Three-dimensional enhanced structure battery and preparation method thereof

Abstract

The invention relates to the technical field of structural batteries, in particular to a three-dimensional reinforced structural battery and a preparation method thereof.The three-dimensional reinforced structural battery comprises a plurality of first reinforced fiber layers, a plurality of first insulating fiber layers, a battery layer, a plurality of second insulating fiber layers and a plurality of second reinforced fiber layers which are sequentially stacked from bottom to top; and a plurality of reinforcing ribs penetrating through the plurality of first insulating fiber layers, the battery layer and the plurality of second insulating fiber layers. According to the method, a reinforcing rib penetrating reinforcing mode is utilized, a three-dimensional cross-linking reinforcing network is constructed in the dimension perpendicular to the laminating direction, a multi-scale space anchoring system is formed through high-strength reinforcing ribs, and the interlayer shear strength and the interface bonding force can be remarkably improved; and moreover, uniform load distribution is realized through mechanical transmission path reconstruction, and the electrochemical function integrity can be kept while crack initiation and expansion are inhibited.

Description

Technical Field

[0001] The present invention relates to the technical field of structural batteries, and in particular to a three-dimensional enhanced structural battery and a preparation method thereof. Background Art

[0002] In the prior art, due to the mutual constraints between the introduction of energy storage functional components in structural batteries (including electrodes and electrolyte materials with poor mechanical strength) and the structural load-bearing requirements, the integration of functional energy storage materials significantly reduces the macroscopic mechanical properties of the material matrix.

[0003] Specifically, when the system is subjected to mechanical loads, the bonding strength at the interface between the energy storage layer and the structural layer is insufficient, causing interlayer shear stress concentration, leading to crack propagation and delamination failure at the interface between the carbon fiber reinforcement and the matrix, and ultimately causing the rapid decay of the overall stiffness and load-bearing capacity of the structural battery. In order to solve the interface delamination failure problem of current carbon fiber reinforced structural batteries, researchers have added binders to the electrode materials and constructed bionic structures to improve the interface strength between the electrode materials and the current collectors. However, this method not only has limited improvement effects, but also reduces the electrochemical performance of the battery as the adhesive (binder) and structure are added.

[0004] Therefore, the prior art still needs to be improved and developed. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, an object of the present invention is to provide a three-dimensional enhanced structural battery and a preparation method thereof, aiming to solve the problem that the electrochemical performance and load-bearing capacity of the existing structural battery cannot be taken into account at the same time.

[0006] The technical solution of the present invention is as follows:

[0007] A three-dimensional reinforced structural battery comprises a plurality of first reinforcing fiber layers, a plurality of first insulating fiber layers, a battery layer, a plurality of second insulating fiber layers and a plurality of second reinforcing fiber layers stacked in sequence from bottom to top; and a plurality of reinforcing ribs arranged through the plurality of first insulating fiber layers, the battery layer and the plurality of second insulating fiber layers.

[0008] In the three-dimensional reinforced structural battery, the ratio of the diameter of the reinforcing rib to the diameter of the fiber bundle in the first reinforcing fiber layer is 0.5-3.

[0009] The three-dimensional reinforced structural battery, wherein the reinforcing ribs are one or more of columnar insulating fibers, linear insulating fibers, columnar fibers with surface insulation treatment, and linear fibers with surface insulation treatment.

[0010] The three-dimensional enhanced structural battery, wherein a plurality of the reinforcing ribs are distributed in a matrix and penetrate through a plurality of the first insulating fiber layers, the battery layer, and a plurality of the second insulating fiber layers.

[0011] The three-dimensional enhanced structural battery, wherein the reinforcing ribs penetrate through a plurality of the first insulating fiber layers, the battery layer, and a plurality of the second insulating fiber layers in one of a lockstitch, a tufted stitch, a blind stitch, and a double-needle double-thread chain stitch.

[0012] The three-dimensional enhanced structural battery, wherein the material of a plurality of the first insulating fiber layers includes one or more of glass fiber, aramid fiber, and basalt fiber; the material of a plurality of the second insulating fiber layers includes one or more of glass fiber, aramid fiber, and basalt fiber.

[0013] The three-dimensional enhanced structural battery, wherein the material of a plurality of the first reinforcing fiber layers includes one or more of carbon fiber, ceramic fiber, boron fiber, glass fiber, aramid fiber, and basalt fiber; the material of a plurality of the second reinforcing fiber layers includes one or more of carbon fiber, ceramic fiber, boron fiber, glass fiber, aramid fiber, and basalt fiber.

