Place the cleaned glass plate on the printing stage and start 3D printing.

[0092] (4) After the electrode paste is printed, the printed core-shell structure is immersed in deionized water for 12 hours, then taken out, the surface moisture is dried, and it is pre-frozen in a refrigerator for 2 hours. Then it is immediately transferred to a freeze dryer and freeze-dried at -50 to -20°C for 8 hours.

[0093] (5) Prepare a 50mL solution of 2MZnSO4 + 1MnSO4, add crosslinking agent and preservative to it, stir rapidly for 15min, then slowly add 0.375g sodium carboxymethyl cellulose while stirring continuously. Cast the solution into the printed core-shell structure (the core-shell structure is covered with a polytetrafluoroethylene mold), dry at room temperature for 24h to allow the solvent to evaporate naturally, and then place it in a 50℃ oven to continue drying for 48h to allow the solvent to evaporate completely. After drying, the finished zinc-ion battery with core-shell structure is obtained.

[0094] Test Example 1

[0095] A core-shell structured flexible zinc-ion battery was obtained according to the method in Example 3, tabs were added, and it was encapsulated using an aluminum-plastic film. The battery was tested at a rate of 2C (1C = 148 mAh g). -1 The charge-discharge test was performed under these conditions, and the test results are as follows: Figure 1 As shown; the charge-discharge curves of the experimental group at weeks 10, 30, and 50 are as follows. Figure 2 As shown.

[0096] Depend on Figure 1 It can be seen that the full cell obtained using the method of Example 3 exhibits a relatively slow rate of capacity decrease and stable cycle performance during 100 cycles; its overall coulombic efficiency is also high, reaching 98.96%. Figure 2 It can be seen that the battery's discharge plateau is 1.7-1.9V, which is long and stable, and the discharge specific capacity can always be maintained at 110mAhg. -1 The capacity remains good. Figure 1 and Figure 2 All of these studies demonstrate the excellent electrochemical performance of the batteries prepared by this method.

[0097] The flexible batteries provided in other embodiments were tested using the same method described above, and all showed good discharge capacity and cycle stability, with a coulombic efficiency close to 100%. This further demonstrates that the proposed flexible battery, prepared by volumetric additive manufacturing based on orthogonal light, has superior flexibility, high capacity, and long service life, and can be used as a structural battery for further promotion and application.

[0098] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A flexible battery fabricated using orthogonal light in volumetric additive manufacturing, characterized in that, The flexible battery is a common secondary battery system with a core-shell structure. The shell is a 3D-printed carbon fiber spherical network structure loaded with positive electrode active material, and the core is a 3D-printed spherical structure loaded with negative electrode active material. The space between the shell and the core is filled with a gel-like electrolyte. The orthogonal light consists of two beams with different wavelengths and an angle difference of 90°.

2. The flexible battery fabricated using orthogonal light for volumetric additive manufacturing according to claim 1, characterized in that, The secondary battery system includes zinc-ion batteries and lithium-ion batteries.

3. The flexible battery fabricated using orthogonal light for volumetric additive manufacturing according to claim 1, characterized in that, The carbon fiber spherical network structure is a warp and weft structure; the positive electrode active material accounts for 10-25 mg / cm³ of the carbon fiber mass concentration. -2 .

4. The flexible battery fabricated using orthogonal light for volumetric additive manufacturing according to claim 1, characterized in that, The gel-like electrolyte comprises a polymer matrix, an electrolyte salt, and a solvent.

5. The flexible battery according to claim 4, characterized in that, The polymer matrix includes at least one of chitosan, hyaluronic acid, alginate, sodium carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, agarose, dextran, gelatin, polyethylene oxide, polypropylene oxide, poly-L-lysine, poly-L-glutamic acid, fibrin, polyethylene glycol, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylonitrile, polyacrylic acid, polyoxyethylene, polyoxypropylene, polyvinyl chloride, polyvinylidene fluoride, polyacrylamide, polyhydroxyethyl methacrylate, polymethacrylic acid, ethylene oxide-propylene oxide-ethylene oxide, polyisoacrylamide-acrylamide, polyvinylidene fluoride-hexafluoropropylene, and polyacrylonitrile-methyl methacrylate.

6. The flexible battery according to claim 4, characterized in that, The electrolyte salt has a cation that is at least one of zinc ions and lithium ions, and is the same as the cation that participates in the reaction in the battery reaction system; the anion includes at least one of sulfate ions, chloride ions, nitrate ions, acetate ions, methanesulfonate ions, trifluoromethanesulfonate ions, difluorosulfonylimide ions, ditrifluoromethanesulfonylimide ions, hexafluorophosphate ions, tetrafluoroborate ions, difluorooxalateborate ions, and perchlorate ions; the concentration of the electrolyte salt is 0.1-3 mol / L.

7. The flexible battery according to claim 4, characterized in that, The solvent includes at least one of water, acetonitrile (ACN), tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-MeTHF), 1,3-dioxolane (DOL), 4-methyl-1,3-dioxolane (4-MeDOL), dimethoxymethane (DMM), 1,2-dimethoxyethylene (DME), 1,2-dimethoxypropane (DMP), diethylene glycol dimethyl ether (Diglyme), N-methylpyrrolidone (NMP), propylene carbonate (PC), ethylene carbonate (EC), butenyl carbonate (BC), diethyl carbonate (DEC), dimethyl carbonate (DMC), methyl ethyl carbonate (EMC), methyl propyl carbonate (MPC), fluoroethylene carbonate (FEC), dimethylformamide (DMF), γ-butyrolactone (BL), methyl acetate (MA), and ethyl acetate (EA).

8. The flexible battery according to claim 1, characterized in that, The positive electrode active material of the flexible battery is selected from at least one of manganese dioxide, manganese trioxide, lithium manganese oxide, vanadium dioxide, vanadium monoxide, vanadium pentoxide, lithium cobalt oxide, lithium iron phosphate, lithium nickel cobalt manganese oxide, and lithium nickel cobalt aluminum oxide.

9. The flexible battery according to claim 1, characterized in that, The negative electrode active material of the flexible battery is selected from at least one of zinc powder, lithium titanate, graphite, hard carbon, soft carbon, titanium dioxide, molybdenum disulfide, aluminum powder, and magnesium powder.

10. A method for fabricating a flexible battery using orthogonal light volumetric additive manufacturing according to claim 1, characterized in that, The liquid slurry for 3D printing is cured by using two beams of different wavelengths with an angle difference of 90°.

11. The preparation method according to claim 10, characterized in that, The flexible battery fabrication method uses a light beam whose wavelength is located at the absorption peaks of the initial and latent states of the two-color photoinitiator molecules, and the photoinitiator is benzophenone and spiropyran; the 3D printing liquid slurry includes a positive electrode slurry and a negative electrode slurry.

12. The preparation method according to claim 11, characterized in that, The positive electrode slurry includes a positive electrode active material, short carbon fibers, a conductive agent, a binder, and water; the negative electrode slurry includes a negative electrode active material, titanium powder, a conductive agent, a binder, and water.

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