Doping enhanced dot matrix sandwich layer composite material structure all-solid-state battery and preparation method thereof

Abstract

The invention belongs to the technical field of composite material structure batteries, and discloses a doped enhanced dot matrix sandwich layer composite material structure all-solid-state battery and a preparation method thereof. According to the structural battery disclosed by the invention, the lattice supporting core layer in the structural battery is highly fused with the battery functional layer, and the doped modified material is integrated in the supporting column structure in advance, so that the weight of a supporting framework does not need to be additionally increased, and meanwhile, electrical isolation between electrode layers is ensured. Due to the adoption of an all-solid-state system, leakage or material displacement cannot occur when the battery is subjected to certain pressure and temperature in the forming process, and a stable solid-solid interface is jointly formed by the battery and the supporting column after curing. Therefore, the structural battery disclosed by the invention has excellent mechanical properties and electrochemical properties, can be applied to new energy automobiles, aerospace, unmanned aerial vehicles, portable equipment, ocean exploration and the like, can be used for remarkably reducing the system weight and improving the electrical property and structural efficiency, and has important practical significance and application value.

Description

Technical Field

[0001] This invention relates to the field of composite material structure battery technology, and in particular to a doped reinforced lattice sandwich composite material structure all-solid-state battery and its preparation method. Background Technology

[0002] With the development of new energy and high-performance equipment, structural batteries, as a technology integrating electrochemical energy storage and load-bearing structure, have attracted widespread attention. Structural batteries aim to enable batteries not only to store energy but also to serve as load-bearing components, thereby reducing the overall system weight and improving space utilization efficiency. In aerospace, new energy vehicles, and drones, structural batteries hold the promise of transforming the weight originally used for battery boxes and supporting structures into useful energy storage components, achieving a structural design with "zero weight increase."

[0003] In existing structural battery solutions, a typical design integrates the battery within a composite sandwich panel. For example, a lightweight, high-strength lattice sandwich core material is placed between an upper and lower skin layer, with electrochemical energy storage units (battery material layers) embedded in the gaps between the core materials. Carbon fiber or aramid fiber composite materials are used as the skin, and lattice sandwich pillars penetrate the positive electrode, solid electrolyte, and negative electrode layers, achieving a combination of load-bearing capacity and energy storage function. This structural battery utilizes the higher specific stiffness / specific strength of lattice materials compared to honeycomb or foam materials to provide internal support, enabling the battery module to withstand certain mechanical loads. Compared to the traditional separate "battery + structure" design, the above-mentioned structural battery has significant advantages in weight reduction and structural stability.

[0004] However, the structural efficiency of existing structural batteries remains insufficient. On the one hand, to balance electrical and mechanical performance, current structural batteries often compromise on material selection: for example, the carbon fiber support used as the core material requires an additional insulating layer to prevent short circuits, increasing manufacturing complexity; and carbon fiber itself is conductive, posing a risk of micro-short circuits inside the battery. Even when using electrically insulating fibers such as aramid, the mechanical strength is relatively low. Overall, reported structural batteries have only achieved about 60% in terms of structural stiffness and strength efficiency, leaving room for improvement in mechanical performance. On the other hand, most existing structural batteries use liquid or gel electrolytes, posing leakage and safety risks, and requiring bulky encapsulation, limiting their application in vehicles and aerospace. All-solid-state batteries, lacking easily leaking electrolytes, possess high safety and high energy density, theoretically making them more suitable for structural batteries; however, the technology for introducing all-solid-state systems into structural batteries is still immature. Furthermore, existing structural battery cells are mostly arranged in a regular symmetrical lattice pattern, without any optimized design for the different stresses in different parts. For example, asymmetric lattice or gradient density support structures could further improve the efficiency of structural batteries under complex load conditions, but no related technologies have been proposed yet.

[0005] In summary, existing battery structures suffer from insufficient mechanical strength, inadequate insulation safety and energy density, and suboptimal structural design, failing to fully meet the high demands of applications such as new energy vehicles and spacecraft. To address these technical challenges, it is necessary to develop a battery structure that, while retaining the advantages of the original lattice sandwich layer embedded energy storage layer structure, achieves comprehensive performance improvements through doping to enhance the core material, employing an all-solid-state electrolyte system, and utilizing innovative lattice configurations. Summary of the Invention

[0006] The purpose of this invention is to provide a doped reinforced lattice sandwich composite material structure all-solid-state battery and its preparation method, which solves the problems of existing battery structures in terms of mechanical performance, insulation safety and electrochemical performance, so as to achieve an organic combination of structural load-bearing and efficient energy storage, significantly improve structural efficiency, safety and energy density, and meet the application needs of multiple fields.

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a doped reinforced lattice sandwich composite material structure all-solid-state battery, including an upper skin layer and a lower skin layer, and a lattice sandwich layer and an electrochemical energy storage layer disposed between the upper skin layer and the lower skin layer; the lattice sandwich layer is embedded in the electrochemical energy storage layer and has a load-bearing capacity perpendicular to the direction of the upper skin layer, and the lattice sandwich layer contains doped reinforcing materials; the electrochemical energy storage layer is one or more interconnected all-solid-state systems, and a single all-solid-state system includes a positive electrode layer, a solid electrolyte layer and a negative electrode layer stacked sequentially; The doped reinforcing material includes one or more of the following: conductive carbon black, carbon nanotubes, nitrogen-doped graphene, boron-doped carbon nanotubes, aramid fibers, functionalized aramid fibers, and composite ceramic particles.

[0008] Furthermore, in the all-solid-state battery structure, the lattice sandwich layer includes a plurality of support units arranged in a lattice pattern along the plane. The support unit is a solid or hollow rod, and the cross-section of the support unit is circular, polygonal, or arbitrary curved. The support unit includes a support body and an insulating layer covering the surface of the support body.

[0009] Furthermore, in the all-solid-state battery structure, the support units are arranged in a lattice pattern with equal spacing and equal size. Alternatively, the support units may be arranged in a lattice pattern with partitioned distribution and / or varying sizes. The partitioning is as follows: Using the long side of the lattice sandwich layer as the x-axis and the wide side as the y-axis, the total length L and total width W of the lattice sandwich layer are determined. The lattice sandwich layer is divided into a central region and an edge region. The central region satisfies 0.3L ≤ x ≤ 0.7L and 0.3W ≤ y ≤ 0.7W. The edge region is the area excluding the central region. The spacing p1 of the support units in the central region is 10~25mm, and the spacing p2 of the support units in the edge region is 25~50mm, and p1... <p2; The dimensions of the support unit vary as follows: the diameter d of the support unit is calculated using formula 1: Formula 1; In formula 1, d (r) is the diameter of the support element when the distance between the geometric center of the support element and the intersection of the diagonals of the lattice sandwich layer is r. d min The minimum diameter of all support units. d max The maximum diameter of all support units. r The distance is the intersection of the geometric center of the support unit and the diagonal of the lattice sandwich layer. R It is half the diagonal length of the lattice sandwich layer. k It is a constant whose value ranges from 1 to 3.

[0010] Furthermore, in the all-solid-state battery structure, the raw materials for preparing the pillar body include a mixture of matrix resin and doped reinforcing material; The matrix resin includes thermosetting resin or thermoplastic resin; The mass ratio of the doped reinforcing material to the main body of the support is 0.001 to 0.1:1.

[0011] Furthermore, in the all-solid-state battery structure, the upper skin layer or the lower skin layer includes one or more of the following: carbon fiber reinforced resin composite board, aramid fiber reinforced resin composite board, glass fiber reinforced resin composite board, basalt fiber reinforced resin composite board, polylactic acid plastic board, nylon plastic board, ABS plastic board, and alloy board. The thickness of the upper skin layer or the lower skin layer is independently 0.1~5mm.

[0012] Furthermore, in the all-solid-state battery structure, the solid electrolyte in the solid electrolyte layer includes one or more of oxide solid electrolyte, sulfide solid electrolyte, and polymer solid electrolyte; The positive electrode active material in the positive electrode layer is a lithium-based positive electrode active material with a specific capacity ≥230mAh / g; the thickness of the positive electrode layer is 10~200μm, and the areal density of the positive electrode active material in the positive electrode layer is 5~20mg / cm³.2 ; The negative electrode active material of the negative electrode layer has an initial specific capacity of 800~1500mAh / g, the thickness of the negative electrode layer is 50~300μm, and the areal density of the negative electrode active material of the negative electrode layer is 3~15mg / cm³. 2 .

