A two-layer electrolyte transfer manufacturing method with optimized positive and negative electrode interfaces for all-solid-state batteries.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- SHANGHAI FIRM LITHIUM NEW ENERGY TECH CO LTD
- Filing Date
- 2026-01-28
- Publication Date
- 2026-08-03
Smart Images
Figure 0007898702000001_ABST
Abstract
Description
[Technical Field]
[0001] The present invention belongs to the field of all-solid-state batteries and relates to a two-layer electrolyte transfer manufacturing method and an all-solid-state battery in which the positive and negative electrode interfaces of the all-solid-state battery are optimized. [Background technology]
[0002] With the increasing demand for higher energy density and safety in electric vehicles and portable electronic devices, all-solid-state batteries (ASSBs) are becoming more prevalent. S Due to their potential for outstanding performance, all-solid-state batteries are considered the focus of next-generation energy storage technologies. Compared to conventional liquid lithium-ion batteries, all-solid-state batteries replace organic electrolytes by employing non-flammable solid electrolytes, theoretically offering higher safety and longer cycle life, and are expected to achieve higher energy density by being compatible with lithium metal anodes. However, several significant challenges must be overcome to realize the widespread application of all-solid-state batteries, among which the interface problem between the positive and negative electrode active materials and the solid electrolyte is particularly prominent.
[0003] The performance of solid-state batteries is largely limited by the quality of the solid-solid interface. On the positive electrode side, the interface generally suffers from poor contact, high interfacial resistance, and poor electrochemical stability, which not only leads to significant voltage drop and capacity reduction but can also cause side reactions and reduce Coulomb efficiency. On the negative electrode side, especially when using lithium metal, interfacial stability and the ability to suppress lithium dendrites are extremely important, as an unstable interface accelerates capacity degradation and poses a safety risk. Current research mainly focuses on optimizing the interface by introducing intermediate buffer layers, surface modification, or developing new types of electrolyte materials. However, prior art still has limitations, and a single solid electrolyte system struggles to simultaneously satisfy the different demands on the interfacial properties of the positive and negative electrodes. For example, sulfide solid electrolytes typically exhibit high ionic conductivity and certain interfacial adaptability on the negative electrode side, but are prone to oxidative decomposition on the high-voltage positive electrode side. Halide (e.g., chloride) electrolytes, on the other hand, have excellent antioxidant stability at high voltages and are very well-suited to the positive electrode side, but may have problems with reduction stability or interfacial impedance on the negative electrode side (especially when in direct contact with lithium metal). Furthermore, conventional methods for constructing multilayer structures, such as continuous coating or lamination, constantly face problems such as weak interlayer bonding, high interfacial resistance, or complex processes prone to defects, making it difficult to accurately and efficiently construct composite electrolyte interface layers with good contact with the surface of the active material and specific functions. Therefore, developing a novel manufacturing method that can accurately construct high-performance composite interface layers for the respective needs of the positive and negative electrodes, achieving strong interlayer bonding and low interfacial impedance, has significant practical importance in overcoming the interface bottleneck of all-solid-state batteries and improving their overall performance. [Overview of the Initiative]
[0004] To address the shortcomings of the prior art, the objective of the present invention is to provide a two-layer electrolyte transfer manufacturing method and an all-solid-state battery in which the positive and negative electrode interfaces of the all-solid-state battery are optimized. To achieve this objective, the present invention employs the following technical approach.
[0005] In the first aspect, the present invention is After mixing S1, a halide electrolyte, nano-α-Al2O3, Li3YCl6 powder, Li2ZrCl6 powder, a rheology modifier, a first binder, and a first organic solvent, a halide electrolyte slurry is obtained. The halide electrolyte slurry is then applied to the substrate surface and dried to form a halide electrolyte layer, thereby obtaining a halide composite layer. S2, The positive electrode sheet and the halide composite layer are laminated and aligned, then rolled to transfer the halide electrolyte layer to the surface of the positive electrode sheet, the substrate is removed to obtain a composite positive electrode sheet. After mixing S3, sulfide electrolyte, nanozirconia, polydopamine nanospheres, hexagonal boron nitride nanosheets, a second binder, and a second organic solvent, a sulfide electrolyte slurry is obtained. This sulfide electrolyte slurry is then applied to the surface of another substrate, dried, and a sulfide electrolyte layer is formed to obtain a sulfide composite layer. S4. The negative electrode sheet and the sulfide composite layer are laminated and aligned, then rolled to transfer the sulfide electrolyte layer to the surface of the negative electrode sheet, the substrate is removed, and a composite negative electrode sheet is obtained. S5. The composite positive electrode sheet and the composite negative electrode sheet are stacked, welded, and packaged to obtain an all-solid-state battery. The present invention provides a two-layer electrolyte transfer manufacturing method for an all-solid-state battery, characterized by including the following:
[0006] The manufacturing method provided by the present invention significantly optimizes the interfacial performance of all-solid-state batteries by cooperating a stepwise transfer process with a functionalized electrolyte. First, a halide electrolyte layer containing nano-α-Al2O3 and a lithium salt additive is independently manufactured on a substrate (to improve the high-voltage stability and mechanical strength on the positive electrode side), transferred to a positive electrode sheet by rolling to form a tight interface, and a sulfide electrolyte layer containing nanometer zirconia / polydopamine / hexahedral boron nitride is manufactured on another substrate (to improve the dendrite suppression force and interfacial wettability on the negative electrode side), transferred to a negative electrode sheet to construct a self-adaptive interface, and finally integrated into a two-layer electrolyte electrode, simultaneously achieving low interfacial impedance, high cycle stability, and high process reliability, breaking through the performance bottleneck of the conventional single electrolyte system.
[0007] On the positive electrode side, a halide electrolyte with high oxidation stability is mainly adopted, and by adding nano-α-Al2O3, the mechanical elastic modulus of the electrolyte layer is improved to resist the positive electrode cycle stress. At the same time, Li3YCl6 and Li2ZrCl6 powders are introduced as surfactants. Li3YCl6 optimizes the ion path by filling grain boundaries, and Li2ZrCl6 can form a stable ion conduction phase at the interface, together reducing the potential barrier of charge transfer at the positive electrode - electrolyte interface. On the negative electrode side, a sulfide electrolyte with high ionic conductivity is adopted. The mechanical strength is improved by nanometer zirconia to physically suppress the penetration of dendrites. The polydopamine nanospheres improve the wetting contact between the electrolyte and the negative electrode due to their excellent surface adhesion and lithium affinity characteristics, guiding the uniform deposition of lithium ions. The hexahedral boron nitride nanosheet provides a fast in-plane ion channel due to its layered structure to deflect the growth direction of dendrites. The three cooperate to form a spatial and electrochemical dual dendrite suppression.
[0008] As a preferred technical solution of the present invention, in step S1, the halide electrolyte includes any one or at least two combinations of Li3InCl6, Li3YCl6, or Li4YI7.
[0009] In some arbitrary examples, the particle size D50 of the halide electrolyte is 5 to 15 μm, and may be, for example, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, or 15 μm, but other unlisted values within this range are also applicable, not limited to the listed values.
[0010] In some arbitrary examples, the amount of nano-α-Al2O3 added is 3-4 wt% of the mass of the halide electrolyte, and may be, for example, 3.0 wt%, 3.1 wt%, 3.2 wt%, 3.3 wt%, 3.4 wt%, 3.5 wt%, 3.6 wt%, 3.7 wt%, 3.8 wt%, 3.9 wt%, or 4.0 wt%, but is not limited to the listed values, and other unlisted values within this range are also applicable.
