A quick-response in-situ temperature-controllable adhesive as well as a preparation method and application thereof

Abstract

The application belongs to the technical field of battery preheating, and particularly relates to a fast-response in-situ temperature control binder as well as a preparation method and application thereof. The application proposes a new binder, which uses hyperbranched polymers carrying a large number of charges to load fast-response particles through electrostatic interaction and redox reaction, and designs an external miniature heating device cooperating with the fast-response binder, so that the impedance of the battery is not increased, and the effect of non-contact fast heating of the battery interior can be achieved only by using the binder when assembling the battery and cooperating with the external device. The battery can be raised from minus 60 degrees Celsius to room temperature in 5 seconds, and the battery in hibernation due to low temperature can be quickly woken up to discharge and work again. The application has great significance for the field of battery low-temperature preheating, and provides a brand-new heating strategy, which creates an unprecedented new idea for the use of the battery at low temperature.

Description

Technical Field

[0001] This invention belongs to the field of battery preheating technology, specifically relating to a fast-response in-situ temperature-controlled binder, its preparation method, and its application. Background Technology

[0002] The rapid development of electric vehicles has been driven by the energy crisis and environmental pressures. However, the performance of lithium-ion batteries deteriorates significantly in low-temperature environments, especially below zero degrees Celsius. Therefore, to popularize electric vehicles in Northeast China, it is essential to improve the low-temperature performance of batteries.

[0003] Many scholars have studied the reasons for battery performance degradation at low temperatures from different perspectives, mainly focusing on two aspects: First, the solid-phase diffusion coefficient decreases significantly, causing very large concentration gradient polarization, which quickly brings the battery terminal voltage to the cutoff voltage, resulting in a sharp drop in battery capacity; second, the charge transfer resistance increases. More seriously, the electrolyte can freeze at extremely low temperatures, preventing discharge. Furthermore, the charging and discharging process at low temperatures is also highly susceptible to safety accidents. For example, lithium dendrites generated during charging and discharging may penetrate the separator, causing short circuits and leading to thermal runaway. Therefore, battery preheating technology is a key means to address battery performance degradation at low temperatures and prevent safety issues.

[0004] Traditional battery preheating strategies include external heating and internal heating. External heating technologies use external heat sources to heat the battery, including resistive preheating, layer effect preheating, and electrothermal film preheating. Internal heating technologies utilize the battery's energy to preheat it or apply current to generate heat through internal impedance. However, these heating strategies suffer from problems such as poor safety, high cost, slow heating rate, and poor reliability. Summary of the Invention

[0005] To address the aforementioned problems, this invention proposes a novel binder that utilizes a hyperbranched polymer carrying a large amount of charge to load fast-response particles through electrostatic interaction and redox reactions. Furthermore, an external micro-heating device is designed to work in conjunction with this fast-response binder. Without increasing the internal impedance of the battery, this binder, used in conjunction with the external device during battery assembly, achieves contactless and rapid heating of the battery's internal components. It can raise the battery from -60 degrees Celsius to room temperature within 5 seconds and quickly awaken dormant batteries caused by low temperatures, enabling them to resume discharge and operation. This invention is of great significance in the field of low-temperature battery preheating, providing a completely new heating strategy and opening up unprecedented new ideas for the use of batteries at low temperatures.

[0006] The technical solution of the present invention is as follows:

[0007] A fast-response in-situ temperature-controlled binder is formed by loading a high-viscosity hyperbranched polymer onto the surface of fast-response nanoparticles. The fast-response nanoparticles have a large number of charges on their surface, and the two are combined through electrostatic interactions of positive and negative charges and redox reactions.

[0008] The fast-response nanoparticles described herein consist of a fast-response core composed of metal oxides such as iron, cobalt, and nickel, and an outer layer encapsulating the core, with a diameter greater than 100 nanometers. Specifically, the fast-response nanoparticles refer to one or more of the following: iron oxide nanoparticles, silver nanoparticles, CoNi alloy nanoparticles, nickel beads, silica microspheres, and magnetic nanoparticles.

[0009] The high-viscosity hyperbranched polymer is a water-soluble partially branched polymer with a large number of polar functional groups and a relative molecular mass between 70,000 and 100,000. Specifically, it refers to a mixture of one or more of polyethyleneimine, polytetrafluoroethylene, carboxymethyl cellulose, polyvinyl alcohol, polyvinylidene fluoride, and polyacrylic acid.

[0010] The specific steps of the above-mentioned fast-response in-situ temperature-controlled adhesive preparation method are as follows:

[0011] Step (1): Disperse the inorganic metal salt, organic salt and surfactant evenly in the solvent to obtain solution A;

[0012] Step (2): Stir solution A vigorously at 150℃-180℃ to form a uniform dark solution. Heat the dark solution to 200℃-300℃ and maintain it for 12-18h. Then cool it to room temperature. Wash the obtained dark product with solvent several times, collect it by suction filtration, and finally dry it in a vacuum oven overnight to obtain solid product B.

[0013] Step (3): Dissolve the high-viscosity hyperbranched polymer in a solvent, add solid product B and adjust the pH of the solution to obtain solution C;

[0014] Step (4): Disperse solution C evenly by ultrasonication and heat it to 170℃-200℃ by stirring to obtain a fast-response in-situ temperature-controlled adhesive.