[0013] Furthermore, in the all-solid-state battery structure, a positive electrode lead is provided on the positive electrode layer; The negative electrode layer is provided with a negative electrode lead wire.

[0014] Furthermore, in the all-solid-state battery structure, one side of the upper skin layer contact lattice sandwich layer also includes an upper current collector layer; One side of the lower skin layer contact lattice sandwich layer also includes a lower current collector layer; The positive electrode lead is electrically connected to the upper current collector layer; The negative electrode lead is electrically connected to the lower current collector layer.

[0015] Furthermore, in the all-solid-state battery structure, the lattice sandwich layer and the electrochemical energy storage layer are bonded together by a curing adhesive or co-curing molding method; The upper skin layer, the lower skin layer, and the lattice sandwich layer are fixedly connected.

[0016] This invention also provides a method for preparing an all-solid-state battery with a doped reinforced lattice sandwich composite material structure, comprising the following steps: The matrix resin is mixed with the doped reinforcing material to obtain the modified composite material; several pillar units are prepared using the modified composite material. A positive electrode, a solid electrolyte layer, and a negative electrode are prepared separately and stacked sequentially to obtain an all-solid-state battery blank. Several through holes are machined through the all-solid-state battery layer blank. The support units are inserted into the through holes according to the lattice arrangement, so that the lattice sandwich layer is inserted into the electrochemical energy storage layer. The lower skin layer covers one side of the all-solid-state battery blank with the dot matrix sandwich layer, and the upper skin layer covers the other side. The upper skin layer, lattice sandwich layer, electrochemical energy storage layer and lower skin layer are solidified to obtain a structurally all-solid-state battery.

[0017] As can be seen from the above technical solution, compared with the prior art, the present invention has the following beneficial effects: (1) Significantly enhanced mechanical properties: By doping the lattice core material with high-strength nanophases such as graphene and carbon nanotubes, and introducing ceramic microparticles and functional fibers, the tensile / compressive strength and modulus of the pillar composite material are greatly improved, which can increase the load-bearing capacity of the overall structure battery by 20-100%. At the same time, the doping modification improves the electrical insulation performance of the core material, and can form an interruption or coating effect on the surface of each pillar, thereby effectively preventing the risk of internal short circuit. This design, which takes into account both mechanical enhancement and insulation optimization, ensures that the internal cells of the structure battery are not damaged when subjected to vibration and impact loads, making it safe and reliable.

[0018] (2) Improved Electrical Performance and Energy Density: This invention employs a combination of high-capacity lithium-rich manganese-based cathode and silicon-carbon anode, supplemented by a solid electrolyte with high ionic conductivity, enabling the specific capacity and energy density of the battery cells to reach or exceed the levels of traditional liquid lithium batteries (mass specific energy can reach the range of 200~300Wh / kg). Although the internal lattice support structure occupies a certain volume, the overall system-level specific energy is actually improved by using higher energy density active materials and eliminating the heavy metal battery casing. For example, in automotive applications, since the battery also serves as a structural component, a separate battery box and bracket are no longer needed, increasing the energy density of the entire vehicle battery system by approximately 10~20%. In addition, the all-solid electrolyte improves the battery's cycle life and safety, and its high flame retardancy and leak-proof characteristics allow it to withstand a wider operating temperature range and more severe environments, meeting the electrical performance requirements of complex application scenarios.

[0019] (3) Weight Reduction and Improved Structural Efficiency: The integrated design of the structural battery significantly reduces the additional structural weight. This invention replaces traditional aluminum shells and steel frames with a lattice core layer for load bearing, achieving a weight reduction of 10-30% for the entire component (depending on the specific application). Simultaneously, due to the optimized material utilization achieved through asymmetric / gradient arrangement, the structural efficiency (i.e., stiffness and strength per unit weight) of the structural battery in this invention is at least 20% higher than existing structural batteries, achieving higher structural stiffness and strength efficiency. This means that less material is required to meet the same load requirements, or that a greater load can be sustained at the same weight.

[0020] (4) Multifunctional Integration and Space Utilization: This invention embeds energy storage components into the load-bearing structure to achieve functional integration and maximize the utilization of limited space. In systems such as new energy vehicles and aerospace vehicles, structural batteries can replace some of the original load-bearing components, achieving dual-purpose functionality. For example, automotive body panels serve as both body structures and battery modules; satellite structural panels serve as both load-bearing skins and energy storage. This integration makes the system design more compact, helps reduce system complexity and assembly processes, and improves reliability (because fewer components mean fewer points of failure).

[0021] (5) Advantages of Customization: The structural battery provided by this invention can be customized for different application fields through modular design of materials and structural configuration. In various embodiments, this invention demonstrates that in fields such as new energy vehicles, aerospace, drones, portable electronic devices, and marine exploration, the optimal balance between weight, electrical performance, and mechanical performance can be achieved by adjusting the lattice structure parameters, material combinations, and manufacturing processes, exhibiting comprehensive performance advantages that are difficult for traditional batteries to match. Therefore, this invention has broad application prospects and significant socio-economic value.

[0022] In summary, this invention achieves a significant performance leap in all-solid-state batteries with integrated structural support through a series of improvements in structure, electrochemical materials, and processes. It greatly improves energy density and structural efficiency while ensuring safety, and has important practical significance. Detailed Implementation

[0023] It should be understood that the terms "first," "second," "upper," and "lower," etc., used in this specification are for descriptive purposes only, to distinguish different components, and should not be construed as indicating or implying relative importance, quantity, or absolute location. Terms such as "include" or "contain" are intended to indicate the presence of that feature, step, or component, but do not exclude the presence or addition of one or more other features, steps, components, or combinations thereof.

[0024] This invention provides a doped reinforced lattice sandwich composite material structure all-solid-state battery, including an upper skin layer and a lower skin layer, and a lattice sandwich layer and an electrochemical energy storage layer disposed between the upper skin layer and the lower skin layer; the lattice sandwich layer is embedded in the electrochemical energy storage layer and has a load-bearing capacity perpendicular to the direction of the upper skin layer, and the lattice sandwich layer contains doped reinforcing materials; the electrochemical energy storage layer is one or more interconnected all-solid-state systems, and a single all-solid-state system includes a positive electrode layer, a solid electrolyte layer and a negative electrode layer stacked sequentially; The doped reinforcing material includes one or more of the following: conductive carbon black, carbon nanotubes, nitrogen-doped graphene, boron-doped carbon nanotubes, aramid fibers, functionalized aramid fibers, and composite ceramic particles.

[0025] In this invention, the upper or lower skin layer preferably comprises one or more of the following: carbon fiber reinforced resin composite board, aramid fiber reinforced resin composite board, glass fiber reinforced resin composite board, basalt fiber reinforced resin composite board, polylactic acid plastic board, nylon plastic board, ABS plastic board, and alloy board. The material of the skin layer is not limited; it can be selected according to requirements. The function of the upper and lower skin layers is to provide in-plane stiffness and protect the internal battery cell.

[0026] In this invention, the thickness of the upper skin layer or the lower skin layer is preferably 0.1~5mm, more preferably 0.5~3mm, and even more preferably 1~2mm. The purpose of limiting the thickness of the upper and lower skin layers is to balance load-bearing capacity and lightweight design.

[0027] In this invention, the lattice sandwich layer preferably includes a plurality of support units arranged in a lattice pattern along the plane.

[0028] In this invention, the support unit is preferably a solid or hollow rod.

[0029] In this invention, the cross-section of the support unit is preferably circular, polygonal, or any curved shape.

[0030] In this invention, the support unit preferably includes a support body and an insulating layer covering the surface of the support body. When the support body is an insulator, the insulating layer can be omitted. The insulating layer is not limited; any insulating material and thickness well-known to those skilled in the art can be used.

[0031] In this invention, the support unit is either a vertically continuous column or a three-dimensional truss structure formed by interlacing at angles in a spatial lattice pattern.

[0032] In this invention, the support unit is arranged in a dot matrix with equidistant and equal-sized distribution; Alternatively, the support units may be arranged in a lattice pattern with partitioned distribution and / or varying sizes.

