A method for 3D printing and packaging lithium-ion batteries

Abstract

The present invention relates to a method for 3D printing and packaging lithium ion batteries. Firstly, 3D printing slurry is prepared, a battery shell is obtained by printing with a 3D printing device, positive and negative electrode sheets and a separator are wound or laminated to form a battery core, the battery core and the printed battery shell are assembled and then liquid is injected, the battery core is allowed to stand, and activated by chemical formation, and a resin slurry is used to fill and cover the assembly gap of the battery shell, and a 3D printed packaged battery is obtained after curing.

Description

Technical Field

[0001] The invention belongs to the technical field of batteries, and in particular relates to a method for 3D printing and packaging lithium-ion batteries. Background Art

[0002] With the continuous advancement of science and technology, energy storage has become crucial in modern society. As an efficient energy storage device, lithium-ion batteries are widely used in many fields such as electronic equipment and electric vehicles. In the traditional lithium-ion battery manufacturing process, mold molding is usually used for packaging, which has certain limitations. First of all, it is difficult for traditional processes to achieve battery packaging of complex shapes. For some scenarios with special shape requirements, such as miniaturization and special-shaped electronic devices, traditional packaging methods are difficult to meet. Secondly, the accuracy of traditional manufacturing processes is relatively low, which may lead to poor consistency or performance stability of batteries. In addition, traditional packaging processes are often more complicated and involve multiple processes, and production efficiency needs to be improved. In addition, with the continuous development of electronic products, the requirements for battery performance are becoming higher and higher, including higher energy density, higher safety performance and longer cycle life. The existence of the packaging area not only occupies the effective space of the battery, reduces the proportion of active substances that exert energy in the battery structure, but also affects the packaging reliability. At present, most of the structures of consumer batteries are assembled and manufactured by aluminum-plastic film punching and forming and pole groups. Hot pressing is required to encapsulate aluminum-plastic film to prevent moisture and air from adversely affecting battery performance. Finally, a sufficient width packaging area will be reserved on the battery structure to ensure battery sealing. Traditional packaging technologies face challenges in meeting these new requirements. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a method for 3D printing and packaging lithium-ion batteries.

[0004] The technical solution adopted by the present invention is: a method for 3D printing and packaging lithium-ion batteries, characterized in that: 3D printing slurry is prepared, a battery shell is printed by 3D printing technology, and after the assembled battery core is assembled into the battery shell, the gap of the battery shell is filled with resin slurry to obtain a 3D printed packaged battery.

[0005] Preferably, the 3D printing slurry comprises 86%-97.3% by weight of polymer material, 0.5%-2% of nucleating agent, 2%-10% of toughening agent, 0.1%-1% of light stabilizer and 0.1%-1% of antioxidant.

[0006] Preferably, the polymer material is polylactic acid, polypropylene or a blend of polylactic acid and polypropylene.

[0007] Preferably, the nucleating agent is a mixture of one or more of nano disorbitol, calcium carbonate, silicon dioxide, T-ZnO whisker, and montmorillonite;

[0008] The toughening agent is a mixture of one or more of styrene-butadiene rubber, ethylene-propylene rubber, polybutylene succinate, and thermoplastic polyurethane;

[0009] The light stabilizer is a mixture of one or more of benzophenone and benzotriazole;

[0010] The antioxidant is a mixture of one or more of antioxidant 1010, antioxidant 1076 and triphenyl phosphite.

[0011] Preferably, the resin slurry comprises epoxy resin and photoinitiator; the mass proportion of the photoinitiator is 1%-5%.

[0012] Preferably, the epoxy resin is a mixture of one or more of bisphenol A epoxy acrylate, polyurethane acrylate, alicyclic epoxy acrylate, oligomer epoxy resin, and silicone-modified epoxy resin;

[0013] A photoinitiator is a mixture of one or more of diphenylacetophenone, α,α-dimethoxy-α-phenylacetophenone, α-hydroxyalkyl phenone, bisbenzoylphenylphosphine oxide, benzophenone, and halogenated methyl aromatic ketone,

[0014] Preferably, the battery housing comprises a main body and an upper cover, the main body and the upper cover can be buckled together, the main body or the upper cover is provided with an injection hole for adding electrolyte, and the main body or the upper cover is provided with a slit channel.

[0015] Preferably, the battery casing has a thickness of 0.1-1 mm.