[0015] The solvents in steps (1), (2), and (3) are one or more of water, anhydrous ethanol, and ethylene glycol.

[0016] In step (1), the inorganic metal salt is one or a mixture of two or more of FeCl3·6H2O, FeCl2·4H2O, Fe(acac)3, CoSO4, NiSO4, and Ni(C5H5)2; the organic salt is one or a mixture of two of NH4Ac and (NH4)2C2O4; and the surfactant is one or a mixture of two or more of hydrazine, polyethylene glycol, sodium citrate, and ammonia.

[0017] In step (1), the concentration of solution A is 38-70 mg / mL. -1 .

[0018] In step (3), the mass ratio of solid product B to high-viscosity hyperbranched polymer is 1:5-1:10; the hyperbranched polymer is one or more of polyethyleneimine, polytetrafluoroethylene, carboxymethyl cellulose, polyvinyl alcohol, polyvinylidene fluoride, and polyacrylic acid.

[0019] In step (3), the pH is adjusted to 6.8-8.

[0020] In step (4), the ultrasound duration is more than 1 hour. The ultrasound frequency is 50Hz-70Hz.

[0021] The aforementioned hyperbranched polymer binder loaded with fast-response nanoparticles can be used in conjunction with a micro induction heating device, applicable to various batteries and used as a preheating device in extremely cold regions. The micro heating device is assembled by using a DC power supply to provide current, oscillating and boosting the voltage using diodes and metal-oxide-semiconductor field-effect transistors, and finally converting the voltage into a sine wave output to the induction coil using a parallel circuit of inductors and capacitors.

[0022] The beneficial effects of this invention are:

[0023] (1) This invention utilizes a combination of positive and negative charges and redox reactions to in-situ load fast-response nanoparticles onto the surface of a hyperbranched polymer as a binder within the electrode. This uniformly disperses the fast-response particles within the electrode, generating heat through the effect of the fast-response particles in an external field, thus uniformly heating the entire electrode. This accelerates ion transport within the battery at low temperatures, increases the solid-phase diffusion coefficient, reduces charge transfer resistance, and accelerates the electrochemical reaction rate. This enables the battery to revive at low temperatures and cope with extreme low-temperature conditions.

[0024] (2) The fast-response binder prepared in this invention can be applied to various batteries. When used with external devices, it can achieve rapid heating of the battery, enabling it to start and operate at ultra-low temperatures. This invention proposes a contactless multi-field coupling battery preheating method for the first time. Compared with traditional heating methods, this invention consumes less electrical energy in battery preheating; the preheating time is extremely fast; the temperature of battery cells, modules, and battery packs is very uniform; and the complexity is not increased (e.g., additional equipment, weight, and space are required due to the integration of the heating system).

[0025] (3) Compared with traditional battery preheating methods, the present invention has a much faster heating rate, which can greatly reduce the adverse effects on battery aging during the preheating process. Attached Figure Description

[0026] Figure 1 This is a schematic diagram illustrating the preparation principle of the fast-response hyperbranched adhesive of the present invention.

[0027] Figure 2 This is a scanning electron microscope image of the fast-response hyperbranched adhesive of the present invention.

[0028] Figure 3 This is a graph (magnification) showing the electrochemical performance of the fast-response hyperbranched binder in this embodiment of the invention.

[0029] Figure 4 This is a graph showing the electrochemical performance (cycles) of the fast-response hyperbranched binder in an embodiment of the present invention.

[0030] Figure 5 The heating effect of the fast-response hyperbranched adhesive in the embodiments of the present invention is shown. Detailed Implementation

[0031] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and technical solutions.

[0032] The following examples illustrate the preparation of different fast-response hyperbranched binders (the process of loading high-viscosity hyperbranched polymers onto the surface of fast-response nanoparticles is as follows). Figure 1 As shown in the figure, it was used as a binder for the positive electrode of lithium-sulfur batteries to prepare corresponding lithium-sulfur batteries.

[0033] Example 1:

[0034] (1) Dissolve 0.99 g FeCl₂·4H₂O, 3.85 g NH₄Ac, and 0.032 g hydrazine in 100 mL ethylene glycol. Stir the mixture vigorously at 150 °C for 1 hour to form a homogeneous black solution, then transfer it to a 200 mL Teflon-lined stainless steel autoclave. Heat to 200 °C and maintain for 12 hours, then cool to room temperature. Wash the black product twice with ethanol, collect it by suction filtration, and finally dry it overnight in a vacuum oven at 40 °C to obtain the final product.

[0035] (2) Weigh 1g of the above product and disperse it in a solvent. Weigh 5g of polyacrylamide and add it to the solution. Sonicate it for 30 minutes and heat it to 170 degrees Celsius and stir for 2 hours. The mass ratio of the added fast-response nanoparticles to the hyperbranched polymer is 1:5.

[0036] (3) The obtained binder is ground in a ratio of 7:2:1 for electrode material: conductive agent: binder. An appropriate amount of water is added to assist the grinding to form a uniformly dispersed slurry. The slurry is then coated on aluminum foil and dried under vacuum.

[0037] (4) The aluminum foil from the previous step was punched to form an electrode sheet. The electrode sheet and the lithium metal sheet were assembled into a CR2032 type coin cell, and the electrochemical performance was tested. The electrolyte was 1.0M LiTFSI in DOL:DME=1:1 Vol% with 2.0% LiNO3 lithium-sulfur battery electrolyte.