[0014] The three-dimensional enhanced structural battery, wherein the battery layer includes a battery positive electrode layer, a battery negative electrode layer, and a separator and electrolyte composite layer sandwiched between the battery positive electrode layer and the battery negative electrode layer.

[0015] A preparation method of a three-dimensional enhanced structural battery, comprising the steps of:

[0016] Stacking a plurality of first insulating fibers, a battery layer, and a plurality of second insulating fibers in sequence to obtain a composite layer;

[0017] Performing a stitching process on the lamination direction of the composite layer by using an insulating needle and a linear reinforcing rib to obtain a stitched body;

[0018] Disposing a plurality of first reinforcing fibers and a plurality of second reinforcing fibers on both sides of the stitched body respectively and in a mold, filling resin into the mold, and demolding after curing to obtain a three-dimensional enhanced structural battery.

[0019] A preparation method of a three-dimensional enhanced structural battery, comprising the steps of:

[0020] Stacking a plurality of first reinforcing fiber layers, a plurality of first insulating fiber layers, a battery layer, a plurality of second insulating fiber layers, and a plurality of second reinforcing fiber layers in sequence to obtain a three-dimensional enhanced structural battery precursor;

[0021] Performing a drilling process on the lamination direction of the three-dimensional enhanced structural battery precursor to obtain a three-dimensional enhanced structural battery precursor with through holes;

[0022] Insert a columnar reinforcing rib into the through-hole, and fill the interface between the columnar reinforcing rib and the through-hole with a resin material. After curing, a three-dimensionally reinforced structural battery is obtained.

[0023] Beneficial effects: The present invention provides a three-dimensionally reinforced structural battery and a preparation method thereof. The three-dimensionally reinforced structural battery includes a plurality of first reinforcing fiber layers, a plurality of first insulating fiber layers, a battery layer, a plurality of second insulating fiber layers, and a plurality of second reinforcing fiber layers that are sequentially stacked from bottom to top; and a plurality of reinforcing ribs that penetrate through a plurality of the first insulating fiber layers, the battery layer, and a plurality of the second insulating fiber layers. The present invention uses the method of penetrating and reinforcing with reinforcing ribs to construct a three-dimensional cross-linked reinforcement network in the dimension of the vertical lamination direction, and forms a multi-scale spatial anchoring system with high-strength reinforcing ribs, which can significantly improve the interlayer shear strength and interface bonding force; moreover, by reconstructing the mechanical transmission path to achieve uniform load distribution, it can inhibit the initiation and propagation of cracks while maintaining the integrity of the electrochemical function. Description of the Drawings

[0024] Figure 1 It is a schematic structural diagram of a three-dimensionally reinforced structural battery of the present invention;

[0025] Figure 2 It is a schematic diagram of a lockstitch;

[0026] Figure 3 It is a schematic diagram of suturing the structural battery;

[0027] Figure 4 It is a stress-strain curve diagram of the unsutured structural battery and the sutured structural battery in Example 1;

[0028] Figure 5 It is an actual effect diagram of the load test of the unsutured structural battery and the sutured structural battery in Example 1. Detailed Embodiments

[0029] The present invention provides a three-dimensionally reinforced structural battery and a preparation method thereof. To make the purpose, technical solution and effects of the present invention clearer and more definite, the present invention is further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0030] Those skilled in the art can understand that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those of ordinary skill in the art to which this invention belongs. It should also be understood that terms such as those defined in a general dictionary should be understood to have a meaning consistent with the meaning in the context of the prior art, and will not be interpreted in an idealized or overly formal sense unless specifically defined as here.

[0031] Structural batteries are a disruptive energy storage technology. By using composite materials with both high mechanical strength and energy storage capacity (such as carbon fiber reinforced polymers), the batteries are directly embedded in the structural components of the device, enabling them to perform the dual functions of energy storage and mechanical support simultaneously. This design breaks through the limitations of traditional batteries installed independently, significantly reduces the system weight and optimizes the space utilization rate, and has great potential in fields that require both lightweight and efficient energy management, such as electric vehicles (integration of body and battery), aerospace (structural power generation and energy storage of aircraft), and wearable devices (flexible and lightweight power supply), and is expected to promote the deep integration of future sustainable energy and intelligent materials.

