3D coaxial printing flame-retardant intelligent solid-state lithium battery and preparation method thereof
Patent Information
- Application Number
- CN202611014581.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-09
- Publication Date
- 2026-09-15
Smart Images
Figure CN122762844A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of lithium batteries, specifically a 3D coaxial printed flame-retardant smart solid-state lithium battery and its preparation method. Background Technology
[0002] With the world's energy consumption increasing daily, severe environmental pollution and energy shortages are occurring, hindering sustainable development. Therefore, developing low-carbon, stable, and safe energy storage technologies has become crucial for addressing environmental pollution and the energy crisis. Lithium-ion batteries, due to their environmental friendliness, high energy density, and long cycle life, are widely used in portable electronic devices and electric vehicles. With the increasing demand for higher energy density, lithium metal batteries have received widespread attention. However, spontaneous side reactions between the lithium metal anode and the liquid electrolyte can form an unstable SEI film, shortening battery life. Furthermore, the flammability of liquid electrolytes poses significant safety hazards such as leakage, combustion, and even explosion. Solid-state electrolytes, due to their high safety and stability, have become key to solving the safety problems of lithium metal batteries.
[0003] However, solid-state electrolytes also present some challenges. For example, deformation from bending or impact can cause minute, undetectable damage to the solid electrolyte, reducing the cycle life of lithium metal batteries and posing a risk of combustion. Studies have shown that solid-state electrolytes burn faster than lithium-ion batteries, making them more dangerous. Directly adding flame retardants to the electrolyte can severely negatively impact the electrochemical performance of lithium metal batteries. Therefore, to enable lithium metal batteries to possess a certain degree of self-healing capability to withstand deformation during use, without affecting their electrochemical performance during normal use after adding flame retardants, and to respond quickly and suppress combustion in the event of combustion, a flame-retardant solid-state lithium metal battery fabrication method based on [the specific technology / method] is proposed. Summary of the Invention
[0004] To address the aforementioned technical problems, this invention provides a method for preparing a 3D coaxially printed flame-retardant smart solid-state lithium battery, thereby resolving the issues in the prior art.
[0005] A method for fabricating a 3D coaxially printed flame-retardant smart solid-state lithium battery includes the following steps:
[0006] S1. Add flame-retardant organic compounds and vinylidene fluoride to an organic solution and dissolve them to obtain a precursor organic compound solution;
[0007] S2. Add vinylidene fluoride, polyhydroxy organic powder, and filler to the organic solution and dissolve to obtain a precursor mixed solution;
[0008] S3. The precursor organic solution and the precursor mixture solution are coaxially printed onto a glass plate using the syringe of the 3D printer;
[0009] S4. Perform post-processing operations on the substrate printed onto the glass plate;
[0010] S5. Immerse the post-processed sample in a borate aqueous solution and cure it through solvent exchange;
[0011] S6. The cured sample is dried to obtain a flame-retardant solid electrolyte.
[0012] S7. Assemble the obtained flame-retardant solid electrolyte with the positive electrode and the lithium metal negative electrode to obtain a flame-retardant solid lithium metal battery.
[0013] Preferably, in step S1, the flame-retardant organic compound is at least one of triphenyl phosphate, trimethyl phosphate, dimethyl methyl phosphate, paraffin, n-hexadecane, n-octadecane, stearic acid, palmitic acid, and ionic liquid; the vinylidene fluoride is a vinylidene fluoride copolymer; the mass of the vinylidene fluoride added is 5%-40% of the total mass of the organic components in the precursor organic compound solution; and the organic solvent is at least one of N-methylpyrrolidone, N,N-diethylformamide, N,N-dimethylformamide, dimethylacetamide, and acetone.