[0016] Preferably, the specific steps are as follows:

[0017] Step 1: Design a battery shell model according to the shape and size of the battery, import the designed shell model into the 3D printing equipment, and set and adjust the printing parameters;

[0018] Step 2: Mix the raw materials for preparing 3D printing slurry in proportion to obtain 3D printing slurry, load it into a 3D printer, and print it according to a preset model to obtain a battery shell;

[0019] Step 3: In a dry environment, the positive and negative electrodes and the separator are wound or stacked to form a battery cell;

[0020] Step 4: Assemble the battery cell and the battery shell in a dry environment, inject liquid, let it stand, and activate it;

[0021] Step 5: Fill and cover the assembled battery gaps with resin slurry. After the epoxy resin is completely cured, a 3D printed packaged battery is obtained.

[0022] A lithium-ion battery is prepared by a method for packaging lithium-ion batteries through 3D printing.

[0023] The advantages and positive effects of the present invention are: the battery is manufactured by the 3D printing battery shell packaging process, the battery packaging shell has higher dimensional accuracy, more flexible shape, and higher consistency in battery size; it is particularly suitable for manufacturing special-shaped batteries and customized batteries; the 3D printing shell packaging reduces the space occupied by the packaging area, improves the battery space utilization and the content of active substances in the battery, and has great advantages in improving the battery energy density in terms of structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The structural diagram of the battery packaged in the 3D printed shell of the present invention;

[0025] Figure 2 An exploded view of a battery packaged in a 3D printed housing according to the present invention;

[0026] In the figure, 1. main body, 2. upper cover, 21. slit channel, 22. liquid injection hole, 3. battery cell. DETAILED DESCRIPTION

[0027] The embodiments of the present invention are described below with reference to the accompanying drawings.

[0028] The present invention relates to a method for 3D printing and packaging lithium ion batteries. Firstly, 3D printing slurry is prepared, a battery shell is obtained by printing with a 3D printing device, positive and negative electrode sheets and a separator are wound or laminated to form a battery core, the battery core and the printed battery shell are assembled and then liquid is injected, the battery core is allowed to stand, and activated by chemical formation, and a resin slurry is used to fill and cover the assembly gap of the battery shell, and a 3D printed packaged battery is obtained after curing.

[0029] The 3D printing slurry includes polymer materials, nucleating agents, toughening agents, light stabilizers and antioxidants; the nucleating agent accounts for 0.5%-2% of the total material, the toughening agent accounts for 2%-10% of the total material, the light stabilizer accounts for 0.1%-1% of the total material, the antioxidant accounts for 0.1%-1% of the total material, and the rest is polymer materials. Among them, the polymer material is polylactic acid, polypropylene or a blend of polylactic acid and polypropylene; the nucleating agent is one or more of nano disorbitol, calcium carbonate, silicon dioxide, T-ZnO whisker, montmorillonite, the toughening agent is one or more of styrene-butadiene rubber, ethylene-propylene rubber, polybutylene succinate, thermoplastic polyurethane, the light stabilizer is one or more of benzophenone and benzotriazole, and the antioxidant is one or more of antioxidant 1010, antioxidant 1076, and triphenyl phosphite. During preparation, the components are mixed in proportion and stirred evenly to obtain the 3D printing slurry.

[0030] 3D printing has a high degree of design freedom, can achieve rapid manufacturing of complex shapes, and can accurately control size and structure. Therefore, 3D printing is regarded as a disruptive manufacturing process for the new generation of high-performance batteries. The specific method of printing and packaging lithium-ion batteries through 3D printing technology is as follows;

[0031] Step 1: Design a battery shell model according to the shape and size of the battery. The battery shell can be a conventional shape, such as a column with a circular, elliptical, rectangular or triangular cross-section, or an irregular shape with specific structural characteristics; import the designed shell model into the 3D printing device and adjust the printing parameters;

[0032] Step 2: Load the prepared 3D printing slurry into a 3D printer, and print the battery shell according to the model; wherein the battery shell includes a main body and an upper cover, the main body and the upper cover can be buckled, and a through hole for filling electrolyte is provided on the main body or the upper cover, and a slit channel is provided on the main body or the upper cover, and the slit channel is used for the battery tab to pass through; the thickness of the 3D printed shell is 0.1-1mm, and the preferred thickness is 0.15mm;

[0033] Step 3: In a dry environment, the positive and negative electrode sheets and the separator are wound or stacked to form a battery cell, and the prepared battery cell is dried;

[0034] Step 4: In a dry environment, the battery cell and the battery shell obtained by 3D printing are assembled using the lithium-ion battery manufacturing process, injected with liquid, left to stand, and activated;

[0035] Step 5: Use resin slurry to fill and cover the gaps on the assembled battery. The resin slurry includes epoxy resin and photoinitiator. The epoxy resin is a light-curing epoxy resin, including bisphenol A epoxy acrylate, polyurethane acrylate, alicyclic epoxy acrylate, oligomer epoxy resin, silicone-modified epoxy resin, one or more; the photoinitiator is diphenylacetophenone, α, α-dimethoxy-α-phenylacetophenone, α-hydroxyalkyl phenone, bisbenzoylphenylphosphine oxide, dibenzophenone, halogenated methyl aromatic ketone, one or more, and the photoinitiator accounts for 1% to 5% of the total weight of the epoxy resin; after filling, natural curing or light curing is used, and the curing time is 0.5-8h. After the epoxy resin is completely cured, a 3D printed packaged battery is obtained.