[0011] This invention particularly limits the amount of nano-α-Al2O3 added to 3-4 wt% of the mass of the halide electrolyte. Within this range, nano-α-Al2O3 can be effectively dispersed and embedded in the halide substrate, forming a support network that significantly improves the overall rigidity and compressive strength of the material. This is crucial for mitigating volume changes during positive electrode cycling and maintaining interfacial contact stability. At the same time, this amount does not excessively block the main pathway for lithium ion transport, allowing the halide particles to maintain relatively good continuity, and the rheological properties and film-forming density of the slurry are also advantageous for subsequent coating and transfer processes.
[0012] If the amount of nano-α-Al2O3 added is less than 3 wt%, the number density of nano-α-Al2O3 in the substrate becomes insufficient, making it difficult to form an effective mechanically reinforcing framework. The composite layer has a relatively weak ability to resist stress, and during the long-term operation of the battery, the positive electrode active material repeatedly expands and contracts, which can easily cause microcracks or localized detachment of the electrolyte layer. This reduces the contact points at the interface, and the interface impedance gradually increases over time, affecting the cycle life. Furthermore, the insufficient mechanical strength of the thin film also increases the risk of failure during the transfer or assembly process.
[0013] When the amount of nano-α-Al2O3 added exceeds 4 wt%, the excess nano-α-Al2O3 severely fragments the continuous phase of the halide electrolyte, not only significantly increasing the degree of bending and potential barrier of lithium ion transfer, but also leading to a significant decrease in bulk phase and interfacial ionic conductivity, making it prone to nanoparticle aggregation and forming localized defects. Excessive addition of nano-α-Al2O3 affects the dispersibility of the slurry, increases the brittleness of the thin film, makes it difficult to obtain a perfectly uniform transfer layer, and ultimately impairs the battery's rate performance.
[0014] In some arbitrary examples, the amount of Li3YCl6 powder added is 4-5 wt% of the mass of the halide electrolyte, for example, 4.0 wt%, 4.1 wt%, 4.2 wt%, 4.3 wt%, 4.4 wt%, 4.5 wt%, 4.6 wt%, 4.7 wt%, 4.8 wt%, 4.9 wt%, or 5.0 wt%, but other unlisted values within this range are also applicable, not limited to the listed values.
[0015] This invention is particularly limited to a Li3YCl6 powder addition amount of 4-5 wt% of the mass of the halide electrolyte. Within this range, the Li3YCl6 powder particles can be distributed relatively uniformly in the main halide electrolyte, mainly concentrating in the grain boundary regions between particles. In the subsequent rolling process, under constant pressure and temperature, these powders partially soften, creating weak surface interactions with the main electrolyte, effectively filling minute gaps at particle contact points and reducing lithium ion transfer resistance at grain boundaries. At the same time, Y 3+ This facilitates the formation of a contact interface favorable for ion transport between the halide electrolyte and the positive electrode active material, thereby cooperatively reducing the charge transfer impedance on the positive electrode side.
[0016] When the amount of Li3YCl6 powder added is less than 4 wt%, the number of powder particles that can disperse and act effectively in the grain boundary region is limited, making it difficult to adequately cover or modify the crucial inter-particle contact areas. It cannot adequately fill or activate gaps and defects at the grain boundaries, making it difficult to effectively improve ion conduction at the grain boundaries. At the same time, its effect of promoting activation at the cathode-electrolyte interface is also not fully realized due to the insufficient concentration, limiting the reduction in interfacial impedance.
[0017] If the amount of Li3YCl6 powder added exceeds 5 wt%, the excess powder occupies too much volume within the halide electrolyte substrate. Although it is an ion conductor itself, its crystal structure and ion transport characteristics differ from those of the main halide electrolyte. The presence of a large amount of powder disrupts the natural continuous conduction pathway of the main electrolyte, increasing the degree of bend in lithium ion transport in the bulk phase, and conversely leading to a decrease in the overall ionic conductivity of the bulk phase of the composite electrolyte layer. Furthermore, excess Li3YCl6 powder is more prone to localized aggregation, forming relatively large aggregates. These aggregates may become non-uniform points or stress concentration points in the composite layer, which is detrimental to the formation of a homogeneous and dense thin film structure.
[0018] In some arbitrary examples, the amount of Li2ZrCl6 powder added is 3 to 4 wt% of the mass of the halide electrolyte, and may be, for example, 3.0 wt%, 3.1 wt%, 3.2 wt%, 3.3 wt%, 3.4 wt%, 3.5 wt%, 3.6 wt%, 3.7 wt%, 3.8 wt%, 3.9 wt%, or 4.0 wt%, but is not limited to the listed values, and other unlisted values within this range are also applicable.
[0019] This invention particularly limits the amount of Li2ZrCl6 powder added to 3-4 wt% of the mass of the halide electrolyte. Within this range, the Li2ZrCl6 powder can be distributed relatively uniformly in the main electrolyte, and is particularly concentrated at the particle contact interfaces. During the rolling stage of the manufacturing process, under mild heating conditions, the added Li2ZrCl6 participates in and promotes the ion exchange process at the interface, helping to form smoother contact interfaces for ion transport between particles of the halide electrolyte and between the halide layer and the positive electrode active material. 4+ Compounds containing this compound tend to form a more stable lithium-conducting phase at the interface, thus contributing to a certain degree of interfacial stabilization.
[0020] When the amount of Li2ZrCl6 powder added is less than 3 wt%, it is not possible to adequately modify or cover the regions that are very important for these ion transports, resulting in a relatively large number of potential high-impedance points at the grain boundaries, which limits its contribution to reducing the overall interfacial impedance.
[0021] If the amount of Li2ZrCl6 powder added exceeds 4 wt%, the excess Li2ZrCl6 powder occupies too large a proportion of the halide electrolyte substrate, disrupting the continuous and efficient ion conduction network formed between the main electrolyte particles. The excess Li2ZrCl6 powder itself hinders the movement of lithium ions into the bulk phase of the material due to the regions where it concentrates, increasing the degree of transport bend and consequently reducing the overall ionic conductivity of the bulk phase of the composite electrolyte layer to some extent. Furthermore, the difficulty of dispersing the powder at high addition levels increases, raising the risk of aggregation and making it easier to form localized heterogeneous regions in the thin film. These regions become structural weak points or stress concentration points, affecting the mechanical integrity and uniformity of the thin film.
[0022] In some arbitrary examples, the rheological modifier comprises polyoxyethylene castor oil ester and / or hydrogenated polybutadiene.
[0023] In some arbitrary examples, the rheological modifier is 2-3 wt% of the mass of the halide electrolyte, and may be, for example, 2.0 wt%, 2.1 wt%, 2.2 wt%, 2.3 wt%, 2.4 wt%, 2.5 wt%, 2.6 wt%, 2.7 wt%, 2.8 wt%, 2.9 wt%, or 3.0 wt%, but is not limited to the listed values; other unlisted values within this range are also applicable.
[0024] In a preferred technical application of the present invention, in step S1, the first binder comprises polyisobutylene and / or styrene-butadiene rubber.
[0025] In some arbitrary examples, the amount of the first binder added is 4 to 6 wt% of the mass of the halide electrolyte, and may be, for example, 4.0 wt%, 4.2 wt%, 4.4 wt%, 4.6 wt%, 4.8 wt%, 5.0 wt%, 5.2 wt%, 5.4 wt%, 5.6 wt%, 5.8 wt%, or 6.0 wt%, but is not limited to the listed values, and other unlisted values within this range are also applicable.