[0014] Preferably, in step S2, the polyhydroxy organic compound is at least one of polyvinyl alcohol, polyacryl alcohol, polyethylene glycol, methylcellulose, carboxymethylcellulose, and polyvinylpyrrolidone, and its mass fraction is 0.2%-15%. The vinylidene fluoride is a vinylidene fluoride copolymer, and the mass of the vinylidene fluoride added is 5%-40% of the total mass of the organic components in the precursor mixture solution. The organic solvent is at least one of N-methylpyrrolidone, N,N-diethylformamide, N,N-dimethylformamide, dimethylacetamide, and acetone. The filler is one or more of graphene oxide, lithium lanthanum zirconium oxide, lithium lanthanum titanium oxide, lithium titanium aluminum phosphate, lithium lanthanum titanate, and lithium lanthanum zirconium tantalum oxide, and the mass of the filler added is 0.1%-20% of the mass of the organic matrix in the precursor mixture solution.
[0015] Preferably, in step S2, after the polyhydroxy organic powder is added to an organic solvent for ultrasonic dispersion, vinylidene fluoride and filler are added to the organic solution and stirred with a magnetic stirrer until completely dissolved. The ultrasonic dispersion time is 0.2-1.5 h, the ultrasonic dispersion power is 50-400 W, the stirring temperature of the magnetic stirrer is controlled between 25-100 °C, and the stirring time is controlled between 0.5-2 h.
[0016] Preferably, in step S3, the printing pressure of the 3D printer is 10-80 pounds per square inch.
[0017] Preferably, in step S5, the borate is at least one of sodium metaborate, lithium metaborate, potassium metaborate, sodium borate, lithium borate, and potassium borate, and the mass percentage concentration of the borate aqueous solution is 0.1-20%.
[0018] Preferably, in step S6, the curing time is 0.1-10h; the drying temperature is between 25-100℃, and the drying time is 1-24h.
[0019] Compared with the prior art, the present invention has the following beneficial effects:
[0020] 1. In this invention, the acid salt and polyhydroxy organic compounds undergo a cross-linking reaction to form a three-dimensional network structure composed of borate ester bonds, which enhances the strength and toughness of the material. In addition, the hydroxyl groups in the polyhydroxy organic compounds can form hydrogen bonds with the oxygen atoms in the borate ester bonds, enhancing the stability of the borate ester bonds. The dynamic reversibility of the borate ester bonds can give the material continuous self-healing properties, effectively encapsulating flame retardants and preventing the impact of flame retardant leakage on the electrochemical performance of lithium metal batteries during normal use. It can also effectively repair minor deformations and damages that occur during the use of lithium metal batteries, thereby improving the cycle life of the battery.
[0021] 2. This invention uses 3D coaxial printing technology to manufacture the electrolyte, which can effectively encapsulate the flame retardant in the polymer shell, ensuring that the electrochemical performance of the lithium metal battery will not be degraded due to flame retardant leakage during normal use.
[0022] 3. The preparation method of this invention is simple and low-cost, and the solid electrolyte has a certain degree of self-healing properties, which can effectively repair minor damage and deformation that occurs during the normal operation of lithium metal batteries. Simultaneously, 3D coaxial printing technology is used to effectively encapsulate the flame retardant, avoiding the impact on the electrochemical performance of the lithium metal battery caused by flame retardant leakage and enabling a response in the early stages of thermal runaway, effectively improving the safety of lithium metal batteries. Attached Figure Description
[0023] Figure 1 This is a comparison chart of the flame-retardant properties of the flame-retardant solid electrolyte prepared in Example 1 of the present invention and a commercial diaphragm.
[0024] Figure 2 The diagram shows the self-healing properties of the flame-retardant solid electrolyte prepared in Example 1 of this invention.
[0025] Figure 3 SEM image of the flame-retardant solid electrolyte prepared in Example 1 of this invention;
[0026] Figure 4 XPS image of the flame-retardant solid electrolyte prepared in Example 1 of this invention;
[0027] Figure 5 The Raman spectrum of the flame-retardant solid electrolyte prepared in Example 1 of this invention;
[0028] Figure 6 Fourier transform infrared spectrum of the flame-retardant solid electrolyte prepared in Example 1 of this invention;
[0029] Figure 7 The cycling performance diagram of the flame-retardant solid lithium metal battery prepared in Example 1 of the present invention is shown.
[0030] Figure 8 This is a comparison chart of the rate performance of a flame-retardant solid lithium metal battery prepared in Example 1 of the present invention and a lithium metal battery using a commercial separator. Detailed Implementation
[0031] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.