[0036] The battery is made by 3D printing battery shell packaging technology. The battery packaging shell has higher dimensional accuracy, more flexible shape, and higher consistency of battery size, which has great advantages for making special-shaped batteries and customized batteries. 3D printing can create objects with high flexibility and customizability. Battery shells of various shapes and sizes can be designed and manufactured according to the specific use environment and space, and batteries can be created to fit the design.

[0037] On the other hand, compared with the production method of aluminum-plastic film packaging of soft-pack batteries, 3D printed shell packaging reduces the space occupied by the packaging area, reduces the space waste caused by the packaging area, improves the battery space utilization rate and the content of active substances in the battery, and has great advantages in improving the battery energy density in structure. Therefore, the use of one-step molding technology for battery shells is an effective means to improve the energy density of batteries from a structural perspective. By controlling the ratio of printed materials and the thickness of printing, a packaging shell with a soft texture and a certain toughness can be obtained. Its performance is similar to that of the aluminum-plastic film of soft-pack batteries, which can effectively isolate water and air outside the battery and prevent corrosion from the electrolyte. Furthermore, the assembled battery can be further filled and reinforced with epoxy resin, and the epoxy resin has heat resistance and electrical insulation after curing.

[0038] In actual battery production, the use of 3D printed shells can not only save mold processing, but also its packaging process is simpler than aluminum-plastic film packaging, and does not affect the reliability of the battery. In addition, the material cost of 3D printed shells is lower than that of aluminum-plastic film.

[0039] The scheme of the present invention is described below in conjunction with the accompanying drawings, wherein the experimental methods without specific operating steps are all carried out in accordance with the corresponding product instructions, and the instruments, reagents, and consumables used in the examples can all be purchased from commercial companies unless otherwise specified.

[0040] Embodiment 1:

[0041] The battery shell model is designed according to the shape and size of the battery, including a main body 1 and an upper cover 2. The main body 1 and the upper cover 2 can be buckled together to form a rectangular parallelepiped shape. A slit channel 21 and a liquid injection hole 22 are provided in the battery upper cover. The slit channel 21 can accommodate the battery tab to pass through, and the liquid injection hole 22 can be used to inject electrolyte. The designed shell model is imported into the 3D printing device to adjust the printing parameters.

[0042] A 3D printing slurry was prepared, with polylactic acid as the main polymer component, and further comprising 1% silica, 3% polybutylene succinate, 0.2% benzophenone, and 0.3% triphenyl phosphite. The components were evenly mixed in proportion to obtain a 3D printing slurry, which was loaded into a printer, and the printing parameters were adjusted to print according to the designed battery shell shape. The shell printing wall thickness was 0.15 mm.

[0043] In a dry environment, the positive and negative electrode sheets and the separator are wound to form a battery cell 3, and the prepared battery cell 3 is dried under vacuum conditions at a drying temperature of 70° C. In a dry environment, the battery cell and the battery shell are assembled, liquid is injected, allowed to stand, and activated by formation using the same manufacturing process as that of an ion battery.

[0044] Prepare resin slurry, mix bisphenol A epoxy acrylate and diphenylacetophenone, wherein the mass proportion of diphenylacetophenone is 2%, and mix them evenly to obtain resin slurry; fill and seal the assembly gap and injection hole of the battery shell with the resin slurry, place the battery under ultraviolet light for curing for 2 hours, and obtain a 3D printed shell encapsulated battery after the epoxy resin is cured.

[0045] Embodiment 2:

[0046] The battery shell model is designed according to the shape and size of the battery, including a main body 1 and an upper cover 2. The main body 1 and the upper cover 2 can be buckled together to form a cylindrical shape. A slit channel 21 and a liquid injection hole 22 are provided in the battery upper cover. The slit channel 21 can accommodate the battery tab to pass through, and the liquid injection hole 22 can be used to inject electrolyte. The designed shell model is imported into the 3D printing device and the printing parameters are adjusted.

