3D printing overhang paste, electrode tab, battery cell and preparation method thereof and solid-state battery

Abstract

The application relates to the technical field of solid-state batteries, and discloses a 3D printing overhang slurry, which comprises a polymer base, a functional material and a solvent, the functional material comprises one or more of an oxygen adsorbent, a water adsorbent and a heat-absorbing agent, the solid content of the 3D printing overhang slurry is 20%-80%, and the mass ratio of the polymer base to the functional material is (70-90):(10-30). The packaging structure can absorb water and oxygen, absorb heat and relieve stress, thereby providing an effective prevention means for problems such as leakage, temperature rise and expansion that are prone to occur in the operation process of the solid-state battery, fully utilizing overhang gaps and improving the function of the solid-state battery. The application further discloses an electrode pole piece, a battery cell and a preparation method thereof and a solid-state battery.

Description

Technical Field

[0001] The present application relates to the field of solid-state battery technology, for example, to a 3D printed overhang slurry, an electrode plate, a battery cell and a preparation method thereof, and a solid-state battery. Background Art

[0002] In recent years, with the growing demand for energy storage and increasingly stringent requirements for battery safety, energy density and other performance, solid-state batteries, as a new battery technology with great development potential, have received widespread attention and in-depth research. Compared with traditional liquid batteries, solid-state batteries use solid electrolytes instead of liquid electrolytes, which have many significant advantages, such as higher energy density, better safety and a wider operating temperature range. They are expected to be widely used in many fields such as electric vehicles, portable electronic devices and large-scale energy storage systems. However, in the development of solid-state batteries, there are also some technical challenges that need to be solved urgently. For example, the problem of uneven stress caused by the overhang area and thus causing short circuit is one of the key factors affecting the performance and safety of solid-state batteries. There are also problems such as the instability of sulfide electrolytes to water and oxygen, and the tendency to cause thermal runaway when paired with ternary positive electrodes. These problems pose challenges to the battery operating environment, the control of positive electrode oxygen release, and the control of battery temperature.

[0003] The negative electrode overhang area refers to the portion of the negative electrode sheet that exceeds the positive electrode sheet in the length and / or width direction. This design is mainly to prevent lithium ions from precipitating on the surface of the negative electrode to form lithium dendrites during charging, thereby piercing the diaphragm and causing a short circuit in the battery, triggering thermal runaway, and improving the safety of the battery. However, the height difference generated in the overhang area will cause uneven stress in the solid-state battery during pressurized molding and pressurized operation. This uneven stress can easily lead to deformation of the edges of the electrode and the solid electrolyte, and may even cause local stratification, rupture, etc., ultimately causing a short circuit failure inside the battery, seriously affecting the battery's service life, charge and discharge performance, and overall safety.

[0004] To address the problem of battery short circuits easily occurring in solid-state batteries due to the negative electrode overhang area, most methods adopt the method of setting / filling materials (corresponding to the packaging structure of the present application) in the overhang gaps corresponding to the negative electrode overhang area for support, thereby alleviating the stress unevenness problem caused by the overhang, ensuring the interface stability between the electrode and the solid electrolyte, and thus reducing the occurrence of short circuits. Alternatively, an insulating coating is set at the edge of the positive electrode plate, which replaces the function of the overhang area with its insulating properties, and can effectively avoid the risk of short circuits caused by abnormal contact of the edge of the plate.

[0005] Currently, methods for placing or filling materials in the overhang gap generally include coating and pouring. However, these methods cannot effectively control the amount of material placed or filled during the placement or filling process, resulting in the overhang gap not being filled as expected. Providing an insulating coating on the edge of the positive electrode plate can alleviate the stress caused by the overhang area to a certain extent, but the area where the insulating coating is applied is not utilized and will also increase the battery mass.

[0006] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of this application, and therefore may include information that does not constitute prior art known to ordinary technicians in this field. Summary of the Invention

[0007] In order to provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. The summary is not an extensive review, nor is it intended to identify key / critical elements or delineate the scope of protection of these embodiments, but rather serves as a prelude to the detailed description that follows.

[0008] The embodiments of the present disclosure provide a 3D printed overhang slurry, an electrode plate, a battery cell, a preparation method thereof, and a solid-state battery. The 3D printed overhang slurry is applicable to the 3D printing method and can absorb the stress of the solid-state battery electrode volume change, alleviate the interface failure problem caused by local stress, and improve the performance of the solid-state battery.

[0009] In some embodiments, the 3D printing overhang slurry includes: a polymer substrate, a functional material and a solvent, the functional material includes one or more of an oxygen adsorbent, a water adsorbent and a heat absorbent, wherein the solid content of the 3D printing overhang slurry is 20% to 80%, and the mass ratio of the polymer substrate to the functional material is (70 to 90): (10 to 30).

[0010] In some embodiments, the method for preparing the 3D printing overhang slurry includes: preparing various raw materials according to the aforementioned 3D printing overhang slurry; adding the polymer substrate to a solvent and dissolving it to obtain solution A; adding the functional material to solution A to obtain the 3D printing overhang slurry.

[0011] In some embodiments, the electrode plate is a positive electrode plate or a negative electrode plate; when the electrode plate includes a positive electrode plate, the positive electrode plate includes a hollow foil area, and the hollow foil area is provided with a 3D printed overhang slurry; when the electrode plate includes a negative electrode plate, the negative electrode plate includes an overhang area, and the overhang area of ​​the negative electrode plate is provided with a 3D printed overhang slurry; the electrode plate includes a negative electrode plate and a combined negative electrode plate having a solid electrolyte layer on both sides of the negative electrode plate, and a 3D printed overhang slurry is provided on the surface of the solid electrolyte layer of the combined negative electrode plate corresponding to the overhang area of ​​the negative electrode plate; wherein the 3D printed overhang slurry is the aforementioned 3D printed overhang slurry or a 3D printed overhang slurry prepared by the aforementioned method for preparing the 3D printed overhang slurry.

[0012] In some embodiments, the battery cell includes a laminate structure, the laminate structure includes alternatingly stacked positive electrode sheets and negative electrode sheets, and a solid electrolyte layer is arranged between adjacent positive electrode sheets and negative electrode sheets; at least one side of the negative electrode sheet extends beyond the positive electrode sheet to form an overhang area; wherein a packaging structure is provided in the overhang gap area corresponding to the overhang area; wherein the packaging structure is obtained by arranging a 3D printed overhang slurry in the overhang gap area; the 3D printed overhang slurry is the aforementioned 3D printed overhang slurry or a 3D printed overhang slurry prepared by the aforementioned method for preparing the 3D printed overhang slurry.

[0013] In some embodiments, the preparation method of the battery cell includes: preparing a positive electrode sheet, a negative electrode sheet and a solid electrolyte layer; wherein the size of the negative electrode sheet is larger than the size of the positive electrode sheet on at least one circumferential side, so that the negative electrode sheet has an overhang area; wherein the positive electrode sheet adopts the aforementioned positive electrode sheet, or the negative electrode sheet adopts the aforementioned negative electrode sheet or a combination of negative electrode sheets; the positive electrode sheets and the negative electrode sheets are alternately stacked, and a solid electrolyte layer is provided between adjacent positive electrode sheets and negative electrode sheets to obtain a battery cell; wherein the overhang gap of the battery cell is provided with a solidified 3D printed overhang slurry.

[0014] In some embodiments, the method for preparing the battery cell includes: stacking the positive electrode sheet, the negative electrode sheet and the solid electrolyte layer in the order of the positive electrode sheet, the solid electrolyte layer, the negative electrode sheet and the solid electrolyte layer to obtain a laminated structure; wherein an overhanging gap area is formed on the peripheral side surface of the laminated structure; and setting a 3D printed overhang slurry in the overhanging gap area of ​​the laminated structure to obtain a battery cell with a packaging structure.

[0015] In some embodiments, the solid-state battery includes: the aforementioned electrode plate; or the aforementioned battery cell; or a battery cell prepared by the aforementioned battery cell preparation method.

[0016] The 3D printed overhang slurry, electrode sheet, battery cell, preparation method thereof, and solid-state battery provided in the embodiments of the present disclosure can achieve the following technical effects:

[0017] In the 3D printing overhang slurry of the disclosed embodiment, the polymer base and the solvent make the slurry fluid. The solid content of the 3D printing overhang slurry is between 20% and 80%, which can take into account the solid content and rheological properties of the slurry, making the overhang slurry suitable for 3D printing methods, ensuring both printing strength and printing smoothness, thereby achieving a packaging structure with the desired effect at the overhang gap and solving the problem of edge collapse and short circuit of solid-state batteries.

[0018] At the same time, the 3D printed overhang slurry also contains functional materials, and the mass ratio of the polymer substrate and the functional materials is maintained within the scope of this solution. In this way, the packaging structure can also take into account functions such as adsorbing water and oxygen, absorbing heat, and relieving stress, thereby providing an effective preventive measure for problems such as leakage, temperature rise, and expansion that are prone to occur during the operation of solid-state batteries. In this way, the 3D printed overhang slurry provided by the embodiment of the present disclosure can not only play a supporting role, but also enable the packaging structure formed by the 3D printed overhang slurry to have other functions to ensure the stable and safe operation of the solid-state battery, making full use of the overhang gap, thereby improving the performance of the solid-state battery.

[0019] The electrode plates of the disclosed embodiment can be printed to set up an overhang packaging structure through a 3D printing method, and the printing volume can be precisely controlled, thereby being able to well control parameters such as the thickness and uniformity of the packaging structure, with fast printing speed and high efficiency.

[0020] The above general description and the following description are exemplary and explanatory only and are not intended to limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] One or more embodiments are exemplarily described by corresponding drawings. These exemplary descriptions and drawings do not limit the embodiments. Elements with the same reference numerals in the drawings are shown as similar elements. The drawings do not constitute a scale limitation. In addition,

[0022] Figure 1 is a schematic structural diagram of an existing solid-state battery provided by an embodiment of the present disclosure;

[0023] Figure 2is a structural diagram of a packaging structure provided by an embodiment of the present disclosure;

[0024] Figure 3 Schematic diagram of the partial structure of the solid-state battery prepared in Example 1 provided in the embodiments of the present disclosure;

[0025] Figure 4 Schematic diagram of the partial structure of the solid-state battery prepared in Example 2 provided in the embodiments of the present disclosure;

[0026] Figure 5 Schematic diagram of the partial structure of the solid-state battery prepared in Example 3 provided in the embodiments of the present disclosure;

[0027] Figure 6 Schematic diagram of the exploded structure of the solid-state battery prepared in Example 1 provided in the embodiments of the present disclosure;

[0028] Figure 7 Schematic diagram of the exploded structure of the solid-state battery prepared in Example 2 provided in the embodiments of the present disclosure;

[0029] Figure 8 Schematic diagram of the exploded structure of the solid-state battery prepared in Example 3 provided in the embodiments of the present disclosure;

[0030] Figure 9 is a structural schematic diagram of a battery cell provided by an embodiment of the present disclosure;

[0031] Figure 10 is a schematic diagram of a partially enlarged structure of another battery cell provided by an embodiment of the present disclosure;

[0032] Figure 11 This is a flowchart of a method for preparing a 3D printing overhang slurry provided by an embodiment of the present disclosure;

[0033] Figure 12 This is a flowchart of a method for preparing a battery cell provided by an embodiment of the present disclosure;

[0034] Figure 13 This is a flowchart of another method for preparing a battery cell provided by an embodiment of the present disclosure;

[0035] Figure 14 This is a flowchart of another method for preparing a battery cell provided in an embodiment of the present disclosure.

[0036] Reference numerals:

[0037] 10: laminated structure; 11: negative electrode pole piece; 111: overhang area; 112: negative electrode active material layer; 113: negative electrode current collector; 12: positive electrode pole piece; 121: positive electrode active material layer; 122: positive electrode current collector; 13: solid electrolyte layer; 2: packaging structure; 21: filling part; 211: supporting part; 212: penetration part; 22: coating part. DETAILED DESCRIPTION

[0038] In order to be able to understand the features and technical content of the embodiments of the present disclosure in more detail, the implementation of the embodiments of the present disclosure is described in detail below in conjunction with the accompanying drawings. The accompanying drawings are for reference only and are not used to limit the embodiments of the present disclosure. In the following technical description, for the sake of convenience of explanation, a full understanding of the disclosed embodiments is provided through multiple details. However, one or more embodiments can still be implemented without these details. In other cases, to simplify the drawings, well-known structures and devices can be simplified for display.

[0039] In the description and claims of the embodiments of the present disclosure, as well as in the accompanying drawings, the terms "first," "second," and the like are used to distinguish similar objects and are not necessarily used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate to facilitate understanding of the embodiments of the present disclosure described herein. In addition, the terms "including," "having," and any variations thereof are intended to cover non-exclusive inclusions.

[0040] In the embodiments of the present disclosure, the terms "upper", "lower", "inside", "middle", "outside", "front", "back" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. These terms are mainly intended to better describe the embodiments of the present disclosure and their embodiments, and are not intended to limit the indicated devices, elements or components to having a specific direction, or to be constructed and operated in a specific direction. Moreover, in addition to being used to indicate directions or positional relationships, some of the above terms may also be used to indicate other meanings. For example, the term "upper" may also be used to indicate a certain dependency or connection relationship in certain circumstances. For those of ordinary skill in the art, the specific meanings of these terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0041] Furthermore, the terms "disposed," "connected," and "fixed" should be interpreted broadly. For example, "connected" can mean a fixed connection, a removable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection, an indirect connection through an intermediary, or an internal connection between two devices, elements, or components. Those skilled in the art will understand the specific meanings of these terms in the embodiments of this disclosure based on the specific circumstances.

[0042] Unless otherwise stated, the term "plurality" means two or more.

[0043] In the embodiment of the present disclosure, the character " / " indicates that the preceding and following objects are in an "or" relationship. For example, A / B means: A or B.

[0044] The term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.

[0045] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present disclosure can be combined with each other.

[0046] An embodiment of the present disclosure provides a 3D printing overhang slurry, comprising: a polymer substrate, a functional material and a solvent, wherein the functional material comprises one or more of an oxygen adsorbent, a water adsorbent and a heat absorbent.