[0032] Example 1:
[0033] 40g of triphenyl phosphate powder was added to 100ml of N-methylpyrrolidone solution to obtain a precursor organic solution. The precursor organic solution was added to a magnetic stir bar and stirred on a magnetic stirrer for 1 hour to fully dissolve it. 15g of polyvinylidene fluoride-hexafluoropropylene powder was added and stirred on a magnetic stirrer until homogeneous to obtain a precursor organic solution. 1g of polyvinyl alcohol powder was added to 100ml of N-methylpyrrolidone solution and ultrasonically dispersed at 80W for 1 hour. Then, a magnetic stir bar was added and stirred on a magnetic stirrer for 2 hours at 100℃ to fully dissolve it. After that, it was allowed to cool completely at room temperature. 25g of polyvinylidene fluoride-hexafluoropropylene powder and 0.1g of graphene oxide were added and stirred until homogeneous to obtain a precursor organic solution.
[0034] Weigh 1g of polyvinyl alcohol powder and add it to 100ml of N-methylpyrrolidone solution. After ultrasonic dispersion for 1 hour using an ultrasonic power of 80W, add a magnetic stir bar and stir on a magnetic stirrer for 2 hours at a stirring temperature of 100℃ to ensure complete dissolution. Then, allow it to cool completely at room temperature, add 25g of polyvinylidene fluoride-hexafluoropropylene powder and 0.1g of graphene oxide, and continue stirring until homogeneous to obtain a precursor mixture solution.
[0035] The precursor organic solution and the precursor mixture were loaded into the inner and outer injectors of the 3D printer at a pressure of 70 PSI and extruded evenly onto the glass substrate. The substrate was then post-treated with the precursor mixture. The post-treated substrate was then placed in a 0.25% sodium metaborate aqueous solution for solvent exchange and cured. After curing for 6 hours, the substrate was removed and dried in a vacuum drying oven at 60°C for 6 hours to obtain a flame-retardant solid electrolyte.
[0036] like Figure 1 As shown, the commercial diaphragm completely combusted within 0.5 seconds of ignition. Due to the presence of the flame retardant, triphenyl phosphate generates phosphorus-containing free radicals in the early stages of combustion, which eliminate free radicals released by the electrolyte combustion and terminate the combustion reaction. The flame-retardant solid electrolyte showed no significant morphological change within 0.5 seconds of ignition, indicating that the flame-retardant solid electrolyte has excellent flame-retardant properties.
[0037] like Figure 2 As shown, after the electrolyte was cut and left at room temperature for 10 seconds, the fracture site could successfully self-heal due to the presence of borate ester bonds in the electrolyte. Furthermore, the electrolyte did not show significant fracture after being stretched again, indicating that the electrolyte has good self-healing properties.
[0038] pass Figure 3 It can be seen that the prepared solid electrolyte produces a large number of pores on its surface after solvent exchange, which is beneficial to the migration of lithium ions during charging and discharging. In addition, the electrolyte surface is smooth, so it has good contact with the electrode interface, which is beneficial to improving the electrochemical performance of the battery.
[0039] pass Figure 4 It can be seen that the prepared solid electrolyte has COB chemical bonds at 532.52 eV, indicating the presence of borate ester bonds in the solid electrolyte.
[0040] pass Figure 5 It can be seen that the Raman characteristic peaks of the self-healing solid electrolyte match the characteristic peaks of graphene oxide, indicating that the self-healing process does not cause structural changes inside the electrolyte.
[0041] pass Figure 6 It can be seen that the solid electrolyte contains PO and P=O peaks at 1184 cm⁻¹ and 1287 cm⁻¹, indicating the presence of triphenyl phosphate. The presence of a COB peak at 1335 cm⁻¹ indicates the presence of borate ester bonds in the solid electrolyte. The peak at 3389 cm⁻¹ indicates the presence of numerous hydroxyl groups in PVA.
[0042] A lithium metal battery was assembled using the aforementioned solid electrolyte, and the performance of the flame-retardant solid lithium metal battery was tested. Lithium iron phosphate was used as the positive electrode, and lithium metal sheets were used as the negative electrode.