[0038] (5) Place the electrode sheet prepared in the previous step on the micro induction heating device and place it in liquid nitrogen. Start the induction heating device and use an infrared thermal imager to observe the temperature rise.

[0039] Example 2:

[0040] (1) Dissolve 1.35 g FeCl3·6H2O, 3.85 g NH4Ac, and 0.032 g hydrazine in 100 mL of ethylene glycol. Stir the mixture vigorously at 150 °C for 1 hour to form a homogeneous black solution, then transfer it to a 200 mL Teflon-lined stainless steel autoclave. Heat to 200 °C and maintain for 12 hours, then cool to room temperature. Wash the black product twice with ethanol, collect it by suction filtration, and finally dry it overnight in a vacuum oven at 40 °C to obtain the final product.

[0041] (2) Weigh 1g of the above product and disperse it in a solvent. Weigh 5g of polyacrylamide and add it to the solution. Sonicate it for 30 minutes and heat it to 170 degrees Celsius and stir for 2 hours. The mass ratio of the added fast-response nanoparticles to the hyperbranched polymer is 1:5.

[0042] (3) The obtained binder is ground in a ratio of 7:2:1 for electrode material: conductive agent: binder. An appropriate amount of water is added to assist the grinding to form a uniformly dispersed slurry. The slurry is then coated on aluminum foil and dried under vacuum.

[0043] (4) The aluminum foil from the previous step was punched to form an electrode sheet. The electrode sheet and the lithium metal sheet were assembled into a CR2032 type coin cell, and the electrochemical performance was tested. The electrolyte was 1.0M LiTFSI in DOL:DME=1:1 Vol% with 2.0% LiNO3 lithium-sulfur battery electrolyte.

[0044] (5) Place the electrode sheet prepared in the previous step on the micro induction heating device and place it in liquid nitrogen. Start the induction heating device and use an infrared thermal imager to observe the temperature rise.

[0045] Example 3:

[0046] (1) Dissolve 1.765 g Fe(acac)3, 3.08 g NH4Ac, and 0.032 g hydrazine in 100 mL of ethylene glycol. Stir the mixture vigorously at 150 °C for 1 hour to form a homogeneous black solution, then transfer it to a 200 mL Teflon-lined stainless steel autoclave. Heat to 200 °C and maintain for 13 hours, then cool to room temperature. Wash the black product twice with ethanol, collect it by suction filtration, and finally dry it overnight in a vacuum oven at 40 °C to obtain the final product.

[0047] (2) Weigh 1g of the above product and disperse it in a solvent. Weigh 5g of PAM and add it to the solution. Sonicate it to disperse and dissolve it. Sonicate for 30min and heat it to 170 degrees Celsius and stir for 2 hours. The mass ratio of the fast-response nanoparticles to the hyperbranched polymer is 1:5.

[0048] (3) The obtained binder is ground in a ratio of 7:2:1 for electrode material: conductive agent: binder. An appropriate amount of water is added to assist the grinding to form a uniformly dispersed slurry. The slurry is then coated on aluminum foil and dried under vacuum.

[0049] (4) The aluminum foil from the previous step was punched to form an electrode sheet. The electrode sheet and the lithium metal sheet were assembled into a CR2032 type coin cell, and the electrochemical performance was tested. The electrolyte was 1.0M LiTFSI in DOL:DME=1:1 Vol% with 2.0% LiNO3 lithium-sulfur battery electrolyte.

[0050] (5) Place the electrode sheet prepared in the previous step on the micro induction heating device and place it in liquid nitrogen. Start the induction heating device and use an infrared thermal imager to observe the temperature rise.

[0051] Example 4:

[0052] (1) Dissolve 1.765 g Fe(acac)3, 3.08 g NH4Ac, and 0.032 g hydrazine in 100 mL of anhydrous ethanol. Stir the mixture vigorously at 150 °C for 1 hour to form a homogeneous black solution, then transfer it to a 200 mL Teflon-lined stainless steel autoclave. Heat to 200 °C and maintain for 13 hours, then cool to room temperature. Wash the black product twice with ethanol, collect it by suction filtration, and finally dry it overnight in a vacuum oven at 40 °C to obtain the final product.

[0053] (2) Weigh 1g of the above product and disperse it in a solvent. Weigh 6g of PAM and add it to the solution. Sonicate it to disperse and dissolve it. Sonicate for 30min and heat it to 170 degrees Celsius and stir for 2 hours. The mass ratio of the added fast-response nanoparticles to the hyperbranched polymer is 1:6.

[0054] (3) The obtained binder is ground in a ratio of 7:2:1 for electrode material: conductive agent: binder. An appropriate amount of water is added to assist the grinding to form a uniformly dispersed slurry. The slurry is then coated on aluminum foil and dried under vacuum.

[0055] (4) The aluminum foil from the previous step was punched to form an electrode sheet. The electrode sheet and the lithium metal sheet were assembled into a CR2032 type coin cell, and the electrochemical performance was tested. The electrolyte was 1.0M LiTFSI in DOL:DME=1:1 Vol% with 2.0% LiNO3 lithium-sulfur battery electrolyte.