[0026] In some arbitrary examples, the first organic solvent includes one or at least two of toluene, xylene, or dibutyl ether.
[0027] In some arbitrary examples, the amount of the first organic solvent added is 60 to 80 wt% of the mass of the halide electrolyte, and may be, for example, 60 wt%, 62 wt%, 64 wt%, 66 wt%, 68 wt%, 70 wt%, 72 wt%, 74 wt%, 76 wt%, 78 wt%, or 80 wt%, but is not limited to the listed values, and other unlisted values within this range may also apply.
[0028] In a preferred technical configuration of the present invention, in step S1, the material of the substrate is PET.
[0029] In some arbitrary examples, the drying temperature is 100-110°C, and may be, for example, 100°C, 101°C, 102°C, 103°C, 104°C, 105°C, 106°C, 107°C, 108°C, 109°Ch, or 110°C, but is not limited to the listed numbers; other unlisted numbers within this range are also applicable.
[0030] In some arbitrary examples, the drying time is 3 to 4 hours, and may be, for example, 3.0h, 3.1h, 3.2h, 3.3h, 3.4h, 3.5h, 3.6h, 3.7h, 3.8h, 3.9h, or 4.0h, but other unlisted numbers within this range are also applicable, not limited to the listed numbers.
[0031] In some arbitrary examples, the thickness of the halide electrolyte layer is 10 to 12 μm, and may be, for example, 10 μm, 10.2 μm, 10.4 μm, 10.6 μm, 10.8 μm, 11 μm, 11.2 μm, 11.4 μm, 11.6 μm, 11.8 μm, or 12 μm, but is not limited to the listed values; other unlisted values within this range are also applicable.
[0032] As a preferred technical solution of the present invention, in step S2, the pressure of the rolling is 20 to 30 MPa. For example, it may be 20 MPa, 21 MPa, 22 MPa, 23 MPa, 24 MPa, 25 MPa, 26 MPa, 27 MPa, 28 MPa, 29 MPa or 30 MPa. However, it is not limited to the listed values, and other unlisted values within this numerical range can also be similarly applicable.
[0033] In some optional examples, the temperature of the rolling is 80 to 90 °C. For example, it may be 80 °C, 81 °C, 82 °C, 83 °C, 84 °C, 85 °C, 86 °C, 87 °C, 88 °C, 89 °C or 90 °C. However, it is not limited to the listed values, and other unlisted values within this numerical range can also be similarly applicable.
[0034] As a preferred technical solution of the present invention, in step S3, the sulfide electrolyte is Li6PS5X, Li 10 GeP2S 12 、Li 3.25 Ge 0.25 P 0.75 S4 or Li7P3S 11 and includes any one or at least a combination of two of them, where X is Cl, Br, I.
[0035] In some optional examples, the particle size D50 of the sulfide electrolyte is 5 to 15 μm. For example, it may be 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm or 15 μm. However, it is not limited to the listed values, and other unlisted values within this numerical range can also be similarly applicable.
[0036] In some arbitrary examples, the amount of nanozirconia added is 2-3 wt% of the mass of the sulfide electrolyte, for example, 2.0 wt%, 2.1 wt%, 2.2 wt%, 2.3 wt%, 2.4 wt%, 2.5 wt%, 2.6 wt%, 2.7 wt%, 2.8 wt%, 2.9 wt%, or 3.0 wt%, but is not limited to the listed values; other unlisted values within this range are also applicable.
[0037] This invention particularly limits the amount of nanozirconia added to 2-3 wt% of the mass of the sulfide electrolyte. Within this range, nanozirconia particles can be uniformly dispersed in the sulfide substrate, forming localized hardening points that significantly improve the overall hardness and compressive strength of the composite layer. This enhancement is crucial for suppressing the physical penetration of lithium dendrites. The presence of nanozirconia increases the degree of bending in the dendrite growth path, deflecting the dendrites or allowing them to penetrate only at higher energies. At the same time, this amount does not block the ion pathways formed by the sulfide particles over a large area, allowing lithium ions to still be effectively transported through the gaps between particles or along the sulfide-zirconia interface, thus controlling the impact on the overall electrical conductivity and contributing to maintaining good processing performance of the slurry.
[0038] When the amount of nanozirconia added is less than 2 wt%, the nanozirconia lacks sufficient density in the substrate, making it difficult to form an effective spatial barrier network. The small amount of dispersed particles limits the improvement in the overall rigidity of the composite layer, and thus does not significantly improve its ability to resist penetration by lithium dendrites. The dendrites more easily find relatively direct growth paths in the sparse areas of nanozirconia, reducing the physical barrier effect of the electrolyte layer. In this case, the safety risk of operation at relatively high current densities of the battery increases, and the improvement in critical current density is not significant.
[0039] If the amount of nanozirconia added exceeds 3 wt%, the volume occupied by the excess nanozirconia becomes too large, severely fragmenting the continuous phase of the sulfide electrolyte, significantly blocking the lithium ion transport pathway, and drastically reducing the ionic conductivity of the bulk phase of the composite layer. At the same time, nanozirconia at high concentrations is highly prone to aggregation, forming micron-scale clusters. These clusters not only significantly hinder ion conduction but also become stress concentration points or structural defects within the electrolyte layer, weakening its mechanical integrity. Simultaneously, the viscosity of the slurry increases, making it prone to cracking or thickness inconsistencies during the coating and film formation process, ultimately impairing the battery's rate performance and interfacial stability.
[0040] In some arbitrary examples, the amount of polydopamine nanospheres added is 0.3 to 0.5 wt% of the mass of the sulfide electrolyte, and may be, for example, 0.3 wt%, 0.32 wt%, 0.34 wt%, 0.36 wt%, 0.38 wt%, 0.4 wt%, 0.42 wt%, 0.44 wt%, 0.46 wt%, 0.48 wt%, or 0.5 wt%, but other unlisted values within this range are also applicable, not limited to the listed values.
[0041] This invention particularly limits the amount of polydopamine nanospheres added to 0.3-0.5 wt% of the mass of the sulfide electrolyte. Within this range, the polydopamine nanospheres can be dispersed in the sulfide substrate, and the abundant functional groups on their surface (e.g., amino groups, phenolic hydroxyl groups) can enhance physical adsorption and chemical affinity with the lithium metal or silicon-carbon anode surface, thereby effectively increasing the wet contact area between the electrolyte layer and the anode and reducing the interfacial gap. At the same time, these lithium-parent sites guide lithium ions to deposit more uniformly at the interface, mitigating localized current concentration and helping to suppress the premature formation of lithium dendrites. The addition of trace amounts has relatively little interference with the sulfide electrolyte's own ion conduction network and does not significantly affect the conductivity of the bulk phase, and its own certain viscoelasticity can also provide weak stress relaxation at the interface.
[0042] When the amount of polydopamine nanospheres added is less than 0.3 wt%, the polydopamine nanospheres have difficulty forming sufficiently effective coverage points on the broad surface of the negative electrode, resulting in poor improvement of interfacial wetting and reduced effectiveness in guiding lithium ions for uniform deposition. This fails to adequately mitigate the problem of poor contact at the negative electrode-electrolyte interface, and the risk of interfacial fracture becomes relatively high, especially at relatively high current densities or during long cycles.
