A solid-state battery, its preparation method, and its electrical device

Abstract

This invention relates to a solid-state battery and its preparation method and electrical device; the solid-state battery includes: an electrode core and a polymer layer covering the surface of the electrode core; wherein, the polymer layer is formed by curing a curable resin containing polymerizable active functional groups; the polymerizable active functional groups include at least one of: carbon-carbon double bonds, epoxy groups, hydroxymethyl groups, isocyanate groups and furan rings; it can solve the problem of uneven stress in existing solid-state batteries under high pressure environments.

Description

Technical Field

[0001] This invention relates to the field of solid-state battery technology, specifically to a solid-state battery and its preparation method and electrical device. Background Technology

[0002] As the energy source for electric products, the electrochemical performance of batteries directly determines the upper limit of product use. Currently, traditional liquid batteries are limited by their material systems, and their energy density and safety have reached their limits. Meanwhile, with the advancement of AI and communication, various electric products are showing a vibrant and dynamic development, making the development of new high-energy-density, high-safety battery cells an urgent priority. All-solid-state batteries, due to their absence of electrolyte and higher electrode surface density, offer better safety and energy density, making them the mainstream development direction for batteries today.

[0003] However, in order to maintain the flatness of the interface during charging and discharging, current all-solid-state batteries need to operate normally under a relatively high pressure environment (>30MPa). This is because the internal structure of all-solid-state batteries relies on solid electrolyte for power transmission, and a relatively high pressure is required to maintain a tight contact between the internal electrode and the electrolyte membrane, so as to avoid poor contact inside the cell caused by electrode expansion during charging and discharging.

[0004] However, during the pressurization process, uneven stress on the battery can lead to cell damage, reducing the yield of solid-state battery production. Summary of the Invention

[0005] One objective of this invention is to provide a solid-state battery to solve the problem of uneven stress distribution in existing solid-state batteries under high-pressure environments; another objective is to provide a method for preparing a solid-state battery; and a third objective is to provide an electrical device.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A solid-state battery includes: an electrode core and a polymer layer coated on the surface of the electrode core; wherein the polymer layer is formed by curing a curable resin containing polymerizable active functional groups; the polymerizable active functional groups include at least one of carbon-carbon double bonds, epoxy groups, hydroxymethyl groups, isocyanate groups and furan rings.

[0007] Based on the aforementioned technical methods, the curable resin, before curing, possesses fluidity and can encapsulate the entire electrode core. The polymer layer formed by the curable resin after the curing reaction, containing polymerizable active functional groups, combines insulation, elasticity, and sealing properties. This allows for insulation between the electrode core and the battery casing, preventing damage to the electrode core under high-pressure environments, significantly improving cell manufacturing yield, reducing the dependence of solid-state batteries on applied pressure, and minimizing damage during battery movement. By introducing at least one polymerizable active functional group from carbon-carbon double bonds, epoxy groups, hydroxymethyl groups, isocyanate groups, and furan rings into the curable resin, faster curing is achieved, while also providing functions such as heat resistance, flame retardancy, elastic buffering, and environmental adaptability.

[0008] Furthermore, the curable resin includes at least one of the following: bisphenol A type epoxy resin, methyl phenolic resin, polyurethane, acrylate, unsaturated polyester resin, cyanoacrylate monomer, furfuryl alcohol resin, and furfuryl ketone resin.

[0009] Based on the above-mentioned technical means, curable resins can be cured into polymer layers relatively quickly, and can also have functions such as heat resistance, flame retardancy, elastic cushioning, and environmental adaptability.

[0010] Furthermore, the polymer layer material includes at least one of epoxy resin, phenolic resin, polyurethane resin, polyacrylate resin, unsaturated polyester resin, polycyanoacrylate resin, polyfurfuryl alcohol resin, and polyfurfuryl ketone resin.

[0011] Based on the above-mentioned technical means, curable resins can be cured into polymer layers relatively quickly, and can also have functions such as heat resistance, flame retardancy, elastic cushioning, and environmental adaptability.