[0056] (5) Place the electrode sheet prepared in the previous step on the micro induction heating device and place it in liquid nitrogen. Start the induction heating device and use an infrared thermal imager to observe the temperature rise.

[0057] Example 5:

[0058] (1) Dissolve 0.77 g NiSO4, 3.08 g NH4Ac, and 0.032 g hydrazine in 100 mL anhydrous ethanol. Stir the mixture vigorously at 150 °C for 1 hour to form a homogeneous black solution, then transfer it to a 200 mL Teflon-lined stainless steel autoclave. Heat to 200 °C and maintain for 14 h, then cool to room temperature. Wash the black product twice with ethanol, collect it by suction filtration, and finally dry it overnight in a vacuum oven at 40 °C to obtain the final product.

[0059] (2) Weigh 1g of the above product and disperse it in a solvent. Weigh 6g of polyvinyl alcohol and add it to the solution. Sonicate it to disperse and dissolve it. Sonicate for 30 minutes and heat it to 170 degrees Celsius and stir for 2 hours. The mass ratio of the added fast-response nanoparticles to the hyperbranched polymer is 1:6.

[0060] (3) The obtained binder is ground in a ratio of 7:2:1 for electrode material: conductive agent: binder. An appropriate amount of water is added to assist the grinding to form a uniformly dispersed slurry. The slurry is then coated on aluminum foil and dried under vacuum.

[0061] (4) The aluminum foil from the previous step was punched to form an electrode sheet. The electrode sheet and the lithium metal sheet were assembled into a CR2032 type coin cell, and the electrochemical performance was tested. The electrolyte was 1.0M LiTFSI in DOL:DME=1:1 Vol% with 2.0% LiNO3 lithium-sulfur battery electrolyte.

[0062] (5) Place the electrode sheet prepared in the previous step on the micro induction heating device and place it in liquid nitrogen. Start the induction heating device and use an infrared thermal imager to observe the temperature rise.

[0063] Example 6:

[0064] (1) Dissolve 1.765 g Fe(acac)3, 4.96 g (NH4)2C2O4, and 0.258 g sodium citrate in 100 mL of anhydrous ethanol. The mixture was vigorously stirred at 160 °C for 1 hour to form a homogeneous black solution, which was then transferred to a Teflon-lined stainless steel autoclave (200 mL capacity). The autoclave was heated to 250 °C and maintained for 16 h, then cooled to room temperature. The black product was washed twice with ethanol, collected by vacuum filtration, and finally dried overnight in a vacuum oven at 40 °C to obtain the final product.

[0065] (2) Weigh 1g of the above product and disperse it in a solvent. Weigh 6g of polyvinyl alcohol and add it to the solution. Sonicate it to disperse and dissolve it. Sonicate for 30 minutes and heat it to 180 degrees Celsius and stir for 2 hours. The mass ratio of the added fast-response nanoparticles to the hyperbranched polymer is 1:6.

[0066] (3) The obtained binder is ground in a ratio of 7:2:1 for electrode material: conductive agent: binder. An appropriate amount of water is added to assist the grinding to form a uniformly dispersed slurry. The slurry is then coated on aluminum foil and dried under vacuum.

[0067] (4) The aluminum foil from the previous step was punched to form an electrode sheet. The electrode sheet and the lithium metal sheet were assembled into a CR2032 type coin cell, and the electrochemical performance was tested. The electrolyte was 1.0M LiTFSI in DOL:DME=1:1 Vol% with 2.0% LiNO3 lithium-sulfur battery electrolyte.

[0068] (5) Place the electrode sheet prepared in the previous step on the micro induction heating device and place it in liquid nitrogen. Start the induction heating device and use an infrared thermal imager to observe the temperature rise.

[0069] Example 7:

[0070] (1) Dissolve 0.77 g NiSO4, 4.96 g (NH4)2C2O4, and 0.258 g sodium citrate in 100 mL anhydrous ethanol. Stir the mixture vigorously at 160 °C for 1 hour to form a homogeneous black solution, then transfer it to a Teflon-lined stainless steel autoclave (200 mL capacity). Heat to 250 °C and maintain for 14 h, then cool to room temperature. Wash the black product twice with ethanol, collect it by suction filtration, and finally dry it overnight in a vacuum oven at 40 °C to obtain the final product.

[0071] (2) Weigh 1g of the above product and disperse it in a solvent. Weigh 7g of polyacetylimide and add it to the solution. Sonicate it for 30 minutes and heat it to 180 degrees Celsius and stir for 2 hours. The mass ratio of the added fast-response nanoparticles to the hyperbranched polymer is 1:7.

[0072] (3) The obtained binder is ground in a ratio of 7:2:1 for electrode material: conductive agent: binder. An appropriate amount of water is added to assist the grinding to form a uniformly dispersed slurry. The slurry is then coated on aluminum foil and dried under vacuum.

[0073] (4) The aluminum foil from the previous step was punched to form an electrode sheet. The electrode sheet and the lithium metal sheet were assembled into a CR2032 type coin cell, and the electrochemical performance was tested. The electrolyte was 1.0M LiTFSI in DOL:DME=1:1 Vol% with 2.0% LiNO3 lithium-sulfur battery electrolyte.

[0074] (5) Place the electrode sheet prepared in the previous step on the micro induction heating device and place it in liquid nitrogen. Start the induction heating device and use an infrared thermal imager to observe the temperature rise.

