Polymer-graphene composite, component for hydrogen storage and / or transport, and hydrogen carrier

Abstract

The present disclosure relates to a polymer-based composite material and an assembly for hydrogen storage and / or transport comprising a hollow body and at least one hydrogen barrier liner disposed on the body wherein the at least one hydrogen barrier liner comprises the polymer-based composite material. A method of manufacturing an assembly for hydrogen storage and / or transport includes lining an inner surface of the assembly with one of the at least one hydrogen barrier liner.

Description

Technical Field

[0001] This patent disclosure is in the field of hydrogen transport and storage and polymer-based materials for such transport and storage. Specific embodiments relate to polymer-based composite materials, components for hydrogen storage and / or transport, methods for making such components, and uses of polymer-based composite materials. Background Art

[0002] In recent years, there has been growing interest in using hydrogen in fuel cells to generate electricity. As long as green hydrogen is produced in a process that does not produce carbon dioxide, it can be considered a zero-carbon source of electricity.

[0003] However, for hydrogen to reach its full potential as a clean energy source, it will need to be transported to where it is to be used, which can be quite far. For example, hydrogen may have to be transported from where it is produced to factories, or to various vehicles such as cars, trucks, and buses, where it can be used as a fuel source. Transporting both liquid and gaseous hydrogen is challenging due to its small size. Hydrogen is highly permeable, making it difficult to contain.

[0004] In recent years, numerous reports have discussed the increasing amount of hydrogen in the air. It has been discussed that hydrogen in the air can affect other substances such as methane, ozone, and water vapor. This has led to hydrogen being considered an indirect greenhouse gas, with an estimated global warming potential of 5.8 over a 100-year timeframe. Therefore, hydrogen leakage into the atmosphere is undesirable and a potential risk to the hydrogen economy.

[0005] For hydrogen storage, different types of vessels are used, such as Type III and Type IV vessels. Type IV pressure vessels are containers made of carbon / glass fiber with a polymer lining material, while Type III pressure vessels are metal based. The vessels operate at pressures between 300 bar and 750 bar. For transportation, different types of pipes are used, such as metal based or polymer based pipes. Polymer linings can also be added to existing metal based pipes to improve the permeability characteristics and chemical resistance of the pipes. Polymer based pipes are known to be less exposed to corrosion than metal pipes, which are typically steel based. The polymers offer fatigue resistance, low cost and high durability, but also have high H2 permeability compared to Type III pressure vessels or metal pipes. Therefore, there is a need to improve the permeability of existing polymers for storing and transporting hydrogen.

[0006] The polymer that is generally used for hydrogen storage and transportation is polyolefin and polyamide.When being used as hydrogen storage and transportation material, compared with polyamide, polyolefin (such as polyethylene) shows some advantages and some not too beneficial characteristics.A shortcoming of polyolefin is that the permeability of hydrogen is about an order of magnitude higher than polyamide.Therefore, polyolefin is generally used for storing and transporting under relatively low pressure, such as storing hydrogen under the pressure up to about 350 bar, and polyamide is used under the higher pressure up to 700 bar.Yet polyolefin, such as high density polyethylene (HDPE), is easier to process than polyamide, and there are some limitations in polyamide, such as crystallization rate height, melt flow rate (MFR) is too high and degraded because of moisture absorption.On the other hand, compared with polyolefin, polyamide has better mechanical properties, such as higher ultimate strength, but also tends to be more brittle, causes elongation at break to reduce and impact strength to reduce.

[0007] US2022 / 0003362 states in its abstract that a device for transporting hydrogen includes a hydrogen tank and at least one pipeline for transporting hydrogen, wherein at least one surface of the hydrogen tank or the hydrogen transport pipeline is covered with a two-dimensional material mixed with a polydopamine-type polymer.

[0008] One of the objects is to provide improved components for hydrogen storage and / or transport. Another object is to provide improved materials that can be used in components for hydrogen storage and / or transport. Summary of the Invention

[0009] To this end, a polymer-based composite material is provided, comprising a polyethylene-based polymer matrix and reduced graphene oxide in an amount of 1.2% to 15% by weight per weight of the polyethylene-based polymer matrix, wherein the polyethylene-based polymer matrix is ​​a high-density polyethylene-based polymer matrix.

[0010] The provided polymer-based composites containing reduced graphene oxide exhibit reduced hydrogen permeability and increased ultimate strength compared to bare polyethylene-based polymers (such as HDPE) while maintaining the same level of elongation at break as HDPE without reduced graphene oxide. Figure 3 The experimental results obtained for composite materials falling within this range, as described in [ 1 ], show a clear trend of decreasing hydrogen permeability with increasing reduced graphene oxide content in the composite material. Furthermore, within this reduced graphene oxide concentration range of 0.1% to 15% by weight relative to the polyethylene-based polymer matrix, the composite material can be processed using standard polymer processing techniques (such as injection molding, rotational molding, compression molding, blow molding, and / or extrusion). At reduced graphene oxide concentrations above 15% by weight, although hydrogen permeability is lower than at lower reduced graphene oxide concentrations in the composite material, processing of the composite material becomes relatively cumbersome.