[0033] In this invention, the partitioning distribution is as follows: taking the long side of the lattice sandwich layer as the x-axis and the wide side as the y-axis, the total length of the lattice sandwich layer is determined to be L and the total width to be W. The lattice sandwich layer is then divided into a central region and an edge region. The central region satisfies 0.3L≤x≤0.7L and 0.3W≤y≤0.7W, while the edge region is the area excluding the central region. The spacing p1 of the support units in the central region is preferably 10~25mm, more preferably 15~25mm, and even more preferably 20mm. The spacing p2 of the support units in the edge region is preferably 25~50mm, more preferably 35~45mm, and even more preferably 40mm. <p2。

[0034] In this invention, the dimensions of the support unit vary as follows: the diameter d of the support unit is calculated with reference to Formula 1: Formula 1; In formula 1, d (r) is the diameter of the support element when the distance between the geometric center of the support element and the intersection of the diagonals of the lattice sandwich layer is r. d minThe minimum diameter of all support units. d max The maximum diameter of all support units. r The distance is the intersection of the geometric center of the support unit and the diagonal of the lattice sandwich layer. R It is half the diagonal length of the lattice sandwich layer. k It is a constant whose value ranges from 1 to 3.

[0035] In this invention, the raw materials for preparing the support body preferably include a mixture of matrix resin and doped reinforcing material.

[0036] In this invention, the matrix resin preferably includes a thermosetting resin or a thermoplastic resin. The type of thermosetting or thermoplastic resin is not limited, and any resin well-known to those skilled in the art can be used. For example, thermosetting resins include, but are not limited to, epoxy resins, phenolic resins, unsaturated polyesters and their composites, and thermoplastic resins include, but are not limited to, PEEK, PA, thermoplastic polyimides and their composites. The matrix resin is preferably an epoxy resin.

[0037] In this invention, the doped reinforcing material includes multiple materials selected from conductive carbon black, carbon nanotubes, nitrogen-doped graphene, boron-doped carbon nanotubes, aramid fibers, functionalized aramid fibers, and composite ceramic particles. The functions of the doped reinforcing material are as follows: doping with graphene or carbon nanotubes can improve the bonding strength of the carbonaceous reinforcing phase, fill defects, and prevent crack propagation; introducing polar functional groups onto the surface of functionalized aramid fibers can enhance their interfacial adhesion with the resin matrix; and the composite ceramic particles possess both high insulation and high thermal conductivity, which helps to improve the thermal stability and electrical insulation strength of the core material.

[0038] In this invention, the functionalized aramid fiber preferably comprises para-aramid / meta-aramid chopped fibers with one or more polar functional groups selected from carboxyl, hydroxyl, sulfonic acid, amide, and epoxy groups introduced onto their surface. The functionalized aramid fiber is preferably prepared by a combination of acid oxidation-alkali washing activation followed by grafting of a silane coupling agent (such as KH-550, KH-560) and / or plasma surface activation-grafting of polar monomers (such as acrylic acid, methacrylic acid). The preparation conditions for the functionalized aramid fiber are not limited; any method well-known to those skilled in the art can be used.

[0039] In this invention, the composite ceramic particles preferably include one or more of boron nitride, alumina, boron oxide, silicon dioxide, aluminum nitride, silicon nitride, and zirconium oxide, more preferably boron nitride, alumina, boron oxide, silicon dioxide, or silicon nitride, and more preferably sheet-like boron nitride, boron oxide, spherical alumina, or nano-silica particles.

[0040] In this invention, the composite ceramic particles are also subjected to surface modification treatment.

[0041] In this invention, the mass ratio of the doped reinforcing material to the support body is preferably 0.001~0.1:1, more preferably 0.01~0.05:1, and even more preferably 0.02~0.03:1. The purpose of using the doped reinforcing material in this amount is to significantly improve the material properties (e.g., increase the compressive strength of the support by at least 20~50%) without excessively reducing the toughness and uniformity of the resin matrix.

[0042] In this invention, the raw materials for preparing the support body also include carbon fiber, polyolefin fiber, or oxide fiber. The carbon fiber (or the polyolefin fiber, or the oxide fiber) is impregnated in a mixture of matrix resin and doped reinforcing material to serve as the raw material for preparing the support body.

[0043] In this invention, the preparation method of the support body is not limited. Vacuum casting, prepreg curing molding method, and additive manufacturing (3D printing) method known to those skilled in the art can be used to ensure that the support body is dense and pore-free and that the doped reinforcing material is uniformly dispersed.

[0044] In this invention, the upper skin layer, the lower skin layer, and the lattice core layer are fixedly connected. The method of fixed connection is not limited; adhesive bonding or co-curing methods well-known to those skilled in the art can be used to form a rigid box-like structure.

[0045] In this invention, the lattice sandwich layer functions as a core load-bearing component. The two ends of each support are closely attached and bonded to the inner surface of the skin, thereby forming a load transfer path between the skin and the core material. When the skin is subjected to bending load, the tensile and compressive stresses are transferred through the support, which greatly reduces the strain borne by the electrochemical energy storage layer and protects the brittle internal electrochemical energy storage layer.

[0046] In this invention, the solid electrolyte in the solid electrolyte layer preferably includes one or more of oxide solid electrolytes, sulfide solid electrolytes, and polymer solid electrolytes. The oxide solid electrolyte includes, but is not limited to, ceramic perovskite or garnet-type materials (e.g., LLZO-type yttrium / tantalum doped oxides, Li...). 1.5 Al 0.5 Ge 1.5 (PO4)3 (LAGP), NASICON type phosphate glass ceramic), with >10 -4 The sulfide solid electrolyte exhibits a room-temperature ionic conductivity of S / cm and good chemical stability; it includes, but is not limited to, Li. 10 GeP2S 12 (LGPS), Li7P3S 11Alternatively, a sulfide glass or glass-ceramic of Li6PS5Cl (the sulfide solid electrolyte can also be impregnated with an ionic liquid), with an ionic conductivity as high as 10. -3 ~10 -2 The S / cm ratio and good interfacial contact are mentioned. The polymer solid electrolyte includes, but is not limited to, polyethylene glycol dimethyl ether-lithium salt (PEGDME-LiX) gel, PVDF-HFP based gel electrolyte, polyether solid electrolyte, and solid polymer electrolyte reinforced with inorganic nanofillers, so as to balance mechanical flexibility and ionic conductivity.

[0047] In this invention, the positive electrode active material in the positive electrode layer is preferably a lithium-based positive electrode active material with a specific capacity ≥230 mAh / g, more preferably ≥250 mAh / g, and even more preferably >250 mAh / g. The positive electrode active material includes, but is not limited to, lithium iron phosphate and lithium-rich manganese-based positive electrode materials (such as Li...). 1.2 Mn 0.54 Ni 0.13 Co 0.13 O2, Li 1.2 Mn 0.6 Ni 0.2 O2), high-nickel ternary layered oxides (such as NCM811, NCM622), sulfur cathodes (such as S / CMK-3 composite materials, which need to be paired with lithium anodes), ceramic electrolytes (such as Li) 6.5 La3Zr 1.5 Ta 0.5 O 12 ).

[0048] In this invention, the positive electrode active material in the positive electrode layer is compounded with a polymer electrolyte (such as a PEO-based polymer electrolyte or a PVDF-HFP-based gel electrolyte).

[0049] In this invention, the thickness of the positive electrode layer is preferably 10~200μm, more preferably 40~150μm, and even more preferably 50~100μm.

[0050] In this invention, the positive electrode slurry includes a positive electrode active material.

[0051] In this invention, the areal density of the positive electrode active material in the positive electrode layer is preferably 5~20 mg / cm³. 2 Further preferred is 8~15 mg / cm³ 2 More preferably 10~12 mg / cm³ 2 .

[0052] In this invention, the positive electrode layer includes a positive electrode current collector and a positive electrode slurry coating applied to the surface of the positive electrode current collector.

[0053] In this invention, the negative electrode active material of the negative electrode layer is preferably a negative electrode active material with an initial specific capacity of 800-1500 mAh / g, more preferably 1000-1500 mAh / g, and even more preferably 1200-1400 mAh / g. The negative electrode active material includes, but is not limited to, silicon-carbon composite negative electrodes, lithium metal, and lithium-rich alloy negative electrodes (sulfide solid electrolytes such as Li). 10 GeP2S 12 (Can be used as an additive).

[0054] In this invention, the thickness of the negative electrode is preferably 50~300μm, more preferably 100~250μm, and even more preferably 150~200μm.

[0055] In this invention, the negative electrode slurry includes a negative electrode active material.

[0056] In this invention, the areal density of the negative electrode active material in the negative electrode layer is preferably 3~15 mg / cm³. 2 Further preferred is 5~12 mg / cm³ 2 More preferably 8~10 mg / cm³ 2 .

[0057] In this invention, the negative electrode layer comprises a negative electrode current collector and a negative electrode slurry coating (or a negative electrode active layer applied to the surface of the negative electrode current collector). The negative electrode current collector is preferably copper foil or nickel foil.