[0075] Example 8:

[0076] (1) Dissolve 0.77 g NiSO4, 4.96 g (NH4)2C2O4, and 0.258 g sodium citrate in 100 mL anhydrous ethanol. Stir the mixture vigorously at 160 °C for 1 hour to form a homogeneous black solution, then transfer it to a Teflon-lined stainless steel autoclave (200 mL capacity). Heat to 250 °C and maintain for 15 h, then cool to room temperature. Wash the black product twice with ethanol, collect it by suction filtration, and finally dry it overnight in a vacuum oven at 40 °C to obtain the final product.

[0077] (2) Weigh 1g of the above product and disperse it in a solvent. Weigh 7g of polyacetylimide and add it to the solution. Sonicate it for 30 minutes and heat it to 180 degrees Celsius and stir for 2 hours. The mass ratio of the added fast-response nanoparticles to the hyperbranched polymer is 1:7.

[0078] (3) The obtained binder is ground in a ratio of 7:2:1 for electrode material: conductive agent: binder. An appropriate amount of water is added to assist the grinding to form a uniformly dispersed slurry. The slurry is then coated on aluminum foil and dried under vacuum.

[0079] (4) The aluminum foil from the previous step was punched to form an electrode sheet. The electrode sheet and the lithium metal sheet were assembled into a CR2032 type coin cell, and the electrochemical performance was tested. The electrolyte was 1.0M LiTFSI in DOL:DME=1:1 Vol% with 2.0% LiNO3 lithium-sulfur battery electrolyte.

[0080] (5) Place the electrode sheet prepared in the previous step on the micro induction heating device and place it in liquid nitrogen. Start the induction heating device and use an infrared thermal imager to observe the temperature rise.

[0081] Example 9:

[0082] (1) Dissolve 0.98 g FeCl2·4H2O, 4.96 g (NH4)2C2O4, and 0.258 g sodium citrate in 100 mL of ethylene glycol. The mixture is stirred vigorously at 160 °C for 1 hour to form a uniform black solution, which is then transferred to a Teflon-lined stainless steel autoclave (capacity 200 mL). The autoclave is heated to 250 °C and maintained for 15 h, then cooled to room temperature. The black product is washed twice with ethanol, collected by vacuum filtration, and finally dried overnight in a vacuum oven at 40 °C to obtain the product.

[0083] (2) Weigh 1g of the above product and disperse it in a solvent. Weigh 7g of hydroxymethyl cellulose and add it to the solution. Sonicate it for 30 minutes and heat it to 190 degrees Celsius and stir for 2 hours. The mass ratio of the added fast-response nanoparticles to the hyperbranched polymer is 1:7.

[0084] (3) The obtained binder is ground in a ratio of 7:2:1 for electrode material: conductive agent: binder. An appropriate amount of water is added to assist the grinding to form a uniformly dispersed slurry. The slurry is then coated on aluminum foil and dried under vacuum.

[0085] (4) The aluminum foil from the previous step was punched to form an electrode sheet. The electrode sheet and the lithium metal sheet were assembled into a CR2032 type coin cell, and the electrochemical performance was tested. The electrolyte was 1.0M LiTFSI in DOL:DME=1:1 Vol% with 2.0% LiNO3 lithium-sulfur battery electrolyte.

[0086] (5) Place the electrode sheet prepared in the previous step on the micro induction heating device and place it in liquid nitrogen. Start the induction heating device and use an infrared thermal imager to observe the temperature rise.

[0087] Example 10:

[0088] (1) Dissolve 0.98 g FeCl2·4H2O, 3.08 g NH4Ac, and 0.258 g sodium citrate in 100 mL of ethylene glycol. Stir the mixture vigorously at 170°C for 1 hour to form a homogeneous black solution, then transfer it to a 200 mL Teflon-lined stainless steel autoclave. Heat to 250°C and maintain for 16 hours, then cool to room temperature. Wash the black product twice with ethanol, collect it by suction filtration, and finally dry it overnight in a vacuum oven at 40°C to obtain the final product.

[0089] (2) Weigh 1g of the above product and disperse it in a solvent. Weigh 8g of polyacetylimide and add it to the solution. Sonicate it for 30 minutes and heat it to 190 degrees Celsius and stir for 2 hours. The mass ratio of the added fast-response nanoparticles to the hyperbranched polymer is 1:8.

[0090] (3) The obtained binder is ground in a ratio of 7:2:1 for electrode material: conductive agent: binder. An appropriate amount of water is added to assist the grinding to form a uniformly dispersed slurry. The slurry is then coated on aluminum foil and dried under vacuum.

[0091] (4) The aluminum foil from the previous step was punched to form an electrode sheet. The electrode sheet and the lithium metal sheet were assembled into a CR2032 type coin cell, and the electrochemical performance was tested. The electrolyte was 1.0M LiTFSI in DOL:DME=1:1 Vol% with 2.0% LiNO3 lithium-sulfur battery electrolyte.

[0092] (5) Place the electrode sheet prepared in the previous step on the micro induction heating device and place it in liquid nitrogen. Start the induction heating device and use an infrared thermal imager to observe the temperature rise.