[0043] When the amount of polydopamine nanospheres added exceeds 0.5 wt%, the polydopamine nanospheres tend to concentrate and form relatively large clusters. These clusters, on the one hand, obstruct the composite electrolyte layer, hindering the transport of lithium ions in the bulk phase and at the interface and increasing impedance. On the other hand, the cluster sites become stress concentration points or areas of weak interfacial contact, which is detrimental to uniformity. Furthermore, excessive polydopamine nanospheres also partially clog the gaps between sulfide particles, affecting the density of the electrolyte and the continuity of ion pathways.
[0044] In some arbitrary examples, the amount of hexagonal boron nitride nanosheets added is 0.8 to 1.2 wt% of the mass of the sulfide electrolyte, and may be, for example, 0.8 wt%, 0.85 wt%, 0.9 wt%, 0.95 wt%, 1.0 wt%, 1.15 wt%, 1.1 wt%, 1.15 wt%, or 1.2 wt%, but is not limited to the listed values; other unlisted values within this range are also applicable.
[0045] This invention particularly limits the amount of hexagonal boron nitride nanosheets added to 0.8 to 1.2 wt% of the mass of the sulfide electrolyte. Within this range, the hexagonal boron nitride nanosheets can be appropriately dispersed in the sulfide substrate and, with the help of their layered structure, exert multiple effects. On the one hand, hexagonal boron nitride nanosheets oriented parallel to the electrode surface provide an auxiliary pathway for low-resistance in-plane lithium ion transport, optimizing the distribution of local ion flow. On the other hand, their high hardness and smooth interlayer surface effectively deflects vertically growing lithium dendrites, increasing the difficulty of dendrite penetration and thus increasing the critical current density. At the same time, hexagonal boron nitride nanosheets at this addition amount are less prone to severe aggregation.
[0046] When the amount of hexagonal boron nitride nanosheets added is less than 0.8 wt%, the distribution density of the hexagonal boron nitride nanosheets in the composite layer becomes insufficient. The sparse sheet layer structure makes it difficult to effectively form a spatial delimiting network, allowing dendrites to easily find vertical growth paths in the gaps between the sheet layers, thus weakening the physical suppression effect. At the same time, its guiding effect on ion flow is also limited by insufficient coverage, preventing sufficient improvement in the uniformity of ion transport at the interface. In this case, the battery exhibits poor dendrite suppression ability and cycle stability at relatively high current densities.
[0047] If the amount of hexagonal boron nitride nanosheets added exceeds 1.2 wt%, the excess hexagonal boron nitride nanosheets are prone to stacking or aggregation. The stacked sheet layers severely block lithium ion transport channels, significantly increasing ion transfer resistance at the bulk phase and interface, and drastically reducing electrical conductivity. Aggregates become fault points and stress concentration sources, impairing the mechanical uniformity of the electrolyte layer. Furthermore, if the amount of hexagonal boron nitride nanosheets added is too high, it greatly affects the slurry fluidity, making it easy for disorder or localized concentration of nanosheet orientation to occur during coating, and forming weak regions or crack sources after drying.
[0048] In a preferred technical application of the present invention, in step S3, the second binder comprises polyisobutylene and / or styrene-butadiene rubber.
[0049] In some arbitrary examples, the amount of the second binder added is 5 to 8 wt% of the mass of the sulfide electrolyte, for example, 5.0 wt%, 5.5 wt%, 6.0 wt%, 6.5 wt%, 7.0 wt%, 7.5 wt%, or 8.0 wt%, but other unlisted values within this range are also applicable, not limited to the listed values.
[0050] In some arbitrary examples, the second organic solvent includes one or at least two of toluene, xylene, or dibutyl ether.
[0051] In some arbitrary examples, the amount of the first organic solvent added is 60-80 wt% of the mass of the sulfide electrolyte, and may be, for example, 60 wt%, 62 wt%, 64 wt%, 66 wt%, 68 wt%, 70 wt%, 72 wt%, 74 wt%, 76 wt%, 78 wt%, or 80 wt%, but is not limited to the listed values, and other unlisted values within this range may also apply.
[0052] In a preferred technical configuration of the present invention, in step S3, the material of the substrate is PET.
[0053] In some arbitrary examples, the drying temperature is 100-110°C, and may be, for example, 100°C, 101°C, 102°C, 103°C, 104°C, 105°C, 106°C, 107°C, 108°C, 109°C, or 110°C, but is not limited to the listed numbers; other unlisted numbers within this range are also applicable.
[0054] In some arbitrary examples, the drying time is 1 to 2 hours, and may be, for example, 1.0h, 1.1h, 1.2h, 1.3h, 1.4h, 1.5h, 1.6h, 1.7h, 1.8h, 1.9h, or 2.0h, but other unlisted numbers within this range are also applicable, not limited to the listed numbers.
[0055] In some arbitrary examples, the thickness of the sulfide electrolyte layer is 15 to 18 μm, and may be, for example, 15 μm, 15.5 μm, 16 μm, 16.5 μm, 17 μm, 17.5 μm, or 18 μm, but is not limited to the listed values; other unlisted values within this range are also applicable.
[0056] As a preferred technical example of the present invention, in step S4, the rolling pressure is 15 to 25 MPa, and may be, for example, 15 MPa, 16 MPa, 17 MPa, 18 MPa, 19 MPa, 20 MPa, 21 MPa, 22 MPa, 23 MPa, 24 MPa, or 25 MPa, but is not limited to the listed values, and other unlisted values within this range can also be applied.
[0057] In some arbitrary examples, the rolling temperature is 80-90°C, and may be, for example, 80°C, 81°C, 82°C, 83°C, 84°C, 85°C, 86°C, 87°C, 88°C, 89°C, or 90°C, but is not limited to the listed numbers; other unlisted numbers within this range are also applicable.
[0058] In a second aspect, the present invention provides an all-solid-state battery that can be manufactured by employing the manufacturing method described in the first aspect.
[0059] Compared to the prior art, the beneficial effects of the present invention are as follows:
[0060] The manufacturing method provided by the present invention significantly optimizes the interface performance of all-solid-state batteries through the cooperation of a stepwise transfer process and a functionalized electrolyte. First, a halide electrolyte layer containing nano-α-Al2O3 and lithium salt additives is independently manufactured on a substrate (enhancing high-voltage stability and mechanical strength on the positive electrode side), and then transferred to the positive electrode sheet by rolling to form a tight interface. Next, a sulfide electrolyte layer containing nano-zirconia / polydopamine / hexagonal boron nitride is manufactured on another substrate (improving dendrite suppression and interface wettability on the negative electrode side), and then transferred to the negative electrode sheet to construct a self-adaptive interface. Finally, these are assembled into a two-layer electrolyte electrode, simultaneously achieving low interface impedance, high cycle stability, and high process reliability, thus overcoming the performance bottleneck of conventional single-electrolyte systems. [Brief explanation of the drawing]
[0061] [Figure 1] This is a flowchart of the two-layer electrolyte transfer manufacturing method for all-solid-state batteries with optimized positive and negative electrode interfaces, as provided by Examples 1 to 17 of the present invention. [Modes for carrying out the invention]
[0062] The technical proposals of the present invention will be described in detail below in conjunction with specific embodiments and accompanying drawings. The embodiments described herein are specific embodiments of the present invention and are intended to illustrate the concept of the present invention. All of these descriptions are interpretable and illustrative and should not be understood as limitations on the embodiments or scope of protection of the present invention. In addition to the embodiments described herein, those skilled in the art may further adopt other obvious technical proposals based on the claims and specifications of this application, including technical proposals obtained by obvious substitutions and modifications to the embodiments described herein.
