A high-energy-density all-solid-state battery with a biomimetic lightning structure and a preparation method thereof

Abstract

This invention discloses a high-energy-density all-solid-state battery with a biomimetic lightning structure and its fabrication method. By drawing inspiration from the multi-level energy storage mechanism of natural lightning systems, a unique multi-level cloud-like composite cathode structure is constructed, enabling the battery to simultaneously possess the synergistic capabilities of high-capacity energy storage and ultra-fast charging and discharging. This satisfies both long-range battery life requirements and ultra-fast charging. The interface buffer layer design specifically addresses the industry challenges of high interface impedance and poor contact in traditional solid-state batteries. Combined with a ceramic composite solid-state electrolyte, this significantly improves the battery's cycle stability, ensuring consistent performance over long-term use. Furthermore, the all-solid-state structure eliminates the flammability risks associated with liquid electrolytes. It effectively prevents fire and explosion under extreme conditions such as puncture, compression, or overcharging, thereby enhancing the overall safety and reliability of the battery.

Description

Technical Field

[0001] This invention belongs to the field of solid-state battery fabrication technology, specifically a high-energy-density all-solid-state battery with a biomimetic lightning structure and its fabrication method. Background Technology

[0002] Solid-state batteries are a novel battery technology that uses a solid electrolyte to replace the flammable liquid electrolyte and separator in traditional lithium-ion batteries, and are considered a core development direction for next-generation power batteries. Based on different solid electrolyte material systems, they are mainly divided into three major technical routes: oxide, sulfide, and polymer. Their core advantage lies in significantly improving the inherent safety of the battery, fundamentally solving the risks of leakage, volatilization, and thermal runaway-induced combustion and explosion in traditional batteries. Due to the higher mechanical strength and electrochemical stability of solid electrolytes, solid-state batteries can be compatible with both metallic lithium anodes and high-voltage cathode materials, thus significantly breaking through the energy density bottleneck of existing batteries and theoretically achieving longer driving ranges. Furthermore, this technology also has a wider temperature adaptability range and longer cycle life. Although there are still technical challenges in solid electrolyte ionic conductivity, solid-solid interface contact resistance, and mass production processes, it has become a strategic high ground for global new energy industry research and development because it addresses the pain points of safety and range in new energy vehicles.

[0003] However, existing all-solid-state batteries have the following bottlenecks: 1. Slow charging speed, making it difficult to achieve safe fast charging at the 10-minute level; 2. Difficulty in balancing energy density and fast charging performance; 3. Liquid electrolyte is flammable and poses a risk of thermal runaway; 4. Solid-state batteries have high interface impedance and limited cycle life; capacity decay is severe and charging and discharging are difficult in low-temperature environments. Summary of the Invention

[0004] The purpose of this invention is to provide a high-energy-density all-solid-state battery with a biomimetic lightning structure and its preparation method in order to solve the problems mentioned above.

[0005] The technical solution adopted in this invention is as follows: a high-energy-density all-solid-state battery with a biomimetic lightning structure, comprising: a positive electrode shell, a positive electrode current collector, a multi-level cloud-like composite positive electrode, an interface buffer layer, a ceramic composite solid electrolyte membrane, a negative electrode, a negative electrode current collector, and a negative electrode shell; The positive electrode shell is the outermost encapsulation structure, and the inner side of the positive electrode shell is tightly attached to the positive electrode current collector. The multi-level cloud-like composite cathode is directly coated on the surface of the cathode current collector, and an interface buffer layer is formed on the outer surface of the cathode by a spraying process. The ceramic composite solid electrolyte membrane covers the outside of the interface buffer layer and is in close contact with the negative electrode. The negative electrode is connected to a negative current collector on its outer side, and the outermost layer of the negative electrode is encapsulated by a negative electrode shell. After all components are stacked in sequence, they are compacted and sealed using a button cell sealing machine to form a complete sealed battery system.

[0006] In a preferred embodiment, the positive electrode shell is the outermost encapsulation component of the battery.

[0007] In a preferred embodiment, the positive current collector is made of aluminum foil and is a key conductive component connecting the positive electrode shell and the multi-stage cloud-like composite positive electrode.

[0008] In a preferred embodiment, the multi-level cloud-like composite cathode is composed of nano-MoO3 or LiV3O8, Ti3C2, carbon nanotubes, Super P conductive carbon black, and PVDF-HFP binder.