[0043] Figure 7 The graph shows the cycle performance of the flame-retardant solid-state lithium metal battery. Under 0.1C conditions, the discharge specific capacity is 166.40 mAh / g in the first cycle and 158.54 mAh / g after 100 cycles, with a capacity retention of 95.27%. The charge-discharge curve is stable and the capacity decay is slow, indicating that the flame-retardant solid-state lithium metal battery has good electrochemical performance.
[0044] like Figure 8 As shown, flame-retardant solid-state lithium metal batteries exhibit better cycle stability due to the presence of borate ester bonds with self-healing capabilities in the flame-retardant solid electrolyte, which can repair minor damage and deformation that occurs during normal use. Furthermore, graphene oxide and borate ester bonds enhance the lithium-ion transport kinetics during charging and discharging in flame-retardant solid-state lithium metal batteries. Therefore, flame-retardant solid-state lithium metal batteries demonstrate better discharge capacity at high rates. Compared to lithium metal batteries using commercial separators, flame-retardant solid-state lithium metal batteries exhibit superior rate performance.
[0045] Example 2:
[0046] Weigh 40g of triphenyl phosphate powder and add it to 100ml of N-methylpyrrolidone solution. Add a magnetic stir bar and stir on a magnetic stirrer for 1 hour to fully dissolve it. Add 15g of polyvinylidene fluoride-hexafluoropropylene powder and continue stirring on a magnetic stirrer. After stirring evenly, a precursor organic solution is obtained.
[0047] Weigh 25g of polyvinylidene fluoride-hexafluoropropylene powder and add it to 100ml of N-methylpyrrolidone solution. After ultrasonic dispersion for 1 hour with an ultrasonic power of 80W, add a magnetic stir bar and stir on a magnetic stirrer for 2 hours at a stirring temperature of 100℃ to fully dissolve it and obtain a precursor mixture solution.
[0048] The precursor organic solution and the precursor mixture were loaded into the inner and outer injectors of the 3D printer at a pressure of 70 PSI and extruded evenly onto the glass substrate. The substrate was then post-treated with the precursor mixture. The post-treated substrate was then placed in a 0.25% sodium metaborate aqueous solution for solvent exchange and cured. After curing for 6 hours, the substrate was removed and dried in a vacuum drying oven at 60°C for 6 hours to obtain a flame-retardant solid electrolyte.
[0049] Example 3:
[0050] Weigh 40g of triphenyl phosphate powder and add it to 100ml of N-methylpyrrolidone solution. Add a magnetic stir bar and stir on a magnetic stirrer for 1 hour to fully dissolve it. Add 15g of polyvinylidene fluoride-hexafluoropropylene powder and continue stirring on a magnetic stirrer. After stirring evenly, a precursor organic solution is obtained.
[0051] Weigh 1g of polyvinyl alcohol powder and add it to 100ml of N-methylpyrrolidone solution. After ultrasonic dispersion for 1 hour using an ultrasonic power of 80W, add a magnetic stir bar and stir on a magnetic stirrer for 2 hours at a stirring temperature of 100℃ to ensure complete dissolution. Then, allow it to cool completely at room temperature, add 25g of polyvinylidene fluoride-hexafluoropropylene powder and 0.1g of lithium lanthanum zirconium oxide, and continue stirring until homogeneous to obtain a precursor mixture solution.
[0052] The precursor organic solution and the precursor mixture were loaded into the inner and outer injectors of the 3D printer at a pressure of 70 PSI, and then uniformly extruded onto the glass substrate. The substrate was then post-treated with the precursor mixture. The post-treated substrate was then cured by solvent exchange in a 0.25% sodium metaborate aqueous solution for 6 hours. After curing, it was removed and dried in a vacuum drying oven at 60°C for 6 hours to obtain a flame-retardant solid electrolyte.
[0053] The embodiments of the present invention are given for the purposes of illustration and description. Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.