[0058] In this invention, the aforementioned limitations on the electrochemical energy storage layer serve to ensure a short ion conduction path and stable mechanical support at the all-solid interface, further guaranteeing the overall performance of the battery after embedding the lattice support. Since the lattice pillars penetrate the structure, the positive and negative electrode sheets are perforated at the corresponding pillar positions. These perforation edges may lose their active material coverage, forming tiny inactive areas. The use of high-capacity positive and negative electrode materials can compensate for the loss of active area caused by the presence of the pillars; simultaneously, doping enhances the pillars, improving structural stability and ensuring that the layers remain adhered when subjected to mechanical loads, thus guaranteeing a stable ion transport path. Furthermore, in addition to conducting ions, the solid electrolyte layer also acts as a binder in the structure: after solidification, the solid electrolyte (especially polymer or organic-inorganic composite electrolyte) bonds the positive, negative, and pillars together, further enhancing the overall integrity of the battery structure.

[0059] In this invention, the lattice sandwich layer and the electrochemical energy storage layer are bonded together by a curing adhesive or co-curing molding method.

[0060] In this invention, the positive electrode layer is provided with a positive electrode lead-out line; the negative electrode layer is provided with a negative electrode lead-out line.

[0061] In this invention, one side of the upper skin layer contact lattice sandwich layer further includes an upper current collector layer; one side of the lower skin layer contact lattice sandwich layer further includes a lower current collector layer.

[0062] In this invention, the positive electrode lead is electrically connected to the upper current collector layer; the negative electrode lead is electrically connected to the lower current collector layer. This configuration serves to directly function as a busbar, further reducing weight and the number of components.

[0063] This invention also provides a method for preparing an all-solid-state battery with a doped reinforced lattice sandwich composite material structure, comprising the following steps: The matrix resin is mixed with the doped reinforcing material to obtain the modified composite material; several pillar units are prepared using the modified composite material. A positive electrode, a solid electrolyte layer, and a negative electrode are prepared separately and stacked sequentially to obtain an all-solid-state battery blank. Several through holes are machined through the all-solid-state battery layer blank. The support units are inserted into the through holes according to the lattice arrangement, so that the lattice sandwich layer is inserted into the electrochemical energy storage layer. The lower skin layer covers one side of the all-solid-state battery blank with the dot matrix sandwich layer, and the upper skin layer covers the other side. The upper skin layer, lattice sandwich layer, electrochemical energy storage layer and lower skin layer are solidified to obtain a structurally all-solid-state battery.

[0064] In this invention, the preparation methods of the positive electrode, the solid electrolyte layer, and the negative electrode are not limited, and any scheme well known to those skilled in the art can be used.

[0065] In this invention, the through hole is preferably processed using laser or mechanical drilling. The diameter of the through hole is preferably 0.1 to 0.5 mm larger than the diameter of the support unit.

[0066] In this invention, through holes corresponding to the positions of the through holes in the all-solid-state battery layer blank are pre-drilled on the upper and lower skin layers to facilitate assembly and alignment.

[0067] In this invention, the method for curing the upper skin layer, the lattice sandwich layer, the electrochemical energy storage layer and the lower skin layer is as follows: adding a curing adhesive or prepreg and curing under vacuum pressure.

[0068] In this invention, the all-solid-state battery structure is further encapsulated, for example, by coating the four edges with insulating sealant and waterproof coating, and installing external output terminals, making the battery structure a module that can be used directly.

[0069] In this invention, other conditions in the preparation method are not limited, and any scheme well known to those skilled in the art can be used.

[0070] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0071] Example 1

[0072] This embodiment provides a method for preparing a structural battery for new energy vehicles, including the following steps: (1) The upper and lower skin layers are made of carbon fiber reinforced epoxy resin boards with a thickness of about 1.5 mm (each layer contains 55 vol% carbon fiber, and the tensile strength of the laminate is about 600 MPa). The lattice sandwich layer is composed of hollow pillars with a diameter of 2 mm and a length of 20 mm (a four-sided hollow pillar structure with a wall thickness of 0.5 mm to reduce weight). The material is a doped reinforced epoxy composite material: the matrix is ​​tough epoxy resin (from the Y01-4R epoxy resin system of Shenzhen Langbowan Advanced Materials Co., Ltd.), the reinforcing fiber is meta-aramid fiber bundle (the reinforcing fiber accounts for 65 wt%), and it is filled with 2 wt% nitrogen-doped graphene and 1 wt% hexagonal boron nitride (h-BN) micro flakes. The surface of the pillars is vacuum impregnated and coated with a polyimide insulating coating with a thickness of about 0.1 mm to ensure electrical isolation. The dot matrix layout employs an asymmetric gradient design: in the central region (with the long side of the dot matrix sandwich layer as the x-axis and the wide side as the y-axis, determining the total length L and total width W of the dot matrix sandwich layer, dividing the dot matrix sandwich layer into a central area and an edge area, where the central area satisfies 0.3L≤x≤0.7L and 0.3W≤y≤0.7W), the support column spacing is 20mm; in the edge area (excluding the central area), the support column spacing is 40mm. The supports primarily connect the upper and lower skins vertically. (2) The electrochemical energy storage layer is a high-energy-density all-solid-state lithium-ion battery: the positive electrode adopts lithium-rich manganese-based solid oxide Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O2 (particle size 5μm) and Li 6.5 La3Zr 1.5 Ta 0.5 O 12 (LLZTO) ceramic electrolyte powder was mixed at a mass ratio of 7:3 to form the positive electrode active layer, which was then coated onto aluminum foil. The positive electrode sheet had an area of ​​500mm × 1000mm, a thickness of 70μm, and an active material surface density of 15mg / cm³. 2The negative electrode is a silicon-carbon composite negative electrode, in which graphite and silicon nanoparticles (20% silicon content) are doped with 10% sulfide solid electrolyte (Li). 10 GeP2S 12 The coating is applied to copper foil, with the same area as the negative electrode, a thickness of 50 μm, and an areal density of 10 mg / cm³. 2 The solid electrolyte layer uses an 80μm thick Li7P3S layer. 11 Sulfide electrolyte membrane (cold-pressed and sintered, ionic conductivity 2×10⁻⁶) -3 (S / cm). After sequentially hot-pressing and stacking the above positive electrode / solid electrolyte membrane / negative electrode, the individual all-solid system is stacked in series to achieve the required thickness of the electrochemical energy storage layer. Picosecond lasers are used to drill holes on it according to the pillar arrangement, and the prepared lattice pillars are precisely inserted. Finally, it is co-cured with the skin plate to obtain a large-size structured solar panel of 500mm×1000mm×23mm.

[0073] Performance testing: The solar panel structure of Example 1 was tested as part of the car floor and compared with the control scheme. Comparison Scheme A is a design consisting of a carbon fiber composite sandwich panel of the same size and a conventional battery module. The sandwich panel uses Nomex honeycomb core and carbon fiber skin, weighing 12.0 kg. The battery module uses several 21700 cells with the same positive and negative electrode materials connected in parallel, with a total capacity of 2 kWh. Including the aluminum alloy shell, the total weight is about 15.0 kg, and the overall assembled weight is 27.0 kg. Scheme B is the structure of the solar panel (integrated structure + battery) of Example 1, with a total mass of 21.8 kg, including about 12.5 kg of active battery material and about 9.3 kg of composite material structure (skin + support).

[0074] Regarding electrical performance, both solutions have a total energy storage of approximately 2 kWh. However, the specific energy (system-level calculation including structural components) is approximately 74 Wh / kg for solution A and approximately 92 Wh / kg for solution B, representing a 24% improvement. This means that the proposed solution can provide a longer driving range without increasing weight. Battery charge-discharge tests show that solution B's capacity at 0.2C discharge is comparable to that of the conventional battery module in solution A (due to the slight increase in internal resistance of the solid electrolyte being compensated by the high-capacity material); the rate performance is slightly lower (90% capacity retention at 1C discharge), but still within the range required for automotive buffer current. After 100 charge-discharge cycles, solution B's capacity retention reaches over 95%, slightly better than solution A's 93%, indicating that the use of a solid electrolyte brings better cycle stability.