[0063] Example 1 This embodiment provides a two-layer electrolyte transfer manufacturing method in which the positive and negative electrode interfaces of an all-solid-state battery are optimized, as shown in Figure 1. After mixing S1, Li3InCl6 (particle size D50: 5μm), nano-α-Al2O3, Li3YCl6 powder, Li2ZrCl6 powder, polyoxyethylene castor oil ester, polyisobutylene, and toluene, a halogenated electrolyte slurry was obtained in which the amount of nano-α-Al2O3 added was 3 wt% of the mass of Li3InCl6, the amount of Li3YCl6 powder added was 4 wt% of the mass of Li3InCl6, the amount of Li2ZrCl6 powder added was 3 wt% of the mass of Li3InCl6, the amount of polyoxyethylene castor oil ester added was 2 wt% of the mass of Li3InCl6, the amount of polyisobutylene added was 4 wt% of the mass of Li3InCl6, and the amount of toluene added was 60 wt% of the mass of Li3InCl6. A halogenated electrolyte slurry is applied to the surface of a PET substrate, dried at 100°C for 4 hours, and then a halogenated electrolyte layer with a thickness of 10 μm is formed to obtain a halogenated composite layer. S2, the positive electrode sheet and the halogen composite layer are laminated and aligned so that the halogen electrolyte layer is transferred to the positive electrode sheet surface, then rolled at 20 MPa and 90°C, the PET substrate is removed, and a composite positive electrode sheet is obtained. After mixing S3, Li6PS5I (particle size D50: 5μm), nanozirconia, polydopamine nanospheres, hexagonal boron nitride nanosheets, polyisobutylene, and toluene, a sulfide electrolyte slurry was obtained, in which the amount of nanozirconia added was 2 wt% of the mass of Li6PS5I, the amount of polydopamine nanospheres added was 0.3 wt% of the mass of Li6PS5I, the amount of hexagonal boron nitride nanosheets added was 0.8 wt% of the mass of Li6PS5I, the amount of polyisobutylene added was 5 wt% of the mass of Li6PS5I, and the amount of toluene added was 60 wt% of the mass of Li6PS5I. A sulfide electrolyte slurry is applied to the surface of another PET substrate, dried at 100°C for 2 hours, and then a sulfide electrolyte layer with a thickness of 15 μm is formed to obtain a sulfide composite layer. S4. After laminating and aligning the negative electrode sheet and the sulfide composite layer so as to transfer the sulfide electrolyte layer to the negative electrode sheet surface, the layers are rolled at 15 MPa and 90°C, the PET substrate is removed, and a composite negative electrode sheet is obtained. S5. The composite positive electrode sheet and composite negative electrode sheet are stacked, welded, and packaged to obtain an all-solid-state battery. This includes the following.
[0064] Example 2 This embodiment provides a two-layer electrolyte transfer manufacturing method in which the positive and negative electrode interfaces of an all-solid-state battery are optimized, as shown in Figure 1. After mixing S1, Li3InCl6 (particle size D50: 8μm), nano-α-Al2O3, Li3YCl6 powder, Li2ZrCl6 powder, polyoxyethylene castor oil ester, polyisobutylene, and toluene, a halogenated electrolyte slurry was obtained, in which the amount of nano-α-Al2O3 added was 3.2 wt% of the mass of Li3InCl6, the amount of Li3YCl6 powder added was 4.2 wt% of the mass of Li3InCl6, the amount of Li2ZrCl6 powder added was 3.2 wt% of the mass of Li3InCl6, the amount of polyoxyethylene castor oil ester added was 2.2 wt% of the mass of Li3InCl6, the amount of polyisobutylene added was 4.5 wt% of the mass of Li3InCl6, and the amount of toluene added was 65 wt% of the mass of Li3InCl6. A halogenated electrolyte slurry is applied to the surface of a PET substrate and dried at 102°C for 3.8 hours to form a halogenated electrolyte layer with a thickness of 10.5 μm, thereby obtaining a halogenated composite layer. S2, the positive electrode sheet and the halogen composite layer are laminated and aligned so that the halogen electrolyte layer is transferred to the positive electrode sheet surface, then rolled at 22 MPa and 88°C, the PET substrate is removed, and a composite positive electrode sheet is obtained. After mixing S3, Li6PS5Cl (particle size D50: 8μm), nanozirconia, polydopamine nanospheres, hexagonal boron nitride nanosheets, polyisobutylene, and toluene, a sulfide electrolyte slurry was obtained, in which the amount of nanozirconia added was 2.2 wt% of the mass of Li6PS5Cl, the amount of polydopamine nanospheres added was 0.35 wt% of the mass of Li6PS5Cl, the amount of hexagonal boron nitride nanosheets added was 0.9 wt% of the mass of Li6PS5Cl, the amount of polyisobutylene added was 6 wt% of the mass of Li6PS5Cl, and the amount of toluene added was 65 wt% of the mass of Li6PS5Cl. A sulfide electrolyte slurry is applied to the surface of another PET substrate, dried at 102°C for 1.8 hours, and then a sulfide electrolyte layer with a thickness of 16 μm is formed to obtain a sulfide composite layer. S4. After laminating and aligning the negative electrode sheet and the sulfide composite layer so as to transfer the sulfide electrolyte layer to the negative electrode sheet surface, the layers are rolled at 18 MPa and 88°C, the PET substrate is removed, and a composite negative electrode sheet is obtained. S5. The composite positive electrode sheet and composite negative electrode sheet are stacked, welded, and packaged to obtain an all-solid-state battery. This includes the following.
[0065] Example 3 This embodiment provides a two-layer electrolyte transfer manufacturing method in which the positive and negative electrode interfaces of an all-solid-state battery are optimized, as shown in Figure 1. After mixing S1, Li3YCl6 (particle size D50: 10 μm), nano-α-Al2O3, Li3YCl6 powder, Li2ZrCl6 powder, hydrogenated polybutadiene, styrene-butadiene rubber, and xylene, a halogenated electrolyte slurry was obtained, in which the amount of nano-α-Al2O3 added was 3.5 wt% of the mass of Li3YCl6, the amount of Li3YCl6 powder added was 4.5 wt% of the mass of Li3YCl6, the amount of Li2ZrCl6 powder added was 3.5 wt% of the mass of Li3YCl6, the amount of hydrogenated polybutadiene added was 2.5 wt% of the mass of Li3YCl6, the amount of styrene-butadiene rubber added was 5 wt% of the mass of Li3YCl6, and the amount of xylene added was 70 wt% of the mass of Li3YCl6. A halogenated electrolyte slurry is applied to the surface of a PET substrate, dried at 105°C for 3.5 hours, and then a halogenated electrolyte layer with a thickness of 11 μm is formed to obtain a halogenated composite layer. S2, the positive electrode sheet and the halogen composite are stacked and aligned so that the halogen electrolyte layer is transferred to the positive electrode sheet surface, then rolled at 25 MPa and 85°C, the PET substrate is removed, and a composite positive electrode sheet is obtained. S3, Li 10 GeP2S 12 (Particle size D50: 10 μm), nanozirconia, polydopamine nanospheres, hexagonal boron nitride nanosheets, styrene-butadiene rubber and xylene are mixed to obtain a sulfide electrolyte slurry, in which the amount of nanozirconia added is Li 10 GeP2S 12 The amount of polydopamine nanospheres added is 2.5 wt% of the mass, and Li 10 GeP2S 12 The amount of hexagonal boron nitride nanosheets added is 0.4 wt% of the mass, and Li 10 GeP2S 12 The amount of styrene-butadiene rubber added is 1 wt% of the mass of Li 10 GeP2S 12 It is 6 wt% of the mass, and the amount of xylene added is Li 10 GeP2S 12 It is 70 wt% of the mass, A sulfide electrolyte slurry is applied to the surface of another PET substrate and dried at 105°C for 1.5 hours to form a sulfide electrolyte layer with a thickness of 17 μm, thereby obtaining a sulfide composite layer. S4. After laminating and aligning the negative electrode sheet and the sulfide composite layer so as to transfer the sulfide electrolyte layer to the negative electrode sheet surface, the layers are rolled at 20 MPa and 85°C, the PET substrate is removed, and a composite negative electrode sheet is obtained. S5. The composite positive electrode sheet and composite negative electrode sheet are stacked, welded, and packaged to obtain an all-solid-state battery. This includes the following.