[0032] However, composite material structural batteries may delaminate under external forces due to the weak interfacial bonding force between the glass fiber layer and the positive or negative electrode layer of the battery, as well as between the positive and negative electrodes of the battery and the battery separator.

[0033] Based on this, as Figure 1 shown, the present invention provides a three-dimensional reinforced structural battery, including a plurality of first reinforcing fiber layers 10, a plurality of first insulating fiber layers 20, a battery layer 30, a plurality of second insulating fiber layers 40, and a plurality of second reinforcing fiber layers 50, which are sequentially stacked from bottom to top; and a plurality of reinforcing ribs 60 penetrating through the plurality of first insulating fiber layers 20, the battery layer 30, and the plurality of second insulating fiber layers 40.

[0034] In this embodiment, by using the method of penetrating and reinforcing with reinforcing ribs, a three-dimensional cross-linked reinforcement network is constructed in the dimension of the vertical lamination direction, and a multi-scale spatial anchoring system is formed by using high-strength reinforcing ribs, which can significantly improve the interlaminar shear strength and interfacial bonding force; moreover, by reconstructing the mechanical transmission path to achieve uniform load distribution, the crack initiation and propagation can be inhibited while maintaining the integrity of the electrochemical function.

[0035] Specifically, reinforcing ribs are introduced in a direction perpendicular to the reinforcing fiber layer, the insulating fiber layer, and the battery layer, and the parts of the structural battery prone to delamination are strengthened by the reinforcing ribs in the vertical direction; further, the plane where the fibers and the battery are located is defined as the XY plane, and the direction perpendicular to the XY plane is the Z direction. Reinforcing ribs are introduced in the Z direction, passing through the first insulating fiber layer, the battery layer, and the second insulating fiber layer. When the structural battery is stressed in the Z direction, it plays a load-bearing role and prevents interlayer failure.

[0036] In some embodiments, the ratio of the diameter of the reinforcing rib to the diameter of the fiber bundle in the first reinforcing fiber layer is 0.5 to 3. Combining with the actual application requirements of the structural battery, by controlling the diameter of the reinforcing rib, the bearing capacity of the structural battery can be adjusted, thereby preventing interlayer failure.

[0037] In a preferred embodiment, the ratio of the diameter of the reinforcing rib to the diameter of the fiber bundle in the first reinforcing fiber layer is 1.5 or 0.5.

[0038] In some embodiments, the reinforcing rib is one or more of columnar insulating fibers, linear insulating fibers, columnar fibers with surface insulation treatment, and linear fibers with surface insulation treatment. Combining with the actual application of the structural battery, the type of the reinforcing rib can be selected. The columnar reinforcing rib realizes the three-dimensional reinforcement of the structural battery by means of open-hole implantation, and the linear reinforcing rib realizes the three-dimensional reinforcement of the structural battery by means of stitching.

[0039] Specifically, columnar insulating fibers or linear insulating fibers can be directly introduced into the lamination direction of the structural battery as reinforcing ribs without affecting the performance of the battery; while using non-insulating fibers as reinforcing ribs, their surfaces need to be insulated to avoid causing battery short-circuit.

[0040] In a preferred embodiment, the reinforcing rib is made of linear glass fiber or columnar carbon fiber with surface insulation treatment.

[0041] In some embodiments, a plurality of the reinforcing ribs are distributed in a matrix and penetrate through a plurality of the first insulating fiber layers, the battery layer, and a plurality of the second insulating fiber layers. The reinforcing ribs distributed in a matrix can make the three-dimensional load-bearing structure of the structural battery uniform, improve the uniformity of the bearing capacity of the structural battery, and thus prevent interlayer failure.

[0042] In some embodiments, the reinforcing rib penetrates through a plurality of the first insulating fiber layers, the battery layer, and a plurality of the second insulating fiber layers in one of lockstitch, tufting stitch, blind stitch, and double-needle double-thread chain stitch. By manufacturing the composite material structural battery in the way of fiber penetration and stitching reinforcement, reinforcing ribs can be introduced in the stacking direction of a two-dimensional stacked and distributed structural battery to form a three-dimensional load-bearing structure, thereby preventing interlayer failure.

[0043] In some embodiments, such as Figure 2 shown, the reinforcing ribs penetrate through a plurality of the first insulating fiber layers, the battery layer, and a plurality of the second insulating fiber layers in a lockstitch pattern, which is more conducive to reducing concentrated stress and improving the interlayer damage tolerance. Compared with the traditional lockstitch pattern, there are no interlocking coils inside the improved lockstitch preform, reducing the bending of the sewing thread and the wear between the sewing threads.