[0012] Furthermore, the curing time of the curable resin under preset conditions ranges from 10s to 120s.

[0013] Based on the above technical means, energy consumption can be reduced, and rapid shaping can be achieved while ensuring sufficient wetting and leveling of the curable resin. At the same time, the quality of uniform structure, low internal stress and few defects can be obtained, providing a reliable guarantee for the long-term cycle stability and safety of the battery.

[0014] Furthermore, the preset conditions include: curing within a temperature range of 25℃ to 120℃; or, curing under light.

[0015] The above-mentioned technical means can be used to fully cure the curable resin, thereby obtaining a polymer layer that is uniform inside and out and completely cured.

[0016] A method for fabricating a solid-state battery includes: providing an electrode core; coating the surface of the electrode core with a curable resin; the curable resin containing polymerizable active functional groups; and curing the electrode core coated with the curable resin to cure the resin and form a polymer layer.

[0017] Furthermore, coating the electrode core surface with a curable resin includes: providing a clamp; placing the electrode core in the clamp; and injecting the curable resin into the clamp to coat the electrode core with the curable resin.

[0018] Based on the above technical means, a polymer layer with good coverage can be obtained when the battery casing is a soft pack.

[0019] Furthermore, coating the electrode core surface with a curable resin includes: placing the electrode core within an aluminum casing of the solid-state battery; and injecting the curable resin into the aluminum casing to coat the electrode core with the curable resin.

[0020] Based on the above technical means, a polymer layer with good coverage can be obtained when the battery casing is a rigid package.

[0021] Furthermore, an electrode core is provided, comprising: pressing a positive electrode sheet, an electrolyte layer, and a negative electrode sheet together by isostatic pressing to form an electrode core.

[0022] According to the above technical means, isostatic pressing can gradually densify the electrode core at each pressure stage, so as to ensure that the electrode core reaches a uniform and fully dense state, and can prevent curable resin from penetrating into the electrode core and causing damage to the electrode core.

[0023] An electrical device includes a solid-state battery as described above or a solid-state battery prepared by the method described above.

[0024] The beneficial effects of this invention are: (1) In the solid-state battery of the present invention, the curable resin has fluidity before curing and can wrap the entire electrode core. It contains polymer layers formed by the curable resin after curing reaction with polymerizable active functional groups. It has insulation, elasticity and sealing properties, which can insulate the electrode core from the battery shell and avoid the electrode core from being damaged under high pressure environment. It significantly improves the cell preparation yield and reduces the dependence of the solid-state battery on external pressure and reduces the damage during the movement of the solid-state battery.

[0025] (2) The curable resin of the present invention can cure the curable resin into a polymer layer more quickly, and can also have functions such as heat resistance, flame retardancy, elastic buffering, and environmental adaptability.

[0026] (3) The solid-state battery of the present invention has a simple preparation method, fast curing speed, and is applicable to both soft-pack and hard-pack solid-state batteries, making it suitable for mass production. Attached Figure Description

[0027] Figure 1 This is a cross-sectional view of the solid-state battery of the present invention; Figure 2 This is a schematic diagram of the solid-state battery of the present invention; Figure 3 This is a flowchart of the solid-state battery preparation method of the present invention; Figure 4 This is a diagram of the apparatus for fabricating the solid-state battery of the present invention.

[0028] Among them, 100-solid-state battery; 101-core electrode; 11-tab electrode; 102-polymer layer; 103-battery casing; 31-explosion-proof valve. Detailed Implementation

[0029] The embodiments of the present invention will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention and not for limiting the scope of protection of the present invention.

[0030] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0031] In some implementations, lithium ion conduction is achieved by wetting the interface of the electrode core with a liquid or gel-like electrolyte, which fills the pores between the electrode core and the electrolyte.

[0032] However, one of the main reasons why all-solid-state batteries have good safety performance is that they do not contain liquid electrolyte. The above-mentioned implementation methods introduce electrolyte, which will relatively damage the safety performance of the battery, fail to reflect the advantages of solid-state batteries, and have complicated and inefficient processes.