[0066] Example 4 This embodiment provides a two-layer electrolyte transfer manufacturing method in which the positive and negative electrode interfaces of an all-solid-state battery are optimized, as shown in Figure 1. After mixing S1, Li3YCl6 (particle size D50: 12 μm), nano α-Al2O3, Li3YCl6 powder, Li2ZrCl6 powder, hydrogenated polybutadiene, styrene-butadiene rubber, and xylene, a halogenated electrolyte slurry was obtained in which the amount of nano α-Al2O3 added was 3.8 wt% of the mass of Li3YCl6, the amount of Li3YCl6 powder added was 4.8 wt% of the mass of Li3YCl6, the amount of Li2ZrCl6 powder added was 3.8 wt% of the mass of Li3YCl6, the amount of hydrogenated polybutadiene added was 2.8 wt% of the mass of Li3YCl6, the amount of styrene-butadiene rubber added was 5.5 wt% of the mass of Li3YCl6, and the amount of xylene added was 75 wt% of the mass of Li3YCl6. A halogenated electrolyte slurry is applied to the surface of a PET substrate, dried at 108°C for 3.2 hours, and then a halogenated electrolyte layer with a thickness of 11.5 μm is formed to obtain a halogenated composite layer. S2, the positive electrode sheet and the halogen composite layer are laminated and aligned so that the halogen electrolyte layer is transferred to the positive electrode sheet surface, then rolled at 28 MPa and 82°C, the PET substrate is removed, and a composite positive electrode sheet is obtained. S3, Li 3.25 Ge 0.25 P 0.75 After mixing S4 (particle size D50: 12 μm), nanozirconia, polydopamine nanospheres, hexagonal boron nitride nanosheets, styrene-butadiene rubber, and xylene, a sulfide electrolyte slurry was obtained, in which the amount of nanozirconia added was Li 3.25 Ge 0.25 P 0.75 The amount of polydopamine nanospheres added is 2.8 wt% of the mass of S4, and Li 3.25 Ge 0.25 P 0.75 The amount of S4 is 0.45 wt%, and the amount of hexagonal boron nitride nanosheets added is Li 3.25 Ge 0.25 P 0.75 The amount of S4 is 1.1 wt%, and the amount of styrene-butadiene rubber added is Li3.25 Ge 0.25 P 0.75 The amount of xylene added is 7 wt% of the mass of S4, and the amount of xylene added is Li 3.25 Ge 0.25 P 0.75 It is 75 wt% of the mass of S4. A sulfide electrolyte slurry is applied to the surface of another PET substrate and dried at 108°C for 1.2 hours to form a sulfide electrolyte layer with a thickness of 17 μm, thereby obtaining a sulfide composite layer. S4. After laminating and aligning the negative electrode sheet and the sulfide composite layer so as to transfer the sulfide electrolyte layer to the negative electrode sheet surface, the layers are rolled at 22 MPa and 82°C, the PET substrate is removed, and a composite negative electrode sheet is obtained. S5. The composite positive electrode sheet and composite negative electrode sheet are stacked, welded, and packaged to obtain an all-solid-state battery. This includes the following.
[0067] Example 5 This embodiment provides a two-layer electrolyte transfer manufacturing method in which the positive and negative electrode interfaces of an all-solid-state battery are optimized, as shown in Figure 1. After mixing S1, Li4YI7 (particle size D50: 15 μm), nano-α-Al2O3, Li3YCl6 powder, Li2ZrCl6 powder, hydrogenated polybutadiene, styrene-butadiene rubber, and dibutyl ether, a halogenated electrolyte slurry was obtained, in which the amount of nano-α-Al2O3 added was 4 wt% of the mass of Li4YI7, the amount of Li3YCl6 powder added was 5 wt% of the mass of Li4YI7, the amount of Li2ZrCl6 powder added was 4 wt% of the mass of Li4YI7, the amount of hydrogenated polybutadiene added was 3 wt% of the mass of Li4YI7, the amount of styrene-butadiene rubber added was 6 wt% of the mass of Li4YI7, and the amount of dibutyl ether added was 80 wt% of the mass of Li4YI7. A halogenated electrolyte slurry is applied to the surface of a PET substrate, dried at 110°C for 3 hours, and then a halogenated electrolyte layer with a thickness of 12 μm is formed to obtain a halogenated composite layer. S2. The positive electrode sheet and the halogen composite layer are laminated and aligned so that the halogen electrolyte layer is transferred to the positive electrode sheet surface, then rolled at 30 MPa and 80°C to remove the PET substrate and obtain a composite positive electrode sheet. S3, Li7P3S 11 (Particle size D50: 15 μm), nanozirconia, polydopamine nanospheres, hexagonal boron nitride nanosheets, styrene-butadiene rubber, and dibutyl ether are mixed to obtain a sulfide electrolyte slurry, in which the amount of nanozirconia added is Li7P3S 11 The amount of polydopamine nanospheres added is 3 wt% of the mass, and Li7P3S 11 The amount of hexagonal boron nitride nanosheets added is 0.5 wt% of the mass, and Li7P3S 11 The amount of styrene-butadiene rubber added is 1.2 wt% of the mass, and Li7P3S 11 The amount of dibutyl ether added is 8 wt% of the mass, and Li7P3S 11 It is 80 wt% of the mass, A sulfide electrolyte slurry is applied to the surface of another PET substrate, dried at 110°C for 1 hour, and then a sulfide electrolyte layer with a thickness of 18 μm is formed to obtain a sulfide composite layer. S4. After laminating and aligning the negative electrode sheet and the sulfide composite layer so as to transfer the sulfide electrolyte layer to the negative electrode sheet surface, the layers are rolled at 25 MPa and 80°C, the PET substrate is removed, and a composite negative electrode sheet is obtained. S5. The composite positive electrode sheet and composite negative electrode sheet are stacked, welded, and packaged to obtain an all-solid-state battery. This includes the following.
[0068] Example 6 This embodiment provides a two-layer electrolyte transfer manufacturing method with optimized positive and negative electrode interfaces for all-solid-state batteries. The difference from Example 1 is that the amount of nano-α-Al2O3 added was adjusted to 2 wt% of the mass of the halide electrolyte, while other process parameters and operating steps are exactly the same as in Example 1.