[0047] The polymer base and solvent in the 3D printing overhang slurry take into account both high solid content and rheological properties, making it suitable for 3D printing methods, achieving the printability and high strength of high-solid content slurries, ensuring both printing strength and smoothness, thereby achieving the desired packaging structure 2 at the overhang gap, solving the problem of edge collapse and short circuit in solid-state batteries. At the same time, the 3D printing overhang slurry also contains functional materials, so that the packaging structure 2 can also take into account functions such as adsorbing water and oxygen, absorbing heat, and relieving stress, thereby providing an effective preventive measure for problems such as leakage, temperature rise, and expansion that are prone to occur during battery operation. During the cycling process of the solid-state battery, the functional material can quench the oxygen generated in the positive electrode or the water / oxygen leaked from the environment, slowing the decomposition of the solid-state electrolyte, especially the sulfide solid electrolyte, reducing side reactions in the solid-state battery, and improving the thermal stability of the solid-state electrolyte. Combined with the elastic properties of the polymer, it absorbs the stress of the solid-state battery electrode volume change, alleviates the interface failure problem caused by local stress, and improves the performance of the solid-state battery.

[0048] Optionally, the solid content of the 3D printing overhang slurry is 20% to 80%, or the solid content of the 3D printing overhang slurry is 20% to 60%, or the solid content of the 3D printing overhang slurry is 35% to 60%, or the solid content of the 3D printing overhang slurry is 60% to 75%, or the solid content of the 3D printing overhang slurry is 60% to 80%, or the solid content of the 3D printing overhang slurry is any value within the range of 20% to 80%.

[0049] The 3D printing overhang slurry of the disclosed embodiment adopts a solid content within the above-mentioned range, achieving a balance between the slurry's rheological properties and high solid content. This ensures that the 3D printing overhang slurry has a reasonable number of solid phase particles and an appropriate particle spacing, thereby having reasonable rheological properties, making it suitable for 3D printing methods, ensuring the processability and stability of 3D printing, and ensuring the strength and density of the printed overhang packaging structure 2. It is understood that the solid content of the 3D printing overhang slurry can be either mass solid content or volume solid content, without limitation.

[0050] Optionally, the solid content of the 3D printing overhang slurry is the mass solid content. The solid content is adjusted by the amount of solvent added. That is, the amount of solvent used in the 3D printing overhang slurry of the present disclosure is determined based on the solid content of the slurry. The type of solvent is not limited.

[0051] Optionally, the solid content of the 3D printing overhang slurry is 20%, 30%, 35%, 40%, 45%, 50%, 60%, 65%, 75% or any value within the range of 20% to 80%.

[0052] Optionally, the mass percentage of the polymer substrate in the dry solids of the 3D printing overhang slurry is 60% to 90%, or the mass percentage of the polymer substrate in the dry solids of the 3D printing overhang slurry is 70% to 90%, or the mass percentage of the polymer substrate in the dry solids of the 3D printing overhang slurry is 60% to 80%, or the mass percentage of the polymer substrate in the dry solids of the 3D printing overhang slurry is any value within the range of 60% to 90%.

[0053] In the 3D printing overhang slurry of the embodiment of the present disclosure, the overall proportion of the polymer substrate in the solid content of the 3D printing overhang slurry is within the above-mentioned range, which can provide sufficient elasticity and strength for the packaging structure 2, thereby ensuring that the packaging structure has sufficient supporting force and buffering force, and ensuring that the packaging structure 2 has sufficient mechanical strength and thermal stability.

[0054] Optionally, the mass percentage of the polymer substrate in the dry solids content of the 3D printing overhang slurry is 60%, 65%, 70%, 75%, 80%, 90% or any value within the range of 60% to 90%.

[0055] The mass of solids in the 3D printing overhang slurry refers to the mass of the solids in the 3D printing overhang slurry after drying.

[0056] Optionally, the functional material accounts for 5% to 40% by mass of the solid content in the 3D printing overhang slurry, or the functional material accounts for 10% to 40% by mass of the solid content in the 3D printing overhang slurry, or the functional material accounts for 10% to 35% by mass of the solid content in the 3D printing overhang slurry, or the functional material accounts for 10% to 30% by mass of the solid content in the 3D printing overhang slurry, or the functional material accounts for any value between 5% and 40% by mass of the solid content in the 3D printing overhang slurry.

[0057] The 3D printing overhang slurry of the embodiment of the present disclosure has a functional material content within the above range, which can not only regulate the microenvironment inside the battery to protect the battery, but also ensure the mechanical strength and stability of the packaging structure 2, and ensure the supporting effect of the packaging structure 2 on the overhang.

[0058] Optionally, the mass percentage of the functional material in the solid content of the 3D printing overhang slurry is 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40% or any value within 5% to 40%.

[0059] Optionally, the mass ratio of the polymer substrate to the functional material is (70-90):(10-30).

[0060] In the 3D printed overhang slurry of the disclosed embodiment, the mass of the polymer substrate is greater than the mass of the functional material. In this way, the polymer substrate absorbs the stress of the solid-state battery electrode volume change, alleviates the interface failure problem caused by local stress, and improves the performance of the solid-state battery. The functional material makes the packaging structure 2 also have specific functions, providing an effective preventive measure for problems such as leakage, temperature rise, and expansion that are prone to occur during battery operation. The mass ratio of the polymer substrate and the functional material achieves a balance between the mechanical strength and function of the packaging structure 2 within the above range.

[0061] Optionally, the mass ratio of the polymer substrate to the functional material is 70:30, 80:30, 90:30, 70:20, 80:20, 90:20, 70:10, 80:10, 90:10, etc.

[0062] Optionally, the polymer substrate includes one or more of polyisobutylene, polyphenylene ether, polyimide, polyacrylonitrile, polyvinylidene fluoride, polyethylene glycol, polyethylene oxide, sodium carboxymethyl cellulose, styrene-butadiene rubber and polyacrylic acid.

[0063] The 3D-printed overhang slurry and polymer substrate of the disclosed embodiments utilize the aforementioned materials, ensuring sufficient strength for the package structure 2 to support the overhang. These materials also possess a moderate elastic modulus and viscoelastic properties, enabling the package structure 2 to provide support without being brittle. This provides excellent stress buffering, ensuring interfacial stability between the electrode and solid electrolyte, and thus reducing the risk of short circuits.

[0064] Optionally, the solvent includes one or more of dimethyl sulfoxide, N,N-dimethylacetamide, N-methylpyrrolidone and dimethylformamide.

[0065] Optionally, the water adsorbent includes one or more of zeolite, calcium chloride, magnesium chloride, sodium polyacrylate and polyvinyl alcohol.

[0066] The 3D printing overhang slurry of the disclosed embodiment can use the above-mentioned materials as the water adsorbent, which can effectively adsorb the residual water in the battery and reduce the side reactions in the solid-state battery.

[0067] Optionally, the oxygen adsorbent includes one or more of polydopamine, lithium phytate, 4-tert-butylcatechol, N-phenyl-N'-phenylenediamine, naphthylamine, diphenylamine and p-phenylenediamine.

[0068] The 3D printed overhang slurry of the disclosed embodiment uses the above-mentioned material as the oxygen adsorbent. During the cycle of the solid-state battery, the oxygen adsorbent can quench the oxygen generated in the positive electrode or the oxygen leaked from the environment, avoiding the oxidation reaction between the active substance in the electrode and oxygen, thereby preventing the electrode from being oxidized and corroded, slowing down the decomposition of the solid-state electrolyte, especially the sulfide solid electrolyte, reducing the side reactions in the solid-state battery, and improving the thermal stability of the solid-state electrolyte.

[0069] Optionally, the heat absorbent includes one or more of polyethylene glycol and polyvinyl alcohol.

[0070] The 3D printing overhang slurry of the disclosed embodiment and the heat absorber using the above-mentioned material can effectively absorb the heat from battery operation, absorb local hot spots, and ensure the safety of the battery.

[0071] Optionally, when the polymer substrate includes a first polymer and a second polymer, the elastic modulus of the first polymer is greater than the elastic modulus of the second polymer, and the strength of the second polymer is greater than the strength of the first polymer; wherein the first polymer accounts for 50% to 80% by mass of the polymer substrate, or the first polymer accounts for 50% to 75% by mass of the polymer substrate, or the first polymer accounts for 60% to 75% by mass of the polymer substrate; the second polymer accounts for 20% to 60% by mass of the polymer substrate, or the second polymer accounts for 25% to 50% by mass of the polymer substrate, or the second polymer accounts for 25% to 40% by mass of the polymer substrate.

[0072] The 3D printing overhang slurry of the disclosed embodiment can use a polymer substrate composited with multiple polymers, combined with high elasticity and high strength materials, so that the packaging structure 2 can not only resist external impact and constrain expansion, but also has good flexibility and can adapt to the overall expansion and contraction of the battery without breaking.

[0073] Optionally, the mass percentage of the first polymer to the polymer substrate is 50%, 55%, 60%, 65%, 70%, 75%, 80% or any value within the range of 50% to 80%.

[0074] Optionally, the mass percentage of the second polymer to the polymer substrate is 20%, 25%, 20%, 30%, 35%, 40%, 45%, 50%, 60% or any value within the range of 20% to 60%.

[0075] Optionally, when the functional material includes an oxygen adsorbent, the mass percentage of the oxygen adsorbent in the functional material is 10% to 60%, or the mass percentage of the oxygen adsorbent in the functional material is 10% to 50%, or the mass percentage of the oxygen adsorbent in the functional material is 20% to 50%, or any range of 10% to 60% of the mass percentage of the oxygen adsorbent in the functional material.

[0076] In the 3D printing overhang slurry of the embodiment of the present disclosure, the oxygen adsorbent can effectively ensure the adsorption of oxygen by the oxygen adsorbent within the above-mentioned range, thereby inhibiting the effect of oxidation side reactions. At the same time, the functional material can also be mixed with other functional materials to improve the versatility of the packaging structure 2 and comprehensively protect the safety, stability of use and service life of the battery.

[0077] Optionally, when the functional material includes an oxygen adsorbent, the mass percentage of the oxygen adsorbent in the functional material is 10%, 20%, 30%, 40%, 50%, 60% or any value within the range of 10% to 60%.

[0078] Optionally, when the functional material includes a water adsorbent, the mass percentage of the water adsorbent in the functional material is 20% to 70%, or the mass percentage of the water adsorbent in the functional material is 20% to 60%, or the mass percentage of the water adsorbent in the functional material is 30% to 60%, or the mass percentage of the water adsorbent in the functional material is any range of 20% to 70%.

[0079] In the 3D printed overhang slurry of the disclosed embodiment, the content of the water adsorbent is within the above-mentioned range, which can effectively prevent water vapor from entering the interior of the battery cell and prevent the electrode materials and electrolytes in the battery cell from undergoing hydrolysis reactions, so that the 3D printed slurry maintains appropriate viscosity and stability.

[0080] Optionally, when the functional material includes a water adsorbent, the mass percentage of the water adsorbent in the functional material is 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 70% or any value between 20% and 70%.

[0081] Optionally, when the functional material includes an endothermic agent, the mass percentage of the endothermic agent in the functional material is 20% to 100%, or the mass percentage of the endothermic agent in the functional material is 20% to 40%, or the mass percentage of the endothermic agent in the functional material is 60% to 100%, or the mass percentage of the endothermic agent in the functional material is 80% to 100%, or the mass percentage of the endothermic agent in the functional material is any value within the range of 20% to 100%.

[0082] In the 3D printed overhang slurry of the disclosed embodiments, the heat absorber, within the aforementioned range, can effectively absorb some of the heat generated by the battery cell during operation, reducing the local temperature of the battery cell and preventing safety issues such as thermal runaway caused by overheating. It can also alleviate thermal stress caused by temperature differences between the slurry and the battery cell, reducing cracking and deformation of the package structure 2, and improving the integrity and reliability of the package structure 2.

[0083] Optionally, the mass percentage of the heat absorbent to the functional material is 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100% or any value within the range of 20% to 100%.

[0084] Optionally, the functional material includes auxiliary additives, and the auxiliary additives include one or more of a reinforcing agent, a compatibilizer, a coupling agent, a surfactant, and an inorganic filler, which can further improve the function of the packaging structure 2 .

[0085] Optionally, the functional material includes auxiliary additives, with the auxiliary additives comprising 0% to 40% by weight of the functional material, or 10% to 40% by weight of the functional material, or 20% to 40% by weight of the functional material. By mixing different auxiliary additives, the functionality of the 3D printing overhang slurry is further enhanced. When multiple auxiliary additives are used, the proportions of the various auxiliary additives are not limited.

[0086] Optionally, the reinforcing agent includes hydrophobic fumed silica, which can improve the barrier properties and abrasion resistance of the coating.

[0087] In some optional embodiments, the 3D printing overhang slurry includes a first slurry, and the solid content of the first slurry is 20% to 65%, or the solid content of the first slurry is 30% to 60%, or the solid content of the first slurry is 35% to 60%, or the solid content of the first slurry is any range within 20% to 65%. In the battery cell of the disclosed embodiment, the solid content of the first slurry is within the above range, so that the 3D printing overhang slurry has good fluidity and wettability, can penetrate into the internal layer of the battery material, and can also take into account mechanical strength and provide sufficient support stress.

[0088] Optionally, the solid content of the first slurry is 20%, 25%, 30%, 35%, 40%, 45%, 50%, 60%, 65% or any value within the range of 20% to 65%.

[0089] Optionally, the polymer base in the first slurry includes one or more of polyvinylidene fluoride, polyacrylonitrile, and polyethylene oxide. The polymer base in the first slurry is selected from the group consisting of the above, so that the package structure has a certain elastic modulus and viscoelasticity, can provide flexible support and stress buffering, and prevent the package structure from breaking.

[0090] In some embodiments, the solid content of the first slurry is 35% to 60%, and the polymer matrix in the first slurry includes one or more of polyvinylidene fluoride, polyacrylonitrile and polyethylene oxide. Such a solid content of 35% to 60% makes the 3D printed overhang slurry have good fluidity, which can not only fill the overhang void area, but also penetrate into the interior of the sheet layer, thereby improving the bonding strength between the packaging structure and the battery cell. In addition, the first slurry uses one or more of polyvinylidene fluoride, polyacrylonitrile and polyethylene oxide, so that the 3D printed overhang slurry has a certain elasticity, so that the formed packaging structure has a certain deformation ability and improves the cohesion. This can solve the stress unevenness problem caused by overhang, ensure the interface stability between the electrode and the solid electrolyte, thereby reducing the occurrence of short circuits, and further adapt to the molding pressure of the battery cell and the volume change of the active material, avoid the packaging structure 2 from being out of contact with the sheet layer and excessive deformation, resulting in new edge stress, thereby improving the performance of the solid-state battery.

[0091] Optionally, the functional material in the first slurry includes one or more of an oxygen adsorbent, a water adsorbent and a heat absorbent.