[0044] In some embodiments, a plurality of the reinforcing ribs also penetrate through a plurality of the first reinforcing fiber layers and a plurality of the second reinforcing fiber layers, further improving the interlayer shear strength and the interfacial bonding force.

[0045] In some embodiments, when the reinforcing ribs reinforce the structural battery by stitching, the area occupied by the reinforcing ribs in the plane of the first insulating fiber layer is 5%-30% of the area within the region where the reinforcing ribs are located.

[0046] In some embodiments, when the reinforcing ribs reinforce the structural battery by stitching, the stitching pattern includes, but is not limited to, a square pattern of horizontal and vertical intersections, a diagonal line pattern, a fragment pattern, etc.

[0047] In some embodiments, the material of a plurality of the first insulating fiber layers includes one or more of glass fiber, aramid fiber, and basalt fiber; the material of a plurality of the second insulating fiber layers includes one or more of glass fiber, aramid fiber, and basalt fiber. Using the first insulating layer and the second insulating layer as the coating layers of the battery layer can improve the bearing capacity of the structural battery, and using the above-mentioned insulating fibers can prevent the coating layers from interfering with the battery.

[0048] In some embodiments, such as Figure 3 shown, the battery layer includes a plurality of battery packs connected in series or in parallel. The first insulating fiber layer and the second insulating fiber layer form a sandwich relationship with it, and a plurality of reinforcing ribs are provided in its lamination direction, while improving the bearing capacity and maintaining the original electrochemical performance of the battery.

[0049] In some embodiments, the material of a plurality of the first reinforcing fiber layers includes one or more of carbon fiber, ceramic fiber, boron fiber, glass fiber, aramid fiber, and basalt fiber; the material of a plurality of the second reinforcing fiber layers includes one or more of carbon fiber, ceramic fiber, boron fiber, glass fiber, aramid fiber, and basalt fiber. The first reinforcing fiber layer and the second reinforcing fiber layer play a role in further enhancing the bearing capacity of the structural battery and further strengthening the mechanical strength of the structural battery.

[0050] In some embodiments, the battery layer includes a battery positive electrode layer, a battery negative electrode layer, and a separator and electrolyte composite layer sandwiched between the battery positive electrode layer and the battery negative electrode layer.

[0051] In some embodiments, the battery positive electrode layer includes a positive electrode current collector and a positive electrode material attached to the positive electrode current collector; the positive electrode current collector includes, but is not limited to, carbon fiber, copper foil, and aluminum foil.

[0052] In some embodiments, the battery negative electrode layer includes a negative electrode current collector and a negative electrode material attached to the negative electrode current collector; the negative electrode current collector includes, but is not limited to, carbon fiber, copper foil, and aluminum foil.

[0053] In some embodiments, the electrolyte in the separator and electrolyte composite layer is a resin-based electrolyte, which may be, but is not limited to, other solid electrolytes such as sulfides or oxides.

[0054] In some embodiments, the separator in the separator and electrolyte composite layer may be, but is not limited to, other materials such as PP and cellulose used as battery separators (isolating electrons and allowing ions to pass through).

[0055] In addition, the present invention also provides a method for preparing a three-dimensional enhanced structural battery, including the steps of:

[0056] Step S10: Stack a plurality of first insulating fibers, a battery layer, and a plurality of second insulating fibers in sequence to obtain a composite layer;

[0057] Step S20: Use an insulating needle and a linear reinforcing rib to perform suture treatment on the lamination direction of the composite layer to obtain a sutured body;

[0058] Step S30: Dispose a plurality of first reinforcing fibers and a plurality of second reinforcing fibers on both sides of the sutured body respectively and place them in a mold. Fill the mold with resin, and after curing, demold to obtain a three-dimensional enhanced structural battery.

[0059] In this embodiment, the above preparation method can be used to obtain a sutured three-dimensional enhanced structural battery. By using an insulating needle and a linear reinforcing rib, the composite layer composed of a plurality of first insulating fibers, a battery layer, and a plurality of second insulating fibers can be sutured, and a reinforcing rib is introduced in the stacking direction to form a three-dimensional load-bearing structure. Finally, through the further encapsulation treatment using reinforcing fibers and resin, the overall mechanical performance and load-bearing capacity of the structural battery are improved, thereby preventing interlayer failure.