[0075] For mechanical properties, components from both schemes were fixed to the vehicle frame and subjected to a three-point bending test. Structural stiffness: Scheme A, due to the thinness of the honeycomb sandwich panel, relies on the vehicle chassis beams for support; the overall bending stiffness was measured to be approximately 1.8 × 10⁻⁶. 4 N·m 2 In Scheme B, the solar panel itself serves as the load-bearing component, with the skin and matrix supports forming the frame, exhibiting a bending stiffness of approximately 2.3 × 10⁻⁶. 4 N·m 2 The structural strength was improved by approximately 28%. In terms of structural strength, under progressive loading to failure, Scheme A showed buckling and collapse of the honeycomb core at a load of approximately 5 kN, while Scheme B only experienced localized skin cracks at a load of 6.5 kN, resulting in a maximum load-bearing capacity increase of approximately 30%. Furthermore, vibration durability and simulated impact tests were conducted: After 20 hours of vertical vibration of 10g and a 20-200Hz frequency sweep, the internal cells of Scheme B remained intact, and there was no delamination between the support pillars and the skin. In simulated bottom impact (the bottom plate being impacted by a stone at 30 km / h), Scheme B only showed slight whitening of the skin surface, while Scheme A experienced localized crushing of the honeycomb core and loosening of the battery module fixings. Therefore, it is evident that the structural battery of this invention is significantly superior to traditional schemes in terms of structural safety.

[0076] In summary, Example 1 demonstrates that applying this invention in the field of new energy vehicles can effectively reduce overall weight and increase the specific energy of the battery system while ensuring or improving the structural strength of the vehicle, thereby enhancing the overall vehicle range and safety performance. For example, an electric vehicle equipped with a battery chassis based on the structure of this invention will have its body weight reduced by approximately 40 kg, its range increased by approximately 10%, and its chassis structure simplified with fewer components. This will significantly improve the energy efficiency and economy of new energy vehicles.

[0077] Example 2

[0078] This embodiment provides a method for fabricating a structural battery for aerospace vehicles, including the following steps: (1) The panel size is 300mm×300mm×10mm, which can be used as both the bulkhead structure and battery assembly of the satellite. The upper skin layer is made of a 0.5mm thick high-strength carbon fiber / epoxy prepreg layer (using the Y0761 epoxy resin system of Shenzhen Langbowan Advanced Materials Co., Ltd., combined with T800 grade carbon fiber / epoxy prepreg), covered with a 0.1mm aluminum foil (as a radiation shielding coating and anode current collector on the outer surface of the satellite); the lower skin layer is a 0.5mm thick carbon fiber / epoxy laminate (using the Y01-2 epoxy resin of Shenzhen Langbowan Advanced Materials Co., Ltd., combined with T800 grade carbon fiber / epoxy laminate, with 0.1mm copper foil locally laid on the inner side as a cathode lead-out current collector). The lattice sandwich layer uses carbon fiber hollow braided tubes as support units, each with a diameter of 1.5mm and a wall thickness of 0.2mm. The hollow part is used to further reduce weight. The support structure was made by impregnating carbon fiber multifilaments with resin (the resin being the Y01-2 epoxy resin system from Shenzhen Langbowan Advanced Materials Co., Ltd.) with 1 wt% boron-doped carbon nanotubes (B-CNTs) and 3 wt% boron oxide ceramic microparticles. The lattice supports are arranged in a regular grid pattern within the panel, with a uniform spacing of 10 mm, to provide uniform stiffness in all directions. Due to the vacuum and large temperature differences in the satellite's orbital environment, all supports are bonded to the skin using heat-resistant adhesives and cured by baking at 130℃ to ensure the joints do not loosen under temperature cycling conditions of -60 to +80℃. (2) The electrochemical energy storage layer is designed as a high-safety-margin all-solid-state lithium battery: the positive electrode uses a mixture of LiFePO4 (lithium iron phosphate) and LLZTO ceramic electrolyte in a 6:4 ratio to form a positive electrode film with a thickness of 50μm, which is coated on a lightweight and porous carbon fiber felt current collector (to further reduce weight), and the surface density of the active material is 10mg / cm³. 2 The negative electrode uses an ultra-thin lithium metal foil (20 μm thick) attached to a copper mesh current collector (30 μm thick); the solid electrolyte layer is a 100 μm thick Li₂O₃. 1.5 Al 0.5 Ge 1.5 A porous ceramic membrane of (PO4)3 (abbreviated as LAGP) is impregnated with an ionic liquid (the ionic liquid is 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, [EMIM][TFSI], with a mass fraction of 15 wt% in the composite electrolyte) to form a composite electrolyte, thereby improving low-temperature performance. After the above-mentioned positive electrode / solid electrolyte membrane / negative electrode are sequentially hot-pressed together, the individual all-solid-state systems are stacked and connected in series to achieve the required thickness of the electrochemical energy storage layer. Similar to Example 1, holes are drilled at the corresponding support positions of the battery layer and supports are installed, and then bonded to the skin to form an integrated plate.

[0079] Performance testing: The structure of the battery panel in Example 2 is compared with a control scheme based on a conventional satellite power supply + structure. Compared to Option A, which consists of a honeycomb aluminum alloy sandwich panel of the same size (10mm thick) and an external small lithium battery pack (8 cylindrical lithium batteries installed in a dedicated battery box, with a total weight of 0.5kg), Option A's panel (aluminum honeycomb + carbon fiber skin) weighs approximately 0.8kg, the battery pack weighs 0.5kg, and the total weight is 1.3kg. Scheme B is the structure of the solar panel in Example 2, with a total mass of approximately 0.9 kg, in which the structure and the battery are combined into one.

[0080] In terms of weight, Option B is about 30% lighter than Option A, which can significantly reduce launch costs for spacecraft such as satellites.

[0081] In space environment simulation experiments, Scheme B demonstrated superior performance: it withstood 20 cycles of thermal vacuum testing (-60℃ to +80℃, vacuum degree 1×10⁻⁶). -5 After a thermal cycle (Pa), the battery panel in Scheme B remained intact with almost no degradation in electrical performance. In contrast, the traditional lithium battery pack in Scheme A experienced a capacity decrease of approximately 5% after a similar thermal cycle and showed signs of loosening of the casing, requiring additional tightening. After a mechanical vibration test (8.8 grms random vibration for 2 minutes), the panel of Scheme B showed no cracks or delamination, and the internal batteries functioned normally; the battery box fixing screws in Scheme A showed slight signs of loosening and required further tightening. In terms of specific energy, the panel of Scheme B provides approximately 2 Wh / g of energy, while the battery pack in Scheme A provides approximately 1.5 Wh / g. If the weight of the structural panel is included, the specific energy is only about 0.6 Wh / g. This invention converts structural weight into effective energy storage, achieving a significant improvement in system specific energy.

[0082] In terms of mechanical properties, the bending stiffness of panel B is slightly higher than that of aluminum honeycomb panel A. Under three-point bending tests, panel B shows approximately 15% higher load-bearing capacity when reaching the same deflection. Furthermore, finite element simulations show that panel B exhibits good resistance to in-plane loads (such as in-plane stress caused by launch acceleration), with the maximum stress below half of the material's allowable value, indicating a more conservative and safe design. Panel A, on the other hand, has higher local stress concentration due to the need for openings in the panel to install the battery box, resulting in some structural weakening.

[0083] In summary, in aerospace applications, the battery structure of this invention not only reduces weight and increases energy density, but also improves system reliability—eliminating the risks of component detachment and connector failure by eliminating the need for independent battery cells. Simultaneously, the all-solid-state electrolyte avoids problems such as battery leakage and gas expansion, making it ideal for vacuum environments. Therefore, for satellites and spacecraft, adopting this invention can extend their lifespan and improve attitude control stability (due to its high mass concentration and excellent structural integrity), which is of great significance.