[0092] In the embodiment of the present disclosure, the functional material enables the packaging structure to not only support the overhang area 111, but also to regulate the microenvironment inside the battery cell, reduce the side reactions within the solid-state battery, and improve the thermal stability of the solid-state battery. When the first slurry is arranged inside the sheet layer of the battery cell, it can even penetrate between the sheets. Therefore, one or more of the oxygen adsorbent, water adsorbent and heat absorbent added to the first slurry can be used to coordinately regulate the environment inside the battery cell. The water adsorbent can efficiently capture the residual moisture inside the battery cell. The oxygen adsorbent can inhibit the oxidation side reaction inside the battery cell, and the heat absorbent can absorb local hot spots, thereby regulating the environment inside the battery cell, while solving the stress problem caused by the overhang area 111, further improving the performance and safety of the solid-state battery.

[0093] Optionally, the mass percentage of the oxygen adsorbent in the first slurry to the functional material is 10% to 60%, or the mass percentage of the oxygen adsorbent in the first slurry to the functional material is 10% to 50%, or the mass percentage of the oxygen adsorbent in the first slurry to the functional material is 20% to 50%, or the mass percentage of the oxygen adsorbent in the first slurry to the functional material is 30% to 60%, or the mass percentage of the oxygen adsorbent in the first slurry to the functional material is any range within 10% to 60%.

[0094] The mass percentage of the oxygen adsorbent in the first slurry to the functional material can be flexibly selected within the above-mentioned multiple ranges to meet the requirements of different application scenarios for oxygen adsorption capacity and comprehensive performance of the slurry. For example, for lithium iron phosphate batteries with low positive electrode oxygen release intensity, a lower content of oxygen adsorbent can be used to achieve basic protection and block the slow oxidation of trace oxygen. For some ternary batteries with average positive electrode oxygen release intensity, a medium content of oxygen adsorbent can be used to inhibit the oxidative decomposition reaction of ions in the battery. For ternary batteries with high positive electrode oxygen release intensity, a higher content of oxygen adsorbent can be used to strongly capture the release of lattice oxygen to prevent oxygen from reacting with the electrolyte.

[0095] Optionally, the mass percentage of the oxygen adsorbent to the functional material in the first slurry is 10%, 20%, 30%, 40%, 50%, 60% or any value within the range of 10% to 60%.

[0096] Optionally, the oxygen adsorbent in the first slurry includes one or more of polydopamine nanoparticles, lithium phytate, 4-tert-butylcatechol, N-phenyl-N'-phenylenediamine, naphthylamine, diphenylamine, and p-phenylenediamine.

[0097] Preferably, the oxygen adsorbent in the first slurry includes polydopamine nanoparticles. As an oxygen adsorbent, polydopamine nanoparticles can provide ultra-high specific surface area and adsorption efficiency, improve the oxygen capture capacity per unit mass, and can respond to changes in oxygen concentration as needed to extend the shelf life.

[0098] Optionally, the mass percentage of the water adsorbent in the first slurry to the functional material is 20% to 70%, or the mass percentage of the water adsorbent in the first slurry to the functional material is 20% to 60%, or the mass percentage of the water adsorbent in the first slurry to the functional material is 30% to 60%, or the mass percentage of the water adsorbent in the first slurry to the functional material is any range within 20% to 70%.

[0099] The weight percentage of water adsorbent relative to the functional materials in the first slurry can be adjusted based on the application scenario. For specialized battery cells with extremely high requirements for water vapor resistance (such as those operating in high-humidity environments), a higher proportion of water adsorbent can be selected. For battery cells operating in general environments or in scenarios requiring other functions (such as heat absorption and enhancement), the water adsorbent ratio can be appropriately reduced to highlight the role of other functional materials.

[0100] Optionally, the mass percentage of the water adsorbent to the functional material in the first slurry is 20%, 30%, 40%, 50%, 60%, 70% or any value within the range of 20% to 70%.

[0101] Optionally, the water adsorbent in the first slurry includes one or more of zeolite, calcium chloride, magnesium chloride, sodium polyacrylate and polyvinyl alcohol.

[0102] Optionally, the water adsorbent in the first slurry includes zeolite. Zeolite is low-cost, highly adsorbent, and has a high adsorption capacity. Zeolite is well compatible with a variety of polymer substrates and evenly disperses in the slurry, forming a stable system that avoids stratification and precipitation, ensuring slurry uniformity and consistency. Zeolite can also work synergistically with other functional materials, such as oxygen adsorbents and heat absorbers, to achieve comprehensive optimization of slurry performance, including multiple functions such as adsorbing water, oxygen, and absorbing heat.

[0103] Optionally, the mass percentage of the heat absorber in the first slurry to the functional material is 10% to 50%, or the mass percentage of the heat absorber in the first slurry to the functional material is 20% to 50%, or the mass percentage of the heat absorber in the first slurry to the functional material is 20% to 40%, or the mass percentage of the heat absorber in the first slurry to the functional material is any range within 10% to 50%.

[0104] The battery cells of the disclosed embodiments have a relatively high percentage of heat absorbent by mass, allowing the slurry to absorb significant amounts of heat. This makes them suitable for packaging battery cells that generate significant heat during charging and discharging, such as high-rate lithium-ion batteries or large-capacity energy storage batteries. This effectively reduces the battery cell temperature, avoids safety issues caused by overheating, and maintains stable operation. The relatively low percentage of heat absorbent by mass meets the temperature control requirements of generally heat-generating battery cells, preventing overheating while minimizing potential changes in slurry performance or other adverse effects caused by excessive heat absorption. This makes them suitable for packaging most common battery cells.

[0105] Optionally, the mass percentage of the heat absorbent to the functional material in the first slurry is 10%, 20%, 30%, 40%, 50% or any value within the range of 10% to 50%.

[0106] Optionally, the heat absorber in the first slurry includes polyethylene glycol. Polyethylene glycol can absorb a large amount of heat during its phase transition between solid and liquid states, effectively reducing the heat generated by the battery cell during charging and discharging, preventing safety issues caused by overheating, and maintaining stable operation of the battery cell. Furthermore, the polyethylene glycol can automatically adjust its heat absorption process based on changes in the battery cell's temperature. When the battery cell temperature rises, the polyethylene glycol absorbs heat, slowing the temperature rise; when the battery cell temperature drops, it does not release heat too quickly, helping to maintain a relatively stable battery cell temperature.

[0107] In some optional embodiments, the functional materials in the first slurry include zeolite, polydopamine nanoparticles and a heat absorber, wherein the zeolite accounts for 30-60% by mass of the functional material, so that the zeolite can efficiently capture residual moisture; the polydopamine nanoparticles account for 20-50% by mass of the functional material, which can effectively inhibit oxidative side reactions; and the polyethylene glycol accounts for 20-40% by mass of the functional material, which can absorb local hot spots.

[0108] In another optional embodiment, the 3D printing overhang slurry further includes a second slurry, and the solid content of the second slurry is 60% to 80%, or the solid content of the second slurry is 60% to 80%, or the solid content of the second slurry is 60% to 75%, or the solid content of the second slurry is any range within 60% to 80%.

[0109] In the battery cell of the embodiment of the present disclosure, the solid content of the second slurry is within the above range, which can form a rigid, tough and dense packaging structure 2, so that the edges of the electrode or the bonding of the end face of the diaphragm can be better sealed, thereby improving the sealing effect of the battery cell and isolating the oxygen and water from the external environment.

[0110] Optionally, the solid content of the second slurry is 60%, 65%, 70%, 75%, 80%, 85%, 90% or any value within the range of 60% to 90%.

[0111] Optionally, the polymer substrate in the second slurry includes a first polymer and a second polymer, the elastic modulus of the first polymer is greater than the elastic modulus of the second polymer, and the strength of the second polymer is greater than the strength of the first polymer, wherein the content of the first polymer is greater than the content of the second polymer, or the mass percentage of the first polymer in the polymer substrate is 50% to 80%, or the mass percentage of the first polymer in the polymer substrate is 50% to 75%, or the mass percentage of the first polymer in the polymer substrate is 60% to 75%; the mass percentage of the second polymer in the polymer substrate is 20% to 60%, or the mass percentage of the second polymer in the polymer substrate is 25% to 50%, or the mass percentage of the second polymer in the polymer substrate is 25% to 40%.

[0112] In the battery cells of the disclosed embodiments, the polymer matrix in the second slurry is a composite of multiple polymers, combining a high-elasticity elastomer with a high-strength material. This results in a higher content of the first polymer (high elastic modulus) than the second polymer (higher strength). This allows the resulting package structure to possess sufficient elastic modulus and toughness, providing sufficient expansion adaptability to resist external impact and constrain expansion. It also possesses good flexibility, allowing it to adapt to overall expansion and contraction without cracking. The second polymer imparts sufficient mechanical strength and thermal stability to the package structure.

[0113] Optionally, the mass percentage of the first polymer to the polymer substrate is 50%, 55%, 60%, 65%, 70%, 75%, 80% or any value between 50% and 80%.

[0114] Optionally, the mass percentage of the second polymer to the polymer substrate is 20%, 25%, 30%, 35%, 40%, 45%, 50% or any value between 20% and 60%.

[0115] In some embodiments, the solids content of the second slurry is 60% to 75%. The polymer matrix in the second slurry includes a first polymer and a second polymer. The first polymer includes polyisobutylene, and the second polymer includes polyimide or polyphenylene ether. The polyisobutylene accounts for 60% to 75% of the polymer matrix by weight, and the polyimide or polyphenylene ether accounts for 25% to 40% of the polymer matrix by weight. Polyisobutylene provides expansion adaptability, while polyimide or polyphenylene ether imparts mechanical strength and thermal stability. The good flexibility of polyisobutylene enables the package structure to adapt to the slight expansion and contraction of the battery cell during charging and discharging, preventing cracking of the package structure 2 due to excessive rigidity. The high strength and rigidity of polyimide or polyphenylene ether provide good mechanical support for the package structure 2, enhancing its stability.

[0116] Optionally, in the second slurry, the functional material accounts for 5% to 40% by mass of the dry solid content of the 3D printing overhang slurry, or the functional material accounts for 10% to 40% by mass of the dry solid content of the 3D printing overhang slurry, or the functional material accounts for 10% to 35% by mass of the dry solid content of the 3D printing overhang slurry, or the functional material accounts for 10% to 30% by mass of the dry solid content of the 3D printing overhang slurry.

[0117] Optionally, the functional material in the second slurry includes a heat absorber, and the mass percentage of the heat absorber in the functional material is 60% to 100%, or the mass percentage of the heat absorber in the functional material is 80% to 100%, or the mass percentage of the heat absorber in the functional material is 60% to 90%.

[0118] The second slurry contains a high concentration of heat absorbent and can be placed around the outside of the cell structure to provide overall protection. This high concentration of heat absorbent allows it to absorb significant amounts of heat during the cell's charge and discharge process, rapidly reducing the cell's surface temperature and preventing safety issues such as thermal runaway caused by overheating. This is particularly important for high-power cells, ensuring stability under high loads.

[0119] Optionally, the functional material in the second slurry includes a heat absorber, and the mass percentage of the heat absorber to the functional material is 60%, 70%, 80%, 90%, 100% or any value within the range of 60% to 100%.

[0120] Optionally, the functional material in the second slurry includes a heat absorber, and the heat absorber includes polyethylene glycol or polyvinyl alcohol. Both polyethylene glycol and polyvinyl alcohol have high specific heat capacity and good thermal conductivity, and can quickly absorb the heat generated by the battery cell during the charging and discharging process, reduce the surface temperature of the battery cell, and prevent safety problems caused by overheating of the battery cell, such as thermal runaway. Both polyethylene glycol and polyvinyl alcohol have a certain viscosity regulating effect, which can improve the rheological properties of the slurry, making it more suitable for 3D printing process requirements. Under the premise of ensuring heat absorption performance, the viscosity and fluidity of the slurry can be adjusted by adjusting the amount of polyethylene glycol or polyvinyl alcohol to ensure that the slurry can evenly cover the surrounding side of the battery cell during the printing process to form a complete coating layer.

[0121] Optionally, the functional material in the second slurry further includes a reinforcing agent, and the reinforcing agent includes hydrophobic fumed silica, which can improve the barrier properties and wear resistance of the packaging structure.

[0122] Optionally, the functional material of the second slurry includes a reinforcing agent, and the weight percentage of the reinforcing agent in the functional material is 0 to 40%.

[0123] In some optional embodiments, the functional material in the second slurry accounts for 10% to 30% by weight of the dry solids content of the second slurry, and the functional material includes high molecular weight polyethylene glycol or polyvinyl alcohol, and the high molecular weight polyethylene glycol or polyvinyl alcohol accounts for 60% to 100% by weight of the functional material. Optionally, the functional material also includes hydrophobic fumed silica, and the hydrophobic fumed silica accounts for 0% to 40% by weight of the functional material.

[0124] Combine Figure 11 As shown, the embodiment of the present disclosure provides a method for preparing a 3D printing overhang slurry, comprising the following steps:

[0125] S110. Prepare the raw materials for the 3D printing overhang slurry according to any of the preceding embodiments. In this step S110, the raw materials include at least a polymer substrate, a solvent, and a functional material, wherein the functional material includes at least one or more of an oxygen adsorbent, a water adsorbent, and a heat absorbent. The amounts of the raw materials used should meet the requirements of the 3D printing overhang slurry according to any of the preceding embodiments.

[0126] S120, adding the polymer substrate to a solvent and dissolving the polymer substrate to obtain a solution A;

[0127] S130, functional material is added to solution A to obtain 3D printing overhang slurry.

[0128] In the method of the embodiments of the present disclosure, the polymer substrate is added to the solvent to obtain solution A, so that the polymer chains in solution A are fully stretched to form a three-dimensional network structure. Then, the functional material is added to solution A, so that the functional material is wrapped by the three-dimensional network structure in solution A, improving the mixing uniformity and avoiding density differences. Moreover, the Brownian motion of the functional material in solution A is weakened, and the steric hindrance effect can inhibit agglomeration, ensuring the uniformity and granularity of the 3D printing overhang slurry.

[0129] Optionally, in S120, the polymer substrate is slowly added to the solvent, and stirred in a magnetic stirrer for 4 hours. After the polymer is completely dissolved, solution A is obtained to improve the solubility of the polymer substrate.

[0130] Optionally, in S130, after the functional material is added to solution A, high-speed stirring is performed for 1 hour to obtain the 3D printing overhang slurry.

