Functional gradient type nano composite glass fiber hydrogen storage bottle and preparation and monitoring method thereof

Abstract

The invention discloses a functional gradient type nano-composite glass fiber hydrogen storage bottle and a preparation and monitoring method thereof, and relates to the technical field of high-pressure gas storage equipment. The functional gradient type nano-composite glass fiber hydrogen storage cylinder comprises a modified polymer liner, a hydrogen storage functional layer, a gradient enhancement layer, a self-repairing protective layer and an embedded monitoring unit embedded in the structure which are sequentially arranged from inside to outside, so that the integration of structure enhancement, active hydrogen storage, damage self-repairing and intelligent monitoring is realized; the gradient enhancement layer optimizes material distribution according to stress distribution, and the overall mechanical efficiency and the lightweight level are improved; the hydrogen storage functional layer endows the bottle body structure with an auxiliary hydrogen storage capability; through cooperation of the self-repairing protective layer and the embedded monitoring unit, active repairing and real-time sensing of micro-damage are achieved, the reliability and safety of the hydrogen storage bottle are improved, and the service life of the hydrogen storage bottle is prolonged.

Description

Technical Field

[0001] This invention relates to the field of high-pressure gas storage equipment technology, specifically to a functionally graded nanocomposite glass fiber hydrogen storage bottle and its preparation and monitoring methods. Background Technology

[0002] High-pressure hydrogen storage cylinders are core components of hydrogen energy systems, and their performance directly affects the safety of the hydrogen storage system. Existing technologies mainly employ fully wound metal or plastic liner composite material structures for hydrogen storage cylinders. Among these, glass fiber reinforced composite materials are widely used as reinforcing layers due to their high strength and lightweight properties. For example, an existing patent (CN115164091B) discloses a three-dimensional braided cryogenic high-pressure hydrogen storage tank, which improves fatigue resistance by optimizing winding parameters; another solution (CN114953645A) uses a three-dimensional braided glass fiber layer with the inner and outer liner structures to improve thermal compatibility.

[0003] However, in existing technologies, the glass fiber layer mainly serves a mechanical reinforcement function, and its structure is usually homogeneous or a simple stack. It fails to strengthen the material properties according to the stress distribution in different areas of the bottle, which can easily lead to material redundancy or localized strength weaknesses. At the same time, the hydrogen storage capacity of existing hydrogen storage bottles relies entirely on high-pressure physical compression, and the glass fiber reinforcement itself does not have an auxiliary hydrogen storage function, resulting in a small increase in hydrogen storage density per unit mass. In terms of safety, existing technologies mostly rely on external sensors or periodic inspections, lacking real-time, online damage perception and early warning capabilities that are deeply integrated with the bottle structure. Furthermore, there is a lack of active repair mechanisms for damage such as cracks that occur during use, posing potential safety risks in long-term service. To address the shortcomings of existing technologies, this invention provides a functionally graded nanocomposite glass fiber hydrogen storage bottle and its preparation and monitoring methods to solve the above problems. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a functionally graded nanocomposite glass fiber hydrogen storage bottle and its preparation and monitoring methods. By constructing a multi-layered composite structure consisting of a modified polymer liner, a hydrogen storage functional layer, a gradient reinforcement layer, a self-healing protective layer, and an embedded monitoring unit, the invention achieves integrated structural reinforcement, active hydrogen storage, damage self-repair, and intelligent monitoring. The gradient reinforcement layer optimizes material distribution according to stress distribution, improving overall mechanical efficiency and lightweighting. The hydrogen storage functional layer endows the bottle structure with auxiliary hydrogen storage capabilities. The synergy between the self-healing protective layer and the embedded monitoring unit enables active repair and real-time sensing of micro-damage, improving the reliability, safety, and service life of the hydrogen storage bottle.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution: a functionally graded nanocomposite glass fiber hydrogen storage bottle, comprising, from the inside out, a modified polymer inner liner, a hydrogen storage functional layer, a gradient enhancement layer, a self-healing protective layer, and an embedded monitoring unit embedded in the structure.