[0047] Prepare 3D printing slurry, mix equal volumes of polylactic acid and polypropylene, add 1.5% calcium carbonate, 5% styrene-butadiene rubber, 0.2% benzophenone, and 0.5% antioxidant 1010, mix the components evenly in proportion to obtain 3D printing slurry, load the printing slurry into the printer, adjust the printing parameters, and print according to the designed battery shell shape. The shell printing wall thickness is 0.2 mm.

[0048] In a dry environment, the positive and negative electrode sheets and the separator are wound to form a battery cell 3, and the prepared battery cell 3 is dried under vacuum conditions at a drying temperature of 70° C. In a dry environment, the battery cell and the battery shell are assembled, liquid is injected, allowed to stand, and activated by formation using the same manufacturing process as that of an ion battery.

[0049] Prepare resin slurry, mix polyurethane acrylate and α-hydroxyalkyl phenone, wherein the mass proportion of α-hydroxyalkyl phenone is 3%, and mix them evenly to obtain resin slurry; fill and seal the assembly gap and injection hole of the battery shell with the resin slurry, place the battery under ultraviolet light for curing for 4 hours, and obtain a 3D printed shell-encapsulated battery after the epoxy resin is cured.

[0050] The embodiments of the present invention are described in detail above, but the contents described are only preferred embodiments of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A method for 3D printing and packaging lithium-ion batteries, characterized in that: A 3D printing slurry is prepared, and a battery shell is obtained by printing using 3D printing technology. After the assembled battery cell is assembled into the battery shell, the gaps in the battery shell are filled with resin slurry to obtain a 3D printed packaged battery.

2. The method for 3D printing and packaging lithium-ion batteries according to claim 1, characterized in that: The 3D printing slurry includes 86%-97.3% polymer material by weight, 0.5%-2% nucleating agent, 2%-10% toughening agent, 0.1%-1% light stabilizer and 0.1%-1% antioxidant.

3. The method for 3D printing and packaging lithium-ion batteries according to claim 2, characterized in that: The polymer material is polylactic acid, polypropylene or a blend of polylactic acid and polypropylene.

4. The method for 3D printing and packaging lithium-ion batteries according to claim 3, characterized in that: The nucleating agent is a mixture of one or more of nano disorbitol, calcium carbonate, silicon dioxide, T-ZnO whisker, and montmorillonite; The toughening agent is a mixture of one or more of styrene-butadiene rubber, ethylene-propylene rubber, polybutylene succinate, and thermoplastic polyurethane; The light stabilizer is a mixture of one or more of benzophenone and benzotriazole; The antioxidant is a mixture of one or more of antioxidant 1010, antioxidant 1076 and triphenyl phosphite.

5. The method for 3D printing and packaging lithium-ion batteries according to claim 1, characterized in that: The resin slurry includes epoxy resin and photoinitiator; the mass proportion of the photoinitiator is 1%-5%.

6. The method for 3D printing and packaging lithium-ion batteries according to claim 5, characterized in that: The epoxy resin is a mixture of one or more of bisphenol A epoxy acrylate, polyurethane acrylate, alicyclic epoxy acrylate, oligomer epoxy resin, and silicone-modified epoxy resin; The photoinitiator is a mixture of one or more of diphenylacetophenone, α,α-dimethoxy-α-phenylacetophenone, α-hydroxyalkyl phenone, bisbenzoylphenylphosphine oxide, benzophenone, and halogenated methyl aromatic ketone.

7. The method for 3D printing and packaging lithium-ion batteries according to claim 1, characterized in that: The battery shell includes a main body and an upper cover. The main body and the upper cover can be buckled together. The main body or the upper cover is provided with an injection hole for adding electrolyte, and the main body or the upper cover is provided with a slit channel.

8. The method for 3D printing and packaging lithium-ion batteries according to claim 7, characterized in that: The thickness of the battery shell is 0.1-1mm.

9. The method for 3D printing and packaging lithium-ion batteries according to any one of claims 1 to 8, characterized in that: The specific steps are as follows: Step 1: Design a battery shell model according to the shape and size of the battery, import the designed shell model into the 3D printing equipment, and set and adjust the printing parameters; Step 2: Mix the raw materials for preparing 3D printing slurry in proportion to obtain 3D printing slurry, load it into a 3D printer, and print it according to a preset model to obtain a battery shell; Step 3: In a dry environment, the positive and negative electrodes and the separator are wound or stacked to form a battery cell; Step 4: Assemble the battery cell and the battery shell in a dry environment, inject liquid, let it stand, and activate it; Step 5: Fill and cover the assembled battery gaps with resin slurry. After the epoxy resin is completely cured, a 3D printed packaged battery is obtained.

10. A lithium ion battery, characterized in that: The method is prepared by the 3D printing and packaging lithium-ion battery method described in any one of claims 1 to 9.

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