[0131] In combination with Figures 2 to 8 As shown in the drawings, the embodiments of the present disclosure provide an electrode tab, which is a positive electrode tab 12 or a negative electrode tab 11. When the electrode tab includes the positive electrode tab 12, the positive electrode tab 12 includes an empty foil region, and the empty foil region is provided with the 3D printing overhang slurry. When the electrode tab includes the negative electrode tab 11, the negative electrode tab 11 includes an overhang region 111, and the overhang region 111 of the negative electrode tab 11 is provided with the 3D printing overhang slurry. When the electrode tab includes the negative electrode tab 11 and the negative electrode tab 11 is a combined negative electrode tab provided with a solid electrolyte layer 13 on both side surfaces thereof, the 3D printing overhang slurry is provided on the surface of the solid electrolyte layer 13 of the combined negative electrode tab corresponding to the overhang region 111 of the negative electrode tab 11. The 3D printing overhang slurry is the 3D printing overhang slurry of any one of the preceding embodiments or the 3D printing overhang slurry prepared by the preparation method of the 3D printing overhang slurry of any one of the preceding embodiments.

[0132] The region of the electrode tab of the embodiments of the present disclosure corresponding to the overhang region 111 is provided with the 3D printing overhang slurry, for example, the empty foil region of the positive electrode tab 12, the surface of the overhang region 111 of the negative electrode tab 11, or the surface of the solid electrolyte layer of the combined negative electrode tab corresponding to the overhang region 111, so that the 3D printing overhang slurry is provided in the overhang gap of the battery cell obtained by layering, and the overhang packaging structure 2 is obtained after solidification.

[0133] The 3D printing overhang slurry provided on the electrode plate of the embodiment of the present disclosure can be printed and provided using a 3D printing method.

[0134] The 3D printed overhang slurry provided on the electrode plate of the embodiment of the present disclosure can be kept in a slurry state before entering the subsequent process; or the 3D printed overhang slurry can be solidified before entering the subsequent process, which is not limited and is determined according to actual conditions.

[0135] In the battery cell of the disclosed embodiment, the 3D printed overhang slurry is cured to form the package structure 2. Curing is the process of evaporating the solvent in the slurry. Therefore, the curing temperature is determined by the type of solvent used. Optionally, the temperature is 60°C to 150°C.

[0136] In some embodiments, the positive electrode sheet 12 adopts the positive electrode sheet 12 of any of the electrode sheets in the foregoing embodiments; or, the negative electrode sheet 11 adopts the negative electrode sheet 11 of any of the electrode sheets in the foregoing embodiments or a combined negative electrode sheet.

[0137] Existing battery cell structures such as Figure 1 As shown, the battery cell includes alternating stacked positive electrode sheets 12 and negative electrode sheets 11, and a solid electrolyte layer 13 is provided between adjacent positive electrode sheets 12 and negative electrode sheets 11; the negative electrode sheet 11 extends beyond the positive electrode sheet 12 on at least one side in the circumferential direction to form an overhang region 111. The positive electrode sheet 12 includes a positive electrode current collector 122 and a positive electrode active material layer 121 provided on the positive electrode current collector 122. The negative electrode sheet 11 includes a negative electrode current collector 113 and a negative electrode active material layer 112 provided on the negative electrode current collector 113. The solid electrolyte layer 13 connects the negative electrode active material layer 112 and the positive electrode active material layer 121 to each other, providing lithium ion transmission.

[0138] An embodiment of the present disclosure provides a battery cell, which includes a laminate structure 10 and a packaging structure 2. The laminate structure 10 includes alternatingly stacked positive electrode sheets 12 and negative electrode sheets 11, and a solid electrolyte layer 13 is arranged between adjacent positive electrode sheets 12 and negative electrode sheets 11; the negative electrode sheet 11 extends beyond the positive electrode sheet 12 on at least one side in a circumferential direction to form an overhang area 111; wherein, a packaging structure 2 is provided in an overhang gap area corresponding to the overhang area 111; wherein, the packaging structure 2 is obtained by arranging a 3D-printed overhang slurry in the overhang gap area; the 3D-printed overhang slurry is the 3D-printed overhang slurry of any of the aforementioned embodiments or a 3D-printed overhang slurry prepared by the preparation method of the 3D-printed overhang slurry of any of the aforementioned embodiments.

[0139] The battery cell of the embodiment of the present disclosure includes the 3D printed overhang slurry of any of the aforementioned embodiments. The battery cell has all the technical effects of the 3D printed overhang slurry, which will not be repeated here.

[0140] Optionally, the packaging structure 2 includes a filling portion 21 and a covering portion 22 connected to each other, at least a portion of the filling portion 21 is located in the overhanging gap area, and the covering portion 22 covers the peripheral side surface of the laminate structure 10 .

[0141] In the embodiment of the present disclosure, the overhang gap area is an overhang gap area (i.e., an overhang gap) corresponding to the overhang area 111 formed by the negative electrode plate 11 extending beyond the positive electrode plate 12 on at least one side of the circumference. In this case, the negative electrode plate 11 is designed to be larger than the positive electrode plate 12, so that at least one side of the negative electrode plate 11 extends beyond the overhang area 111 formed by the positive electrode plate 12 on the circumference. Relative to the outer contour of the circumference of the laminate structure 10, the overhang gap area extends inwardly of the laminate structure 10 and has a certain depth (see Figure 10 The depth indicated by d1 in the figure is prone to stress concentration under the molding pressure during solid-state battery assembly, causing short circuits in the battery cells, thereby reducing the manufacturing yield and performance consistency of the battery cells. The filling portion 21 of the packaging structure 2 fills the overhanging gap areas, thereby resolving the problem of stress concentration in these overhanging gap areas under molding pressure, which can cause short circuits in the battery cells.

[0142] The covering portion 22 of the packaging structure 2 compensates for defects left over from the previous process such as edge defects of the electrode, burrs on the foil, and misalignment of the stacking sheets by wrapping the peripheral end faces of the battery cell. The fully enclosed outer frame packaging design not only protects the environment inside the battery cell, but also accommodates the volume changes during the operation of the battery cell, thereby comprehensively improving the yield rate of battery cell manufacturing and the safety performance of the battery cell. For example, the covering portion 22 can cover the burrs and edge defects of the electrode on the negative electrode collector 113, as well as the misaligned protrusions and misaligned depressions caused by misaligned stacking sheets. Burrs can easily pierce the solid electrolyte layer, causing a micro-short circuit between the positive and negative electrodes, leading to self-discharge of the battery and degradation of the electrochemical performance. In terms of safety, the local current density at the micro-short circuit exceeds 100A / cm 2 (far exceeding the 1~5 A / cm of normal charge and discharge 2 ), which will quickly accumulate heat and cause thermal runaway of the battery in severe cases.

[0143] Optionally, the filling portion 21 includes a supporting portion 211 and a penetrating portion 212, wherein the supporting portion 211 is located in the overhanging gap area, and the penetrating portion 212 is a portion extending from the supporting portion 211 and penetrating into the interior of the sheet around the overhanging gap area; the penetration depth of the penetrating portion 212 is greater than or equal to 1 μm.

[0144] In the battery cell of the embodiment of the present disclosure, in addition to the support portion 211 arranged in the overhanging gap area, the packaging structure 2 also includes a penetration portion 212 that penetrates into the sheet layer around the overhanging gap area. The setting of the penetration portion 212 ensures the interface bonding effect between the packaging structure 2 and the sheet layer of the laminated structure 10, improves the bonding strength between the packaging structure 2 and the sheet layer, and the penetration portion 212 penetrates into the active material area of ​​the electrode pole piece to enhance the cohesive force and has a certain deformation ability to adapt to the molding pressure of the laminated battery cell and the volume change of the active material (including the molding pressure and the volume change caused by charging and discharging), avoids the packaging structure 2 and the sheet layer (electrode pole piece and / or solid electrolyte layer 13) from being out of contact and excessive deformation to cause new edge stress, thereby improving the performance of the solid-state battery.

[0145] In the battery cell of the embodiment of the present disclosure, the bonding strength between the packaging structure 2 and the laminated structure 10 reaches 1.2 MPa or above. The first-cycle discharge specific capacity of the solid-state battery obtained by assembling the battery cell of the embodiment of the present disclosure can be improved.

[0146] In the battery cell of the embodiment of the present disclosure, “inside the sheet layer” refers to the inside of the positive electrode sheet 12 , the negative electrode sheet 11 and the solid electrolyte layer 13 , more specifically, the positive electrode active material layer 121 , the negative electrode active material layer 112 and the solid electrolyte layer 13 .

[0147] In the battery cell of the embodiment of the present disclosure, the filling rate of the overhanging gap area of ​​the encapsulation structure 2 is greater than or equal to 60%. Optionally, the filling rate is greater than or equal to 70%. Optionally, the filling rate is greater than or equal to 80%. Optionally, the filling rate is greater than or equal to 90%.

[0148] The battery cell of the embodiment of the present disclosure is a laminated battery cell, which can be used as a battery cell of a solid-state battery. Optionally, the laminate structure 10 includes one or more laminate units, and each laminate unit includes a negative electrode sheet 11, a solid electrolyte layer 13 and a positive electrode sheet 12 stacked in sequence. When the laminate structure 10 includes multiple laminate units, the positive electrode sheet 12 of one laminate unit is stacked with the negative electrode sheet 11 of the adjacent laminate unit through the solid electrolyte layer 13. That is, the laminate structure 10 is arranged and stacked in the manner of negative electrode sheet 11 / solid electrolyte layer 13 / positive electrode sheet 12 / solid electrolyte layer 13 / negative electrode sheet 11 / solid electrolyte layer 13 / positive electrode sheet 12 / …. Generally, the electrode sheets on both surfaces of the laminate structure 10 are negative electrode sheets 11, but of course it is not limited to this.

[0149] The penetration portion 212 of the packaging structure 2 penetrates into the sheet layers around the overhanging gap area of ​​the laminated structure 10. For example, the penetration portion 212 penetrates into the active material of the positive electrode plate 12 around the overhanging gap area and the solid electrolyte layer 13 and the active material of the negative electrode plate 11. Therefore, in theory, the 3D printing overhang slurry penetrating into the sheet layers will cause the positive electrode plate 12 to lose part of its theoretical capacity. However, in actual applications, the provision of the penetration portion 212 can not only improve the bonding strength between the packaging structure 2 and the laminated structure 10 and improve the battery cell yield, but also greatly improve the actual capacity of the battery cell, improve the first-cycle specific capacity and cycle performance of the battery, and thus improve the battery performance.

[0150] In some embodiments, as Figure 10 As shown, the penetration depth d2 of the penetration portion 212 is greater than or equal to 1 μm. By controlling the penetration depth, the theoretical capacity loss and the actual capacity improvement are balanced to ensure that the battery performance can be improved. Optionally, the penetration depth of the penetration portion 212 is greater than or equal to 1 μm and less than or equal to 300 μm. Optionally, the penetration depth of the penetration portion 212 is greater than or equal to 10 μm and less than or equal to 300 μm. Optionally, the penetration depth of the penetration portion 212 is greater than or equal to 50 μm and less than or equal to 300 μm. Optionally, the penetration depth of the penetration portion 212 is greater than or equal to 100 μm and less than or equal to 300 μm. Optionally, the penetration depth of the penetration portion 212 is greater than or equal to 150 μm and less than or equal to 300 μm. Optionally, the penetration depth of the penetration portion 212 is greater than or equal to 200 μm and less than or equal to 250 μm. By controlling the penetration depth of the penetration portion 212 and thus controlling the theoretical capacity loss, the battery performance can be improved while ensuring the bonding strength to increase the cell yield.

[0151] In some embodiments, the percentage of the penetration area of ​​the permeable portion 212 to the electrode sheet area is less than or equal to 1%. In this embodiment, by controlling the penetration percentage of the permeable portion 212, the theoretical capacity loss and the actual capacity increase are balanced to ensure improved battery performance. Optionally, the percentage of the penetration area of ​​the permeable portion 212 to the electrode sheet area is less than or equal to 0.8%.

[0152] Optionally, the penetration depth d2 of the penetration portion 212 is less than or equal to 300 μm, and the penetration percentage of the penetration area of ​​the penetration portion 212 to the electrode plate area is less than or equal to 1%.

[0153] The battery cell of the disclosed embodiment is more suitable for large-sized battery cells. It is understandable that the larger the battery cell size, the smaller the penetration depth / penetration area of ​​the penetration portion 212 relative to the electrode plate area, and the smaller the theoretical capacity loss. However, the bonding strength between the packaging structure 2 and the laminated structure 10 is not affected. While the battery cell yield is improved, the actual capacity of the battery cell can be greatly increased, the first-cycle specific capacity and cycle performance of the battery can be improved, and thus the battery performance can be improved.

[0154] Alternatively, as Figure 2 and Figure 9 As shown, in the case where the packaging structure 2 includes a connected filling portion 21 and a covering portion 22, and the filling portion 21 includes a supporting portion 211 and a permeable portion 212, the supporting portion 211 and the permeable portion 212 are made of the same material, while the covering portion 22 is made of a different material from the filling portion 21. The filling portion 21 needs to fill the overhanging gap area, and a 3D printing overhang slurry with a certain degree of permeability is required to ensure that the 3D printing overhang slurry can enter the overhanging gap area and penetrate into the sheet layer. The covering portion 22, on the other hand, covers the peripheral side of the laminate structure 10 and can use a non-permeable 3D printing overhang slurry.

[0155] Optionally, the filling portion is formed of a first slurry, the covering portion is formed of a second slurry, and the solid content of the first slurry is less than or equal to the solid content of the second slurry.

[0156] In the battery cell of the disclosed embodiment, when the filling portion is formed by the first slurry, the solid content of the first slurry is relatively low, which can ensure the fluidity and wettability of the 3D printed overhang slurry, so that the filling portion 21 can penetrate into the overhanging gap area, and even penetrate into the interior of the sheet layer, while also taking into account mechanical strength, providing sufficient supporting stress, and improving the filling effect. The coating portion uses a second slurry with a higher solid content to form a thick, tough, dense coating on the peripheral side of the laminate structure 10. This can better seal the edge of the pole piece or the bonding of the end face of the diaphragm, cover the peripheral side of the battery cell, improve the sealing effect of the battery cell, and isolate oxygen and water from the external environment. Improve the safety performance of the battery cell.

[0157] The filling part of the embodiment of the present disclosure adopts a first slurry, and the polymer base of the first slurry includes one or more of polyvinylidene fluoride, polyacrylonitrile and polyethylene oxide, so that the filling part 21 has a certain elastic modulus and viscoelasticity, can provide flexible support and stress buffering, and avoid the support part 211 from breaking.