[0009] In a preferred embodiment, the ceramic composite solid electrolyte membrane is made of polyethylene oxide, LiFSI lithium salt, LLZTO ceramic powder and epoxy modifier.

[0010] In a preferred embodiment, the negative electrode is a pre-lithiated silicon-carbon or a protective lithium metal material.

[0011] In a preferred embodiment, the negative current collector is a copper foil material, which is tightly connected between the negative electrode and the negative electrode shell.

[0012] In a preferred embodiment, the interface buffer layer is an MXene layer, which is prepared by spraying an MXene ethanol dispersion onto the surface of a multi-level cloud-like composite cathode and then drying it.

[0013] In a preferred embodiment, the negative electrode shell and the positive electrode shell cooperate to form a sealed outer casing of the battery. The negative electrode shell covers the outside of the negative electrode current collector, and through the compaction operation of the button battery sealing machine, it forms a stable integral encapsulation structure with the positive electrode shell.

[0014] In a preferred embodiment, a method for fabricating a high-energy-density all-solid-state battery with a biomimetic lightning structure includes the following steps: S1: Weigh out nano MoO3, MXene, carbon nanotubes, SuperP conductive carbon black and PVDF-HFP binder according to the proportion, add these materials to NMP solvent and stir thoroughly for more than 4 hours to form a uniform multi-level cloud-like composite cathode slurry, which is ready for the subsequent coating process.

[0015] S2: The prepared positive electrode slurry is evenly coated on the surface of the positive electrode current collector made of aluminum foil, and then placed in a vacuum drying oven and dried at 60°C for 8 hours. After drying, it is punched into a circular sheet of a specified size to obtain an integrated positive electrode sheet, which provides a flat substrate for the subsequent spraying of the interface buffer layer.

[0016] S3: MXene ethanol dispersion is uniformly sprayed onto the surface of the positive electrode sheet. After spraying, it is dried to form an ultra-thin interface buffer layer. This layer will then be in close contact with the ceramic composite solid electrolyte membrane to optimize interface compatibility.

[0017] S4: Weigh PEO, LiFSI lithium salt, LLZTO ceramic powder and epoxy modifier, dissolve these materials in acetonitrile solvent and stir for 6 hours until completely transparent, make a thin film by casting process, dry at room temperature in the dark for 24 hours and then punch it into a round piece without pinholes or cracks to obtain a ceramic composite solid electrolyte membrane, which provides a core ion transport component for subsequent battery assembly.

[0018] S5: In an anhydrous and oxygen-free glove box, place the positive electrode shell on the assembly platform, and stack the positive electrode sheet with the interface buffer layer, the ceramic composite solid electrolyte membrane, the pre-lithiated silicon carbon negative electrode, the gasket, and the spring sheet in sequence to ensure that each layer is aligned and fits together, in preparation for final packaging.

[0019] S6: Cover the outside of the stacked components with the negative electrode shell, and use a button cell sealing machine to press and seal it to complete the assembly of the entire battery. Then, activation and performance testing can be carried out to verify whether the battery's various indicators meet the requirements.

[0020] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. This invention, by drawing inspiration from the multi-level energy storage mechanism of lightning systems in nature, constructs a unique multi-level cloud-like composite cathode structure. This allows the battery to simultaneously possess the dual-mechanism synergy of high-capacity energy storage and ultra-fast charging and discharging, meeting both long-range battery life requirements and enabling ultra-fast charging. The interface buffer layer design specifically addresses the industry challenges of high interface impedance and poor contact in traditional solid-state batteries. Combined with a ceramic composite solid electrolyte, it significantly improves the battery's cycle stability, ensuring good performance throughout long-term use. Simultaneously, the all-solid-state structural design eliminates the flammability risks associated with liquid electrolytes. Even in extreme situations such as puncture, compression, or overcharging, it effectively prevents fire and explosion, thereby improving the overall safety and reliability of the battery.