[0011] The presence of reduced graphene oxide in the composite material has an additional benefit: the composite material becomes more conductive than the bare polyethylene-based polymer matrix without the presence of reduced graphene oxide. Because a mixture of hydrogen and air has a relatively low ignition energy, discharge can be a problem when storing and transporting hydrogen. In applications where the composite material comes into contact with hydrogen, safety is improved because the chance of static discharge from the polyethylene-based polymer is reduced.

[0012] In one embodiment, the reduced graphene oxide is distributed and / or dispersed in the polyethylene-based polymer matrix. The reduced graphene oxide is preferably uniformly distributed and / or dispersed in the polyethylene-based polymer matrix. Advantageously, the distributed and / or dispersed reduced graphene oxide is beneficial in terms of gas permeability (such as hydrogen permeability).

[0013] In one embodiment, the polymer-based composite material comprises reduced graphene oxide in an amount of 0.5% to 9% by weight per weight of the polyethylene-based polymer matrix. This range results in a composite material having a favorable combination of reduced hydrogen permeability and processability of the composite material using standard polymer processing techniques.

[0014] In one embodiment, the amount of reduced graphene oxide in the polymer-based composite is 0.5% to 5% by weight per weight of the polyethylene-based polymer matrix. This range results in a composite material having an even more favorable combination of reduced hydrogen permeability and processability of the composite material using standard polymer processing techniques.

[0015] In one embodiment, the amount of reduced graphene oxide in the polymer-based composite material is 2.5% to 5% by weight per weight of the polyethylene-based polymer matrix.

[0016] In one embodiment, the amount of reduced graphene oxide in the polymer-based composite material is 3% to 5% by weight per weight of the polyethylene-based polymer matrix.

[0017] In one embodiment, the amount of reduced graphene oxide in the polymer-based composite material is 3.4% to 5%, preferably 3.8% to 5% by weight per weight of the polyethylene-based polymer matrix. These concentration ranges of reduced graphene oxide particularly have a combination of reduced hydrogen permeability and reduced resistivity.

[0018] In one embodiment, the polymer-based composite material comprises reduced graphene oxide in an amount of 2% to 9% by weight per weight of the polyethylene-based polymer matrix.

[0019] In one embodiment, the amount of reduced graphene oxide in the polymer-based composite material is 2% to 7% by weight per weight of the polyethylene-based polymer matrix.

[0020] In one embodiment, the amount of reduced graphene oxide in the polymer-based composite material is 2.3% to 7% by weight per weight of the polyethylene-based polymer matrix, preferably 2.3% to 5% by weight per weight of the polyethylene-based polymer matrix, such as 2.5% to 5% and 3% to 5% by weight per weight of the polyethylene-based polymer matrix.

[0021] In one embodiment, the polymer-based composite has a hydrogen permeability as measured according to ASTM D1434-82 Procedure M that is reduced by at least 15%, preferably at least 20%, more preferably at least 30% compared to neat high density polyethylene.

[0022] In one embodiment, the polyethylene-based polymer matrix is ​​based on extrusion grade high density polyethylene and the polymer-based composite has a hydrogen permeability as measured according to ASTM D1434-82 Procedure M that is reduced by at least 13%, preferably at least 17%, more preferably at least 47% compared to neat high density polyethylene.

[0023] In one embodiment, the polyethylene-based polymer matrix is ​​based on injection molding grade high density polyethylene, and the polymer-based composite has a hydrogen permeability as measured according to ASTM D1434-82 Procedure M that is reduced by at least 28%, preferably at least 56%, more preferably at least 63% compared to neat high density polyethylene.

[0024] In one embodiment, the polymer-based composite has an elongation at break, as measured according to ISO 527:2019 at 23°C, that is similar to or equal on average to neat high density polyethylene.

[0025] In one embodiment, the polymer-based composite material has an ultimate strength as measured according to ISO 527:2019 at 23°C which is increased by at least 10%, preferably 12%, compared to neat high density polyethylene.

[0026] In one embodiment, the polymer-based composite material further comprises nanoclay.

[0027] In one embodiment, the polymer-based composite material comprises nanoclay in an amount equal to 90 to 110 weight percent per weight of reduced graphene oxide.

[0028] In one embodiment, the nanoclay comprises or consists of nanoparticles based on layered mineral silicates.

[0029] In one embodiment, the layered mineral silicate-based nanoparticles comprise one or more selected from montmorillonite nanoparticles, bentonite nanoparticles, kaolinite nanoparticles, hectorite nanoparticles, and halloysite nanoparticles.

[0030] In one embodiment, the reduced graphene oxide in the polymer-based composite material comprises a Li salt. The results of hydrogen permeability show that the hydrogen permeability of the polymer-based composite material comprising reduced graphene oxide and a Li salt is even lower.

[0031] In one embodiment, the polymer-based composite material comprises a Li salt in a concentration of 1 to 50 wt%, preferably 2 to 30 wt%, more preferably 5 to 20 wt%, per weight of reduced graphene oxide.