[0158] In some embodiments, when the filling portion is formed by the first slurry, the solid content of the first slurry is 35% to 60%, and the polymer matrix in the first slurry includes one or more of polyvinylidene fluoride, polyacrylonitrile, and polyethylene oxide. Such a solid content of 35% to 60% makes the filling portion 21, especially the penetration portion 212, have good fluidity, which can not only fill the overhanging gap area, but also penetrate into the interior of the sheet layer, thereby improving the bonding strength between the packaging structure 2 and the laminated structure 10. In addition, the first slurry uses one or more of polyvinylidene fluoride, polyacrylonitrile, and polyethylene oxide, so that the filling portion 21 has a certain elasticity, which not only makes the support portion 211 have a certain deformation ability, but also the penetration portion 212 has a certain deformation ability, thereby improving the cohesion. This can solve the stress unevenness problem caused by overhang, ensure the interface stability between the electrode and the solid electrolyte, thereby reducing the occurrence of short circuits, and further adapt to the molding pressure of the laminated battery cell and the volume change of the active material, avoiding the packaging structure 2 from being out of contact with the sheet layer and excessive deformation causing new edge stress, thereby improving the performance of the solid-state battery.

[0159] Optionally, when the filling portion is formed by a first slurry, the functional material in the first slurry includes a plurality of oxygen adsorbents, water adsorbents and heat absorbers. The functional material enables the filling portion 21 to not only support the overhang area 111, but also to regulate the microenvironment inside the battery cell, reduce side reactions within the solid-state battery, and improve the thermal stability of the solid-state battery. Since the filling portion 21 is located inside the laminated structure 10 and can even penetrate between the layers, the filling portion 21 can add one or more of oxygen adsorbents, water adsorbents and heat absorbers to coordinately regulate the environment inside the battery cell. The water adsorbent can efficiently capture residual moisture inside the battery cell. The oxygen adsorbent can inhibit the oxidation side reaction inside the battery cell, while the heat absorber can absorb local hot spots, thereby regulating the environment inside the battery cell, while solving the stress problem caused by the overhang area 111, further improving the performance and safety of the solid-state battery.

[0160] Optionally, when the filling portion is formed from a first slurry, the water adsorbent in the first slurry includes zeolite. Zeolite is low in cost, has strong adsorption properties, and possesses a high adsorption capacity. Zeolite is highly compatible with a variety of polymer substrates and is evenly dispersed in the slurry, forming a stable system that avoids stratification and precipitation, ensuring the uniformity and consistency of the slurry. Zeolite can also work in conjunction with other functional materials such as oxygen adsorbents and heat absorbers to jointly perform multiple functions, such as adsorbing water, oxygen, and absorbing heat, to achieve comprehensive optimization of slurry performance.

[0161] In some optional embodiments, when the filling part is formed by the first slurry, the functional material includes zeolite, polydopamine nanoparticles, and a heat-absorbing agent, wherein the mass percentage of the zeolite in the functional material is 30-60%, so that the zeolite can efficiently capture residual moisture; the mass percentage of the polydopamine nanoparticles in the functional material is 20-50%, so that the polydopamine nanoparticles can effectively inhibit the oxidation side reaction; and the mass percentage of the polyethylene glycol in the functional material is 20-40%, so that the polyethylene glycol can absorb local hot spots.

[0162] The coating part of the embodiments of the present disclosure is formed by the second slurry, and the polymer base in the second slurry is a plurality of polymer composites combined with a high elastomer and a high-strength material. In this way, the content of the first polymer with a high elastic modulus is higher than that of the second polymer with a higher strength, so that the coating part 22 has a sufficient elastic modulus and toughness, can provide sufficient expansion adaptability, resist external impact and constraint expansion, and also has good flexibility, can adapt to overall expansion and contraction without being broken. The second polymer can endow the coating part 22 with sufficient mechanical strength and thermal stability.

[0163] In some embodiments, when the coating part is formed by the second slurry, the solid content of the second slurry is 60-75%, the polymer base in the second slurry includes a first polymer and a second polymer, the first polymer includes polyisobutylene, and the second polymer includes polyimide or polyphenyl ether. The mass percentage of the polyisobutylene in the polymer base is 60-75%, and the mass percentage of the polyimide or polyphenyl ether in the polymer base is 25-40%. The polyisobutylene provides expansion adaptability, and the polyimide or polyphenyl ether endows mechanical strength and thermal stability. The polyisobutylene has good flexibility, so that the coating part 22 can adapt to the slight expansion and contraction of the battery cell in the charging and discharging process, and avoid cracking of the packaging structure 2 due to excessive rigidity. The polyimide or polyphenyl ether has high strength and rigidity, and provides good mechanical support for the coating part 22, and enhances the stability of the packaging structure 2.

[0164] Optionally, when the coating part is formed by the second slurry, the functional material in the second slurry includes a heat-absorbing agent, and the mass percentage of the heat-absorbing agent in the functional material is 60%, 70%, 80%, 90%, 100%, or any value within the range of 60-100%.

[0165] Optionally, when the coating is formed by the second slurry, the functional material in the second slurry includes a heat absorber, and the heat absorber includes polyethylene glycol or polyvinyl alcohol. Both polyethylene glycol and polyvinyl alcohol have a high specific heat capacity and good thermal conductivity, and can quickly absorb the heat generated by the battery cell during the charging and discharging process, reduce the surface temperature of the battery cell, and prevent safety problems caused by overheating of the battery cell, such as thermal runaway. Both polyethylene glycol and polyvinyl alcohol have a certain viscosity regulating effect, which can improve the rheological properties of the slurry, making it more suitable for 3D printing process requirements. Under the premise of ensuring heat absorption performance, the viscosity and fluidity of the slurry can be adjusted by adjusting the amount of polyethylene glycol or polyvinyl alcohol to ensure that the slurry can evenly cover the surrounding side of the battery cell during the printing process to form a complete coating layer.

[0166] Optionally, when the covering portion is formed by the second slurry, the functional material in the second slurry further includes a reinforcing agent, and the reinforcing agent includes hydrophobic fumed silica, which can improve the barrier properties and wear resistance of the covering portion 22 .

[0167] In some optional embodiments, when the coating is formed from the second slurry, the functional material in the second slurry accounts for 10% to 30% by weight of the dry solids content of the second slurry, and the functional material includes high molecular weight polyethylene glycol or polyvinyl alcohol, and the high molecular weight polyethylene glycol or polyvinyl alcohol accounts for 60% to 100% by weight of the functional material. Optionally, the functional material also includes hydrophobic fumed silica, and the hydrophobic fumed silica accounts for 0% to 40% by weight of the functional material.

[0168] It can be understood that the filling portion 21 and the covering portion 22 of the packaging structure 2 can also adopt any components and proportions in the above-mentioned 3D printing overhang slurry. In actual applications, the components and proportions in the 3D printing overhang slurry can be adjusted according to different battery materials and types.

[0169] Optionally, the positive electrode sheet 12 includes a positive electrode current collector 122 and a positive electrode active material layer 121 disposed on the positive electrode current collector 122. The positive electrode active material layer 121 is covered on one or both sides of the positive electrode current collector 122, depending on actual needs.

[0170] In this embodiment, the positive electrode current collector 122 is typically made of a metal material. Optionally, the material of the positive electrode current collector 122 includes aluminum foil. The thickness of the positive electrode current collector 122 can be controlled to be 6-20 μm. Optionally, the thickness of the positive electrode current collector 122 is 10-20 μm. Optionally, the positive electrode current collector 122 includes aluminum foil with a thickness of 10-20 μm.

[0171] Optionally, the positive electrode active material layer 121 includes a positive electrode active slurry, which is mainly composed of one or more complexes of lithium iron phosphate, lithium cobaltate, lithium manganese oxide, lithium vanadate, lithium nickelate, lithium manganese oxide, lithium nickel manganese oxide, lithium-rich manganese base, lithium iron manganese phosphate, lithium nickel cobalt aluminum oxide, lithium nickel cobalt manganese oxide, lithium iron phosphate, lithium vanadium phosphate, sulfur, lithium sulfide and sulfur iodide.

[0172] Optionally, the negative electrode sheet 11 includes a negative electrode current collector 113 and a negative electrode active material layer 112 disposed on the negative electrode current collector 113 . The negative electrode active material layer 112 includes a negative electrode active slurry, which is determined according to actual needs.

[0173] In this embodiment, the negative electrode current collector 113 is typically made of a metal material. Optionally, the negative electrode current collector 113 includes copper foil. The thickness of the negative electrode current collector 113 can be controlled to be 6-10 μm. Optionally, the thickness of the negative electrode current collector 113 is 6-8 μm. Optionally, the negative electrode current collector 113 includes copper foil with a thickness of 6-10 μm.

[0174] Optionally, the negative electrode active material layer 112 is not limited and is determined according to actual needs. Optionally, the negative electrode active material layer 112 includes a negative electrode active material and other additives, and the other additives include one or more composites of components such as pure silicon material, graphite material, carbon material, silicon-carbon material, and silicon-oxygen material.

[0175] Optionally, a negative electrode plate includes a negative electrode active material layer 112. That is, the negative electrode plate of this embodiment consists solely of the negative electrode active material layer 112. The negative electrode active material layer 112 is designed to reversibly accommodate and release lithium ions and function as an external conductor, eliminating the need for the negative electrode current collector 113 to provide a conductive function. In this case, the negative electrode active material layer 112 is composed of one or more composites of conductive materials such as lithium metal and carbon materials.

[0176] Optionally, the negative electrode plate 11 includes one or more of a lithium metal negative electrode, a lithium alloy negative electrode, a graphite negative electrode, a pure silicon negative electrode, a pure SiO negative electrode, a pure SiC negative electrode, a silicon-graphite mixed negative electrode, a SiO-graphite negative electrode, a SiC-graphite negative electrode, a silicon alloy negative electrode, a pure tin negative electrode and a tin alloy negative electrode.

[0177] In the battery cell of the disclosed embodiment, solid electrolyte layer 13 connects negative electrode active material layer 112 and positive electrode active material layer 121, providing lithium ion transport. Solid electrolyte layer 13 comprises a composite of one or more components selected from sulfide electrolytes, oxide electrolytes, polymer electrolytes, and halide electrolytes.

[0178] Preferably, the solid electrolyte layer 13 includes a sulfide electrolyte, and the sulfide electrolyte includes one or more of lithium phosphorus chlorine sulfur, lithium phosphorus bromine sulfur, lithium phosphorus iodine sulfur, lithium phosphorus silicon sulfur, lithium phosphorus aluminum sulfur, lithium phosphorus germanium sulfur, lithium phosphorus boron sulfur, lithium phosphorus sulfur, lithium silicon sulfur and lithium silicon indium sulfur.

[0179] Optionally, the width of the filling portion 21 is smaller than the width of the overhang area 111. Optionally, the width of the filling portion 21 is 1 mm to 2 mm.

[0180] Combine Figure 12 As shown, the embodiment of the present disclosure provides a method for preparing a battery cell, comprising the following steps:

[0181] S210, prepare a positive electrode sheet 12, a negative electrode sheet and a solid electrolyte layer 13; wherein, the size of the negative electrode sheet is larger than the size of the positive electrode sheet 12 on at least one circumferential side, so that the negative electrode sheet has an overhang area 111; wherein, the positive electrode sheet 12 adopts the positive electrode sheet 12 of any of the aforementioned embodiments, or, the negative electrode sheet adopts the negative electrode sheet 11 of any of the aforementioned embodiments or a combination of negative electrode sheets.

[0182] S220. Alternately stack the positive electrode sheets 12 and the negative electrode sheets, and provide a solid electrolyte layer 13 between adjacent positive electrode sheets 12 and negative electrode sheets to obtain a battery cell; wherein, the overhang gap of the battery cell is provided with a solidified 3D printed overhang slurry.

[0183] Optionally, in step S210, a positive electrode sheet 12 is prepared, including: setting a positive electrode active slurry on a positive electrode collector 122 to obtain a positive electrode active material layer 121, and reserving an empty foil area on the positive electrode collector 122 around the positive electrode active material layer 121; and printing a 3D printed overhang slurry on the empty foil area of ​​the positive electrode sheet 12 by a 3D printing method to obtain a positive electrode sheet 12.

[0184] Optionally, in step S210 , a negative electrode plate is prepared, including: placing a negative electrode active slurry on a negative electrode current collector 113 to obtain a negative electrode active material layer 112 , and printing a 3D printed overhang slurry on the surface of the overhang area 111 of the negative electrode plate by a 3D printing method.

[0185] Optionally, step S210 further includes: transferring the solid electrolyte layer 13 to the two surfaces of the negative electrode sheet, and printing the 3D printed overhang slurry on the surface of the solid electrolyte layer corresponding to the overhang area 111 of the negative electrode sheet by a 3D printing method to obtain a combined negative electrode sheet.

[0186] Optionally, in step S220, before alternately stacking the positive electrode sheets 12 and the negative electrode sheets, the process further includes: 3D printing the positive electrode sheets 12 or the negative electrode sheets using a first slurry, and curing the first slurry disposed on the positive electrode sheets 12 or the negative electrode sheets to obtain the positive electrode sheets 12 or the negative electrode sheets having the filling portion 21. Alternatively, in step S220, after alternately stacking the positive electrode sheets 12 and the negative electrode sheets, the process further includes: curing the stacked laminated cell structure to obtain a cell having the packaging structure 2. The process may be determined based on actual conditions.

[0187] Optionally, in step S220, after obtaining the positive electrode sheet 12 or the negative electrode sheet having the filling portion 21, the method further includes: using a second slurry to 3D print the peripheral side of the battery cell, and curing the second slurry to form a covering portion, which is connected to the filling portion.

[0188] In this way, the first slurry is first printed on the positive electrode sheet or the negative electrode sheet to form a filling part to support the overhang area, and the functional materials added in the filling part can regulate the environment inside the battery cell, such as absorbing oxygen, water and heat, etc., to improve the stability and safety of the battery. The positive electrode sheet, the negative electrode sheet and the solid electrolyte layer are then staggered and stacked to form a battery cell, and then a second slurry is set on the outer side of the battery cell through 3D printing to form a covering part. In this way, the covering part can not only cover the battery cell from the outside, making up for defects left over from the previous process such as electrode edge defects, foil burrs, and misaligned laminations, but also the fully enclosed outer frame packaging design not only protects the environment inside the battery cell, but also accommodates the volume changes during the operation of the battery cell, comprehensively improving the yield rate of battery cell manufacturing and the safety performance of the battery cell.

[0189] Combine Figure 13 As shown, the embodiment of the present disclosure also provides another method for preparing a battery cell, comprising the following steps:

[0190] S310. Stack the positive electrode sheet, the negative electrode sheet, and the solid electrolyte layer in the order of the positive electrode sheet, the solid electrolyte layer, the negative electrode sheet, and the solid electrolyte layer to obtain a laminate structure; wherein an overhanging gap area is formed on the peripheral side surface of the laminate structure.

[0191] S320, placing 3D printing overhang slurry in the overhang gap area of ​​the laminated structure to obtain a battery cell with a packaging structure.