[0021] 2. In this invention, the entire process is compatible with existing solid-state battery production lines, requiring no large-scale addition of equipment, thus lowering the threshold and cost for industrialization. The various steps in the preparation process are closely linked, from cathode slurry preparation to final battery packaging; each step is optimized to improve battery performance, ensuring the finished battery consistently delivers its design advantages. This battery also possesses excellent wide-temperature adaptability, maintaining stable charge and discharge performance even in extreme high and low temperature environments, adapting to the usage needs of different regions and scenarios. With these comprehensive advantages, it is not only suitable for the new energy vehicle field but can also be widely applied in high-end energy storage, special power supplies, and other scenarios, providing efficient and reliable solutions for energy storage needs in various fields. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the battery structure of the present invention; Figure 2 This is a schematic diagram of the preparation method in this invention. Figure 3 This is a schematic diagram comparing the fast charging performance in this invention; Figure 4 This is a schematic diagram comparing energy density and cycle life in this invention; Figure 5 This is a schematic diagram comparing the safety performance of the present invention; Figure 6 This is a schematic diagram comparing the wide temperature range performance of the present invention. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0024] Example: Refer to Figure 1-6 A high-energy-density all-solid-state battery with a biomimetic lightning structure includes: a positive electrode shell, a positive electrode current collector, a multi-level cloud-like composite positive electrode, an interface buffer layer, a ceramic composite solid electrolyte membrane, a negative electrode, a negative electrode current collector, and a negative electrode shell. As the outermost encapsulation component of the battery, the positive electrode shell provides robust structural support and physical protection for the entire battery system. During battery assembly, it serves as the starting base for the stacking operation, sequentially housing core functional layers such as the positive current collector and composite positive electrode. Ultimately, it works in conjunction with the negative electrode shell to achieve a sealed encapsulation of the battery, effectively preventing the intrusion of external impurities such as moisture and oxygen, and ensuring the stability and safety of the battery's internal environment.

[0025] The positive electrode current collector, made of aluminum foil, is a key conductive component connecting the positive electrode shell and the multi-level cloud-structured composite positive electrode. It is tightly bonded to the inner side of the positive electrode shell, and its main function is to efficiently collect the current generated by the positive electrode and stably conduct it to the external circuit. During the battery fabrication stage, the multi-level cloud-structured composite positive electrode slurry is directly coated onto the aluminum foil surface, and after drying and punching, it forms an integrated positive electrode sheet, ensuring the continuity and reliability of the current transmission path.

[0026] The multi-level cloud-like composite cathode is the core energy storage component of the battery, composed of nano-MoO3 or LiV3O8, MXene, carbon nanotubes, Super P conductive carbon black, and PVDF-HFP binder. During preparation, the above materials are added to NMP solvent in a specific ratio and thoroughly stirred to form a homogeneous slurry. This slurry is then coated onto the surface of the cathode current collector, vacuum dried, and die-cut into discs of specified sizes. This component mimics the multi-level cloud structure of a natural lightning system, constructing a three-dimensional conductive network that provides the foundation for efficient charge storage and rapid transfer, making it the core carrier for achieving high energy density and ultra-fast charging performance in batteries.

[0027] The interface buffer layer is an ultrathin MXene layer, prepared by spraying an MXene ethanol dispersion onto the surface of a multi-level cloud-like composite cathode and then drying it. It tightly covers the outer side of the composite cathode, directly contacting the ceramic composite solid electrolyte membrane. Its main function is to optimize the interfacial contact state between the cathode and the electrolyte, reduce interfacial impedance, and alleviate stress caused by volume changes during charging and discharging, thereby improving the battery's cycle stability and charge / discharge efficiency, and solving the industry problem of poor interfacial compatibility in traditional solid-state batteries.

[0028] The ceramic composite solid electrolyte membrane is composed of polyethylene oxide, LiFSI lithium salt, LLZTO ceramic powder, and an epoxy modifier. During preparation, these materials are dissolved in acetonitrile solvent and stirred until completely transparent. The membrane is then cast using a casting process, dried at room temperature in the dark, and finally die-cut into uniform, pinhole-free, and crack-free discs. This membrane layer, located between the interface buffer layer and the negative electrode, enables efficient and rapid lithium-ion transport while physically isolating the positive and negative electrode components to avoid short-circuit risks. It also possesses excellent mechanical strength and resistance to high and low temperatures, ensuring the intrinsic safety of the battery.