[0032] In one embodiment, the Li salt is lithium bis(salicylate)borate. In one embodiment, the polymer-based composite material comprises lithium bis(salicylate)borate in an amount ranging from 2 to 50 wt%, preferably 5 to 30 wt%, more preferably 7 to 20 wt%, per weight of reduced graphene oxide. The exact amount of added Li salt, such as lithium bis(salicylate)borate, is not critical. Adding the Li salt within the specified range beneficially improves the dispersion and / or interaction of rGO with the polymer.

[0033] In one embodiment, the polymer-based composite material comprises a Li salt in the range of 1-50 wt%, preferably 4-20 wt%, more preferably 6-15 wt% relative to the reduced graphene oxide, for example 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, or 14 wt% relative to the reduced graphene oxide.

[0034] In one embodiment, the polyethylene based polymer matrix is ​​a high density polyethylene based polymer matrix.One advantage of using high density polyethylene (HDPE) is that it is known to be suitable for hydrogen applications, such as for use in hydrogen transport pipelines.

[0035] HDPE can have an average molecular weight in the range of 50,000 to 300,000 Da, such as 100,000 to 250,000 Da. HDPE can have a melt flow rate (MFR) in the range of 0.01 to 5 g / 10 min, for example, 0.1 to 4 g / 10 min or 0.5 to 2 g / 10 min, as measured according to ISO 1133 at 190°C with an applied weight of 2.16 kg. It is well known in the polymer processing art that different techniques for manufacturing parts using HDPE typically work best with HDPE of different MFRs. For example, HDPE with a MFR at the lower end of the range, such as 0.1 to 1 g / 10 min, may be more suitable for techniques that prefer higher viscosities, such as extrusion, while HDPE at the higher end of the range, such as 1 to 4 g / 10 min, may be more suitable for other techniques that prefer lower viscosities, such as injection molding. For HDPE in general, including HDPE having the above-mentioned melt flow rates, the polymer-based composites according to the present patent disclosure show beneficial effects such as reduced hydrogen permeation compared to bare HDPE.

[0036] The polymer-based composite material according to any one of the preceding claims, wherein the reduced graphene oxide comprises oxygen in the range of 0.1 to 50 wt%.

[0037] According to a second aspect, there is provided an assembly for hydrogen storage and / or transport, the assembly comprising:

[0038] - a hollow body; and

[0039] - at least one hydrogen barrier lining arranged along a surface of said hollow body;

[0040] wherein the at least one hydrogen barrier liner comprises a polymer-based composite material comprising a polyethylene-based polymer matrix and reduced graphene oxide in an amount of 0.1% to 15% by weight per weight of the polyethylene-based polymer matrix.

[0041] The provided assembly for hydrogen storage and / or transport comprises a polymer-based composite material according to the first aspect, which exhibits reduced hydrogen permeability compared to a bare polyethylene-based polymer. The hollow body is provided with a hydrogen barrier lining made of the polymer-based composite material, thereby reducing leakage of hydrogen to the surface of the hollow body provided with the lining. As a result, the driving force for hydrogen to penetrate into or through the hollow body is also reduced. For example, if the hollow body is made of a polymer material (such as HDPE), hydrogen permeation through the hollow body is reduced. If the hollow body is made of, for example, steel, the hydrogen embrittlement rate is reduced.

[0042] The assembly may be a hydrogen carrying assembly.The assembly may additionally or alternatively be referred to as a hydrogen transport and / or storage assembly.

[0043] The liner may additionally provide a conductive path and thereby reduce the chance of discharge into a hydrogen-rich environment when the assembly is in use.

[0044] In one embodiment, the surface of the hollow body is an inner surface of the hollow body.

[0045] In one embodiment, the hollow body is a can, a vessel, a pipe, a fitting, or a cylinder.

[0046] In one embodiment, the component is a hydrogen storage container or a hydrogen transport container.

[0047] In one embodiment, the hydrogen storage container is a hydrogen storage tank, a hydrogen storage vessel, or a hydrogen bottle.

[0048] In one embodiment, the hydrogen barrier liner is a hydrogen gas barrier liner.

[0049] In one embodiment, the hydrogen cylinder is a hydrogen gas cylinder.

[0050] In one embodiment, the hydrogen transport container is a hydrogen transport pipeline or a connector for connecting a hydrogen transport pipeline.

[0051] In one embodiment, the hollow body is a hollow stainless steel body, a hollow carbon fiber wound body, or a hollow polymer body.

[0052] In one embodiment, the hydrogen barrier liner is attached to the hollow body using an adhesive.

[0053] Alternatively, the hydrogen barrier liner is attached to the hollow body in an adhesive-free manner.

[0054] In one embodiment, the hydrogen barrier liner is a blow molded hydrogen barrier liner.

[0055] In one embodiment, the polymer-based composite material is a polymer-based composite material according to any embodiment of the first aspect and / or any embodiment described below.

[0056] According to a third aspect, there is provided a method of manufacturing a component for hydrogen storage and / or transport, the component comprising a hollow body and at least one hydrogen barrier liner, the method comprising lining a surface of the hollow body with one of the at least one hydrogen barrier liner.

[0057] In one embodiment, the surface of the hollow body that is lined with the hydrogen barrier liner is the interior surface of the hollow body.