[0192] In the battery cell preparation method of the disclosed embodiment, the positive electrode sheet, the negative electrode sheet, and the solid electrolyte layer are first stacked in a specific order to obtain a laminate structure, and then a 3D-printed overhang slurry is applied to the overhanging gap area of ​​the laminate structure. The battery cell preparation method of the disclosed embodiment is more practical, can use continuously coated electrodes, and is compatible with the overhang design and size of the positive and negative electrode sheets. It can simplify the edge short-circuit protection of a single electrode sheet to the edge short-circuit protection packaging of the laminate structure, greatly reducing the difficulty, cycle time, and cost of the battery manufacturing process.

[0193] In the cell preparation method of the disclosed embodiment, in step S310, the positive electrode sheet, solid electrolyte layer, and negative electrode sheet can each be obtained using conventional methods, which are not limited here. The dimensions of the positive and negative electrode sheets can be designed to be equal, or they can be designed to be overhangs, where at least one side of the negative electrode sheet is larger than the positive electrode sheet.

[0194] In step S320, the method for placing the 3D printed overhang slurry into the overhanging void region of the laminate structure is not limited, as long as the encapsulation slurry can be placed in the overhanging void region and penetrate into the surrounding layers. In some embodiments, placing the 3D printed overhang slurry into the overhanging void region of the laminate structure includes: placing the 3D printed overhang slurry into the overhanging void region of the laminate structure using a 3D printing method.

[0195] Optionally, a 3D printing method is used to print and set a 3D printed overhang slurry into the overhanging gap area of ​​the laminated structure. Compared to other methods, the edge packaging of the cell of a laminated solid-state battery using 3D printing technology can precisely control the amount of deposited material. When introducing the 3D printed overhang slurry into the peripheral side surfaces and overhanging gap area of ​​the laminated structure, the appropriate amount of 3D printed overhang slurry can be accurately delivered according to the needs of different locations. At the same time, the non-contact 3D printing manufacturing technology will not cause mechanical damage to the electrode. Moreover, the 3D printing method can construct a support structure within the micron-level gap, thereby effectively ensuring the filling rate of the interlayer gap and the 3D printed overhang slurry can penetrate deep into the overhanging gap area and penetrate into the surrounding layers, thereby more effectively solving the edge stress concentration problem during the pressurized manufacturing or high-voltage operation of the solid-state battery cell. In addition, the 3D printing method has high processing efficiency and high material utilization rate, and can take into account the permeability and overflow prevention of the fluid 3D printed overhang slurry during the printing process. In the embodiment of the present disclosure, the printing path and printing parameters are set according to actual conditions in the 3D printing method without limitation.

[0196] In some embodiments, in step S320, a 3D printed overhang slurry is set in the overhang gap area of ​​the laminate structure, including: setting a first slurry in the overhang gap area of ​​the laminate structure to obtain a first laminate structure having a filling portion; setting a second slurry in the overhang gap area of ​​the first laminate structure, connecting the filling portion outside to form a covering portion, and obtaining a battery cell having a packaging structure; wherein the outer surface of the covering portion is flush with the peripheral side surface of the laminate structure, or the covering portion protrudes from the peripheral side surface of the laminate structure and covers the peripheral side surface of the laminate structure.

[0197] The battery cell preparation method of this embodiment first uses a first slurry for filling and setting, so that the first slurry can penetrate into the layers around the overhanging gap area, and then uses a second slurry to continue to completely fill the overhanging gap area, thereby being able to control the depth of the 3D printed overhang slurry penetrating into the layer, thereby ensuring the interface bonding effect of deep penetration and avoiding edge overflow defects, thereby forming a dense and pore-free packaging structure.

[0198] In one example, a 3D printing device is used to dynamically control the preparation process by placing a 3D printing overhang slurry into the interstitial region of a laminated structure through a 3D printing method. The 3D printing device can include a single discharge head (e.g., a single-head 3D printing device) or multiple discharge heads (e.g., a multi-head 3D printing device). Alternatively, a multi-head 3D printing device is used to dynamically control the encapsulation of the 3D printing overhang slurry into the overhanging interstitial region of the laminated structure. The first discharge head (first print head) is used to output the first slurry, and the second discharge head (second print head) is used to output the second slurry. During the 3D printing process, the printing path and printing parameters (e.g., print speed, layer height, line width, print head aperture, etc.) are determined based on the actual conditions of the overhanging interstitial region, the 3D printing overhang slurry, and are not limited thereto. For example, the printing speed is 25-45 mm / s, the layer height is 10-30 μm, and the line width is 80-120 μm. In the 3D dynamic control preparation method of this embodiment, the printing paths of the first slurry and the second slurry can be the same or different. Optionally, the printing path of the first slurry is a zigzag path, and the printing path of the second slurry is a straight path.

[0199] In some embodiments, in step S320, after "setting 3D printed overhang slurry in the overhanging gap area of ​​the laminate structure", the step also includes: performing a step of hot pressing the laminate structure with the 3D printed overhang slurry. This embodiment performs a hot pressing treatment on the laminate structure with the 3D printed overhang slurry to strengthen the combination of the 3D printed overhang slurry and the edge cavity of the electrode, refill the microscopic depressions on the surface of the electrode (such as cracks <5 μm), and reduce the interface void rate; at the same time, by adding this hot pressing step, the contact of each solid-solid interface in the battery cell can be improved, and by repairing the poor contact interface, the problem of lithium dendrite growth can be alleviated, the ion transmission path can be shortened, etc. The hot pressing treatment of this embodiment can be defined as a secondary curing treatment.

[0200] Optionally, performing a hot pressing treatment on the laminated structure with the 3D printing overhang slurry includes placing the laminated structure with the 3D printing overhang slurry on a heating plate at a first preset temperature and performing the treatment for a first preset time. The hot pressing treatment in this embodiment is referred to as a first hot pressing treatment, wherein the pressure is the pressure of the laminated structure with the 3D printing overhang slurry itself.

[0201] Optionally, the laminated structure with the 3D printing overhang slurry is subjected to a hot pressing treatment, including placing the laminated structure with the 3D printing overhang slurry on a heating plate at a first preset temperature and applying vibration for a second preset time. The hot pressing treatment in this embodiment is referred to as the second hot pressing treatment.

[0202] Optionally, the laminated structure with the 3D printing overhang slurry is subjected to a hot pressing treatment, including placing the laminated structure with the 3D printing overhang slurry on a heating plate at a first preset temperature and applying pressure for a second preset time. The hot pressing treatment in this embodiment is referred to as a third type of hot pressing treatment.

[0203] Optionally, the laminated structure with the 3D printing overhang slurry is subjected to a hot pressing treatment, including placing the laminated structure with the 3D printing overhang slurry on a heating plate at a first preset temperature, and applying pressure and vibration for a second preset time. The hot pressing treatment in this embodiment is referred to as a fourth type of hot pressing treatment.

[0204] In the first to fourth hot pressing treatments, the first preset temperature can make the 3D printing overhang slurry soften again and have a certain fluidity. It is understandable that a heating tank is set on the heating plate, and the tank body of the heating tank is consistent with the outer contour of the laminated structure in which the 3D printing overhang slurry is set. The laminated structure of the 3D printing overhang slurry is placed in the heating tank, and the inner wall of the heating tank body can limit the laminated structure, that is, it can avoid the slippage and dislocation of the sheet layers when pressure is applied, and can also avoid the reheated and softened 3D printing overhang slurry from flowing out of the sheet gap. Optionally, the first preset temperature is greater than or equal to Tmin and less than or equal to T′, T′=Tm in +δ×(T max -T min ), where T max is the upper limit of the melting point range of the 3D printing overhang paste, T min The value of δ is the lower limit of the melting point range of the 3D printing overhang slurry. The range of δ is [0, 1 / 3]. The specific value of δ is determined based on the melting point range of the 3D printing overhang slurry. That is, the first preset temperature is the lower limit of the melting point range of the 3D printing overhang slurry, or a temperature above the lower limit that allows the 3D printing overhang slurry to soften and have a certain degree of fluidity. Optionally, δ is 0, 1 / 5, 1 / 4, or 1 / 3, etc.

[0205] Optionally, the first preset temperature is 60° C. to 70° C. Optionally, the first preset temperature is 60° C.

[0206] Optionally, the first preset time is 20s to 60s. Optionally, the first preset time is 20s to 50s. The first preset time is 20s to 40s. The first preset time is 30s.

[0207] Optionally, the laminated structure with the 3D printed overhang slurry is subjected to hot pressing treatment, including: applying a low pressure of 0.3~0.5MPa and a low frequency vibration of 20 Hz~50 Hz to the laminated structure with the 3D printed overhang slurry for a first preset time, and then increasing the pressure to a high pressure of 1~3MPa and a high frequency vibration of 500Hz~2000Hz for a first preset time.

[0208] In one example, if Figure 14 As shown, a 3D printing control preparation method includes:

[0209] S410. Stack the positive electrode sheet, the negative electrode sheet, and the solid electrolyte layer in the order of the positive electrode sheet, the solid electrolyte layer, the negative electrode sheet, and the solid electrolyte layer to obtain a laminate structure; wherein an overhanging gap area is formed on the peripheral side surface of the laminate structure.

[0210] S420, vertically arrange the laminated structure in a 3D printing device in a manner that the side to be printed faces upward;

[0211] S430, obtain the contour entity data of the side to be printed of the laminated structure; obtain a contour three-dimensional model according to the contour entity data; slice the contour three-dimensional model, plan a path and design a printing parameter, and obtain printing information;

[0212] S440, according to the printing information, print the 3D printing overhang paste on the side to be printed by the 3D printing device, complete the packaging printing of the side to be printed of the laminated structure, and obtain the laminated structure provided with the 3D printing overhang paste.

[0213] In the embodiment, the side to be printed of the laminated structure is one of the side faces of the laminated structure, and the above steps are repeated to complete the packaging of the laminated structure.

[0214] In step S430 of the embodiment, the entity contour data of the side to be printed includes data capable of reflecting key structural nodes of the side to be printed, such as edges, layers and overhang gap areas. Alternatively, the entity contour data of the side to be printed of the laminated structure is obtained by using a high-precision visual scanner or a three-dimensional scanner to scan the side to be printed of the laminated structure, and combining the entity parameters of the laminated structure to obtain the entity contour data of the side to be printed. The entity parameters of the laminated structure include the size of the laminated structure, the number of laminated layers, etc. The side face of the laminated structure is not a flat face, but has an overhang gap area, so the entity contour data includes three-dimensional entity data.

[0215] In step S430, the contour three-dimensional model is obtained according to the contour entity data, including: importing the entity contour data of the side to be printed into a three-dimensional modeling software, modeling, and obtaining the contour three-dimensional model. The three-dimensional modeling software is not limited, for example, MeshLab, Blender, etc. In the modeling process, the entity contour data can be processed, including removing noise, filling holes, optimizing grids, etc.

[0216] Alternatively, in step S430, the contour three-dimensional model is sliced by a slicing software, wherein the slicing software generates printing information according to the shape, size and printing parameter of the model. The printing parameter includes printing layer height, filling density, printing speed, printing head temperature, printing bed temperature, etc. The printing information includes printing path and printing parameter, the printing path determines the moving track of the printing head, and the printing parameter includes printing speed, material extrusion amount, printing layer height, material heating temperature, printing head temperature, etc. The printing path is output in the form of G-code instructions that can be recognized by the 3D printing device.

[0217] Optionally, the slicing software includes Cura, PrusaSlicer, etc.

[0218] It can be understood that the peripheral side surface of the laminate structure includes four side surfaces in different directions, and each side surface is a side surface to be packaged.

[0219] Optionally, if the physical contour data of the side to be printed obtained in step 430 is the physical contour data of the side to be printed currently facing upward in step S420, then the printing path obtained in step S430 is the printing path of the side to be printed currently facing upward. The 3D printing control and preparation method then further includes: repeating steps S420 to S440 to encapsulate and print the sides to be printed of the laminate structure one by one, thereby completing the encapsulation of the laminate structure; and obtaining an encapsulated laminate structure. In this embodiment, in step S420, when encapsulating different sides to be printed, it is necessary to adjust the side to be printed facing upward. For example, the laminate structure may be rotated so that the side to be printed faces upward.

[0220] Alternatively, if the physical contour data of the side to be printed obtained in step S430 is the physical contour data of the entire circumference of the laminate structure obtained in step S410, then the printing path obtained in step S430 is the printing path for all the sides to be printed along the entire circumference. Therefore, when packaging different sides to be printed, the current side to be printed can be adjusted to face upward. For example, the laminate structure can be rotated so that the side to be printed faces upward.

[0221] In some embodiments, the 3D printing control preparation method further includes: subjecting the laminated structure provided with the 3D printing overhang slurry to a hot pressing process. In this embodiment, the hot pressing process is described in the aforementioned related content and will not be repeated here.

[0222] In the preparation method of the battery cell of the embodiment of the present disclosure, after the packaging is completed, for example, after step S440 or the laminated structure provided with the 3D printed overhang slurry is subjected to hot pressing treatment, the laminated structure provided with the 3D printed overhang slurry can also be compressed, for example, isostatic pressing treatment, so that the layers in the laminated structure are pressed and connected with each other.

[0223] In the preparation method of the embodiment of the present disclosure, the laminated structure is set on the 3D printing equipment, and the laminated structure obtained by printing and provided with the 3D printing overhang slurry is placed on the hot pressing device. The operation can be completed manually or through an automated conveying device, depending on the actual situation.

[0224] The embodiments of the present disclosure further provide a solid-state battery, comprising: an electrode plate according to any of the aforementioned embodiments; or a battery cell according to any of the aforementioned embodiments; or a battery cell prepared by the method for preparing a battery cell according to any of the aforementioned embodiments.

[0225] The following specific examples are given to specifically illustrate the 3D printing overhang slurry, electrode pole piece, battery cell and its preparation method and solid-state battery of the embodiment of the present disclosure, so as to more clearly illustrate the technical problems, technical solutions and beneficial effects solved by this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present application and its applications.

[0226] If no specific techniques or conditions are specified in the examples, the experiments were carried out according to the techniques or conditions described in the literature in the field or according to the product instructions. All reagents or instruments used without specifying the manufacturer are commercially available conventional products.