[0033] In addition, during the preparation of the electrode core, the electrode core that has undergone isostatic pressing will also undergo a certain degree of bending deformation. When multiple electrode cores are combined, because the deformation degree of each electrode core is inconsistent, the cell is more likely to break due to uneven stress on the battery during the pressurization process, which reduces the production yield of solid-state batteries.

[0034] Based on this, an embodiment of the present invention provides a solid-state battery 100, such as... Figure 1 and Figure 2As shown, it includes: an electrode core 101 and a polymer layer 102 covering the surface of the electrode core 101; wherein, the polymer layer 102 is formed by curing a curable resin containing polymerizable active functional groups.

[0035] Polymerizable active functional groups refer to reactive groups that exist in monomer, oligomer, or prepolymer molecules and can undergo polymerization reactions to form high molecular weight polymers or three-dimensional cross-linked networks.

[0036] For example, the polymer layer 102 may be disposed within the battery casing 103 of the solid-state battery 100.

[0037] For example, the electrode core 101 includes tabs 11, such as positive or negative tabs; and an electrolyte layer, multiple positive electrode sheets and multiple negative electrode sheets, wherein the electrolyte may be a sulfide electrolyte.

[0038] Understandably, by coating the surface of the electrode core 101 with a polymer layer 102 formed by curing a curable resin containing polymerizable active functional groups, firstly, because the curable resin before curing has good fluidity, it can fully fill the irregular gaps between the electrode cores 101. After curing, the curable resin's own elastic deformation ability allows it to be compressed before the electrode core 101 under external pressure, converting the concentrated load into a uniformly distributed surface pressure and then transmitting it to the electrode core 101, thereby avoiding damage to the electrode core 101 caused by excessive local pressure and significantly improving the yield of battery cell manufacturing.

[0039] Secondly, during battery charging, the electrode core 101 will expand in volume. The polymer layer 102 wrapped around the electrode core 101, with its certain compressive strength and resilience, provides uniform physical constraint on the expansion behavior of the electrode core 101, causing the expansion stress to redistribute on the surface of the electrode core 101. This reduces the need for the electrode core 101 to exert external constraint force on the battery casing 103, and further reduces the external pressure required for the all-solid-state battery 100.

[0040] Furthermore, the polymer layer 102 acts as a protective layer for the electrode core 101, preventing the edges of the electrode core 101 from being scratched by the burrs or sharp edges of the battery casing 103. At the same time, the polymer layer 102 acts as a physical barrier, effectively isolating the electrode core 101 from the external environment. Even if the battery casing 103 is partially damaged, the polymer layer 102 can still prevent external moisture, oxygen, etc. from corroding the electrode core 101, reducing the probability of cell failure due to environmental factors and providing double protection for the electrode core 101.

[0041] In addition, the polymer layer 102 itself has good electrical insulation properties, which can realize electrical isolation between the electrode core 101 and the battery casing 103. At the same time, the polymer layer 102 forms a closed coating structure on the surface of the electrode core 101, which can prevent moisture in the air from reacting with the internal materials of the electrode core 101 (especially the all-solid electrolyte which is sensitive to humidity), further improving the storage and use safety of the solid-state battery 100 in humid environments.

[0042] Finally, the polymer layer 102 fills the gap between the electrode core 101 and the inner wall of the battery casing 103, thereby reducing the battery's skirt margin. When the solid-state battery 100 is subjected to vibration or impact during use, the polymer layer 102 dissipates its own viscoelastic energy, effectively reducing the relative displacement and vibration amplitude of the electrode core 101 inside the battery casing 103, and reducing the risk of failure such as electrode core 101 damage and electrode tab breakage caused by repeated mechanical collisions.

[0043] Among them, the polymerizable active functional groups include at least one of the following: carbon-carbon double bond, epoxy group, hydroxymethyl group, isocyanate group and furan ring.