Claims
1. A method for preparing a 3D coaxially printed flame-retardant smart solid-state lithium battery, characterized in that: Includes the following steps: S1. Add flame-retardant organic compounds and vinylidene fluoride to an organic solution and dissolve them to obtain a precursor organic compound solution; S2. Add vinylidene fluoride, polyhydroxy organic powder, and filler to the organic solution and dissolve them to obtain a precursor mixed solution; S3. The precursor organic solution and the precursor mixture solution are coaxially printed onto a glass plate using the syringe of the 3D printer; S4. Perform post-processing operations on the substrate printed onto the glass plate; S5. Immerse the post-processed sample in a borate aqueous solution and cure it through solvent exchange. S6. The cured sample is dried to obtain a flame-retardant solid electrolyte. S7. Assemble the obtained flame-retardant solid electrolyte with the positive electrode and the lithium metal negative electrode to obtain a flame-retardant solid lithium metal battery.
2. The method for preparing a 3D coaxial printed flame-retardant smart solid-state lithium battery as described in claim 1, characterized in that: In step S1, the flame-retardant organic compound is at least one of triphenyl phosphate, trimethyl phosphate, dimethyl methyl phosphate, paraffin, n-hexadecane, n-octadecane, stearic acid, palmitic acid, and ionic liquid; the vinylidene fluoride is a vinylidene fluoride copolymer; the mass of the vinylidene fluoride added is 5%-40% of the total mass of the organic components in the precursor organic compound solution; and the organic solvent is at least one of N-methylpyrrolidone, N,N-diethylformamide, N,N-dimethylformamide, dimethylacetamide, and acetone.
3. The method for preparing a 3D coaxial printed flame-retardant smart solid-state lithium battery as described in claim 1, characterized in that: In step S2, the polyhydroxy organic compound is at least one of polyvinyl alcohol, polyacryl alcohol, polyethylene glycol, methylcellulose, carboxymethylcellulose, and polyvinylpyrrolidone, and its mass fraction is 0.2%-15%. The vinylidene fluoride is a vinylidene fluoride copolymer, and the mass of the vinylidene fluoride added is 5%-40% of the total mass of the organic components in the precursor mixture solution. The organic solvent is at least one of N-methylpyrrolidone, N,N-diethylformamide, N,N-dimethylformamide, dimethylacetamide, and acetone. The filler is one or more of graphene oxide, lithium lanthanum zirconium oxide, lithium lanthanum titanium oxide, lithium titanium aluminum phosphate, lithium lanthanum titanate, and lithium lanthanum zirconium tantalum oxide, and the mass of the filler added is 0.1%-20% of the mass of the organic matrix in the precursor mixture solution.
4. The method for preparing a 3D coaxial printed flame-retardant smart solid-state lithium battery as described in claim 1, characterized in that: In step S2, after the polyhydroxy organic powder is added to an organic solvent for ultrasonic dispersion, vinylidene fluoride and filler are added to the organic solution and stirred with a magnetic stirrer until completely dissolved. The ultrasonic dispersion time is 0.2-1.5 h, the ultrasonic dispersion power is 50-400 W, the stirring temperature of the magnetic stirrer is controlled between 25-100℃, and the stirring time is controlled between 0.5-2 h.
5. The method for preparing a 3D coaxial printed flame-retardant smart solid-state lithium battery as described in claim 1, characterized in that: In step S3, the printing pressure of the 3D printer is 10-80 pounds per square inch.
6. The method for preparing a 3D coaxial printed flame-retardant smart solid-state lithium battery as described in claim 1, characterized in that: In step S5, the borate is at least one of sodium metaborate, lithium metaborate, potassium metaborate, sodium borate, lithium borate, and potassium borate, and the mass percentage concentration of the borate aqueous solution is 0.1-20%.
7. The method for preparing a 3D coaxial printed flame-retardant smart solid-state lithium battery as described in claim 1, characterized in that: In step S6, the curing time is 0.1-10h; the drying temperature is between 25-100℃, and the drying time is 1-24h.
8. A 3D coaxial printed flame-retardant smart solid-state lithium battery, a flame-retardant solid-state lithium metal battery prepared by the preparation method of a 3D coaxial printed flame-retardant smart solid-state lithium battery as described in any one of claims 1-7.