[0058] In one embodiment, the lining of the surface of the hollow body is accomplished using blow molding.

[0059] In one embodiment, the assembly for hydrogen storage and / or transport is an assembly for hydrogen storage and / or transport according to any embodiment of the second aspect and / or any embodiment described below.

[0060] According to a fourth aspect, there is provided the use of a polymer-based composite material according to any embodiment of the first aspect as a hydrogen barrier liner.

[0061] Hydrogen carrier

[0062] Hydrogen carriers, such as hydrogen storage vessels and hydrogen transport pipelines, may be used to store and / or transport hydrogen, for example, as liquid hydrogen or pressurized gaseous hydrogen.

[0063] Another object is to provide improved hydrogen carriers for hydrogen storage and / or transport. Yet another object is to provide improved materials for hydrogen carriers that can be used for hydrogen storage and / or transport.

[0064] To this end, in a fifth aspect, a hydrogen carrier for hydrogen storage and / or transport is provided, the hydrogen carrier comprising a hollow body comprising a polymer-based graphene composite material, the composite material comprising a polyethylene-based polymer matrix and reduced graphene oxide in an amount of 0.1% to 15% by weight per weight of the polyethylene-based polymer matrix.

[0065] The hollow body may be made of a polymer-based graphene composite material.

[0066] A hydrogen carrier for hydrogen storage and / or transport is provided, comprising a polymer-based composite material according to the first aspect, which exhibits reduced hydrogen permeability compared to a bare polyethylene-based polymer. The hollow body is composed of the polymer-based composite material, thereby reducing hydrogen leakage to the outer surface of the hollow body.

[0067] A hydrogen carrier may additionally or alternatively be referred to as a hydrogen transport carrier and / or a hydrogen storage carrier.

[0068] The hollow body may additionally provide a conductive path and thus reduce the chance of discharge into a hydrogen-rich environment when the assembly is in use.

[0069] In one embodiment, the hollow body is made of a polymer-based graphene composite material.

[0070] In one embodiment, the hollow body is a can, a vessel, a pipe, a fitting, or a bottle.

[0071] In one embodiment, the hydrogen carrier is a hydrogen storage container or a hydrogen transport carrier.

[0072] In one embodiment, the hydrogen storage container is a hydrogen storage tank, a hydrogen storage vessel, or a hydrogen bottle.

[0073] In one embodiment, the hydrogen cylinder is a hydrogen gas cylinder.

[0074] In one embodiment, the hydrogen transport carrier is a hydrogen transport pipeline or a connector for connecting a hydrogen transport pipeline.

[0075] In one embodiment, the polymer-based composite material is a polymer-based composite material according to any embodiment of the first aspect and / or any embodiment described below.

[0076] In one embodiment, the hollow body is a first hollow body; and the hydrogen carrier further includes a second hollow body concentrically arranged with respect to the first hollow body.

[0077] In one embodiment, the second hollow body is a hollow mechanically reinforced body.

[0078] In one embodiment, the hydrogen carrier may further include a third hollow body disposed between the first hollow body and the second hollow body.

[0079] In one embodiment, at least one of the second and third hollow bodies is a hollow mechanically reinforced body.

[0080] Any additional hollow body may increase the mechanical strength and / or stability of the hydrogen carrier.For example, the hydrogen carrier may have to withstand various conditions during pipeline laying and during use of, for example, high-pressure hydrogen.

[0081] In one embodiment, the second hollow body is made of a polymer-based composite material.

[0082] In one embodiment, the second hollow body is arranged within the first hollow body.

[0083] In an alternative embodiment, the first hollow body is arranged within the second hollow body.

[0084] According to a sixth aspect, a method for manufacturing a hydrogen carrier is provided, wherein the hydrogen carrier is manufactured using extrusion or injection molding.

[0085] In one embodiment, the hydrogen carrier for hydrogen storage and / or transport is a hydrogen carrier for hydrogen storage and / or transport according to any embodiment of the fifth aspect and / or any embodiment described below.

[0086] According to a seventh aspect, there is provided an extruded hydrogen carrier comprising or consisting of a polymer-based composite material comprising a polyethylene-based polymer matrix and reduced graphene oxide in an amount of 0.1% to 15% by weight per weight of the polyethylene-based polymer matrix.

[0087] In one embodiment, the polymer-based composite material is a polymer-based composite material according to any embodiment of the first aspect and / or any embodiment described below.