[0044] The presence of carbon-carbon double bonds allows the resin to be rapidly cured at room temperature or under heating conditions through free radical or anionic addition polymerization reactions. For example, acrylate, unsaturated polyester and cyanoacrylate monomers all rely on this functional group to achieve relatively rapid crosslinking, thereby meeting the requirement of the curable resin to cure the core 101 relatively quickly.

[0045] The epoxy group endows the curable resin with excellent ring-opening polymerization ability. When it reacts with amine, acid anhydride or hydroxyl curing agents, the volume shrinkage rate is extremely small, and the cured product has high mechanical strength and adhesive properties. It can provide a long-lasting and stable constraint for the core 101, while reducing the potential damage of curing stress to the structure of the core 101.

[0046] Hydroxymethyl groups can undergo rapid polycondensation under heating conditions, and the resulting phenolic resin cured product has high heat resistance and flame retardancy, which can significantly improve the safety boundary of the battery under thermal abuse or thermal runaway conditions.

[0047] Isocyanate groups have extremely high reactivity and can react relatively quickly to form a polyurethane network, which has both the elastic cushioning ability of rubber and high tear resistance.

[0048] Furan rings can undergo ring-opening polymerization or condensation polymerization. Their cured products have heat resistance similar to phenolic resins and unique corrosion resistance. At the same time, the raw materials are derived from biomass, which meets the needs of green environmental protection and sustainable development.

[0049] In other words, by introducing at least one polymerizable active functional group from carbon-carbon double bonds, epoxy groups, hydroxymethyl groups, isocyanate groups, and furan rings into curable resins, curable resins can be cured more quickly, and the polymers can also have functions such as heat resistance, elastic cushioning, and environmental adaptability.

[0050] In some embodiments, the curable resin includes at least one of bisphenol A type epoxy resin, methyl phenolic resin, polyurethane, acrylate, unsaturated polyester resin, cyanoacrylate monomer, furfuryl alcohol resin, and furfuryl ketone resin.

[0051] In some embodiments, the polymer layer 102 material includes at least one of epoxy resin, phenolic resin, polyurethane resin, polyacrylate resin, unsaturated polyester resin, polycyanoacrylate resin, polyfurfuryl alcohol resin, and polyfurfuryl ketone resin.

[0052] Understandably, bisphenol A type epoxy resin cures to form epoxy resin; methyl phenolic resin cures to form phenolic resin; polyurethane resin cures to form polyurethane resin; acrylate resin cures to form polyacrylate resin; unsaturated polyester resin cures to form unsaturated polyester resin; cyanoacrylate monomer cures to form polycyanoacrylate resin; furfuryl alcohol resin cures to form polyfurfuryl alcohol resin; and furfuryl ketone resin cures to form polyfurfuryl ketone resin.

[0053] Bisphenol A type epoxy resin has excellent adhesive strength, low curing shrinkage rate and good electrical insulation properties. The three-dimensional cross-linked network in the epoxy resin formed after curing can provide a durable and dimensionally stable constraint for the electrode core 101, while effectively isolating the electrical contact between the electrode core 101 and the battery casing 103.

[0054] A-stage phenolic resin can rapidly condense and cure under heating conditions to form phenolic resin, which has high heat resistance and flame retardant properties. It can delay or inhibit the spread of flames when the battery experiences thermal runaway, significantly improving the safety performance of the battery.

[0055] After curing, polyurethane resins form elastomers or elastic networks within the polyurethane resin, exhibiting high elongation at break and excellent resilience. This effectively buffers external pressure, while the hardness can be adjusted over a wide range by regulating the ratio of soft to hard segments, thus adapting to the different requirements of various battery systems regarding the rigidity and flexibility of the polymer layer.

[0056] Acrylic resins have the characteristic of rapid curing at room temperature or under ultraviolet light, forming polyacrylate resins with excellent weather resistance and transparency.

[0057] Unsaturated polyester resin copolymerized with crosslinking monomers such as styrene forms an unsaturated polyester resin containing a thermosetting network with high rigidity. Its cost is relatively low and its molding process is mature, making it suitable for large-scale energy storage batteries where cost is sensitive.