[0093] Example 11:

[0094] (1) Dissolve 0.94 g Ni(C5H5)2, 3.08 g NH4Ac, and 0.258 g sodium citrate in 100 mL ethylene glycol. Stir the mixture vigorously at 170°C for 1 hour to form a homogeneous black solution, then transfer it to a 200 mL Teflon-lined stainless steel autoclave. Heat to 300°C and maintain for 16 hours, then cool to room temperature. Wash the black product twice with ethanol, collect it by suction filtration, and finally dry it overnight in a vacuum oven at 40°C to obtain the final product.

[0095] (2) Weigh 1g of the above product and disperse it in a solvent. Weigh 8g of polyacetylimide and add it to the solution. Sonicate it for 30 minutes and heat it to 190 degrees Celsius and stir for 2 hours. The mass ratio of the added fast-response nanoparticles to the hyperbranched polymer is 1:8.

[0096] (3) The obtained binder is ground in a ratio of 7:2:1 for electrode material: conductive agent: binder. An appropriate amount of water is added to assist the grinding to form a uniformly dispersed slurry. The slurry is then coated on aluminum foil and dried under vacuum.

[0097] (4) The aluminum foil from the previous step was punched to form an electrode sheet. The electrode sheet and the lithium metal sheet were assembled into a CR2032 type coin cell, and the electrochemical performance was tested. The electrolyte was 1.0M LiTFSI in DOL:DME=1:1 Vol% with 2.0% LiNO3 lithium-sulfur battery electrolyte.

[0098] (5) Place the electrode sheet prepared in the previous step on the micro induction heating device and place it in liquid nitrogen. Start the induction heating device and use an infrared thermal imager to observe the temperature rise.

[0099] Example 12:

[0100] (1) Dissolve 0.94 g Ni(C5H5)2, 3.08 g NH4Ac, and 0.032 g hydrazine in 100 mL of anhydrous ethanol. Stir the mixture vigorously at 170 °C for 1 hour to form a homogeneous black solution, then transfer it to a 200 mL Teflon-lined stainless steel autoclave. Heat to 300 °C and maintain for 17 h, then cool to room temperature. Wash the black product twice with ethanol, collect it by suction filtration, and finally dry it overnight in a vacuum oven at 40 °C to obtain the final product.

[0101] (2) Weigh 1g of the above product and disperse it in a solvent. Weigh 8g of polyvinyl alcohol and add it to the solution. Sonicate it to disperse and dissolve it. Sonicate for 30min and heat it to 200 degrees Celsius and stir for 2 hours. The mass ratio of the added fast-response nanoparticles to the hyperbranched polymer is 1:8.

[0102] (3) The obtained binder is ground in a ratio of 7:2:1 for electrode material: conductive agent: binder. An appropriate amount of water is added to assist the grinding to form a uniformly dispersed slurry. The slurry is then coated on aluminum foil and dried under vacuum.

[0103] (4) The aluminum foil from the previous step was punched to form an electrode sheet. The electrode sheet and the lithium metal sheet were assembled into a CR2032 type coin cell, and the electrochemical performance was tested. The electrolyte was 1.0M LiTFSI in DOL:DME=1:1 Vol% with 2.0% LiNO3 lithium-sulfur battery electrolyte.

[0104] (5) Place the electrode sheet prepared in the previous step on the micro induction heating device and place it in liquid nitrogen. Start the induction heating device and use an infrared thermal imager to observe the temperature rise.

[0105] Example 13:

[0106] (1) Dissolve 0.94 g Ni(C5H5)2, 3.08 g NH4Ac, and 0.032 g hydrazine in 100 mL of anhydrous ethanol. Stir the mixture vigorously at 170 °C for 1 hour to form a homogeneous black solution, then transfer it to a 200 mL Teflon-lined stainless steel autoclave. Heat to 300 °C and maintain for 17 h, then cool to room temperature. Wash the black product twice with ethanol, collect it by suction filtration, and finally dry it overnight in a vacuum oven at 40 °C to obtain the final product.

[0107] (2) Weigh 1g of the above product and disperse it in a solvent. Weigh 9g of polyacetylimide and add it to the solution. Sonicate it for 30 minutes and heat it to 200 degrees Celsius and stir for 2 hours. The mass ratio of the added fast-response nanoparticles to the hyperbranched polymer is 1:9.

[0108] (3) The obtained binder is ground in a ratio of 7:2:1 for electrode material: conductive agent: binder. An appropriate amount of water is added to assist the grinding to form a uniformly dispersed slurry. The slurry is then coated on aluminum foil and dried under vacuum.

[0109] (4) The aluminum foil from the previous step was punched to form an electrode sheet. The electrode sheet and the lithium metal sheet were assembled into a CR2032 type coin cell, and the electrochemical performance was tested. The electrolyte was 1.0M LiTFSI in DOL:DME=1:1 Vol% with 2.0% LiNO3 lithium-sulfur battery electrolyte.

[0110] (5) Place the electrode sheet prepared in the previous step on the micro induction heating device and place it in liquid nitrogen. Start the induction heating device and use an infrared thermal imager to observe the temperature rise.

[0111] Example 14:

[0112] (1) Dissolve 1.35 g FeCl3·6H2O, 3.08 g NH4Ac, and 0.258 g sodium citrate in 100 mL of ethylene glycol. Stir the mixture vigorously at 170 °C for 1 hour to form a homogeneous black solution, then transfer it to a 200 mL Teflon-lined stainless steel autoclave. Heat to 300 °C and maintain for 16 h, then cool to room temperature. Wash the black product twice with ethanol, collect it by suction filtration, and finally dry it overnight in a vacuum oven at 40 °C to obtain the final product.