[0006] The hydrogen storage functional layer includes a glass fiber reinforcement loaded with hydrogen storage active material; the volume fraction of glass fiber in the gradient reinforcement layer varies radially; the self-healing protective layer includes microcapsules encapsulating a repair agent; and the embedded monitoring unit is a conductive fiber network embedded in the bottle structure for real-time monitoring of the structural status.

[0007] Preferably, the modified polymer liner is a polyimide-based nanocomposite material, with a silane coupling agent treatment layer on its outer surface and an inner surface roughness Ra of 1.5 to 2.0 μm.

[0008] Preferably, the amount of nano-montmorillonite added to the modified polymer liner is 5 to 8 wt%.

[0009] Preferably, the hydrogen storage active material in the hydrogen storage functional layer includes titanium silicate nanosheets and Pd nanoparticles;

[0010] The titanosilicate nanosheets have a loading of 10 to 15 wt%, and the Pd nanoparticles have a particle size of 2 to 5 nm and a loading of 0.05 to 0.1 wt%.

[0011] Preferably, the hydrogen storage capacity of the hydrogen storage functional layer is not less than 0.4 wt% under the conditions of 298 K and 20 MPa.

[0012] Preferably, the volume fraction of glass fiber in the gradient reinforcement layer gradually increases from 55% to 75% from the inner layer to the outer layer;

[0013] The gradient reinforcement layer is formed using a laser-assisted winding process, with the inner layer winding angle ranging from 45° to 60° and the outer layer winding angle ranging from 10° to 15°.

[0014] Preferably, the self-healing protective layer is configured with a resin material as the substrate, the microcapsule wall material in the self-healing protective layer is urea-formaldehyde resin, the core material is two-component epoxy resin, and the content of microcapsules in the protective layer is 20 to 25 wt%.

[0015] The self-healing protective layer has a repair efficiency of no less than 80% for cracks with a width not exceeding 50μm.

[0016] Preferably, the conductive fibers in the embedded monitoring unit are carbon nanotube-modified glass fibers, and the spacing between the conductive fibers is 5 to 8 mm.

[0017] The monitoring unit has a damage location accuracy of ±5mm and a response time of no more than 1 second.

[0018] Preferably, the hydrogen storage cylinder also includes an external monitoring terminal that is communicatively connected to the embedded monitoring unit for real-time display of the damage location and repair status.

[0019] This invention also discloses a method for preparing and monitoring a functionally graded nanocomposite glass fiber hydrogen storage bottle, comprising the following steps:

[0020] Step S1: Prepare the modified polymer liner and treat its outer surface with a silane coupling agent;

[0021] Step S2: Titanium silicate nanosheets and Pd nanoparticles are loaded onto the surface of glass fiber to form a hydrogen storage functional layer preform.

[0022] Step S3: Using laser-assisted winding technology, glass fibers are wound layer by layer according to a preset angle and volume fraction gradient to form a gradient reinforcement layer;

[0023] Step S4: Lay a conductive fiber network on the outer surface of the gradient enhancement layer to form an embedded monitoring unit;

[0024] Step S5: Coat the outside of the monitoring unit with a self-healing resin containing microcapsules and cure to form a self-healing protective layer;

[0025] Step S6: Composite each layer sequentially and solidify the whole to complete the preparation of the hydrogen storage bottle;

[0026] Step S7: The embedded monitoring unit collects structural status data in real time to locate and assess the damage.

[0027] The technical effects and advantages of this invention are as follows:

[0028] 1. This functionally graded nanocomposite glass fiber hydrogen storage cylinder achieves integrated structural reinforcement, active hydrogen storage, damage self-repair, and intelligent monitoring by constructing a multi-layered composite structure consisting of a modified polymer inner liner, a hydrogen storage functional layer, a gradient reinforcement layer, a self-healing protective layer, and an embedded monitoring unit. The gradient reinforcement layer optimizes material distribution according to stress distribution, improving overall mechanical efficiency and lightweight level; the hydrogen storage functional layer endows the cylinder structure with auxiliary hydrogen storage capacity; the synergy between the self-healing protective layer and the embedded monitoring unit enables active repair and real-time sensing of micro-damage, improving the reliability, safety, and service life of the hydrogen storage cylinder.