[0058] Cyanoacrylate monomers can be rapidly cured to form polycyanoacrylate resins. Their ability to instantly establish initial strength eliminates the need for heating ovens or settling processes required by traditional resins, significantly saving on equipment investment and energy consumption.

[0059] After curing, furfuryl alcohol resin and furfuryl ketone resin form polyfurfuryl alcohol resin and polyfurfuryl ketone resin, respectively. They have the heat resistance of phenolic resins and unique resistance to acid, alkali and organic solvent corrosion. At the same time, the raw materials are derived from agricultural and forestry waste, which is in line with low-carbon, environmental protection and sustainable development.

[0060] Furthermore, any two or more of the aforementioned curable resins can be used in combination to produce synergistic enhancement effects. For example, blending and curing epoxy resin with polyurethane resin can obtain an epoxy-polyurethane interpenetrating polymer network structure. This structure combines the high strength of epoxy and the high toughness of polyurethane, effectively overcoming the defects of high brittleness of single epoxy resin and low strength of single polyurethane. As another example, adding a small amount of cyanoacrylate monomer to furfuryl alcohol resin can utilize the rapid curing characteristic of cyanoacrylate to quickly form a thin shell on the electrode core surface, providing temporary support and dimensional shaping for the subsequent slow thermal curing of furfuryl alcohol resin, thereby achieving precise regularization of the electrode core morphology without extending the overall process time. Yet another example is the blending of methyl phenolic resin with unsaturated polyester resin, which can introduce the rapid molding capability of unsaturated polyester while maintaining the flame retardancy of phenolic resin, improving the problem of high porosity caused by small molecule volatiles generated during the curing process of pure phenolic resin.

[0061] From the perspective of overall battery performance, by selecting at least one of the above-mentioned curable resins to construct the polymer layer, precise performance matching can be achieved according to the requirements of the specific battery system. For rapid curing, cyanoacrylate monomers or acrylate resins are preferred; for high-power density batteries with high heat resistance requirements, methyl phenolic resins or furfuryl alcohol resins are preferred; for soft-pack battery modules requiring excellent buffering and shock absorption performance, polyurethane resins are preferred; for energy storage batteries that pursue the lowest manufacturing cost, unsaturated polyester resins are preferred; for battery products that emphasize green environmental protection and biomass sources, furfuryl alcohol resins or furfuryl ketone resins are preferred; and for requirements of extremely low curing shrinkage and long-term dimensional stability, bisphenol A type epoxy resins are preferred.

[0062] In other words, the above configuration enables the curable resin to cure into a polymer layer relatively quickly, and also provides functions such as heat resistance, flame retardancy, elastic cushioning, and environmental adaptability.

[0063] In some embodiments, the curing time of the curable resin under preset conditions ranges from 10s to 120s.

[0064] For example, the curing time of the resin under preset conditions can be 10s, 30s, 50s, 70s, 90s, 110s or 120s, etc., and there is no limitation here.

[0065] Understandably, the curing time range of the curable resin under preset conditions is 10 to 120 seconds. This means that after the curable resin is applied to the surface of the electrode core, it can complete the transformation from a liquid or semi-solid state to a solid polymer within a time window of 10 to 120 seconds. This curing time range of 10 to 120 seconds eliminates the need for high-temperature heating equipment to accelerate curing in most cases, significantly reducing energy input. At the same time, it achieves rapid shaping while ensuring sufficient wetting and leveling of the curable resin, avoiding production line efficiency reduction due to slow curing or encapsulation defects due to excessively fast curing. Curing is completed before significant stress relaxation occurs in the electrode core. In addition, it can be fixed with clamps, resulting in a regular and precise polymer layer morphology, improving the dimensional accuracy of the electrode core. It is compatible with various technical solutions such as cyanoacrylate, highly active acrylate, UV-curable resin, and fast epoxy system. The obtained polymer layer has a uniform structure, low internal stress, and few defects, providing a reliable guarantee for the long-term cycle stability and safety of solid-state batteries.