[0113] (2) Weigh 1g of the above product and disperse it in a solvent. Weigh 9g of polyacetylimide and add it to the solution. Sonicate it for 30min and heat it to 200 degrees Celsius and stir for 2 hours. The mass ratio of the added fast-response nanoparticles to the hyperbranched polymer is 1:9.

[0114] (3) The obtained binder is ground in a ratio of 7:2:1 for electrode material: conductive agent: binder. An appropriate amount of water is added to assist the grinding to form a uniformly dispersed slurry. The slurry is then coated on aluminum foil and dried under vacuum.

[0115] (4) The aluminum foil from the previous step was punched to form an electrode sheet. The electrode sheet and the lithium metal sheet were assembled into a CR2032 type coin cell, and the electrochemical performance was tested. The electrolyte was 1.0M LiTFSI in DOL:DME=1:1 Vol% with 2.0% LiNO3 lithium-sulfur battery electrolyte.

[0116] (5) Place the electrode sheet prepared in the previous step on the micro induction heating device and place it in liquid nitrogen. Start the induction heating device and use an infrared thermal imager to observe the temperature rise.

[0117] Example 15:

[0118] (1) Dissolve 1.35 g FeCl3·6H2O, 3.08 g NH4Ac, and 0.25 g sodium citrate in 100 mL ethylene glycol. Stir the mixture vigorously at 170 °C for 1 hour to form a homogeneous black solution, then transfer it to a Teflon-lined stainless steel autoclave (200 mL capacity). Heat to 300 °C and maintain for 18 hours, then cool to room temperature. Wash the black product twice with ethanol, collect it by suction filtration, and finally dry it overnight in a vacuum oven at 40 °C to obtain the final product.

[0119] (2) Weigh 1g of the above product and disperse it in a solvent. Weigh 10g of styrene-butadiene rubber and add it to the solution. Sonicate it for 30min and heat it to 200 degrees Celsius and stir for 2 hours. The mass ratio of the added fast-response nanoparticles to the hyperbranched polymer is 1:10.

[0120] (3) The obtained binder is ground in a ratio of 7:2:1 for electrode material: conductive agent: binder. An appropriate amount of water is added to assist the grinding to form a uniformly dispersed slurry. The slurry is then coated on aluminum foil and dried under vacuum.

[0121] (4) The aluminum foil from the previous step was punched to form an electrode sheet. The electrode sheet and the lithium metal sheet were assembled into a CR2032 type coin cell, and the electrochemical performance was tested. The electrolyte was 1.0M LiTFSI in DOL:DME=1:1 Vol% with 2.0% LiNO3 lithium-sulfur battery electrolyte.

[0122] (5) Place the electrode sheet prepared in the previous step on the micro induction heating device and place it in liquid nitrogen. Start the induction heating device and use an infrared thermal imager to observe the temperature rise.

[0123] Example 16:

[0124] (1) Dissolve 1.35 g FeCl3·6H2O, 3.08 g NH4Ac, and 0.25 g sodium citrate in 100 mL ethylene glycol-ethanol. Stir the mixture vigorously at 170°C for 1 hour to form a homogeneous black solution, then transfer it to a 200 mL Teflon-lined stainless steel autoclave. Heat to 300°C and maintain for 18 hours, then cool to room temperature. Wash the black product twice with ethanol, collect it by suction filtration, and finally dry it overnight in a vacuum oven at 40°C to obtain the final product.

[0125] (2) Weigh 1g of the above product and disperse it in a solvent. Weigh 10g of polyacetylimide and add it to the solution. Sonicate it for 30min and heat it to 200 degrees Celsius and stir for 2 hours. The mass ratio of the added fast-response nanoparticles to the hyperbranched polymer is 1:10.

[0126] (3) The obtained binder is ground in a ratio of 7:2:1 for electrode material: conductive agent: binder. An appropriate amount of water is added to assist the grinding to form a uniformly dispersed slurry. The slurry is then coated on aluminum foil and dried under vacuum.

[0127] (4) The aluminum foil from the previous step was punched to form an electrode sheet. The electrode sheet and the lithium metal sheet were assembled into a CR2032 type coin cell, and the electrochemical performance was tested. The electrolyte was 1.0M LiTFSI in DOL:DME=1:1 Vol% with 2.0% LiNO3 lithium-sulfur battery electrolyte.

[0128] (5) Place the electrode sheet prepared in the previous step on the micro induction heating device and place it in liquid nitrogen. Start the induction heating device and use an infrared thermal imager to observe the temperature rise.

[0129] Comparative Example

[0130] The material preparation method for Comparative Example 1 is as follows:

[0131] (1) Weigh pure polyvinylidene fluoride and grind it. Grind the polymer binder in a ratio of powder: conductive agent: binder of 7:2:1. Add an appropriate amount of NMP to assist grinding to form a uniformly dispersed slurry. Then coat the slurry on aluminum foil and dry it under vacuum.

[0132] (2) The aluminum foil from the previous step was punched to form an electrode sheet. The electrode sheet and the lithium metal sheet were assembled into a CR2032 type coin cell, and the electrochemical performance was tested. The electrolyte was 1.0M LiTFSI in DOL:DME=1:1 Vol% with 2.0% LiNO3 lithium-sulfur battery electrolyte.