[0084] Example 3

[0085] This embodiment provides a method for fabricating a structural battery for unmanned aerial vehicles (UAVs). Optimized for the airframe of a small quadcopter UAV (Drone), it provides a frame-arm type structural battery. A typical UAV has four radial arms connecting to the central fuselage and supporting the motors and propellers. In this embodiment, each arm is designed as a hollow cylindrical structural battery unit, which both provides structural rigidity and serves as a power source. Each arm battery has the following dimensions: diameter 30mm and length 250mm (which can be considered as a slender tubular battery). The method includes the following steps: (1) The outer wall of the support arm is the upper skin layer, which consists of a ring of carbon fiber / epoxy composite material tube wall (1 mm thick) (using Y01-4R epoxy resin from Shenzhen Langbowan Advanced Materials Co., Ltd. combined with T800 grade carbon fiber); the lower skin layer of the inner wall is another ring of composite material tube (same as the upper skin layer, 0.5 mm thick), and the middle interlayer is a circular structure with alternating lattice pillars and battery layers. Specifically, between the inner and outer tube walls, a ring solid battery unit (composed of concentric circular positive electrode, solid electrolyte, and negative electrode sheet) is set every 20 mm, and adjacent battery units are connected and supported by radially arranged Y-shaped lattice pillars (each Y-shape contains 3 inclined pillars, extending from the inner wall to the outer wall at 120° intervals). The entire support arm contains 10 battery units and several Y pillars, forming a periodically repeating structural battery. The lattice support material is made of an epoxy resin composite reinforced with ultra-high molecular weight polyethylene fiber (UHMWPE) (the epoxy resin composite is the Y0761-1 epoxy resin system from Shenzhen Langbowan Advanced Materials Co., Ltd., containing 1 wt% carbon nanotubes), and incorporates 2 wt% functionalized silica nanoparticles (functionalized by silanizing the silica surface with KH-560) to improve rigidity. Each support has a diameter of 3 mm, and its ends are bonded and fixed to the inner and outer tube walls. (2) The electrochemical energy storage layer uses a high-power-density solid-state battery system to meet the high-current discharge requirements of the UAV: ​​the cathode is LiNi 0.8 Co 0.1 Mn 0.1 O2 (high-nickel ternary electrolyte, with high rate performance) and PEO-based polymer electrolyte (polyoxyethylene PEO from Sigma-Aldrich, Mw≈600000) are mixed at a mass ratio of 7:3 and coated onto an aluminum foil ring. The positive electrode thickness is 60μm, and the surface density of the active material is 10mg / cm³. 2 The negative electrode is a lithium titanate (LTO) thick film negative electrode (safe and long lifespan) coated on a copper foil ring, with a thickness of 80 μm and an active material areal density of 8 mg / cm³. 2The solid electrolyte is a PEO film doped with LiTFSI lithium salt (Sigma-Aldrich's polyoxyethylene PEO, Mw≈600000). Each battery cell has a nominal voltage of 2.3V (LTO vs NCM positive electrode), and 10 cells are connected in series to achieve 23V, with a capacity of approximately 2Ah. The batteries and support pillars are arranged in an alternating ring, making full use of the internal space of the cylindrical tube.

[0086] Performance testing: The drone using the battery arm structure of Example 3 will be compared with a traditional drone control scheme: Compared to Option A: The conventional drone frame is made of carbon fiber tubing (outer diameter 30mm), and the battery is an independent lithium battery pack (4 series 2 parallel high-rate soft-pack batteries, capacity 2Ah) installed in the center of the fuselage. The total weight of the drone (excluding the load) is about 1.8kg, of which the battery weighs 0.4kg and the frame and electronic equipment weigh 1.4kg. Option B: Example 3 structure battery frame, without independent battery pack, the total weight of the frame (including battery function) is 1.5kg, of which each support arm battery is about 0.1kg, a total of four arms weighing 0.4kg, and the remaining body weighs 1.1kg.

[0087] Regarding quality, through integration, the overall weight of the drone using the battery frame structure of Example 3 is reduced by approximately 16%.

[0088] Both drones are equipped with the same model of motors and propellers, and have the same rated load. First, a hovering endurance test was conducted: under a rated load of 500g, hovering, Scheme A had an endurance of approximately 22 minutes, while Scheme B achieved an endurance of 26 minutes, an extension of approximately 18%. This is attributed to the increased overall thrust-to-weight ratio after weight reduction, and a slight increase in the specific energy of the structural battery. High-current discharge test: Simulating rapid drone ascent, requiring the battery to discharge at a 10C rate, Scheme A, due to its high-rate pouch battery, experienced a voltage drop of approximately 8%; Scheme B's structural battery voltage dropped by approximately 10%, slightly higher but still within an acceptable range. This indicates that the solid-state battery of this invention can meet the high power requirements of drones. Cycle life: Both schemes were subjected to charge-discharge cycles (2C discharge to 80% DOD, 0.5C charge). Scheme A's battery capacity decayed to 80% after 200 cycles; Scheme B retained 87% capacity after the same number of cycles, showing longer lifespan potential (the combination of LTO anode and solid electrolyte has a significant advantage in long-cycle operation).

[0089] In terms of structural mechanics, the rigidity and strength of the frame of this invention are improved. Torque testing of the outriggers revealed that the outriggers of Scheme B, supported by inner and outer double tubes and Y-shaped struts, are equivalent to a sandwich beam structure, resulting in approximately a 25% increase in torsional stiffness (consistent with actual measurements; the torque required for each outrigger to twist by 1° is approximately 1 / 4 higher than that of hollow carbon fiber tubes). Regarding vibration resistance, the UHMWPE fiber imparts higher damping to the structure, and the frame of Scheme B exhibits better attenuation performance for high-frequency vibrations than carbon fiber tubes—under high-speed rotor excitation, the amplitude at the outrigger tip was reduced by approximately 30%, resulting in significantly more stable flight images. A drop test was also conducted (the drone fell from a height of 10m, impacting the landing outriggers). In Scheme A, two carbon fiber tube outriggers broke; in Scheme B, due to the more resilient polyethylene fiber and flexible solid electrolyte in the outriggers, although the skin cracked, the struts remained connected, preventing battery combustion and explosion, and the remaining batteries remained operational. Therefore, the battery structure of this invention significantly improves the shock and impact resistance and safety of the drone frame.

[0090] In summary, Example 3 demonstrates that applying this invention in the field of drones can achieve longer flight times, lighter airframes, and better dynamic stability. The structural battery frame distributes the battery weight within the fuselage, lowering the center of gravity and reducing the battery compartment volume, resulting in a more compact design. More importantly, with the battery integrated into the structure, a dedicated mounting bracket is no longer needed, thereby reducing the number of components and improving reliability. This is highly attractive for drone designs pursuing extreme lightweighting and performance.

[0091] Example 4

[0092] This embodiment provides a method for fabricating a structural battery for portable electronic devices, targeting portable electronic devices such as smartphones and laptops. Taking a laptop bottom shell as an example, its dimensions are approximately 330mm × 220mm, and its thickness is 5mm. This embodiment fabricates the bottom shell into a structural battery, making it serve as both a support structure and a battery function, thereby reducing the space and weight occupied by a separate battery. The method includes the following steps: (1) The upper skin layer of the bottom shell is a 0.5mm thick magnesium-aluminum alloy plate (AZ91D magnesium-aluminum alloy plate provided by Chinalco, mainly providing electromagnetic shielding and heat dissipation functions, and can also be used as the positive electrode current collector of the battery), and the lower skin layer is a 0.5mm thick carbon fiber composite plate (using the Y0761 epoxy resin system of Shenzhen Langbowan Advanced Materials Co., Ltd. and high modulus M40J grade carbon fiber / epoxy composite plate to provide structural strength, and to coat the negative electrode current collector with a graphene conductive layer). The lattice sandwich layer between the two skins adopts a micro lattice support column array: because the bottom shell is very thin, the column height is only about 4mm and the diameter is 1mm. In order to prevent excessive encroachment on the battery volume, the column spacing is designed to be large (20mm), and it is evenly distributed in the main board and battery area. The column material is a polyimide resin matrix (from the Y082 polyimide resin system of Shenzhen Langbowan Advanced Materials Co., Ltd.), containing 5wt% conductive carbon black and 0.5wt% carbon nanotubes, which are grafted onto the resin molecular chain through in-situ polymerization. The addition of this conductive filler gives the support material a certain degree of conductivity, making it ideal for supporting the negative electrode side, thus also serving as a current-carrying path for the negative electrode. For the positive electrode side supports, pure resin doped with silica insulating particles is used to prevent short circuits. The overall lattice layout is arranged in a honeycomb pattern (with hexagons symmetrically arranged around each support), forming a lightweight yet rigid support network. (2) The electrochemical energy storage layer is a thin solid-state lithium battery stack: the positive electrode uses LiNi 0.6 Co 0.2 Mn 0.2 A mixed coating of O2 (NCM622) and PVDF-HFP based gel electrolyte (manufacturer: Arkema, brand name Kynar FLEX 2801) was applied (NCM622 to gel electrolyte mass ratio: 8:2, positive electrode thickness: 30 μm, active material areal density: 8 mg / cm³). 2 The negative electrode uses a graphite negative electrode (50μm thick) pre-lithi-intercalated to improve energy density. The solid electrolyte is a PVDF-HFP based polymer gel film (50μm thick, containing 50% liquid electrolyte to improve room temperature ionic conductivity; the liquid electrolyte is a power storage battery electrolyte provided by Tinci Materials, with a solvent composition of EC\PC\DMC\EMC\EP, density of 1.16~1.24g / mL, water content of 20ppmMax, conductivity of 8.0~12.0mS / cm, acidity of 50ppmMax, and appearance colorless to pale yellow). The total thickness of the entire battery layer is approximately 0.13mm, and 10 layers can be stacked in series to achieve the voltage required for laptops (approximately 37V). During the stacking process, perforations are made at the corresponding support positions, and a certain amount of elastic silicone is filled between each layer to ensure that the support is tightly contacted with each layer after penetration. Finally, the upper and lower skins, battery layers, and support are pressed together by molding and cured and sealed to form a complete battery bottom shell.