[0066] In some embodiments, the preset conditions include: curing at a temperature range of 25°C to 120°C; or curing under light.

[0067] Understandably, firstly, the wide temperature range of 25℃ to 120℃ covers the entire range from room temperature curing to medium temperature curing, and can be compatible with a variety of curable resins with different curing mechanisms: room temperature (around 25℃) curing conditions are suitable for the polymerization of cyanoacrylate monomers and some highly reactive acrylate resins, which can be cured in a short time without any heating equipment, thus significantly reducing equipment investment and energy consumption; while medium temperature curing conditions of 50℃ to 120℃ are suitable for fast-formulated epoxy resins, methyl phenolic resins, unsaturated polyester resins, and furfuryl alcohol or furfuryl ketone resins. These resins have significantly improved curing speed and more complete curing products under medium temperature heating conditions. At the same time, the upper limit temperature of 120℃ is much lower than the high-temperature curing conditions of more than 150℃ required by traditional thermosetting resins, effectively avoiding thermal damage to heat-sensitive materials (such as sulfide solid electrolytes, polymer electrolytes, or diaphragms) that may exist in the electrode core.

[0068] Secondly, the introduction of photocuring conditions provides an additional process dimension to the technical solution. Ultraviolet or visible light curing can be completed relatively quickly at room temperature. Its curing speed is higher than that of most thermal curing systems. Moreover, photocuring has spatial selectivity. At the same time, no heat accumulation is generated during the photocuring process, and the thermal impact on the core 101 is almost negligible. It is particularly suitable for all-solid-state battery core systems that are extremely sensitive to temperature.

[0069] Furthermore, temperature curing and light curing conditions can be combined to form a light-heat dual curing system. For example, the resin surface can be quickly shaped by short-term light irradiation to maintain the regular morphology of the electrode core, and then the internal resin can be fully cured by medium-temperature heating, thereby obtaining a polymer layer that is uniform inside and out and fully cured.

[0070] Embodiments of the present invention provide a method for preparing a solid-state battery, such as... Figure 3 As shown, it includes: S1~S3.

[0071] S1: Provides the core.

[0072] For example, S1 provides an electrode core, which includes pressing a positive electrode sheet, an electrolyte layer and a negative electrode sheet together by isostatic pressing to form an electrode core.

[0073] For example, the isostatic pressing temperature can be 50℃~100℃, and the process can be to first hold at 100MPa for 2 minutes, then increase the pressure to 200MPa and hold for 2 minutes, then increase the pressure to 300MPa and hold for 2 minutes, then increase the pressure to 400MPa and hold for 2 minutes, and finally increase the pressure to 500MPa and hold for 5 minutes.

[0074] Here, isostatic pressing allows the electrode core to gradually densify at each pressure stage, avoiding damage to the core structure caused by sudden pressure increases. A prolonged pressure holding process at the highest pressure of 500 MPa ensures the electrode core reaches a uniform and fully densified state. Furthermore, a dense electrode core prevents curable resin from penetrating into the core and causing damage.

[0075] Meanwhile, the isostatically pressed electrode core will also undergo a certain degree of bending deformation. The gap between the electrode cores can be filled by the curable resin of the present invention. During the power-on process, the external pressure will first be conducted to the polymer layer, and then transmitted to the electrode core through the polymer layer. The polymer layer will act as a buffer layer to prevent the solid-state battery from being damaged and improve the yield of solid-state battery preparation.

[0076] S2: The surface of the electrode core is coated with a curable resin; the curable resin contains polymerizable active functional groups.

[0077] In some examples, S2 is coated with a curable resin on the core surface, including: S21A~S23A.

[0078] S21A: Provides clamps.

[0079] Here, the fixture can be rectangular in shape; the fixture can be detachable.

[0080] S22A: Place the pole core in the fixture.

[0081] S23A: Inject curable resin into the fixture so that the curable resin covers the electrode core.

[0082] Here, S21A~S23A above applies when the battery casing 103 is a soft pack, such as an aluminum-plastic casing.