[0029] The negative electrode, made of pre-lithiated silicon-carbon or lithium metal with a protective layer, is a key component in the battery responsible for storing and releasing lithium ions. It is tightly bonded to the outside of the ceramic composite solid electrolyte membrane, exchanging lithium ions with the electrolyte membrane during charging and discharging, thus realizing the interconversion of electrical energy and chemical energy. Pre-lithiated silicon-carbon negative electrodes can effectively improve the battery's energy density, while lithium metal negative electrodes with a protective layer offer superior fast-charging performance and cycle life, allowing for flexible selection based on different application requirements.

[0030] The negative electrode current collector is made of copper foil and is tightly connected between the negative electrode and the negative electrode shell. Its main function is to efficiently collect the current generated by the negative electrode and conduct it stably to the external circuit, ensuring smooth current output during battery discharge. During battery assembly, the negative electrode current collector and the negative electrode are tightly bonded together to form the negative electrode plate of the battery, providing stable conductive support for the electrochemical reaction of the negative electrode.

[0031] The negative electrode shell, as the outer packaging component of the battery, works with the positive electrode shell to complete the overall sealed packaging of the battery. Located on the outermost side of the battery structure, it fits tightly against the outside of the negative electrode current collector. After being pressed and sealed by a button cell sealing machine, it provides reliable physical protection for all internal components of the battery, isolates the battery from external environmental interference, maintains the internal pressure balance of the battery, and ensures the structural integrity and performance stability of the battery during charge and discharge cycles.

[0032] A method for fabricating a high-energy-density all-solid-state battery with a biomimetic lightning structure includes the following steps: S1: Weigh out nano MoO3, MXene, carbon nanotubes, SuperP conductive carbon black and PVDF-HFP binder according to the proportion, add these materials to NMP solvent and stir thoroughly for more than 4 hours to form a uniform multi-level cloud-like composite cathode slurry, which is ready for the subsequent coating process.

[0033] S2: The prepared positive electrode slurry is evenly coated on the surface of the positive electrode current collector made of aluminum foil, and then placed in a vacuum drying oven and dried at 60°C for 8 hours. After drying, it is punched into a circular sheet of a specified size to obtain an integrated positive electrode sheet, which provides a flat substrate for the subsequent spraying of the interface buffer layer.

[0034] S3: MXene ethanol dispersion is uniformly sprayed onto the surface of the positive electrode sheet. After spraying, it is dried to form an ultra-thin interface buffer layer. This layer will then be in close contact with the ceramic composite solid electrolyte membrane to optimize interface compatibility.

[0035] S4: Weigh PEO, LiFSI lithium salt, LLZTO ceramic powder and epoxy modifier, dissolve these materials in acetonitrile solvent and stir for 6 hours until completely transparent, make a thin film by casting process, dry at room temperature in the dark for 24 hours and then punch it into a round piece without pinholes or cracks to obtain a ceramic composite solid electrolyte membrane, which provides a core ion transport component for subsequent battery assembly.

[0036] S5: In an anhydrous and oxygen-free glove box, place the positive electrode shell on the assembly platform, and stack the positive electrode sheet with the interface buffer layer, the ceramic composite solid electrolyte membrane, the pre-lithiated silicon carbon negative electrode, the gasket, and the spring sheet in sequence to ensure that each layer is aligned and fits together, in preparation for final packaging.

[0037] S6: Cover the outside of the stacked components with the negative electrode shell, and use a button cell sealing machine to press and seal it to complete the assembly of the entire battery. Then, activation and performance testing can be carried out to verify whether the battery's various indicators meet the requirements.

[0038] Comparative Example 1: Traditional all-solid-state battery (without biomimetic lightning multi-stage structure): Cathode preparation: Weigh lithium cobalt oxide, Super P conductive carbon black, and PVDF-HFP binder, add NMP solvent in proportion and stir for 4 hours to form a uniform slurry, coat it on the surface of aluminum foil current collector, vacuum dry at 60℃ for 8 hours and then punch it into 16mm round pieces without interface buffer layer treatment.

[0039] Electrolyte preparation: Weigh PEO and LiFSI lithium salt and dissolve them in acetonitrile solvent. Stir for 6 hours until completely transparent. After casting into a film, dry at room temperature in the dark for 24 hours and cut into 18mm rounds.

[0040] Battery assembly: In an anhydrous and oxygen-free glove box, stack the batteries in the following order: positive electrode shell → lithium cobalt oxide positive electrode → pure PEO electrolyte membrane → pre-lithiated silicon carbon negative electrode → gasket → spring sheet → negative electrode shell, and then use a button battery sealing machine to press and seal them.