[0029] 2. This functionally graded nanocomposite glass fiber hydrogen storage cylinder features a gradient reinforcement layer where the glass fiber volume fraction increases radially from 55% to 75% from the inside out. Combined with a winding angle design of 45°-60° for the inner layer and 10°-15° for the outer layer, this achieves a precise gradient distribution of mechanical properties, effectively matching the different stress states of the inner and outer layers of the cylinder. This maximizes weight reduction while ensuring load-bearing capacity. The hydrogen storage functional layer, through in-situ loading of titanate nanosheets and Pd nanoparticles, endows the glass fiber reinforcement with significant physicochemical hydrogen storage capacity, achieving a capacity of no less than 0.4 wt% at 298 K and 20 MPa. This represents a functional leap in the structural material, improving the overall hydrogen storage density.

[0030] 3. This functionally graded nanocomposite glass fiber hydrogen storage bottle achieves autonomous repair of microcracks less than 50μm in width by integrating microcapsules containing repair agents into a self-healing protective layer, effectively inhibiting damage propagation. At the same time, the carbon nanotube-modified glass fiber conductive network embedded in the structure constitutes an embedded monitoring unit, which can locate damage in real time with an accuracy of ±5mm and a response within 1 second, and communicate with an external terminal to achieve status visualization. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0033] Figure 2 This is a schematic diagram of the microcapsules of the present invention;

[0034] Figure 3 This is a schematic diagram of the method flow of the present invention.

[0035] In the figure: 1. Modified polymer inner liner; 2. Hydrogen storage functional layer; 3. Gradient reinforcement layer; 4. Self-healing protective layer; 41. Microcapsule; 5. Embedded monitoring unit. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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.

[0037] This embodiment discloses a functionally graded nanocomposite glass fiber hydrogen storage bottle, according to the attached... Figure 1 To be continued Figure 3 As shown, it includes, from the inside out, a modified polymer inner liner 1, a hydrogen storage functional layer 2, a gradient enhancement layer 3, a self-healing protective layer 4, and an embedded monitoring unit 5 embedded in the structure.

[0038] According to the appendix Figure 1 As shown, the modified polymer inner liner 1 constitutes the innermost barrier layer of the hydrogen storage cylinder, which comes into contact with hydrogen gas. Its material is a polyimide-based nanocomposite material, in which nano-montmorillonite is uniformly dispersed at an addition amount of 5 to 8 wt%. The inner surface of the modified polymer inner liner 1 is treated with a specific process, with a roughness Ra controlled at 1.5 to 2.0 μm to increase the specific surface area and affect gas adsorption behavior. The outer surface of the modified polymer inner liner 1 is treated with a silane coupling agent layer to enhance the interfacial bonding force with the outer hydrogen storage functional layer 2 and prevent interlayer delamination.

[0039] According to the appendix Figure 1 As shown, the hydrogen storage functional layer 2 is further tightly wrapped around the modified polymer inner liner 1. The hydrogen storage functional layer 2 includes a glass fiber reinforcement, and its surface is supported by a hydrogen storage active material composed of titanate nanosheets and Pd nanoparticles, grown in situ and loaded using in-situ growth and loading techniques. The titanate nanosheets are loaded with 10 to 15 wt%, and the layered structure of the hydrogen storage functional layer 2 provides abundant adsorption sites. The Pd nanoparticles have a particle size of 2 to 5 nm and a loading of 0.05 to 0.1 wt%, acting as a catalyst to effectively promote the dissociation and recombination of hydrogen. Through this design, the hydrogen storage functional layer 2 achieves a hydrogen storage capacity of no less than 0.4 wt% under conditions of 298 K and 20 MPa, realizing the auxiliary hydrogen storage function of the bottle structure itself.