[0083] In some other examples, such as Figure 4 As shown, the surface of the electrode core is coated with a curable resin, including: S21B~S22B.

[0084] S21B: The electrode core is placed in the aluminum casing of the solid-state battery.

[0085] Here, before S21B, it also includes welding the electrode core to the tabs, inserting it into the shell, and completing the peripheral welding of the aluminum shell.

[0086] S22B: Curable resin is injected into the aluminum shell so that the curable resin covers the electrode core.

[0087] Here, the aluminum casing also includes an explosion-proof valve 31.

[0088] Here, the above 21B~S22B applies to the case where the battery casing 103 is a rigid aluminum casing.

[0089] S3: Curing treatment is performed on the core encapsulating curable resin to cure the resin and form a polymer layer.

[0090] Here, when using a fixture for curing, the fixture is removed after curing to form a flat electrode core with its outer layer completely covered by a polymer layer. Then, electrode tab welding, casing insertion, aluminum-plastic casing perimeter welding, cell encapsulation, and power-on are performed. After this process, the electrode cores inside the battery are completely filled with a polymer layer, which not only insulates the electrode core from the casing but also forms a buffer layer, increasing the electrode core's pressure resistance.

[0091] Embodiments of the present invention also provide an electrical device, including a solid-state battery as described above or a solid-state battery prepared by the method described above.

[0092] Understandably, electrical devices can be electric vehicles, such as pure electric vehicles, hybrid electric vehicles, electric motorcycles, electric bicycles, electric scooters, electric forklifts, electric ships, electric aircraft, etc.; they can also be energy storage systems, consumer electronic devices, such as smartphones, tablets, laptops, wearable devices, digital cameras, portable game consoles, power banks, etc.; as well as power tools or other portable or special equipment, such as medical equipment, aerospace auxiliary power supplies, robots, unmanned logistics vehicles, automated guided vehicles, electric toys, emergency lighting equipment, etc.

[0093] The technical solution of the present invention will be further illustrated by several specific experimental examples below.

[0094] Example 1 Example 1 provides a solid-state battery, the preparation method of which is as follows: (1) Battery manufacturing process: First, the electrode sheets are made, either by dry or wet method. After the positive and negative electrode sheets are made, they are then subjected to electrode die-cutting, stacking, and isostatic pressing processes in sequence. After isostatic pressing, the positive electrode sheet, electrolyte layer and negative electrode sheet of the battery are tightly pressed together during the isostatic pressing process. Isostatic pressing parameters: 100MPa 2min→200MPa 2min→300MPa min→400MPa 2min→500MPa 5min, temperature between 50-100℃.

[0095] (2) Pair the isostatically pressed electrode cores together, and then place the electrode cores into a cuboid curing fixture that matches the size of the electrode cores. The fixture is detachable. Then inject curable resin into the fixture through the injection hole. Then place the electrode cores and the shell that have been injected with resin into the curing station together. After standing for 10 min to 120 min, curing is carried out. Curing parameters: time 10 s to 120 s, temperature 25 ℃ to 120 ℃. Then remove the curing fixture to form an electrode core with a flat surface and the outer layer completely covered by the polymer layer. Then perform electrode tab welding, shell insertion, aluminum-plastic shell peripheral welding, and complete the cell encapsulation.

[0096] Example 2 Example 2 provides a solid-state battery, the preparation method of which is as follows: (1) The manufacturing process is the same as that of the battery in Example 1.

[0097] (2) The isostatically pressed electrode cores are paired and combined, and then the electrode cores are welded with tabs, inserted into the shell, and the aluminum shell is welded around. Then, curable resin is injected into the battery through the injection hole (6). After standing for 10 min to 120 min, it is cured. Curing parameters: time 10 s to 120 s, temperature 25 ℃ to 120 ℃.

[0098] Comparative Example 1 Comparative Example 1 provides a solid-state battery, the preparation method of which is as follows: (1) The manufacturing process is the same as that of the battery in Example 1.