[0227] Example 1

[0228] like Figure 3 and Figure 6 As shown, a solid-state battery, the specific preparation method is as follows:

[0229] (1) Preparation of positive electrode

[0230] The positive electrode active material layer is prepared using a dry process. A mixture of NCM, LPSCl, SP, and PTFE is mixed in a glove box at a ratio of 70:24:5:1. NCM refers to lithium nickel cobalt manganese oxide, LPSCl is a argyrodite-type electrolyte, SP is conductive carbon black, and PTFE is polytetrafluoroethylene. The mixture is uniformly mixed in a high-speed dispersing mixer for 2 hours. The mixture is then ball-milled to fibrousize the PTFE, resulting in a fiberized powder. The fiberized powder is extruded at 80°C to form sheets with a thickness of 250-400μm. This sheet is then roll-pressed to 97μm to form the positive electrode active material layer. The sheet is then die-cut into 112 mm x 84 mm sheets and hot-rolled onto a 116 mm x 88 mm positive current collector. The active material layer is then hot-rolled onto the other side of the current collector in the same manner to form a dry-process electrode sheet.

[0231] (2) Positive electrode processing

[0232] 7 g of polyisobutylene was weighed and slowly added to 40 g of N-methylpyrrolidone (NMP) solvent, and the mixture was placed in a magnetic stirrer and stirred for 4 h. The obtained mixed solution was placed in the barrel of a 3D printer, and the packaging structure was printed on the empty foil area around the electrode obtained in step (1). The electrode processed on one side was transferred to an oven at 60 ° C for 1 h to solidify. After cooling, the packaging structure on one side was printed on the other side of the electrode in the same way, with a thickness of 97 μm and a width of 2 mm. Finally, a positive electrode with a packaging structure on both sides was obtained.

[0233] (3) Preparation of combined negative electrode sheets

[0234] The materials were weighed in a weight ratio of 95:3:2 for micronized silicon: polyvinylidene fluoride (PVDF): vapor-grown carbon fiber (VGCF). PVDF was dissolved in NMP to prepare a 7wt% binder solution. The micronized silicon and VGCF were ball-milled for 30 minutes. The binder paste was added to the mixed powders. A 68wt% negative electrode slurry was prepared and homogenized and dispersed in a deaerator for 3 hours to obtain the negative electrode active slurry. The resulting negative electrode active slurry was coated on the surface of copper foil, dried, and roll-cut into 116 mm x 88 mm pieces. A 98:2 weight ratio for sulfide solid electrolyte (LPSCl): styrene-butadiene-styrene block copolymer (SEBS) was weighed. 5wt% SEBS was dissolved in anisole solvent. The paste was prepared by magnetic stirring for 30 minutes. The electrolyte powders were then added to the paste according to the weight ratio and dispersed in a deaerator for 1 hour to prepare the electrolyte slurry. Use a 50um scraper to scrape the electrolyte slurry on a 15um stainless steel foil, bake it in a vacuum oven at 80℃ to evaporate the solvent, and obtain a solid electrolyte layer. Align the solid electrolyte layer prepared above with the negative electrode, cold press it under a pressure of 3T on a roller press, manually tear open the stainless steel sheet, and transfer the solid electrolyte layer to the negative electrode interface to obtain a combined negative electrode sheet.

[0235] (4) Battery cell assembly

[0236] The processed positive electrode sheet and the transferred combined negative electrode sheet are assembled together through a lamination process to form a solid-state battery cell; the solid-state battery cell is vacuum-encapsulated using an aluminum-plastic film; an isostatic pressing process is applied, and then a heat treatment is performed under a certain pressure to obtain a solid-state lithium-ion battery with an encapsulated structure.

[0237] Example 2:

[0238] like Figure 4 and Figure 7 As shown, a solid-state battery, the specific preparation method is as follows:

[0239] (1) Preparation of positive electrode

[0240] The positive electrode sheet was prepared by a wet method: NCM, LPSCl, carbon nanotubes (CNTs), and styrene-butadiene rubber (SBR) were dispersed in the solvent NMP in a mass ratio of 68.6:29.4:1:1, and the solid content was controlled at about 50%. The slurry was coated on the conductive carbon layer by a traditional wet method. The coated electrode sheet was vacuum dried at 120°C for 10 hours, and rolled and die-cut into a size of 112 mm*84 mm to obtain a wet-process positive electrode sheet.

[0241] (2) Preparation of negative electrode sheet

[0242] According to the weight ratio of micron silicon: PVDF: VGCF = 95:3:2, weigh the component materials, dissolve PVDF in NMP to prepare a 7wt% binder solution, ball-mill the micron silicon and VGCF for 30 minutes, add the binder glue to the mixed powder, prepare 68wt% negative electrode slurry, and homogenize and disperse it in a degassing machine for 3 hours to obtain the negative electrode active slurry. Apply the obtained active slurry on the surface of copper foil, dry it, and roll and die-cut it into 116 mm*88 mm.

[0243] (3) Negative electrode processing

[0244] Weigh 7g of polyisobutylene and slowly add it to 40g of N-methylpyrrolidone solvent, place it in a magnetic stirrer and stir for 4h, place the obtained mixed solution in the barrel of a 3D printer, print the packaging structure on the edge of the negative electrode obtained in step (2), transfer the electrode electrode after single-side processing to an oven at 60℃ for 1h for curing, and after cooling, print the single-sided packaging structure with a thickness of 124μm and a width of 2mm on the other side of the electrode in the same way, and finally obtain a negative electrode electrode with packaging structures on both sides.

[0245] (4) Preparation of self-supporting sulfide solid electrolyte layer

[0246] PTFE powder and LPSCl electrolyte powder were mixed uniformly by hand grinding in a mass ratio of 10:90. The resulting electrolyte mixture was sheared and kneaded at 160°C using a kneader. The sheared and kneaded electrolyte mixture was then processed into a sheet by flat-plate static pressing (500 MPa, 50 min) at 260°C. The resulting electrolyte sheet was densified by isostatic pressing to obtain a 20 μm LPSCl solid electrolyte layer.

[0247] (5) Battery cell assembly

[0248] The positive electrode sheet, the solid electrolyte layer, and the processed negative electrode sheet are assembled together through a lamination process to form a solid-state battery cell; the solid-state battery cell is vacuum-packaged using an aluminum-plastic film; an isostatic pressing process is applied, and then a heat treatment is performed under a certain pressure to obtain a solid-state lithium-ion battery with a packaged structure.

[0249] Example 3:

[0250] like Figure 5 and Figure 8 As shown, a solid-state battery, the specific preparation method is as follows:

[0251] (1) Preparation of positive electrode

[0252] NCM, LPSCl, CNT, and SBR were dispersed in the solvent NMP in a mass ratio of 68.6:29.4:1:1, and the solid content was controlled at about 50%. The slurry was coated on the conductive carbon layer using a traditional wet method. The coated electrode was vacuum dried at 120°C for 10 hours, and rolled and die-cut into 112 mm*84 mm sizes to obtain wet-process positive electrode sheets.

[0253] (2) Preparation of combined negative electrode sheets

[0254] According to the weight ratio of micron silicon: PVDF: VGCF = 95:3:2, weigh the components, dissolve PVDF in NMP, prepare a 7wt% binder solution, ball-mill the micron silicon and VGCF for 30min, add the binder glue to the mixed powder, configure 68wt% negative electrode slurry, homogenize and disperse in a deaerator for 3h to obtain the negative electrode slurry, apply the obtained slurry to the surface of copper foil, dry and roll-die-cut into 116mm*88mm. According to the weight ratio of LPSCl: SEBS = 98:2, weigh the components, dissolve SEBS in anisole solvent at 5wt%, prepare glue by magnetic stirring for 30min, then add the electrolyte powder according to the weight ratio to the glue, and use a deaerator to disperse for 1h to prepare the electrolyte slurry. Use a 50um scraper to scrape the electrolyte slurry on a 15um stainless steel foil, bake it in a vacuum oven at 80℃ to evaporate the solvent, and obtain a solid electrolyte layer. Align the solid electrolyte layer prepared above with the negative electrode, cold press it under a pressure of 3T on a roller press, manually tear open the stainless steel sheet, and transfer the solid electrolyte layer to the negative electrode interface to obtain a combined negative electrode sheet.

[0255] (3) Combined negative electrode sheet processing

[0256] 7 g of polyisobutylene was weighed and slowly added to 40 g of NMP solvent, and the mixture was placed in a magnetic stirrer and stirred for 4 h. The obtained mixed solution was placed in the barrel of a 3D printer, and the packaging structure was printed on the edge of the combined negative electrode obtained in step (2). The electrode processed on one side was transferred to an oven at 60 ° C for 1 h to solidify. After cooling, the packaging structure on one side was printed on the other side of the electrode in the same way, with a thickness of 104 μm and a width of 2 mm. Finally, a combined negative electrode with packaging structures on both sides was obtained.

[0257] (4) Battery cell assembly

[0258] The positive electrode sheet and the processed combined negative electrode sheet are assembled together through a lamination process to form a solid-state battery cell; the solid-state battery cell is vacuum-encapsulated using an aluminum-plastic film; an isostatic pressing process is applied, and then a heat treatment is performed under a certain pressure to obtain a solid-state lithium-ion battery with an encapsulated structure.

[0259] Example 4:

[0260] The solid-state battery of this embodiment differs from that of Example 1 only in that, in step (2), a packaging structure is prepared by weighing 7 g of polyisobutylene and slowly adding it to 40 g of NMP solvent, placing it in a magnetic stirrer and stirring for 4 h. After the polyisobutylene is completely dissolved, 3 g of lithium phytate is added and stirring is continued for 1 h. The resulting mixed solution is placed in the barrel of a 3D printer, and the packaging structure is printed on the empty foil area around the electrode obtained in step (1) of Example 1. The electrode processed on one side is transferred to an oven at 60 ° C for 1 h to solidify. After cooling, a single-sided packaging structure with a thickness of 97 μm and a width of 2 mm is printed on the other side of the electrode in the same manner, finally obtaining a positive electrode with packaging structures on both sides. The remaining steps and parameters are the same as those of Example 1.

[0261] Example 5:

[0262] The only difference between the solid-state battery of this embodiment and that of Example 2 is that, in step (3), a packaging structure is prepared by weighing 7 g of polyisobutylene and slowly adding it to 40 g of NMP solvent. The solution is stirred in a magnetic stirrer for 4 h. After the polyisobutylene is completely dissolved, 3 g of lithium phytate is added and the stirring is continued for 1 h. The resulting mixed solution is placed in the barrel of a 3D printer. The packaging structure is printed on the edge of the negative electrode obtained in step (2) of Example 2. The electrode piece processed on one side is transferred to an oven at 60 ° C for 1 h to solidify. After cooling, a single-sided packaging structure with a thickness of 124 μm and a width of 2 mm is printed on the other side of the negative electrode piece in the same manner, finally obtaining a negative electrode piece with packaging structures on both sides. The remaining steps and parameters are the same as those of Example 2.

[0263] Example 6:

[0264] The solid-state battery of this embodiment differs from that of Example 3 only in that, in step (3), a packaging structure is prepared by weighing 7 g of isobutylene and slowly adding it to 40 g of NMP solvent. The solution is stirred in a magnetic stirrer for 4 h. After the isobutylene is completely dissolved, 3 g of lithium phytate is added and the stirring is continued for 1 h. The resulting mixed solution is placed in the barrel of a 3D printer. The packaging structure is printed on the edge of the combined negative electrode obtained in step (2) of Example 3. The electrode processed on one side is transferred to an oven at 60°C for 1 h for curing. After cooling, a single-sided packaging structure with a thickness of 104 μm and a width of 2 mm is printed on the other side of the electrode in the same manner, ultimately obtaining a combined negative electrode electrode with packaging structures on both sides. The remaining steps and parameters are the same as those of Example 3.

[0265] Comparative Example 1:

[0266] The difference from Example 1 is that step (2) is not included, that is, the printing of the packaging structure in step (2) is not performed. The remaining steps and parameters are the same as those in Example 1.

[0267] Comparative Example 2:

[0268] The difference from Example 2 is that step (3) is not included, that is, the printing of the packaging structure in step (3) is not performed. The remaining steps and parameters are the same as those in Example 2.

[0269] Comparative Example 3:

[0270] The difference from the embodiment is that step (3) is not included, that is, the printing of the packaging structure in step (3) is not performed. The remaining steps and parameters are the same as those in embodiment 3.

[0271] The solid-state batteries of Examples 1 to 6 and Comparative Examples 1 to 3 were subjected to charge and discharge tests in a charge and discharge range of 2.1 V to 4.3 V and a test temperature of 30°C. The test results are shown in Table 1 (0.1C cycle). The obtained charge and discharge test performance data are shown in Table 1.

[0272] Table 1

[0273]

[0274] The results of the above embodiments and comparative examples show that the sulfide solid-state battery containing the packaging structure can effectively avoid the phenomenon of short circuit of the battery during pressurized assembly and pressurized operation. The yield rate of the battery cells of the six embodiments with the addition of the packaging structure has been greatly improved. Even though the battery in comparative example 1 passed the short-circuit test during the trial production process, its capacity performance in the subsequent charge and discharge cycles was poor, indicating that a micro-short circuit occurred inside the battery. The gram capacity, first effect, etc. of the battery cells of Examples 4 to 6 are similar to those of Examples 1 to 3, indicating that the addition of functional materials does not affect the function of the packaging structure. After 100 cycles, the capacity performance of Examples 4 to 6 with the addition of functional materials (lithium phytate) is better than that of Examples 1 to 3. The reason is that lithium phytate quenches the oxygen free radicals or oxygen released during the positive electrode cycle, reducing the decomposition and side reactions of the sulfide electrolyte, thereby showing better capacity and cycle performance.

[0275] From the above description, it can be seen that the above-mentioned embodiments of the present invention achieve the following technical effects: the 3D printing overhang slurry provided in this application not only solves the short circuit problem of solid-state batteries caused by the overhang problem, but also further improves the performance of the battery cell by adding functional materials.

[0276] The above description and the accompanying drawings sufficiently illustrate the embodiments of the present disclosure to enable those skilled in the art to practice them. Other embodiments may include structural, logical, electrical, process and other changes. The embodiments represent only possible variations. Unless expressly required, individual components and functions are optional, and the order of operations may vary. Portions and features of some embodiments may be included in or replace portions and features of other embodiments. Moreover, the terms used in this application are only used to describe the embodiments and are not used to limit the claims. As used in the description of the embodiments and claims, the singular forms "a", "an" and "the" are intended to also include the plural forms unless the context clearly indicates otherwise. Similarly, the term "and / or" as used in this application means any and all possible combinations of one or more of the associated listings. In addition, when used in this application, the term "comprise" and its variations "comprises" and / or comprising refer to the presence of stated features, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or groups thereof. In the absence of further restrictions, an element defined by the sentence "comprising a..." does not exclude the presence of other identical elements in the process, method or device that includes the element. In this article, each embodiment may focus on the differences from other embodiments, and the same and similar parts between the various embodiments can be referenced to each other. For the methods, products, etc. disclosed in the embodiments, if they correspond to the method part disclosed in the embodiments, then the relevant parts can be referred to the description of the method part.