[0040] According to the appendix Figure 1 As shown, furthermore, the gradient reinforcement layer 3 covers the hydrogen storage functional layer 2 and serves as the main load-bearing structure. The volume fraction of glass fiber in the gradient reinforcement layer 3 exhibits a continuous gradient along the radial direction, specifically increasing from approximately 55% in the inner layer near the inner liner to approximately 75% in the outer layer. The gradient reinforcement layer 3 is formed using a laser-assisted winding process, with precise control of resin impregnation and curing through real-time laser heating. The inner layer fiber winding angle is set to 45° to 60° to withstand greater shear stress; the outer layer fiber winding angle is adjusted to 10° to 15° to provide extremely high circumferential tensile strength. This gradient design and angle distribution synergistically optimize the mechanical properties and lightweight level of the bottle.

[0041] According to the appendix Figure 1 and appendix Figure 2As shown, the self-healing protective layer 4 constitutes the outermost protective system. The self-healing protective layer 4 uses epoxy resin or a similar resin material as its base material, in which microcapsules 41 are uniformly dispersed at a content of 20 to 25 wt%. The wall material of the microcapsules 41 is urea-formaldehyde resin, and the core material is a two-component epoxy resin repair agent. When a crack occurs on the exterior of the bottle due to impact, the crack propagation will cause the microcapsules 41 to rupture, and the released repair agent will undergo a polymerization reaction at the crack, thereby achieving self-healing of the crack. The self-healing protective layer 4 has a repair efficiency of no less than 80% for microcracks with a width not exceeding 50 μm.

[0042] According to the appendix Figure 1 As shown, the embedded monitoring unit 5 is a distributed sensing network embedded between the gradient reinforcement layer 3 and the self-healing protective layer 4. The embedded monitoring unit 5 is made of woven or laid conductive fibers, which are glass fibers modified with carbon nanotubes. The spacing between the nodes of the conductive fiber network is 5 to 8 mm. When damage occurs to the bottle structure, such as fiber breakage or matrix cracking, it will cause changes in the resistance or capacitance of the local conductive network. By monitoring these changes in electrical signals through an external circuit, damage events can be detected in real time. The embedded monitoring unit 5 has a positioning accuracy of ±5 mm and a response time of no more than 1 second.

[0043] According to the appendix Figure 1 To be continued Figure 3 As shown, it is particularly important to emphasize that the hydrogen storage cylinder also includes an external monitoring terminal that communicates with the embedded monitoring unit 5 wirelessly or via a wired connection. This terminal receives and processes signals from the embedded monitoring unit 5, and can display the location and extent of damage on a graphical interface in real time, as well as assess the activation status and repair progress of the self-healing protective layer 4, thereby achieving intelligent monitoring and early warning of the hydrogen storage cylinder's health status.

[0044] According to the appendix Figure 1 To be continued Figure 3 As shown, it is particularly important to emphasize that the various functional layers are integrated into a single unit through collaborative design and a one-piece molding process. The modified polymer inner liner 1 provides airtightness and barrier properties; the hydrogen storage functional layer 2 endows the structure with auxiliary hydrogen storage capabilities; the gradient reinforcement layer 3 provides mechanical support for gradient changes; the self-healing protective layer 4 ensures the surface integrity for long-term use; and the embedded monitoring unit 5 enables structural health monitoring throughout the entire life cycle. This multi-layered composite structure collectively improves the hydrogen storage efficiency, safety, reliability, and service life of the hydrogen storage cylinder.

[0045] Example 1: This example uses the preparation of a functionally graded nanocomposite glass fiber hydrogen storage bottle as an example, combined with the attached... Figure 1 To be continued Figure 3 Detailed explanation of its preparation process:

[0046] Step S1: Prepare the modified polymer inner liner 1. Add 6 wt% nano-montmorillonite and uniformly disperse it in a polyimide precursor solution. The mixture is then centrifuged, cast, and imidized to obtain the inner liner preform. The inner surface is mechanically ground to achieve a roughness Ra of 1.8 μm. The outer surface is impregnated with an aminosilane coupling agent solution and dried to form a treated layer.