[0099] (2) The isostatically pressed electrode cores are paired and combined, and then the electrode tabs are welded, the shell is inserted, the aluminum-plastic shell is welded around the perimeter, and the battery cell is packaged.

[0100] Performance testing 1. The above embodiments and comparative examples were subjected to power-on tests, each 10 times, under the conditions of pressure 30MPa and temperature 30±2℃. The results are shown in Table 1 below.

[0101] Table 1. Power-on test results for the embodiments and comparative examples.

[0102] As shown in Table 1, the voltage of the solid-state battery in Comparative Example 1 dropped sharply to 0V in 80% of cases after power-on; while the voltage of the solid-state batteries in Examples 1 and 2 remained basically unchanged after power-on. This indicates that the introduction of the polymer layer has played an effective role in providing a buffer for the electrode core inside the solid-state battery, thereby improving the power-on yield of the solid-state battery.

[0103] 2. The above embodiments and comparative examples were subjected to the first coulombic efficiency test under low pressure, 10 times each, under the conditions of 10 MPa and 30 ± 2℃. The results are shown in Table 2 below.

[0104] Table 2. Initial coulombic efficiency results for the examples and comparative examples.

[0105] As shown in Table 2, the first coulombic efficiency of the solid-state battery in Comparative Example 1 is only about 70% under low pressure, while the first coulombic efficiency of the solid-state batteries in Examples 1 and 2 both exceed 80% under low pressure. This indicates that adding a polymer layer can provide a certain constraint on the expansion of the battery during charging and discharging, reduce the need for external pressure, and further promote the industrialization of all-solid-state batteries.

[0106] The above embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention.

Claims

1. A solid-state battery, characterized in that, include: The electrode core and the polymer layer covering the surface of the electrode core; The polymer layer is formed by curing a curable resin containing polymerizable active functional groups; the polymerizable active functional groups include at least one of carbon-carbon double bonds, epoxy groups, hydroxymethyl groups, isocyanate groups, and furan rings.

2. The solid-state battery according to claim 1, characterized in that, The curable resin includes at least one of the following: bisphenol A type epoxy resin, methyl phenolic resin, polyurethane, acrylate, unsaturated polyester resin, cyanoacrylate monomer, furfuryl alcohol resin, and furfuryl ketone resin.

3. The solid-state battery according to claim 2, characterized in that, The polymer layer material includes at least one of the following: epoxy resin, phenolic resin, polyurethane resin, polyacrylate resin, unsaturated polyester resin, polycyanoacrylate resin, polyfurfuryl alcohol resin, and polyfurfuryl ketone resin.

4. The solid-state battery according to any one of claims 1 to 3, characterized in that, The curing time of the curable resin under preset conditions ranges from 10s to 120s.

5. The solid-state battery according to claim 4, characterized in that, The preset conditions include: curing at a temperature range of 25℃ to 120℃; or curing under light.

6. A method for preparing a solid-state battery, characterized in that, include: Provide the core; The surface of the electrode core is coated with a curable resin; The curable resin contains polymerizable active functional groups; The electrode core, which is coated with curable resin, is cured to form a polymer layer.

7. The method for preparing a solid-state battery according to claim 6, characterized in that, The surface of the electrode core is coated with a curable resin, including: Provide clamps; Place the pole core in the fixture; A curable resin is injected into the fixture so that the curable resin coats the electrode core.

8. The method for preparing a solid-state battery according to claim 6, characterized in that, The surface of the electrode core is coated with a curable resin, including: The electrode core is placed in the aluminum casing of the solid-state battery; A curable resin is injected into the aluminum shell to coat the electrode core.

9. The method for preparing a solid-state battery according to any one of claims 6 to 8, characterized in that, Provides core components, including: The positive electrode, electrolyte layer, and negative electrode are pressed together by isostatic pressing to form the electrode core.

10. An electrical device, characterized in that, Includes the solid-state battery according to any one of claims 1 to 5 or the solid-state battery prepared by any one of claims 6 to 9.

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