[0088] It will be understood that the technical advantages and effects associated with the features and / or embodiments of one aspect are applicable to the corresponding, similar or equivalent features and / or embodiments of other aspects. It will also be apparent that the features of its various aspects and / or embodiments can be applied to their other aspects and / or embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0089] The accompanying drawings are used to illustrate presently preferred non-limiting exemplary embodiments of the apparatus of the present disclosure. The above and other advantages of the features and objects of the present disclosure will become more apparent and the aspects and embodiments will be better understood from the following detailed description when read in conjunction with the accompanying drawings, wherein:

[0090] FIG1a is a schematic diagram of an embodiment of an assembly according to the present patent disclosure;

[0091] FIG1 b is a schematic diagram of another embodiment of an assembly according to the present patent disclosure;

[0092] FIG1c is a schematic diagram of an embodiment of an assembly according to the present patent disclosure;

[0093] FIG1d is a schematic diagram of an embodiment of an assembly according to the present patent disclosure;

[0094] Figure 2 is a schematic diagram of one embodiment of the polymer-based composite material disclosed in this patent;

[0095] Figure 3 is the H2 permeability [mol·m -1 ·s -1 MPa -1 ] as a function of the reduced graphene oxide concentration [wt %];

[0096] Figure 4 is a graph showing volume resistivity (ohm·cm) as a function of reduced graphene oxide concentration (wt %) for various polymer-based composite materials disclosed in this patent;

[0097] Figures 5a-5d are schematic diagrams of various embodiments of hydrogen carriers according to the present disclosure; and

[0098] Figure 6 is the H2 permeability [mol·m -1 ·s -1 MPa -1 ] as a function of reduced graphene oxide concentration [wt %].

[0099] abbreviation

[0100] GO – graphene oxide;

[0101] HDPE – high-density polyethylene;

[0102] LB-lithium bis(salicylate)borate;

[0103] NC – nanoclay;

[0104] rGO – reduced graphene oxide;

[0105] PE – Polyethylene. DETAILED DESCRIPTION

[0106] Components for carrying hydrogen or contacting hydrogen, such as storage containers and transport pipelines and pipeline joints, such as tanks, containers, bottles, etc., are required to have heat resistance, mechanical strength and gas permeability. Examples of storage containers include tanks, containers, bottles, cartridges, canisters, cages and caves. As used herein, components for hydrogen storage and / or transport can be open or closed, and can also be open at one end and closed at the other end.

[0107] Graphene is a two-dimensional carbon material. Graphene is a layered material that takes the form of flakes or sheets. Graphene contains at least 30 at% carbon, has a hexagonal lattice, and is 1-20 times thicker than the atomic size of carbon. In this patent disclosure, reduced graphene oxide (rGO) is used in the composite material.

[0108] In one embodiment of the present disclosure, the composite material comprises a salt, such as a Li salt or a Li borate. In one embodiment, the composite material comprises a graphene material as disclosed in WO 2019 / 054931, such as a graphene composite material comprising lithium bis(salicylate)borate. WO 2019 / 054931 is hereby incorporated by reference in its entirety.

[0109] In FIG1 , an assembly 100 is shown that includes a hollow body 101 and at least one hydrogen barrier liner 102. The at least one hydrogen barrier liner 102 may be at least one hydrogen gas barrier liner 102. The hydrogen barrier layer 102 comprises a polymer-based composite material 200 comprising a polyethylene-based polymer matrix 202 and reduced graphene oxide 201 in an amount of 0.1-15% by weight per weight of the polymer matrix 202. In the polymer-based composite material 200, the reduced graphene oxide 201 may be distributed or dispersed in the polymer matrix 202.

[0110] "Lining" 102 refers to a thin layer or coating disposed on the surface of hollow body 101. Lining 102 may have a thickness in the μm-cm range, for example, 0.1 μm-1 cm. Hollow body 101 may have a thickness in the cm range, for example, 0.5-10 cm. Lining 102 may be directly bonded to mechanical hollow body 101, or an adhesive layer may be provided between hollow body 101 and lining 102. An inner lining or lining may be disposed on inner surface 101a of hollow body 100.

[0111] In some embodiments, the adhesive layer may additionally comprise rGO, in which case the rGO may provide advantageous properties to the adhesive, such as, for example, increased mechanical strength.

[0112] One way to provide a lining or liner in or on a hollow body is by a co-manufacturing technique, such as co-extrusion.Another way to provide a lining or liner is by manufacturing the hollow body and the liner separately and then providing the liner on the inside or outside of the hollow body.

[0113] In Figure 1a, the assembly 100 is implemented as a hydrogen storage container 100 with a closed end. The assembly 100 may include an opening (not shown) for allowing hydrogen to enter and leave the assembly. The opening may be provided with means for attaching other components, such as valves and / or pressure reducers.

[0114] FIG1a shows a schematic diagram of a hydrogen storage container 100 according to the present invention. Such a container 100 can be used for storing and / or transporting hydrogen. FIG1a shows a schematic longitudinal cross-section of the hydrogen storage container 100. As can be seen, the hydrogen storage container 100 is composed of a hollow body 101 (e.g., a hollow stainless steel body provided with a hydrogen barrier liner 102). FIG1b shows a cross-section of the hydrogen storage container 100 shown in FIG1a along line AA.

[0115] The hydrogen storage container 100 may include more than one gas barrier liner 102 and / or more than one hollow body 101. The hydrogen storage container 100 may, for example, have two hollow bodies 101 and 101', each having a hydrogen barrier liner 102 and 102', as shown in FIG1c.

[0116] Hydrogen storage container 100 has an inner surface 100a and an outer surface 100b. Hollow body 101 has inner surface 101a. As shown in Figures 1a-c, liner 102 is typically disposed on inner surface 101a of hollow body 101. Thus, during use of hydrogen storage container 100, when hydrogen is present in interior space 104 within container 100, liner 102 comes into direct contact with the hydrogen. In the example of assembly 100 shown in Figures 1a-c, outer surface 100b is the outer surface of hollow body 101.