[0060] In some embodiments, the materials and equipment used in the stitching process include insulated needles, fiberglass, and a tabletop sewing machine. The composite layers are stitched together using the tabletop sewing machine. Then, a number of first reinforcing fibers and a number of second reinforcing fibers are respectively arranged on both sides of the stitched body, and laid on a glass plate that has been sprayed with a release agent. A release cloth and a flow guide net are laid on it, and flow guide tubes and resin flow guide nozzles are arranged on the short sides of the fiber area. Finally, a vacuum bag is covered over the entire area, evacuated, and then the prepared resin is introduced into the vacuum bag. After the resin completely infiltrates the fibers, the flow is stopped, and the vacuum is maintained in the vacuum bag. It is cured at room temperature for 24 hours, and then demolded to obtain a three-dimensionally reinforced structural battery.

[0061] In addition, the present invention also provides another method for preparing a three-dimensionally reinforced structural battery, including the steps of:

[0062] Step S100: Stack a number of first reinforcing fiber layers, a number of first insulating fiber layers, a battery layer, a number of second insulating fiber layers, and a number of second reinforcing fiber layers in sequence to obtain a precursor of a three-dimensionally reinforced structural battery;

[0063] Step S200: Drill holes in the lamination direction of the precursor of the three-dimensionally reinforced structural battery to obtain a precursor of a three-dimensionally reinforced structural battery with through holes;

[0064] Step S300: Insert columnar reinforcing ribs into the through holes, and fill the interface between the columnar reinforcing ribs and the through holes with a resin material, and after curing, obtain a three-dimensionally reinforced structural battery.

[0065] In this embodiment, an implantable three-dimensionally reinforced structural battery can be obtained by using the above preparation method. By opening holes in the structural battery, then inserting columnar reinforcing ribs and performing insulation treatment and caulking treatment, a three-dimensionally reinforced structural battery can be obtained. The three-dimensionally reinforced structural battery obtained by this preparation method realizes uniform load distribution through the reconstruction of the mechanical transmission path, and can maintain the integrity of the electrochemical function while suppressing the initiation and propagation of cracks.

[0066] The following further gives examples to illustrate the present invention in detail. It should also be understood that the following examples are only used to further illustrate the present invention, and cannot be construed as limiting the protection scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention all fall within the protection scope of the present invention.

[0067] Example 1

[0068] In this example, fiber stitching is used to introduce reinforcing ribs in the Z direction, specifically as follows:

[0069] 1) Preparation of electrodes and electrolytes

[0070] Electrode: Active materials (lithium iron phosphate for cathode and graphite for anode), conductive carbon black and PVDF were fully mixed in a weight ratio of 8:1:1, and then an appropriate amount of NMP was added to prepare positive and negative electrode slurries with suitable viscosity. The prepared positive and negative electrode slurries were evenly scraped on the flat carbon fiber (thickness of 0.1 mm), and then heated in a vacuum drying oven at 80°C for 12 hours to obtain carbon fiber positive and negative electrodes with a two-dimensional planar shape structure.

[0071] Electrolyte and diaphragm: Use resin-based electrolyte to impregnate glass fiber fabric and pre-cure it to achieve a state where the electrolyte does not flow freely but is not completely cured enough to be punctured by a needle, preventing disorderly flow of electrolyte.

[0072] Specifically, the prepared electrolyte is placed at room temperature for 30-60 minutes for pre-curing, and the resin component in the electrolyte will initially react to become a gel; or the resin used in the process of making the electrolyte is a high-viscosity resin (above 2000cps).

[0073] 2) Lamination

[0074] Two layers of glass fiber, a carbon fiber positive electrode, a pre-cured electrolyte-glass fiber, a carbon fiber negative electrode, and two layers of glass fiber are stacked in sequence, and the carbon fiber positive electrode, the pre-cured electrolyte-glass fiber and the carbon fiber negative electrode constitute a battery pack, and the glass fiber sandwich is provided with two battery packs connected in series.

[0075] 3) Suture

[0076] The materials and equipment used in the suturing process include insulated needles, fiberglass, and a table sewing machine. The stitches used for suturing are modified lock stitches (such as Figure 2 Use a sewing machine to sew the seven layers of fiber together, with the stitching area covering the area where the battery material is located (as shown in Figure 3 shown).