[0041] Test conditions: completely consistent with the embodiments of the invention, including activation regime, charge / discharge rate, voltage range, etc.

[0042] Comparative Example 2: All-solid-state battery with a single active material (without MXene composite structure): Positive electrode preparation: Weigh nano MoO3, Super P conductive carbon black, and PVDF-HFP binder, add NMP solvent in proportion and stir for 4 hours to form a uniform slurry, coat it on the surface of aluminum foil current collector, vacuum dry at 60℃ for 8 hours and then punch it into 16mm round pieces without interface buffer layer treatment.

[0043] Electrolyte preparation: exactly the same as in the embodiments of the invention, using a PEO-LiFSI-LLZTO ceramic composite solid electrolyte.

[0044] Battery assembly: In an anhydrous and oxygen-free glove box, stack the cells in the following order: positive electrode shell → MoO3 positive electrode → ceramic composite electrolyte membrane → pre-lithiated silicon carbon negative electrode → gasket → spring sheet → negative electrode shell, and then use a button cell sealing machine to press and seal them.

[0045] Test conditions: completely consistent with the embodiments of the invention.

[0046] For a comparison of fast charging performance data, see Figure 3 For a comparison of energy density and cycle life data, see [link to relevant documentation]. Figure 4 For a comparison of safety performance data, please see [link / reference]. Figure 5 For a comparison of performance data across wide temperature ranges, see [link to relevant documentation]. Figure 6 ; The comparative test data clearly demonstrate that the invention embodiments exhibit significant advantages in fast-charging performance, energy density, cycle life, safety performance, and wide temperature range adaptability. The traditional battery structure in Comparative Example 1, lacking a biomimetic multi-level conductive network, suffers from low charge transfer efficiency, resulting in a significant decrease in fast-charging performance and cycle life. While the single-active-material battery in Comparative Example 2 uses the same ceramic composite electrolyte, the lack of an MXene interface buffer layer and a three-dimensional conductive network leads to higher interface impedance, resulting in significantly lower fast-charging performance and cycle stability compared to the invention embodiments. These comparative data fully validate the crucial role of biomimetic lightning structure design in improving the overall performance of all-solid-state batteries.

[0047] From the above, we can conclude that: This invention utilizes the multi-level energy storage mechanism of natural lightning systems to construct a unique multi-level cloud-like composite cathode structure. This allows the battery to simultaneously possess the dual-mechanism synergy of high-capacity energy storage and ultra-fast charging / discharging, meeting both long-range battery life requirements and enabling ultra-fast charging. The interface buffer layer design specifically addresses the industry challenges of high interface impedance and poor contact in traditional solid-state batteries. Combined with a ceramic composite solid electrolyte, this significantly improves the battery's cycle stability, ensuring consistent performance over long-term use. Furthermore, the all-solid-state structure eliminates the flammability risks associated with liquid electrolytes. Even under extreme conditions such as puncture, compression, or overcharging, it effectively prevents fire and explosion, thereby enhancing the overall safety and reliability of the battery.

[0048] In this invention, the entire process is compatible with existing solid-state battery production lines, requiring no large-scale addition of equipment, thus lowering the threshold and cost for industrialization. The various steps in the preparation process are closely linked; from cathode slurry preparation to final battery packaging, each stage is optimized to improve battery performance, ensuring the finished battery consistently delivers its design advantages. This battery also possesses excellent wide-temperature adaptability, maintaining stable charge and discharge performance even in extreme high and low temperature environments, adapting to the usage needs of different regions and scenarios. With these comprehensive advantages, it is not only suitable for the new energy vehicle field but can also be widely applied in high-end energy storage, special power supplies, and other scenarios, providing efficient and reliable solutions for energy storage needs in various fields.

[0049] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the term "comprising" or any other variations thereof is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0050] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-energy-density all-solid-state battery with a biomimetic lightning structure, characterized in that: include: Positive electrode shell, positive electrode current collector, multi-level cloud-like composite positive electrode, interface buffer layer, ceramic composite solid electrolyte membrane, negative electrode, negative electrode current collector and negative electrode shell; The positive electrode shell is the outermost encapsulation structure, and the inner side of the positive electrode shell is tightly attached to the positive electrode current collector. The multi-level cloud-like composite cathode is directly coated on the surface of the cathode current collector, and an interface buffer layer is formed on the outer surface of the cathode by a spraying process. The ceramic composite solid electrolyte membrane covers the outside of the interface buffer layer and is in close contact with the negative electrode. The negative electrode is connected to the negative electrode current collector on the outside, and the outermost layer of the negative electrode is encapsulated by the negative electrode shell; after all components are stacked in sequence, they are compacted and sealed by a button battery sealing machine to form a complete sealed battery system.