[0117] The cross sections of Figures 1b, 1c and 1d may alternatively be schematic cross sections of hydrogen transport pipelines or pipeline joints. This patent disclosure relates to improving the hydrogen permeability characteristics of hydrogen carrying assemblies and / or hydrogen storage and / or transport assemblies by applying polymer-based composite materials as hydrogen barrier liner 102.

[0118] Other examples of the assembly 100 include three layers: an outer layer 100', an inner layer 100", and an intermediate layer 100'". Such an example is shown in Figure 1d. The assembly implemented as a hydrogen storage container 100 in Figure 1d includes an inner layer 100" as a hydrogen barrier liner 102, an intermediate layer 100'" as a hollow body 101, and an outer layer 100'. The outer layer 100' can be an additional hollow body, layer or lining that provides another function for the hydrogen storage container 100. For example, when the hollow body 101 is used in corrosive conditions, such as in seawater, the additional hollow body, layer or lining can provide improved corrosion resistance to the hollow body.

[0119] The hydrogen barrier liner 102 in all embodiments disclosed herein comprises a polymer-based composite material 200 comprising reduced graphene oxide (rGO) 201 in a polymer matrix 202. The polymer-based composite material 200 may also be referred to as a polymer-graphene composite material. The polymer-graphene composite material 200 will be discussed in more detail below.

[0120] The polymer-graphene composite material 200 is schematically shown in Figure 2As can be seen in the figure, rGO 201 is uniformly or nearly uniformly distributed throughout the polymer matrix 202. Without being bound by any theory, it is believed that the uniform distribution of graphene 201 in the polymer matrix 202 is beneficial in terms of gas permeability. In other words, compared to polymer-based composites (where rGO is more concentrated in certain parts of the composite and less present in other parts of the composite), for polymer-graphene composite 200 (where rGO 201 is distributed throughout the polymer matrix 202), lower gas permeation can be achieved.

[0121] The polymer matrix 202 is made of a type of polyethylene (PE). Polyethylene (PE) is a widely used group of polymers. It accounts for more than a quarter of the total global plastics market. Most types of polyethylene have the general chemical formula (C2H4) n Examples of polyethylene include high-density polyethylene (HDPE), low-density polyethylene (LDPE), and polyethylene terephthalate (PET). It can be processed using standard manufacturing techniques such as extrusion, blow molding, rotational molding, and injection molding. In one embodiment, the polymer-graphene composite material 200 comprises HDPE.

[0122] One advantage of the assembly 100 is that less hydrogen leaks from the assembly 100 than would be the case without the hydrogen barrier liner 102. Additional improved properties of the assembly 100 according to the present patent disclosure may be increased electrical conductivity and reduced electrostatic effects.

[0123] The hydrogen storage container 100 is typically configured to withstand a wide range of temperatures and high pressures. For example, in hydrogen transportation, hydrogen may be transported at pressures ranging from 1 bar to 100 bar (e.g., 10-90 bar). In hydrogen containers (such as hydrogen cylinders), the hydrogen pressure may be as high as 200 or 300 bar. Consequently, the associated components will be subject to considerable mechanical loads. The hollow body 101 may be configured to withstand pressures within these ranges.

[0124] As previously discussed, the assembly 100 as discussed herein may be any type of container for storing and / or transporting hydrogen in liquid and / or gaseous, pressurized gaseous form. Examples include tanks, vessels, pipes, fittings, bottles, boxes, and the like.

[0125] The hydrogen barrier layer or liner 102 comprises a polymer-based composite material 200. As discussed, the polymer-graphene composite material 200 comprises rGO 201 distributed in a polymer matrix 202. The amount of rGO in the polymer-graphene composite material 200 is 0.1-15 wt% per weight of the polymer, 0.5-9 wt% per weight of the polymer, 0.5-5.5 wt% per weight of the polymer, 2.5-5 wt% per weight of the polymer, 3.8-5.5 wt% per weight of the polymer, or 3-5 wt% per weight of the polymer. The rGO can include graphene from any type of graphene source. The rGO can contain 0.1-50 wt% oxygen.

[0126] The purpose of the hydrogen barrier liner 102 is to prevent or reduce the permeability of hydrogen through the walls of the assembly 100 . Figure 3 The measured hydrogen permeability of different polymer-based composite materials according to the present patent disclosure is shown as a function of the amount (wt%) of additive added to the polymer matrix. Figure 3 , results are shown for several graphene-polymer composites 200, each comprising high-density polyethylene (HDPE) and reduced graphene oxide (rGO). All samples were manufactured using twin-screw extrusion and had the same thickness.