[0047] Step S2 involves preparing the hydrogen storage functional layer 2 preform. The cleaned glass fiber fabric is immersed in an alkaline hydrothermal solution containing titanium and silicon sources. After the hydrothermal reaction, titanosilicon nanosheets are grown on the fiber surface. Subsequently, Pd nanoparticles with a particle size of approximately 3 nm are loaded onto the nanosheets using an ion exchange and reduction method, ultimately obtaining the glass fiber preform loaded with the hydrogen storage active material.

[0048] Step S3: Forming the gradient reinforcement layer 3. Epoxy resin-impregnated glass fiber yarn is wound onto a rotating mandrel consisting of the inner liner 1 and the functional layer preform using a laser-assisted winding machine. Through programmed control, the fiber volume fraction linearly and gradually changes from 55% in the inner layer to 75% in the outer layer during winding, while the winding angle gradually transitions from 55° in the inner layer to 12° in the outer layer. The laser beam irradiates the winding points in real time, preheating the resin to optimize wetting and initiate pre-curing.

[0049] Step S4: Integrate the embedded monitoring unit 5. On the outermost surface of the gradient reinforcement layer 3 before curing, a pre-prepared carbon nanotube modified glass fiber sensing network is precisely laid at a spacing of 5 mm and fixed with a small amount of resin to form a distributed monitoring unit.

[0050] Step S5: Form a self-healing protective layer 4 by uniformly coating an epoxy resin coating containing 20wt% urea-formaldehyde resin wall material microcapsules 41 onto the surface of the bottle on which the monitoring unit 5 has been laid, and then curing it at room temperature to form an outer protective layer with self-healing function.

[0051] Step S6, overall curing: The above composite structure is placed in an autoclave and cured according to the set heating and pressurization program to make each layer tightly bonded into an integral structure, thus completing the preparation of the hydrogen storage bottle.

[0052] Example 2: This example uses the real-time monitoring and repair process of a hydrogen storage cylinder as an example, combined with the attached... Figure 1 To be continued Figure 3 The workflow is explained in detail below:

[0053] During use, the external monitoring terminal continuously receives reference electrical signals from the conductive fiber network of the embedded monitoring unit 5. When the cylinder is locally impacted by a foreign object, the gradient reinforcement layer 3 or the self-healing protective layer 4 may suffer micro-damage. At this time, the conductive fibers in the damaged area break or deform, causing a sharp change in the network resistance at that point. The monitoring unit 5 captures this abnormal signal within 1 second and calculates the coordinates of the damage point using a user-preset algorithm, with a positioning accuracy of ±5mm. The damage location and alarm information are immediately sent to the external monitoring terminal and displayed.

[0054] Meanwhile, if damage causes microcracks to appear in the self-healing protective layer 4, the stress at the crack tip will cause the microcapsules 41 to rupture. The core material repair agent flows out and fills the crack gaps, and cross-links and cures under the action of ambient temperature or residual catalyst, thereby bonding and repairing the cracks.

[0055] In summary, integrating auxiliary hydrogen storage, gradient reinforcement, damage self-healing, and real-time health monitoring functions into a single bottle structure solves the problem of traditional hydrogen storage bottles only having load-bearing and airtight functions, thus improving overall performance. Through the synergistic effect of the nanostructures in the hydrogen storage functional layer 2, the material's own hydrogen storage capacity is increased, allowing for the storage of more hydrogen or a reduction in operating pressure under the same pressure, resulting in higher safety. The gradient reinforcement layer 3 is designed to optimally match mechanical properties with material distribution, achieving lightweight while ensuring pressure resistance. The self-healing protective layer 4 can automatically repair microcracks generated during service, effectively delaying damage propagation and extending service life. The embedded monitoring unit 5 enables real-time, online, and precise monitoring of the bottle structure's condition.