2. The high-energy-density all-solid-state battery with a biomimetic lightning structure as described in claim 1, characterized in that: The positive electrode shell is the outermost encapsulation component of the battery.

3. A high-energy-density all-solid-state battery with a biomimetic lightning structure as described in claim 1, characterized in that: The positive electrode current collector is made of aluminum foil and is a key conductive component that connects the positive electrode shell to the multi-stage cloud-like composite positive electrode.

4. A high-energy-density all-solid-state battery with a biomimetic lightning structure as described in claim 1, characterized in that: The multi-level cloud-like composite cathode is composed of nano-MoO3 or LiV3O8, Ti3C2, carbon nanotubes, Super P conductive carbon black, and PVDF-HFP binder.

5. A high-energy-density all-solid-state battery with a biomimetic lightning structure as described in claim 1, characterized in that: The ceramic composite solid electrolyte membrane is made of polyethylene oxide, LiFSI lithium salt, LLZTO ceramic powder and epoxy modifier.

6. A high-energy-density all-solid-state battery with a biomimetic lightning structure as described in claim 1, characterized in that: The negative electrode is a pre-lithiated silicon-carbon or metallic lithium material with a protective layer.

7. A high-energy-density all-solid-state battery with a biomimetic lightning structure as described in claim 1, characterized in that: The negative electrode current collector is made of copper foil and is tightly connected between the negative electrode and the negative electrode shell.

8. A high-energy-density all-solid-state battery with a biomimetic lightning structure as described in claim 1, characterized in that: The interface buffer layer is an MXene layer, which is prepared by spraying an MXene ethanol dispersion onto the surface of a multi-level cloud-like composite cathode and then drying it.

9. A high-energy-density all-solid-state battery with a biomimetic lightning structure as described in claim 1, characterized in that: The negative electrode shell and the positive electrode shell cooperate with each other to form a sealed outer shell of the battery; the negative electrode shell covers the outside of the negative electrode current collector, and through the compaction operation of the button battery sealing machine, it forms a stable overall encapsulation structure with the positive electrode shell.

10. The method for preparing a high-energy-density all-solid-state battery with a biomimetic lightning structure as described in claim 1, characterized in that: The method includes the following steps: S1: Weigh out nano MoO3, MXene, carbon nanotubes, SuperP conductive carbon black and PVDF-HFP binder according to the proportion, add these materials to NMP solvent and stir thoroughly for more than 4 hours to form a uniform multi-level cloud-like composite cathode slurry; S2: The prepared positive electrode slurry is evenly coated on the surface of the positive electrode current collector made of aluminum foil, and then placed in a vacuum drying oven and dried at 60°C for 8 hours. After drying, it is punched into a circular sheet of a specified size to obtain an integrated positive electrode sheet. S3: MXene ethanol dispersion is uniformly sprayed onto the surface of the positive electrode sheet, and then dried after spraying to form an ultra-thin interface buffer layer. S4: Weigh PEO, LiFSI lithium salt, LLZTO ceramic powder and epoxy modifier, dissolve these materials in acetonitrile solvent and stir for 6 hours until completely transparent, make a film by casting process, dry at room temperature in the dark for 24 hours and then punch into round pieces without pinholes and cracks to obtain ceramic composite solid electrolyte membrane. S5: In an anhydrous and oxygen-free glove box, place the positive electrode shell on the assembly platform, and stack the positive electrode sheet with the interface buffer layer, the ceramic composite solid electrolyte membrane, the pre-lithiated silicon carbon negative electrode, the gasket, and the spring sheet in sequence to ensure that each layer is aligned and fits together, in order to prepare for final packaging. S6: Cover the outside of the stacked components with the negative electrode shell, and use a button cell sealing machine to press and seal it to complete the assembly of the entire battery. Then, activation and performance testing can be carried out to verify whether the battery's various indicators meet the requirements.

Images