[0277] Those skilled in the art will appreciate that the units and steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software may depend on the specific application and design constraints of the technical solution. The technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the embodiments of the present disclosure. The technicians will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0278] The flowcharts and block diagrams in the accompanying drawings show the possible implementation architectures, functions and operations of the systems, methods and computer program products according to the embodiments of the present disclosure. In this regard, each box in the flowchart or block diagram can represent a module, program segment or part of the code, and the module, program segment or part of the code contains one or more executable instructions for implementing the specified logical functions. In some alternative implementations, the functions marked in the box can also occur in an order different from that marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, or they can sometimes be executed in the opposite order, which can depend on the functions involved. In the descriptions corresponding to the flowcharts and block diagrams in the accompanying drawings, the operations or steps corresponding to different boxes can also occur in an order different from that disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps can actually be executed substantially in parallel, or they can sometimes be executed in the opposite order, which can depend on the functions involved. Each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented by a dedicated hardware-based system that performs the specified function or action, or may be implemented by a combination of dedicated hardware and computer instructions.

Claims

1. A 3D printing overhang slurry, characterized in that: include: A polymer substrate, a functional material, and a solvent, wherein the functional material comprises one or more of an oxygen adsorbent, a water adsorbent, and a heat absorbent, wherein the solid content of the 3D printing overhang slurry is 20% to 80%, and the mass ratio of the polymer substrate to the functional material is (70-90):(10-30); The 3D printing overhang slurry includes a first slurry having a solid content of 20% to 65%; the 3D printing overhang slurry also includes a second slurry having a solid content of 60% to 80%. In the second slurry, the polymer substrate includes a first polymer and a second polymer, the elastic modulus of the first polymer is greater than the elastic modulus of the second polymer, and the strength of the second polymer is greater than the strength of the first polymer, wherein the content of the first polymer is greater than the content of the second polymer; The first slurry is used to be arranged in the overhanging gap area of ​​the battery core, and the second slurry is used to cover the peripheral side surface of the laminate structure.

2. The 3D printing overhang slurry according to claim 1, characterized in that: The polymer substrate accounts for 60% to 90% by weight of the dry solids content of the 3D printing overhang slurry; and / or, The functional material accounts for 5% to 40% by weight of the dry solid content of the 3D printing overhang slurry; and / or, The polymer substrate comprises one or more of polyisobutylene, polyphenylene ether, polyimide, polyacrylonitrile, polyvinylidene fluoride, polyethylene glycol, polyethylene oxide, sodium carboxymethyl cellulose, styrene-butadiene rubber and polyacrylic acid; and / or, The solvent includes one or more of dimethyl sulfoxide, N,N-dimethylacetamide, N-methylpyrrolidone and dimethylformamide; and / or, The water adsorbent includes one or more of zeolite, calcium chloride, magnesium chloride, sodium polyacrylate and polyvinyl alcohol; and / or, The oxygen adsorbent includes one or more of polydopamine, lithium phytate, 4-tert-butylcatechol, N-phenyl-N'-phenylenediamine, naphthylamine, diphenylamine and p-phenylenediamine; and / or, The heat absorbent includes one or more of polyethylene glycol and polyvinyl alcohol.

3. The 3D printing overhang slurry according to claim 2, characterized in that: The polymer substrate accounts for 70% to 90% by weight of the dry solids content of the 3D printing overhang slurry; and / or, The mass percentage of the functional material in the dry solid content of the 3D printing overhang slurry is 10% to 40%.

4. The 3D printing overhang slurry according to claim 2, characterized in that: The polymer substrate accounts for 60% to 80% by weight of the dry solids content of the 3D printing overhang slurry; and / or, The mass percentage of the functional material in the dry solid content of the 3D printing overhang slurry is 10% to 35%.

5. The 3D printing overhang slurry according to claim 2, characterized in that: The mass percentage of the functional material in the dry solid content of the 3D printing overhang slurry is 10% to 30%.

6. The 3D printing overhang slurry according to any one of claims 2 to 5, characterized in that: When the 3D printing overhang slurry includes a first slurry, the first slurry includes the following characteristics: The solid content of the 3D printing overhang slurry is 30% to 60%; and / or, The functional material includes an oxygen adsorbent, and the oxygen adsorbent accounts for 10% to 60% by mass of the functional material; and / or, The functional material includes a water adsorbent, and the water adsorbent accounts for 20% to 70% by weight of the functional material; and / or, The functional material includes a heat absorbent, and the heat absorbent accounts for 10% to 50% by mass of the functional material; and / or, The polymer substrate comprises one or more of polyvinylidene fluoride, polyacrylonitrile and polyethylene oxide; and / or, The oxygen adsorbent includes one or more of polydopamine nanoparticles and lithium phytate; and / or, The water adsorbent comprises zeolite; and / or, Heat absorbers include polyethylene glycol.

7. The 3D printing overhang slurry according to claim 6, characterized in that: When the 3D printing overhang slurry includes a first slurry, the first slurry includes the following characteristics: The solid content of the 3D printing overhang slurry is 35% to 60%; and / or, The functional material includes an oxygen adsorbent, and the oxygen adsorbent accounts for 10% to 50% by mass of the functional material; and / or, The functional material includes a water adsorbent, and the water adsorbent accounts for 20% to 60% by weight of the functional material; and / or, The functional material includes a heat absorber, and the heat absorber accounts for 20% to 50% by mass of the functional material.

8. The 3D printing overhang slurry according to claim 6, characterized in that: When the 3D printing overhang slurry includes a first slurry, the first slurry includes the following characteristics: The functional material includes an oxygen adsorbent, and the oxygen adsorbent accounts for 20% to 50% by mass of the functional material; and / or, The functional material includes a water adsorbent, and the water adsorbent accounts for 30% to 60% by weight of the functional material; and / or, The functional material includes a heat absorber, and the heat absorber accounts for 20% to 40% by mass of the functional material.

9. The 3D printing overhang slurry according to claim 6, characterized in that: When the 3D printing overhang slurry includes a first slurry, the first slurry includes the following characteristics: The functional material includes an oxygen adsorbent, and the oxygen adsorbent accounts for 30% to 60% of the mass of the functional material.

10. The 3D printing overhang slurry according to any one of claims 2 to 5, characterized in that: When the 3D printing overhang slurry includes a second slurry, the second slurry includes the following characteristics: The solid content of the 3D printing overhang slurry is 65% to 80%; and / or, The first polymer accounts for 50% to 80% of the polymer substrate by mass; and / or, the second polymer accounts for 20% to 60% of the polymer substrate by mass; and / or, The functional material includes a heat absorber, and the heat absorber accounts for 60% to 100% of the mass of the functional material.

11. The 3D printing overhang slurry according to claim 10, characterized in that: When the 3D printing overhang slurry includes a second slurry, the second slurry includes the following characteristics: The solid content of the 3D printing overhang slurry is 60% to 75%; and / or, The first polymer accounts for 50% to 75% of the polymer substrate by mass; and / or, the second polymer accounts for 25% to 50% of the polymer substrate by mass; and / or, The functional material includes a heat absorber, and the heat absorber accounts for 80% to 100% by mass of the functional material.

12. The 3D printing overhang slurry according to claim 10, characterized in that: When the 3D printing overhang slurry includes a second slurry, the second slurry includes the following characteristics: The first polymer accounts for 60% to 75% of the polymer substrate by mass; and / or, the second polymer accounts for 25% to 40% of the polymer substrate by mass; and / or, The functional material includes a heat absorber, and the heat absorber accounts for 60% to 90% by mass of the functional material.

13. The 3D printing overhang slurry according to claim 10, characterized in that: The first polymer comprises polyisobutylene, and the second polymer comprises polyimide or polyphenylene ether; and / or, The heat absorbent comprises polyethylene glycol or polyvinyl alcohol; and / or, The functional material further comprises a reinforcing agent, wherein the reinforcing agent comprises hydrophobic fumed silica; and / or, The functional material also includes a reinforcing agent, and the weight percentage of the reinforcing agent in the functional material is 0 to 40%.

14. The method for preparing a 3D printing overhang slurry according to any one of claims 1 to 13, wherein: include: According to any one of claims 1 to 13, preparing raw materials for the 3D printing overhang slurry; Adding a polymer substrate into a solvent and dissolving it to obtain a solution A; Functional materials were added to solution A to obtain 3D printing overhang slurry.

15. A battery cell, characterized in that: The invention comprises a laminate structure comprising alternating positive and negative electrode sheets, with a solid electrolyte layer disposed between adjacent positive and negative electrode sheets; the negative electrode sheet extends beyond the positive electrode sheet on at least one side thereof to form an overhang region; and an encapsulation structure is disposed in an overhanging gap region corresponding to the overhang region; Wherein, the packaging structure is obtained by arranging a 3D printing overhang slurry in the overhang gap area; the 3D printing overhang slurry is the 3D printing overhang slurry according to any one of claims 1 to 13 or the 3D printing overhang slurry prepared by the preparation method of the 3D printing overhang slurry according to claim 14; The packaging structure includes a connected filling portion and a covering portion, the filling portion is located in the overhang gap area, and the covering portion covers the peripheral side surface of the laminated structure. The filling portion is formed by the first slurry in the 3D printing overhang slurry as described in any one of claims 1 to 9, and the covering portion is formed by the second slurry in the 3D printing overhang slurry as described in any one of claims 1 to 5 and 10 to 13.

16. The battery cell according to claim 15, characterized in that The positive electrode plate includes a hollow foil area, and the hollow foil area is provided with a 3D printed overhang slurry; or, The negative electrode plate includes an overhang area, and the overhang area of ​​the negative electrode plate is provided with a 3D printed overhang slurry; or, The electrode plate includes a negative electrode plate, and the negative electrode plate is a combined negative electrode plate with a solid electrolyte layer provided on both sides of the surface, and a 3D printed overhang slurry is provided on the surface of the solid electrolyte layer of the combined negative electrode plate corresponding to the overhang area of ​​the negative electrode plate.

17. The method for preparing a battery cell according to any one of claims 15 to 16, wherein: include: Prepare a positive electrode sheet, a negative electrode sheet, and a solid electrolyte layer; wherein the size of the negative electrode sheet is larger than that of the positive electrode sheet on at least one circumferential side, so that the negative electrode sheet has an overhang area; wherein the positive electrode sheet includes a hollow foil area, and the hollow foil area is provided with a first slurry from a 3D-printed overhang slurry; or, the negative electrode sheet includes an overhang area, and the overhang area of ​​the negative electrode sheet is provided with the first slurry from the 3D-printed overhang slurry; or, when the negative electrode sheet is a combined negative electrode sheet, and the negative electrode sheet is a combined negative electrode sheet with solid electrolyte layers provided on both surfaces thereof, the first slurry from the 3D-printed overhang slurry is provided on the surface of the solid electrolyte layer of the combined negative electrode sheet corresponding to the overhang area of ​​the negative electrode sheet; Positive and negative electrode sheets are alternately stacked, and a solid electrolyte layer is provided between adjacent positive and negative electrode sheets to obtain a battery cell having a filling portion; wherein a first slurry of the cured 3D printed overhang slurry is provided in the overhang gap of the battery cell, and the cured first slurry forms the filling portion; The second slurry in the 3D printing overhang slurry according to any one of claims 1 to 5 and 10 to 13 is used to perform 3D printing on the peripheral side of the battery cell having the filling portion, and the 3D printed overhang slurry is cured to form a covering portion, and the covering portion is connected to the filling portion to form a packaging structure to obtain a battery cell having a packaging structure.

18. The method for preparing a battery cell according to claim 17, wherein: Before alternately stacking the positive electrode sheets and the negative electrode sheets, the method further includes: using the first slurry of the 3D printing overhang slurry described in any one of 1 to 9 to 3D print the positive electrode sheet or the negative electrode sheet, and curing the 3D printed overhang slurry to obtain a positive electrode sheet or a negative electrode sheet having a filling portion; or After the positive electrode sheets and the negative electrode sheets are alternately stacked, the stacked laminated battery core structure is cured to obtain a battery core with a filling portion.

19. The method for preparing a battery cell according to claim 15, wherein: include: The positive electrode sheet, the negative electrode sheet, and the solid electrolyte layer are stacked in the order of the positive electrode sheet, the solid electrolyte layer, the negative electrode sheet, and the solid electrolyte layer to obtain a laminate structure; wherein an overhanging gap region is formed on the peripheral side surface of the laminate structure; Placing 3D printed overhang slurry into the overhanging gap area of ​​the laminate structure to obtain a battery cell with a package structure; The method comprises placing a 3D printed overhang slurry in the overhang gap area of ​​the laminate structure to obtain a battery cell with a package structure; comprising: Disposing the first slurry of the 3D printing overhang slurry described in any one of 1 to 9 into the overhang gap area of ​​the laminate structure to obtain a first laminate structure having a filling portion; A second slurry in the 3D printed overhang slurry as described in any one of claims 1 to 5 and 10 to 13 is arranged in the overhang gap area of ​​the first laminate structure, and is connected outside the filling portion to form a covering portion to obtain a battery cell with a packaging structure; wherein the outer surface of the covering portion is flush with the peripheral side surface of the laminate structure, or the covering portion protrudes from the peripheral side surface of the laminate structure and covers the peripheral side surface of the laminate structure.

20. The method for preparing a battery cell according to claim 19, wherein: A 3D printing control preparation method is obtained by placing a 3D printing overhang slurry into the overhang gap area of ​​the laminated structure using a 3D printing method, comprising: The positive electrode sheet, the negative electrode sheet, and the solid electrolyte layer are stacked in the order of the positive electrode sheet, the solid electrolyte layer, the negative electrode sheet, and the solid electrolyte layer to obtain a laminate structure; wherein an overhanging gap region is formed on the peripheral side surface of the laminate structure; Place the laminated structure vertically in the printing area of ​​the 3D printing device with the side to be printed facing upwards; Acquire the contour entity data of the side surface to be printed of the laminated structure; obtain the contour three-dimensional model based on the contour entity data; slice the contour three-dimensional model, perform path planning and printing parameter design, and obtain printing information; The 3D printing device prints and sets the 3D printing overhang slurry on the side to be printed according to the printing information, completes the packaging printing of the side to be printed of the laminate structure, and obtains the laminate structure provided with the 3D printing overhang slurry.

21. A solid-state battery, characterized in that: include: The battery cell according to any one of claims 15 to 16; or the battery cell prepared by the method for preparing the battery cell according to any one of claims 17 to 20.

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