[0133] Performance testing:

[0134] Taking Examples 6, 7, 8, and 9 as examples, the battery test voltage range is between 1.5V and 3.0V, and the electrochemical test of the battery is performed using the Land CT2001A system. Figure 3 Example 6 shows the rate of change at current densities of 0.2C, 0.5C, 1C, 2C, 3C, and 4C when the fast-response in-situ temperature-controlled binder is used as a positive electrode binder for lithium-sulfur batteries. Figure 4 Example 7 shows the cycling performance of a fast-response in-situ temperature-controlled binder as a positive electrode binder for lithium-sulfur batteries at a current density of 1C. It can be seen that even with fast-response particles loaded, the binder can still exert its effect and ensure the cycling and rate performance of the lithium-sulfur battery.

[0135] from Figure 2 As can be seen, the hyperbranched polymer in Example 8 is fully and tightly coated on the fast-response nanoparticles, which is attributed to the combination of positive and negative charges and the redox reaction.

[0136] from Figure 5It can be seen that the electrode sheet in (Example 9, Comparative Example 1) exhibits a significant heating effect under the micro induction heating device, rising from -30 degrees Celsius to room temperature within five seconds. In contrast, the electrode sheet in Comparative Example 1 shows almost no heating effect. This is attributed to the fact that when fast-response nanoparticles are in an external field, the mechanical characteristics of the particles continuously change direction with the direction of the external field. When the external field direction changes, this change in mechanical characteristic direction leads to a localized thermal effect within the fast-response nanoparticles, causing the internal temperature of the particles to rise, thereby heating the entire electrode sheet.

Claims

1. A fast-response in-situ temperature-controlled binder-assisted micro induction heating device, applied to batteries as a preheating device in extremely cold regions, characterized in that... The fast-response in-situ temperature-controlled adhesive is formed by loading a high-viscosity hyperbranched polymer onto the surface of fast-response nanoparticles. The fast-response nanoparticles have a large number of charges on their surface, and the two are combined through electrostatic forces of positive and negative charges and redox reactions. The fast-response nanoparticles consist of a fast-response core composed of iron, cobalt, and nickel metal oxides and an outer layer encapsulating the core, with a diameter greater than 100 nanometers. The high-viscosity hyperbranched polymer is a water-soluble partially branched polymer with polar functional groups and a relative molecular mass between 70,000 and 100,000. The fast-response nanoparticles mentioned above are magnetic nanoparticles; The high-viscosity hyperbranched polymer is polyethyleneimine.

2. The fast-response in-situ temperature-controlled binder synergistic micro induction heating device as described in claim 1, applied to batteries as a preheating device in extremely cold regions, is characterized in that... The specific steps of the preparation method of the fast-response in-situ temperature-controlled adhesive are as follows: Step (1): Disperse the inorganic metal salt, organic salt and surfactant evenly in the solvent to obtain solution A; Step (2): Stir solution A vigorously at 150℃-180℃ to form a uniform dark solution. Heat the dark solution to 200℃-300℃ and maintain for 12-18h. Then cool it to room temperature. Wash the obtained dark product with solvent several times, collect it by suction filtration, and finally dry it overnight in a vacuum oven to obtain solid product B. Step (3): Dissolve the high-viscosity hyperbranched polymer in a solvent, add solid product B and adjust the pH of the solution to obtain solution C; Step (4): Disperse solution C evenly by ultrasonication and heat it to 170℃-200℃ by stirring to obtain a fast-response in-situ temperature-controlled adhesive.

3. The fast-response in-situ temperature-controlled binder synergistic micro induction heating device according to claim 2, applied to batteries as a preheating device in extremely cold regions, is characterized in that... The solvent in steps (1), (2), and (3) is one or a mixture of two or more of water, anhydrous ethanol, and ethylene glycol.

4. The fast-response in-situ temperature-controlled binder synergistic micro induction heating device according to claim 2 or 3, applied to batteries as a preheating device in extremely cold regions, characterized in that... In step (1), the inorganic metal salt is one or a mixture of two of FeCl3·6H2O and FeCl2·4H2O, the organic salt is one or a mixture of two of NH4Ac and (NH4)2C2O4, and the surfactant is sodium citrate; in step (3), the hyperbranched polymer is polyethyleneimine.

5. The fast-response in-situ temperature-controlled binder synergistic micro induction heating device according to claim 2, applied to batteries as a preheating device in extremely cold regions, is characterized in that... In step (1), the concentration of solution A is 38-70 mg·mL. -1 In step (3), the mass ratio of solid product B to high-viscosity hyperbranched polymer is 1:5-1:10, and the pH is adjusted to 6.8-8. In step (4), the ultrasonic time is more than 1 hour, and the ultrasonic frequency is 50Hz-70Hz.

6. The fast-response in-situ temperature-controlled binder synergistic micro induction heating device according to claim 5, applied to batteries as a preheating device in extremely cold regions, is characterized in that... The aforementioned miniature induction heating device is assembled by using a DC power supply to provide current, using diodes and metal oxide semiconductor field-effect transistors to oscillate and boost the voltage, and finally using a parallel circuit of inductors and capacitors to convert it into a sine wave output to the induction coil.

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