[0069] Example 7 This embodiment provides a two-layer electrolyte transfer manufacturing method with optimized positive and negative electrode interfaces for all-solid-state batteries. The difference from Example 1 is that the amount of nano-α-Al2O3 added was adjusted to 5 wt% of the mass of the halide electrolyte, while other process parameters and operating steps are exactly the same as in Example 1.
[0070] Example 8 This embodiment provides a two-layer electrolyte transfer manufacturing method with optimized positive and negative electrode interfaces for all-solid-state batteries. The difference from Example 1 is that the amount of Li3YCl6 powder added was adjusted to 3 wt% of the mass of the halide electrolyte, while other process parameters and operating steps are exactly the same as in Example 1.
[0071] Example 9 This embodiment provides a two-layer electrolyte transfer manufacturing method with optimized positive and negative electrode interfaces for all-solid-state batteries. The difference from Example 1 is that the amount of Li3YCl6 powder added was adjusted to 6 wt% of the mass of the halide electrolyte, while other process parameters and operating steps are exactly the same as in Example 1.
[0072] Example 10 This embodiment provides a two-layer electrolyte transfer manufacturing method with optimized positive and negative electrode interfaces for all-solid-state batteries. The difference from Example 1 is that the amount of Li2ZrCl6 powder added was adjusted to 2 wt% of the mass of the halide electrolyte, while all other process parameters and operating steps are exactly the same as in Example 1.
[0073] Example 11 This embodiment provides a two-layer electrolyte transfer manufacturing method with optimized positive and negative electrode interfaces for all-solid-state batteries. The difference from Example 1 is that the amount of Li2ZrCl6 powder added was adjusted to 5 wt% of the mass of the halide electrolyte, while all other process parameters and operating steps are exactly the same as in Example 1.
[0074] Example 12 This embodiment provides a two-layer electrolyte transfer manufacturing method with optimized positive and negative electrode interfaces for all-solid-state batteries, distinguishing it from Example 1 by adjusting the amount of nanozirconia added to 1 wt% of the mass of the sulfide electrolyte, while other process parameters and operating steps are exactly the same as in Example 1.
[0075] Example 13 This embodiment provides a two-layer electrolyte transfer manufacturing method with optimized positive and negative electrode interfaces for all-solid-state batteries, distinguishing it from Example 1 by adjusting the amount of nanozirconia added to 4 wt% of the mass of the sulfide electrolyte, while other process parameters and operating steps are exactly the same as in Example 1.
[0076] Example 14 This embodiment provides a two-layer electrolyte transfer manufacturing method with optimized positive and negative electrode interfaces for all-solid-state batteries, distinguishing it from Example 1 by adjusting the amount of polydopamine nanospheres added to 0.1 wt% of the mass of the sulfide electrolyte, while other process parameters and operating steps are exactly the same as in Example 1.
[0077] Example 15 This embodiment provides a two-layer electrolyte transfer manufacturing method with optimized positive and negative electrode interfaces for all-solid-state batteries, distinguishing it from Example 1 by adjusting the amount of polydopamine nanospheres added to 0.8 wt% of the mass of the sulfide electrolyte, while other process parameters and operating steps are exactly the same as in Example 1.
[0078] Example 16 This embodiment provides a two-layer electrolyte transfer manufacturing method with optimized positive and negative electrode interfaces for all-solid-state batteries. The difference from Example 1 is that the amount of hexagonal boron nitride nanosheets added was adjusted to 0.5 wt% of the mass of the sulfide electrolyte, while all other process parameters and operating steps are exactly the same as in Example 1.
[0079] Example 17 This embodiment provides a two-layer electrolyte transfer manufacturing method with optimized positive and negative electrode interfaces for all-solid-state batteries, distinguishing it from Example 1 by adjusting the amount of hexagonal boron nitride nanosheets added to 1.5 wt% of the mass of the sulfide electrolyte, while other process parameters and operating steps are exactly the same as in Example 1.
[0080] The interfacial contact impedance, critical current density, and 200-cycle capacity retention rate of the all-solid-state batteries manufactured in Examples 1 to 17 were measured, and the specific measurement steps are as follows.
[0081] (1) Interfacial contact impedance A composite positive electrode sheet and stainless steel blocking electrodes were assembled into an asymmetric battery, and the impedance spectrum (0.1Hz~1MHz) was measured at the open-circuit voltage. The normalized interface impedance value was obtained by semicircular EIS fitting in the intermediate frequency region.
[0082] (2)Critical current density The sulfide composite layer (including the PET substrate) manufactured in step S3 is rolled and transferred onto the original lithium metal sheet, the PET substrate is removed to obtain a single interface sample, and two of these samples (with the interface facing inward) are stacked and assembled into a symmetrical battery (structure: Li|sulfide layer|Li).
[0083] 0.1 mA / cm 2 The current density is gradually increased in steps of a certain size (each step lasting 10 minutes), and the current density value is monitored and measured during a sharp voltage drop (>0.5V).
[0084] (3) Capacity retention rate after 200 cycles Assemble the entire battery (composite positive electrode sheet | composite negative electrode sheet), perform 200 charge-discharge cycles at 25°C and a rate of 0.5C, and calculate the percentage ratio of the discharge capacity after the 200th cycle to the discharge capacity after the 5th cycle.
[0085] The measurement results are shown in Table 1. [Table 1] As can be seen from the measurement data of Examples 1, 6, and 7, changes in the amount of nano-α-Al2O3 added significantly affect the performance of the halide electrolyte layer. When the amount of nano-α-Al2O3 added was reduced to 2 wt% (Example 6), the insufficient density of nano-α-Al2O3 in the substrate weakened the mechanical strengthening effect, reducing the composite layer's ability to resist stress. This caused minute cracks to form when the positive electrode active material cyclically expanded and contracted, resulting in an interfacial contact impedance of 35.2 Ω·cm. 2 This increases the critical current density to 0.85 mA / cm². 2 This reduced the interfacial contact points, and simultaneously, the cycle capacity retention rate decreased to 84.5%. When the amount of nano-α-Al2O3 added was increased to 5 wt% (Example 7), the excess nano-α-Al2O3 severely fragmented the continuous phase of the halide electrolyte, significantly increasing the lithium ion migration resistance, drastically reducing the ionic conductivity of the bulk phase, causing the nanoparticles to aggregate and form localized defects, resulting in a critical current density of 0.72 mA / cm². 2 This reduction, along with the increase in bulk phase impedance during the cycle process, reduced the capacitance retention rate to 79.2%.
[0086] As can be seen from the measurement data of Examples 1, 8, and 9, when the amount of Li3YCl6 powder added was reduced to 3 wt% (Example 8), the powder could not sufficiently cover the grain boundary region, the gaps at the grain boundaries were not sufficiently filled, activation could not be achieved, the interfacial activation effect weakened, and the interfacial impedance became 38.5 Ω·cm. 2 By increasing the amount, the cycle capacity retention rate was reduced to 83.1%. When the amount of Li3YCl6 powder added was increased to 6 wt% (Example 9), the excess powder disrupted the continuous conduction pathway of the main electrolyte, and the high degree of bending during transport reduced the bulk phase ion conductivity. Heterogeneous regions formed by partial aggregation further impaired the homogeneity of the thin film, resulting in an impedance of 52.3 Ω·cm. 2 This was increased, reducing the capacity retention rate to 76.8%.