[0127] Figure 3 The samples shown, having the first type of polymer-based composite, were produced using a first-grade HDPE suitable for extrusion. These samples are designated "G1." The first-grade HDPE had a melt flow rate of approximately 0.5 g / 10 min, as measured according to ISO 1133 with a 2.16 kg weight and a temperature of 190°C. The samples shown, having the second type of polymer-based composite, were produced using a second-grade HDPE suitable for injection molding. These samples are designated "G2." The second-grade HDPE had a melt flow rate of approximately 2.0 g / 10 min, as measured according to ISO 1133 with a 2.16 kg weight and a temperature of 190°C. Figure 3 Further shown are the gas permeabilities of polymer-based composites comprising high-density polyethylene (HDPE) and reduced graphene oxide containing lithium bis(salicylate)borate (LB) (denoted as "HDPE LB"), and a mixture of reduced graphene oxide containing lithium bis(salicylate)borate and nanoclay (NC) (denoted as "HDPE LB-NC"). In both cases, a secondary HDPE was used. Additive concentrations represent the total weight percent of additives added to the HDPE polymer matrix.

[0128] As can be seen in the figure, all polymer-based composites containing graphene additives, namely rGO, NC, or rGO containing lithium bis(salicylate)borate, exhibited lower H2 gas permeability compared to the bare HDPE polymer sample with 0 wt% additive concentration. Although the samples with G2 grade HDPE appeared to perform better than the samples with G1 grade HDPE, all samples showed improved hydrogen permeability when the additives were included, regardless of the HDPE used. The higher the concentration of the additive, the lower the H2 gas permeability of all the composites. The best performing composites in terms of hydrogen permeability were the HDPE G2rGO and HDPE LB samples. The performance of the HDPE LB-NC samples was similar to or better than the HDPE G1 rGO samples.

[0129] However, increasing the amount of rGO additive too much is no longer beneficial because it reduces the processability of polymer-based composites. For example, the higher the rGO concentration, the higher the polymer viscosity, making it more difficult to process. Furthermore, increasing the graphene concentration in polymer composites is known to reduce the polymer's flexibility. Large amounts of graphene additive exceeding 15% by weight per weight of the polymer result in materials that are impossible or very difficult to process using standard techniques such as injection molding, blow molding, and extrusion.

[0130] As described above, the rGO in the composite material 200 according to the present disclosure can be any type of rGO, or any type of graphene that is first oxidized and then reduced to form rGO. rGO is a form of graphene oxide (GO) that has been processed to reduce its oxygen content. The processing can be performed chemically, thermally, or by other methods known to those skilled in the art.

[0131] In one embodiment, the polymer-based composite material 200 comprises a mixture of nanoclay and graphene. The nanoclay may comprise or be a layered mineral silicate. The nanoclay may comprise or consist of nanoparticles based on layered mineral silicates. Nanoclays are classified into several types based on chemical composition and morphology: montmorillonite, bentonite, kaolinite, hectorite, and halloysite. In one embodiment disclosed herein, the polymer-based composite material comprises a mixture of nanoclay and reduced graphene oxide as additives. The amounts expressed by weight of the nanoclay and reduced graphene oxide may be equal or nearly equal. The term "equal" herein refers to a difference of 10% or less.

[0132] In one embodiment of the present invention, rGO includes a salt, which can be intercalated between graphene layers. The salt can include Na + or Li +The salt may further comprise Al or B as an anion. In one embodiment, the salt comprises or is lithium bis(salicylate)borate (Li[BScB]).

[0133] The rGO in the composite material 200 may further include Li + and / or Na + This is beneficial in reducing hydrogen permeability, Figure 3 Without being bound by any theory, Li + and / or Na + As a hydrogen storage material, it has a high capacity, wherein hydrogen can be stored reversibly in the material. In addition, pristine graphene and reduced graphene oxide are also capable of reversibly storing hydrogen. Reduced graphene oxide and Li + and / or Na + A highly hydrogen-impermeable composite material is obtained. Figure 3 As can be seen from the data for all types of additives used in this patent disclosure, in this case too, the hydrogen permeability values ​​decrease with increasing additive concentration. The composite material with the lowest measured hydrogen permeability is the composite material comprising rGO and lithium bis(salicylate)borate ("HDPE LB").

[0134] Another benefit of the hydrogen barrier liner 102 is that it can have a low volume or resistivity. Resistivity is a material property that measures how well it resists the flow of electricity. Volume resistivity is measured in ohm-centimeters [Ω·cm] or ohm-meters [Ω·m]. Figure 4 The volume resistivity of a polymer-based composite material 200 according to the present disclosure is shown as a function of the rGO content (wt%). As can be seen from the figure, an increase in the amount of rGO leads to a decrease in resistivity. Between the addition of 3 wt% and 4 wt% rGO, more specifically between 3.3 wt% and 3.8 wt%, the resistivity decreases rapidly to a value close to zero.

[0135] The hydrogen barrier liner 102 can generally be provided in an assembly by providing an inner lining of the graphene-based composite material 200 to a hollow body, such as a stainless steel tank, a carbon fiber wrapped tank, a stainless steel pipe, a polymer pipe, etc. The liner can be manufactured using, for example, extrusion, injection molding, rotational molding, blow molding, or spraying.

[0136] Polymer extrusion is a processing technique in which a polymer is melted and formed into a desired profile. The polymer is melted by a heater and mechanical energy generated by a screw used in the process. The polymer-graphene composite material 101 can be manufactured by mixing the polymer with rGO using, for example, an extruder.