[0093] Performance testing: The battery bottom case of Example 4 was installed on a laptop computer and compared with the original standard bottom case + lithium battery solution.

[0094] Original standard option A: Aluminum alloy bottom shell (1mm thick, 200g), built-in lithium-ion battery pack (4 series 2 parallel soft pack batteries, 5000mAh capacity, 300g weight), total weight 500g; Option B: Example 4: Battery base shell (which is also the battery), with a capacity of 5000mAh and a weight of approximately 380g (the structure and battery are integrated, and no additional shell is required).

[0095] Regarding weight, the solution in Example 4 reduces weight by approximately 24% and frees up approximately 100 cm² of battery compartment space. 3 This allows computers to become thinner or to accommodate other components.

[0096] In terms of electrical performance, both operate at the same voltage. Actual discharge tests show that the discharge curves of Scheme B and Scheme A are basically the same: at 0.2C discharge, both release a capacity of approximately 5000mAh; at 1C discharge, Scheme B experiences a slightly larger capacity decay of 2%, presumably due to the solid polymer electrolyte slightly reducing rate performance, but the impact is minimal. Thermal testing: Simulating battery heating under prolonged high-load use, Scheme A's pouch battery is located inside the casing, relying on thermal pads and the outer shell for heat dissipation, with the highest measured battery temperature reaching 45℃; Scheme B, on the other hand, has its battery materials distributed over a large area of ​​the bottom shell, and both the lower skin carbon fiber and the upper skin magnesium-aluminum alloy have certain thermal conductivity, resulting in a maximum battery temperature of only around 40℃ with uniform temperature distribution, which helps improve battery life and safety.

[0097] In terms of structural performance, the strength and stiffness of the bottom shell in Example 4 are improved. The standard aluminum alloy bottom shell has limited stiffness on its own and must be integrated with the internal frame to prevent deformation; while the structural battery bottom shell, due to carbon fiber reinforcement and lattice support, has better inherent stiffness. In a drop test (1m drop with the bottom landing face down), the bottom shell of Example A showed significant deformation and even cracking, and the internal battery also bulged and deformed due to impact; the bottom shell of Example B remained intact, with only minor scratches on the surface, and no abnormalities were observed in the internal solid-state battery layer. This demonstrates that the structural battery bottom shell improves the impact resistance of the laptop. Furthermore, the all-solid-state nature of the structural battery avoids the risk of leakage and fire that traditional batteries face upon impact, significantly enhancing safety.

[0098] In terms of user experience, the laptop with Solution B is thinner and lighter (thicker reduced by approximately 1.5mm, lighter by 120g), and the reduced battery space allows designers more room to incorporate a larger cooling module or other features. Charging tests show that Solution B's battery can charge to 80% in one hour (supporting fast charging) without significant heat generation; while Solution A's pouch battery is slightly better due to its lower internal impedance, but the difference is not significant. After long-term simulated use (1000 opening and closing cycles, temperature cycling, high humidity storage), Solution B's bottom shell structure and battery performance remained stable, with no encapsulation cracking or abnormal capacity degradation.

[0099] In summary, Example 4 demonstrates that applying this invention to portable electronic devices can result in lighter, thinner product forms and higher security and reliability. Particularly for devices like mobile phones that prioritize maximizing space utilization, this invention can imbue structural components such as the mid-frame and back cover with energy storage capabilities, thereby allowing for larger capacity batteries to be packed into a limited volume or freeing up space for components such as cameras and 5G antennas. This design concept is expected to lead structural innovation in future electronic products, providing new solutions for improving user experience and functional integration.

[0100] Example 5

[0101] This embodiment provides a method for fabricating a structural battery for marine detectors. Specifically, it addresses the power compartment of a deep-sea autonomous underwater vehicle (AUV) and provides a pressure-resistant shell-type structural battery. Deep-sea AUVs typically need to withstand hydrostatic pressures of tens of megapascals, and their battery compartments often consist of a heavy metal pressure-resistant shell and an internal battery pack. Therefore, this embodiment designs a cylindrical pressure-resistant shell structural battery with a diameter of 0.5 m and a length of 1 m to replace the traditional battery compartment, including the following steps: (1) The shell consists of an inner and outer double-layer structure: the outer layer is a metal cylinder (upper skin layer), made of 4mm thick titanium alloy (Ti-6Al-4V), which mainly provides compressive strength and corrosion resistance; the inner layer is a 3mm thick glass fiber reinforced epoxy liner (lower skin layer, formed by combining the Y01-2 epoxy resin system of Shenzhen Langbowan Advanced Materials Co., Ltd. with glass fiber reinforcement material), which provides electrical insulation and serves as the negative electrode current collector coated with carbon fiber cloth. The two layers are spaced 20mm apart, where the lattice sandwich layer and battery pack are arranged. The lattice support is made of ceramic fiber composite material: high-strength alumina fiber (content 60wt%) is impregnated in tough epoxy resin (from the Y01-1R epoxy resin system of Shenzhen Langbowan Advanced Materials Co., Ltd.), doped with 1wt% carbon nanotubes to improve fracture toughness, and after curing, a solid column with a diameter of 5mm is obtained. Ceramic fiber itself is insulating and has almost no compressive deformation under pressure, making it suitable as a deep-sea pressure support. The supports, 20mm high, are arranged in a honeycomb pattern throughout the cylinder wall, with uniform staggered spacing of 50mm. Due to the need for load bearing, the supports are arranged in a regular, symmetrical manner to evenly distribute the load. (2) The electrochemical energy storage layer consists of several flexible all-solid-state lithium-ion battery cells spliced ​​together and covering the outer surface of the inner liner (i.e., located within the space of the lattice grid). Each battery cell is approximately 100mm × 100mm × 5mm in size and adopts a lithium-sulfur battery chemistry system to pursue ultra-high energy density: the positive electrode is an S / CMK-3 composite material (70% sulfur loading, positive electrode thickness of 150μm), the solid electrolyte is a modified PEO film (film thickness of 50μm, doped with 10wt% SiO2 nanoparticles to improve mechanical strength; the SiO2 nanoparticles are Evonik's fumed silica AEROSIL 200; the PEO is Sigma-Aldrich's PEO, Mw≈600000), and the negative electrode is a lithium metal foil with a thickness of 50μm. The single cell capacity is 10Ah, and the energy density is approximately 400Wh / kg. The solid electrolyte avoids the problem of polysulfide leakage in liquid lithium-sulfur batteries and is more suitable for a closed environment. Multiple cells are connected in series and parallel by flexible wires and then connected to an external connector through the insert of the inner liner. During assembly, the battery cells are attached one by one to the corresponding positions on the inner liner, and stacked in series to achieve the required thickness of the electrochemical energy storage layer. Then, the inner and outer cylinder walls with pre-inserted support columns are closed and fixed (similar to the method in Example 1, the support columns are passed through the small holes reserved around the battery cells and welded / glued to the inner and outer cylinders).

[0102] Performance testing: Comparison of the battery casing structure of Example 5 with conventional solutions: Comparison with Option A: Conventional pressure-resistant chamber + lithium battery pack. The chamber is an 8mm thick steel cylinder (with rib reinforcement), weighing approximately 120kg; it contains a lithium-ion battery module (5kWh energy, 50kg weight), for a total weight of 170kg. Option B: Example 5: The battery casing is made of titanium alloy and composite material, with a mass of approximately 90 kg. It contains a built-in lithium-sulfur solid-state battery with a total energy of 5 kWh. The battery material itself weighs only 20 kg, and the total weight is 110 kg.

[0103] Regarding mass, the solution of this invention reduces the total weight by approximately 35%, which is extremely valuable for deep-sea probes, as it can significantly improve buoyancy margin or reduce buoyancy adjustment load.