[0087] As can be seen from the measurement data of Examples 1, 10, and 11, when the amount of Li2ZrCl6 powder added was reduced to 2 wt% (Example 10), the powder did not adequately modify the very important contact area, resulting in insufficient formation of an interfacially stable lithium conductive phase and an interfacial impedance of 36.8 Ω·cm. 2 The amount of Li2ZrCl6 powder added was increased to 5 wt% (Example 11), which disrupted the ion conduction network of the main electrolyte. The concentrated areas of excess powder became an obstacle to movement, forming heterogeneous regions and raising the impedance to 47.2 Ω·cm. 2 This was increased, reducing the capacity retention rate to 78.5%.
[0088] As can be seen from the measurement data of Examples 1, 12, and 13, adjusting the amount of nanozirconia added affects the inhibitory force on dendrites in the sulfide layer. When the amount of nanozirconia added was reduced to 1 wt% (Example 12), the spatial isolation network of zirconia was destroyed, and dendrites grew more easily vertically in sparse areas, with an interfacial impedance of 34.1 Ω·cm. 2 The concentration increased to 0.65 mA / cm². When the amount of nanozirconia added was increased to 4 wt% (Example 13), it caused severe aggregation, with micron clusters blocking ion pathways, and structural defects simultaneously raising the critical current density to 0.65 mA / cm². 2 This reduced the volume retention rate to 73.9%.
[0089] As can be seen from the measurement data of Examples 1, 14, and 15, changes in the amount of polydopamine nanospheres added directly affect interfacial wettability. When the amount of polydopamine nanospheres added was reduced to 0.1 wt% (Example 14), the coverage of the parent lithium site became insufficient, and the non-uniform deposition of lithium ions caused interfacial fracture, resulting in a critical current density of 0.78 mA / cm². 2 The amount was reduced to 0.8 wt%, and the capacity retention rate was reduced to 80.5%. When the amount of polydopamine nanospheres added was increased to 0.8 wt% (Example 15), the nanospheres aggregated and formed transport obstructions, and the clustered areas became weaker parts of the interface, reducing the capacity retention rate to 75.2%.
[0090] As can be seen from the measurement data of Examples 1, 16, and 17, when the amount of hexagonal boron nitride nanosheets added was reduced to 0.5 wt% (Example 16), the distribution density of the sheet layer became insufficient, the ability to deflect dendrites weakened, and the critical current density was 0.79 mA / cm². 2 The impedance decreases to 31.5 Ω·cm², and the interface impedance is 31.5 Ω·cm². 2 The impedance decreased to 49.2 Ω·cm. When the amount of hexagonal boron nitride nanosheets added was increased to 1.5 wt% (Example 17), it caused the sheet layer to stack, blocking the lithium ion pathway and reducing the impedance to 49.2 Ω·cm. 2 This was increased to 0.61 mA / cm². At the same time, crack sources were formed during application, and the critical current density was increased to 0.61 mA / cm². 2 This was reduced, lowering the capacity retention rate to 74.3%.
[0091] The applicant argues that the above is merely a specific embodiment of the present invention, and the scope of protection of the present invention is not limited thereto, and that changes or substitutions that are easily conceivable by those skilled in the art within the scope of the art disclosed herein are included in the scope of protection and disclosure of the present invention.
Claims
1. S1, halide electrolyte, nano-α-Al ２ O ３ Li ３ YCl ６ Powder, Li ２ ZrCl ６ A halogenated electrolyte slurry is obtained by mixing powder, a rheology modifier, a first binder, and a first organic solvent. The halogenated electrolyte slurry is then applied to the surface of a substrate, dried, and a halogenated electrolyte layer is formed to obtain a halogenated composite layer. S2. The positive electrode sheet and the halogen composite layer are laminated and aligned so as to transfer the halogen electrolyte layer to the surface of the positive electrode sheet, then rolled, the substrate is removed, and a composite positive electrode sheet is obtained. After mixing S3, sulfide electrolyte, nanozirconia, polydopamine nanospheres, hexagonal boron nitride nanosheets, a second binder, and a second organic solvent, a sulfide electrolyte slurry is obtained. The sulfide electrolyte slurry is then applied to the surface of another substrate, dried, and a sulfide electrolyte layer is formed to obtain a sulfide composite layer. S4. The negative electrode sheet and the sulfide composite layer are laminated and aligned so as to transfer the sulfide electrolyte layer to the surface of the negative electrode sheet, then rolled, the base material is removed, and a composite negative electrode sheet is obtained. S5. The composite positive electrode sheet and the composite negative electrode sheet are stacked, welded, and packaged to obtain an all-solid-state battery. Including that, In step S1, the halide electrolyte contains Li ３ InCl ６ , Li ３ YCl ６ or Li ４ YI ７ and includes any one kind or a combination of at least two kinds thereof. The particle size D50 of the halogenated electrolyte is 5 to 15 μm. The aforementioned nano-α-Al ２ O ３ The amount added is 3 to 4 wt% of the mass of the halogenated electrolyte. The Li ３ YCl ６ The amount of powder added is 4 to 5 wt% of the mass of the halogenated electrolyte. The Li ２ ZrCl ６ The amount of powder added is 3 to 4 wt% of the mass of the halogenated electrolyte. The rheological modifier comprises polyoxyethylene castor oil ester and / or hydrogenated polybutadiene, The rheological modifier is 2 to 3 wt% of the mass of the halogenated electrolyte. In step S3, the sulfide electrolyte is Li １０ GeP ２ S １２ or Li ７ P ３ S １１ including, The particle size D50 of the sulfide electrolyte is 5 to 15 μm. The amount of nanozirconia added is 2-3 wt% of the mass of the sulfide electrolyte. The amount of polydopamine nanospheres added is 0.3 to 0.5 wt% of the mass of the sulfide electrolyte. The amount of hexagonal boron nitride nanosheets added is 0.8 to 1.2 wt% of the mass of the sulfide electrolyte. A method for manufacturing a two-layer electrolyte in which the positive and negative electrode interfaces of an all-solid-state battery are optimized.
2. In step S1, the first binder comprises polyisobutylene and / or styrene-butadiene rubber, The amount of the first binder added is 4 to 6 wt% of the mass of the halide electrolyte. The first organic solvent comprises one or at least two of toluene, xylene, or dibutyl ether, The amount of the first organic solvent added is 60 to 80 wt% of the mass of the halogenated electrolyte. The manufacturing method according to claim 1, characterized in that it
3. In step S1, the material of the base material is PET, The drying temperature is 100 to 110°C. The drying time is 3 to 4 hours. The thickness of the halogenated electrolyte layer is 10 to 12 μm. The manufacturing method according to claim 1, characterized in that it
4. The manufacturing method according to claim 1, characterized in that in step S2, the rolling pressure is 20 to 30 MPa and the rolling temperature is 80 to 90°C.
5. In step S3, the second binder comprises polyisobutylene and / or styrene-butadiene rubber, The amount of the second binder added is 5 to 8 wt% of the mass of the sulfide electrolyte. The second organic solvent comprises one or at least two of toluene, xylene, or dibutyl ether, The amount of the first organic solvent added is 60 to 80 wt% of the mass of the sulfide electrolyte. The manufacturing method according to claim 1, characterized in that it
6. In step S3, the material of the base material is PET, The drying temperature is 100 to 110°C. The drying time is 1 to 2 hours. The thickness of the sulfide electrolyte layer is 15 to 18 μm. The manufacturing method according to claim 1, characterized in that it
7. The manufacturing method according to claim 1, characterized in that in step S4, the rolling pressure is 15 to 25 MPa and the rolling temperature is 80 to 90°C.