[0056] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A functionally graded nanocomposite glass fiber hydrogen storage bottle, characterized in that, From the inside out, the following are included: Modified polymer liner (1); Hydrogen storage functional layer (2), wherein the hydrogen storage functional layer (2) comprises a glass fiber reinforcement loaded with hydrogen storage active material; The gradient reinforcement layer (3) has a gradient in the volume fraction of glass fibers along the radial direction; The self-healing protective layer (4) contains microcapsules (41) encapsulating a repair agent. The embedded monitoring unit (5) is a conductive fiber network embedded in the bottle structure, used to monitor the structural status in real time.

2. The functionally graded nanocomposite glass fiber hydrogen storage bottle according to claim 1, characterized in that, The modified polymer liner (1) is a polyimide-based nanocomposite material with a silane coupling agent treatment layer on its outer surface and an inner surface roughness Ra of 1.5 to 2.0 μm.

3. The functionally graded nanocomposite glass fiber hydrogen storage bottle according to claim 2, characterized in that, The amount of nano-montmorillonite added in the modified polymer liner (1) is 5 to 8 wt%.

4. The functionally graded nanocomposite glass fiber hydrogen storage bottle according to claim 1, characterized in that, The hydrogen storage active materials in the hydrogen storage functional layer (2) include titanium silicate nanosheets and Pd nanoparticles. The titanosilicate nanosheets have a loading of 10 to 15 wt%, and the Pd nanoparticles have a particle size of 2 to 5 nm and a loading of 0.05 to 0.1 wt%.

5. A functionally graded nanocomposite glass fiber hydrogen storage bottle according to claim 4, characterized in that, The hydrogen storage capacity of the hydrogen storage functional layer (2) under the conditions of 298K and 20MPa is not less than 0.4wt%.

6. A functionally graded nanocomposite glass fiber hydrogen storage bottle according to claim 1, characterized in that, The volume fraction of glass fiber in the gradient reinforcement layer (3) gradually increases from 55% to 75% from the inner layer to the outer layer; The gradient reinforcement layer (3) is formed by laser-assisted winding process, with the inner layer winding angle being 45° to 60° and the outer layer winding angle being 10° to 15°.

7. A functionally graded nanocomposite glass fiber hydrogen storage bottle according to claim 1, characterized in that, The self-healing protective layer (4) is made of resin material as the base material. The wall material of the microcapsules (41) in the self-healing protective layer (4) is urea-formaldehyde resin, and the core material is two-component epoxy resin. The content of microcapsules (41) in the protective layer is 20 to 25 wt%. The self-healing protective layer (4) has a repair efficiency of no less than 80% for cracks with a width not exceeding 50 μm.

8. A functionally graded nanocomposite glass fiber hydrogen storage bottle according to claim 1, characterized in that, The conductive fibers in the embedded monitoring unit (5) are carbon nanotube modified glass fibers, and the spacing between the conductive fibers is 5 to 8 mm. The monitoring unit has a damage location accuracy of ±5mm and a response time of no more than 1 second.

9. A functionally graded nanocomposite glass fiber hydrogen storage bottle according to claim 1, characterized in that, The hydrogen storage cylinder also includes an external monitoring terminal that is communicatively connected to the embedded monitoring unit (5) for real-time display of the damage location and repair status.

10. A method for preparing and monitoring a functionally graded nanocomposite glass fiber hydrogen storage bottle as described in any one of claims 1 to 9, characterized in that, Includes the following steps, Step S1: Prepare the modified polymer inner liner (1) and treat its outer surface with a silane coupling agent; Step S2: Titanium silicate nanosheets and Pd nanoparticles are loaded onto the surface of glass fiber to form a hydrogen storage functional layer (2) preform; Step S3: Using laser-assisted winding technology, glass fibers are wound layer by layer according to a preset angle and volume fraction gradient to form a gradient reinforcement layer (3). Step S4: A conductive fiber network is laid on the outer surface of the gradient enhancement layer (3) to form an embedded monitoring unit (5). Step S5: Coat the outside of the monitoring unit with a self-healing resin containing microcapsules (41) and cure to form a self-healing protective layer (4). Step S6: Composite each layer sequentially and solidify the whole to complete the preparation of the hydrogen storage bottle; Step S7: The embedded monitoring unit (5) collects structural status data in real time to realize the location and repair assessment of damage.

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