[0077] 4) Curing

[0078] Two layers of carbon fiber are set on both sides of the stitched fibers, and laid on a glass plate that has been sprayed with a release agent. A release cloth and a guide net are laid on top, and a guide tube and a resin guide nozzle are arranged on the short side of the fiber area. Finally, a vacuum bag is covered on the entire area, and a vacuum is drawn. The prepared resin is then introduced into the vacuum bag. After the resin has completely infiltrated the fibers, the guide is stopped, the vacuum is maintained in the vacuum bag, and the battery is cured at room temperature for 24 hours to obtain a three-dimensional reinforced structural battery.

[0079] The structural battery obtained by using the same method as above without stitching was used as a control group, and stress-strain tests were carried out on it. The stress-strain curves of the unstitched structural battery (control) and the stitched structural battery (stitching) are as shown in Figure 4 shown, and the actual effect diagram of the load test is as shown in Figure 5 shown; it can be seen that the mechanical properties of the composite laminate decrease significantly after embedding a commercial thin-film battery. The embedding of the battery core will significantly reduce the interlaminar bonding force between the upper and lower fibers of the battery, and obvious delamination will occur under the action of external forces (as shown in Figure 5 a and c in). Stitching fiber lines in the area where the battery core is located adds constraints in the vertical direction to make the two-dimensional fiber distribution composite material into a three-dimensional structure, strengthens the interlaminar bonding force of the composite material, and inhibits the occurrence of delamination (as shown in Figure 5 b and d in).

[0080] Example 2

[0081] In this example, a columnar carbon fiber rod was used to introduce a reinforcing rib in the Z direction, specifically as follows:

[0082] 1) Battery manufacturing. Here, the battery is mainly responsible for the electrochemical energy storage function, and it can be a battery with a carbon fiber current collector resin-based solid electrolyte or a solid battery encapsulated in a plastic soft package.

[0083] 2) Preparation of columnar carbon fiber rods

[0084] Carbon fiber bundle: T800 grade 12K carbon fiber, surface etched with nitric acid to increase roughness (Ra increased from 0.5 to 2.1 μm);

[0085] Pretreatment: Heat treatment in a nitrogen environment at 450 °C to remove organic impurities;

[0086] Gradient insulation coating was carried out on the heat-treated carbon fiber bundle: first, ALD deposition of amorphous Al2O3 (thickness 500 nm, growth rate 0.1 nm / cycle, 250 °C) was carried out on the heat-treated carbon fiber bundle as the bottom layer, and then a SiO2-TiO2 hybrid coating (thickness 2 μm, dielectric strength 30 kV / mm) was coated by the sol-gel method as the intermediate layer, and finally an epoxy resin containing BN nanosheets (30 wt% filling amount, thermal conductivity 5 W / m·K) was used as the outer layer.

[0087] Forming process: A rod with a diameter of 1.2 mm was made by three-dimensional braiding technology, and then vacuum pressure impregnation (0.8 MPa) and high-temperature curing (180 °C / 2 h) were carried out. Finally, surface plasma treatment (Ar / O2 mixed gas) was carried out to improve the bonding force with the matrix to obtain a columnar carbon fiber rod.

[0088] 3) Combination

[0089] Layup sequence: Carbon fiber composite outer layer (2 layers of E-glass / bismaleimide) → positive electrode → separator and electrolyte composite layer → negative electrode → carbon fiber composite outer layer (2 layers of E-glass / bismaleimide).

[0090] Pre-drilling positioning: Laser-induced breakdown to prepare 0.8 mm guiding holes (hexagonal close-packed with a spacing of 3 mm)

[0091] Reinforcing rib implantation: Use ultrasonic vibration to assist in inserting columnar carbon fiber rods (frequency 28 kHz, amplitude 50 μm), and the implantation depth error < 20 μm.

[0092] Interface filling: Inject low-viscosity epoxy silica resin (viscosity 200 cP, volume shrinkage rate < 0.5%) into the gap between the reinforcing ribs and the holes.

[0093] Isolation and protection: Fabricate an annular insulating groove (depth 0.1 mm) in the electrode-reinforcing rib contact area and fill it with BN / epoxy composite material to obtain a three-dimensionally reinforced structural battery.