[0104] The shell of Scheme B was placed in a deep-sea high-pressure simulation chamber for pressure resistance testing: it was maintained at 110MPa (equivalent to a water depth of approximately 11,000m) for 2 hours, and the structure remained intact without leakage, with the internal battery functioning normally. The steel shell of Scheme A also remained intact under the same conditions, but was 60kg heavier. Simulated navigation tests were conducted: under calculated weight reduction conditions, the AUV could carry 35% more scientific instruments, or reduce ballast under the same load, improving maneuverability. Simultaneously, the 5kWh energy provided by the structural battery itself is sufficient to support a cruise of up to 20 hours, extending the range by approximately 50% compared to previous lithium battery packs (which had smaller capacity due to weight limitations). Charge-discharge tests showed that the solid-state lithium-sulfur battery could still discharge stably at 0.1C under conditions of 5MPa and 2℃ (deep-sea environment) with no significant capacity decay; multiple pressure cycles had no adverse effect on battery performance, but rather slightly improved it (pressure helps with solid-state interface contact). In contrast, traditional liquid lithium-ion batteries experience a significant increase in internal resistance and a capacity decay of over 10% under low temperature and high pressure, losing all their advantages.

[0105] In terms of structural performance, the shell of Scheme B exhibits higher compressive stability due to its lattice support. Finite element analysis shows that under the same pressure, the radial deformation of the shell of Scheme B is only about 2 / 3 of that of Scheme A, indicating higher stiffness. This is mainly attributed to the buckling-resistant support of the lattice struts, which effectively prevents excessive circumferential deformation of the shell. In addition, even if a single cell fails (such as slight expansion) inside Scheme B, the lattice structure can provide restraint to avoid a chain reaction; and the solid electrolyte will not leak due to external pressure, resulting in better safety. An extreme test was conducted: under the condition of a single cell failure (artificial short circuit) and an external pressure of 30MPa, the solid battery only heated up and decomposed into an insulator without catching fire or exploding, and the titanium alloy shell was not damaged; while liquid lithium batteries may burn or even explode under atmospheric pressure, and although they do not burn under the high pressure of the deep sea, they may leak and contaminate the equipment inside the cabin. This highlights the inherent safety of the present invention in the deep-sea environment.

[0106] In summary, Example 5 demonstrates the unique advantages of this invention in the field of deep-sea diving: the design of the pressure-resistant casing for the structural battery significantly reduces the weight of the probe, increases energy carrying capacity and safety, making deeper and farther ocean exploration possible. This technology can be widely applied to systems requiring both high strength and independent power supply, such as deep-sea submersibles, seabed observation stations, and oil drilling equipment, and is expected to have a profound impact.

[0107] Therefore, the structural battery prepared by the method described in this invention has a highly integrated internal lattice support core layer and battery functional layer. The doped modified materials are pre-integrated into the pillar structure, eliminating the need for additional support frame weight and ensuring electrical isolation between electrode layers. The use of an all-solid-state system prevents leakage or material displacement when the battery is subjected to certain pressures and temperatures during the molding process, and forms a stable solid-solid interface with the pillars after curing. Thus, the structural battery prepared by this invention possesses both excellent mechanical and electrochemical properties. In applications such as new energy vehicles, aerospace, drones, portable devices, and marine exploration, the structural battery of this invention significantly reduces system weight and improves electrical performance and structural efficiency, possessing significant practical significance and application value.

[0108] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A doped reinforced lattice sandwich composite material structure all-solid-state battery, comprising an upper skin layer and a lower skin layer, and a lattice sandwich layer and an electrochemical energy storage layer disposed between the upper skin layer and the lower skin layer; the lattice sandwich layer is embedded in the electrochemical energy storage layer and has a load-bearing capacity perpendicular to the direction of the upper skin layer, characterized in that, The lattice sandwich layer contains doped reinforcing materials; the electrochemical energy storage layer is one or more interconnected all-solid-state systems, and a single all-solid-state system includes a positive electrode layer, a solid electrolyte layer and a negative electrode layer stacked sequentially. The doped reinforcing material includes one or more of the following: conductive carbon black, carbon nanotubes, nitrogen-doped graphene, boron-doped carbon nanotubes, aramid fibers, functionalized aramid fibers, and composite ceramic particles.

2. The all-solid-state battery structure according to claim 1, characterized in that, The lattice sandwich layer includes several support units arranged in a lattice pattern along the plane; The support unit is a solid or hollow rod, and the cross-section of the support unit is circular, polygonal, or arbitrary curved. The support unit includes a support body and an insulating layer covering the surface of the support body.

3. The all-solid-state battery structure according to claim 2, characterized in that, The support unit is arranged in a dot matrix with equal spacing and equal size; Alternatively, the support units may be arranged in a lattice pattern with partitioned distribution and / or varying sizes. The partitioning is as follows: Using the long side of the lattice sandwich layer as the x-axis and the wide side as the y-axis, the total length L and total width W of the lattice sandwich layer are determined. The lattice sandwich layer is divided into a central region and an edge region. The central region satisfies 0.3L ≤ x ≤ 0.7L and 0.3W ≤ y ≤ 0.7W. The edge region is the area excluding the central region. The spacing p1 of the support units in the central region is 10~25mm, and the spacing p2 of the support units in the edge region is 25~50mm, and p1... <p2; The dimensions of the support unit vary as follows: the diameter d of the support unit is calculated using formula 1: Formula 1: In formula 1, d (r) is the diameter of the support element when the distance between the geometric center of the support element and the intersection of the diagonals of the lattice sandwich layer is r. d min The minimum diameter of all support units. d max The maximum diameter of all support units. r The distance is the intersection of the geometric center of the support unit and the diagonal of the lattice sandwich layer. R It is half the diagonal length of the lattice sandwich layer. k It is a constant whose value ranges from 1 to 3.

4. The all-solid-state battery structure according to claim 2 or 3, characterized in that, The raw materials for preparing the support body include a mixture of matrix resin and doped reinforcing material; The matrix resin includes thermosetting resin or thermoplastic resin; The mass ratio of the doped reinforcing material to the main body of the support is 0.001 to 0.1:

1.

5. The all-solid-state battery structure according to claim 1, characterized in that, The upper skin layer or the lower skin layer includes one or more of the following: carbon fiber reinforced resin composite board, aramid fiber reinforced resin composite board, glass fiber reinforced resin composite board, basalt fiber reinforced resin composite board, polylactic acid plastic board, nylon plastic board, ABS plastic board, and alloy board. The thickness of the upper skin layer or the lower skin layer is independently 0.1~5mm.

6. The all-solid-state battery according to claim 1, characterized in that, The solid electrolyte in the solid electrolyte layer includes one or more of oxide solid electrolytes, sulfide solid electrolytes, and polymer solid electrolytes. The positive electrode active material in the positive electrode layer is a lithium-based positive electrode active material with a specific capacity ≥230mAh / g; the thickness of the positive electrode layer is 10~200μm, and the areal density of the positive electrode active material in the positive electrode layer is 5~20mg / cm³. 2 ; The negative electrode active material of the negative electrode layer has an initial specific capacity of 800~1500mAh / g, the thickness of the negative electrode layer is 50~300μm, and the areal density of the negative electrode active material of the negative electrode layer is 3~15mg / cm³. 2 .

7. The all-solid-state battery according to claim 1, characterized in that, The positive electrode layer is provided with a positive electrode lead-out line; The negative electrode layer is provided with a negative electrode lead wire.

8. The all-solid-state battery according to claim 7, characterized in that, One side of the upper skin layer contact lattice sandwich layer also includes an upper current collector layer; One side of the lower skin layer contact lattice sandwich layer also includes a lower current collector layer; The positive electrode lead is electrically connected to the upper current collector layer; The negative electrode lead is electrically connected to the lower current collector layer.

9. The all-solid-state battery according to claim 1, characterized in that, The lattice sandwich layer and the electrochemical energy storage layer are bonded together by a curing adhesive or co-curing molding method; The upper skin layer, the lower skin layer, and the lattice sandwich layer are fixedly connected.

10. A method for preparing a doped reinforced lattice sandwich composite material structure all-solid-state battery according to any one of claims 1 to 9, characterized in that, Includes the following steps: The matrix resin is mixed with the doped reinforcing material to obtain the modified composite material; Several support units were prepared using modified composite materials; A positive electrode, a solid electrolyte layer, and a negative electrode are prepared separately and stacked sequentially to obtain an all-solid-state battery blank. Several through holes are machined through the all-solid-state battery layer blank. The support units are inserted into the through holes according to the lattice arrangement, so that the lattice sandwich layer is inserted into the electrochemical energy storage layer. The lower skin layer covers one side of the all-solid-state battery blank with the dot matrix sandwich layer, and the upper skin layer covers the other side. The upper skin layer, lattice sandwich layer, electrochemical energy storage layer and lower skin layer are solidified to obtain a structurally all-solid-state battery.

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