[0094] In summary, a three-dimensionally reinforced structural battery and its preparation method provided by the present invention. The three-dimensionally reinforced structural battery includes a plurality of first reinforcing fiber layers, a plurality of first insulating fiber layers, a battery layer, a plurality of second insulating fiber layers, and a plurality of second reinforcing fiber layers that are sequentially stacked from bottom to top; and a plurality of reinforcing ribs that penetrate through the plurality of first insulating fiber layers, the battery layer, and the plurality of second insulating fiber layers. The present invention uses the method of penetrating and reinforcing with reinforcing ribs to construct a three-dimensional cross-linked reinforcement network in the dimension perpendicular to the lamination direction, and forms a multi-scale spatial anchoring system with high-strength reinforcing ribs, which can significantly improve the interlaminar shear strength and interfacial bonding force; moreover, by reconstructing the mechanical transmission path to achieve uniform load distribution, it can suppress the initiation and propagation of cracks while maintaining the integrity of the electrochemical function.

[0095] It should be understood that the application of the present invention is not limited to the above examples. For those of ordinary skill in the art, improvements or transformations can be made according to the above description, and all such improvements and transformations should fall within the protection scope of the appended claims of the present invention.

Claims

1. A three-dimensional enhanced structural battery, characterized in that It includes several first reinforcing fiber layers, several first insulating fiber layers, a battery layer, several second insulating fiber layers, and several second reinforcing fiber layers that are stacked in sequence from bottom to top; and several reinforcing ribs that penetrate through several of the first insulating fiber layers, the battery layer, and several of the second insulating fiber layers.

2. The three-dimensional enhanced structural battery according to claim 1, characterized in that The ratio of the diameter of the reinforcing rib to the diameter of the fiber bundle in the first reinforcing fiber layer is 0.5 to 3.

3. The three-dimensional enhanced structural battery according to claim 1, characterized in that, The reinforcing rib is one or more of columnar insulating fibers, linear insulating fibers, columnar fibers with surface insulation treatment, and linear fibers with surface insulation treatment.

4. The three-dimensional enhanced structural battery according to claim 1, characterized in that, Several of the reinforcing ribs are distributed in a matrix and penetrate through several of the first insulating fiber layers, the battery layer, and several of the second insulating fiber layers.

5. The three-dimensional enhanced structural battery according to claim 1, wherein The reinforcing rib penetrates through several of the first insulating fiber layers, the battery layer, and several of the second insulating fiber layers in one of lockstitch, tufting stitch, blind stitch, and double-needle double-thread chain stitch.

6. The three-dimensional enhanced structural battery according to claim 1, characterized in that, The materials of several of the first insulating fiber layers include one or more of glass fiber, aramid fiber, and basalt fiber; the materials of several of the second insulating fiber layers include one or more of glass fiber, aramid fiber, and basalt fiber.

7. The three-dimensional enhanced structural battery according to claim 1, wherein The materials of several of the first reinforcing fiber layers include one or more of carbon fiber, ceramic fiber, boron fiber, glass fiber, aramid fiber, and basalt fiber; the materials of several of the second reinforcing fiber layers include one or more of carbon fiber, ceramic fiber, boron fiber, glass fiber, aramid fiber, and basalt fiber.

8. The three-dimensional enhanced structural battery according to claim 1, characterized in that, The battery layer includes a battery positive electrode layer, a battery negative electrode layer, and a separator and electrolyte composite layer sandwiched between the battery positive electrode layer and the battery negative electrode layer.

9. A method for preparing a three-dimensional enhanced structural battery according to any one of claims 1-8, characterized in that, It includes steps: Stack several first insulating fibers, a battery layer, and several second insulating fibers in sequence to obtain a composite layer; Use an insulating needle and a linear reinforcing rib to perform stitching treatment on the lamination direction of the composite layer to obtain a stitched body; Set several first reinforcing fibers and several second reinforcing fibers on both sides of the stitched body in a mold, fill resin into the mold, and after curing, demold to obtain a three-dimensionally reinforced structural battery.

10. A method for preparing a three-dimensional enhanced structural battery according to any one of claims 1-8, characterized in that, It includes steps: Stack several first reinforcing fiber layers, several first insulating fiber layers, a battery layer, several second insulating fiber layers, and several second reinforcing fiber layers in sequence to obtain a three-dimensionally reinforced structural battery precursor; Perform drilling treatment on the lamination direction of the three-dimensionally reinforced structural battery precursor to obtain a three-dimensionally reinforced structural battery precursor with through holes; Implant columnar reinforcing ribs into the through holes, and fill a resin material at the interface between the columnar reinforcing ribs and the through holes, and after curing, obtain a three-dimensionally reinforced structural battery.

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