[0137] In one aspect of the present patent disclosure, a method of manufacturing a component for carrying hydrogen or for hydrogen storage and / or transportation is provided, wherein an inner surface 101 a of a hydrogen storage container 100 is lined or coated with a hydrogen barrier liner 102 .

[0138] Typically, the component 100 is manufactured by coating the inner surface of the hollow body with a polymer-based composite material 200. The polymer-based composite material 200 can be manufactured by mixing a polymer with at least rGO using, for example, an extruder.

[0139] experiment

[0140] For all sample preparations, HDPE was used as the polyethylene-based polymer. Therefore, these samples contained a HDPE-based polymer matrix.

[0141] Gas permeability test

[0142] As mentioned above Figure 3 As described above, four different samples were prepared. Further details are described below. For the LB-NC sample, a 50 / 50 ratio in terms of LB / NC weight was used.

[0143] Sample preparation using rGO as an additive

[0144] A batch of HDPE containing 11 wt% rGO was first prepared. This batch was then diluted to concentrations of 0.5, 0.66, 2.75, 3.0, 3.3, 3.85, 5.0, 5.5, 6.93, and 7.4 wt% by mixing with more HDPE.

[0145] Mixed samples, including HDPE LB and LB-NC samples

[0146] Hybrid samples were prepared using an 11 wt% rGO batch. This 11 wt% batch was diluted and then extruded to the desired concentration of additives (including rGO and LB and optionally NC). Extrusion was performed using standard process parameters. The sample, designated LB containing Li salt, contained 10 wt% lithium bis(salicylate)borate relative to rGO.

[0147] Table 1 below shows an overview of all samples prepared for gas permeability testing.

[0148] Table 1. Overview of the first set of samples.

[0149]

[0150] Gas permeability test

[0151] Gas permeability was tested according to ASTM D3985-17. Permeability curves were obtained by placing them in a circular permeation cell. A porous stainless steel plate was used to support the sample under high pressure. The area of ​​the stainless steel plate was 19.6 cm 2 This area is used as the effective area available for permeation and is used for permeation calculations. The seal between the feed and permeate sides is achieved by an O-ring placed between the sample and the feed side of the module. An additional sealing ring placed on the permeate side of the module prevents leakage to the external environment.

[0152] Permeation measurements were performed using a constant pressure method (similar to ASTM D3985-17). The apparatus was designed to withstand pressures up to 30 bar. The permeation cell was placed in a Memmert UF450 forced air oven for temperature control.

[0153] The penetration experiment was performed as follows:

[0154] 1. Seal the sample in the cell and connect it to the device.

[0155] 2. The device was heated to operating temperature (50°C) and exposed to a small overpressure of N2 (1 bar).

[0156] 3. Under stable temperature / pressure and GC analysis, replace N2 with H2 while rapidly increasing the pressure to 20 bar. H2 gradually permeates through the sample, and breakthrough is measured by GC. Permeation is held constant to obtain the permeability at 50°C.

[0157] Gas permeability test results

[0158] Figure 3 A permeability graph is shown, showing the H2 permeability of a first set of samples: HDPE and rGO, a mixture of HDPE and rGO containing lithium bis(salicylate)borate and nanoclay (···), and HDPE and rGO containing lithium bis(salicylate)borate. For all samples, a decrease in permeability is observed with increasing reduced graphene oxide concentration. It can also be seen that the material containing lithium bis(salicylate)borate exhibits the lowest H2 gas permeability.

[0159] The lowest gas permeability of the three samples was shown by the material comprising graphene and lithium bis(salicylate)borate without nanoclay.

[0160] Resistivity test

[0161] The resistivity of six samples was tested: HDPE containing 0.66, 3.3, 3.85, 5.5, 6.93 and 7.37 wt% rGO. The resistivity was obtained by performing a series of measurements and calculations on individual filaments produced by extrusion. First, a linear relationship between the measured resistance and the resistivity value was established by measuring the resistance of a length of up to 1 m using an interval of 10 cm and then deriving the resistivity value by calculating the gradient of the curve of resistance versus length. The linearity was established and therefore the resistivity value was calculated for a 10 cm long filament. A silver colloidal paste was applied to the contact area between the filament and the probe (Electron Microscopy Sciences, USA). The resistance was measured using a four-probe micro-ohmmeter. The results of the resistivity tests are given in Figure 4 The results have been discussed above.

[0162] The second group of samples

[0163] Figure 6 Further results are shown for the hydrogen permeability of a second set of samples. Unless otherwise stated, these samples were prepared and measured as described above.

[0164] The polymer-based composite samples were processed in a 24-mm twin-screw extruder, where graphene was fed through a side feeder to mix with pure polyethylene grades.

[0165] The compounding process is carried out in two steps. The first step is to prepare a masterbatch with a high content of rGO, namely about 8% by weight relative to the total weight of the polymer-based composite. In the second step, the masterbatch is mixed with pellets of pure polyethylene, and the mixture is then extruded to obtain the polymer-based composite with a given graphene concentration. Figure 6 The data samples shown in are based on an extrusion HDPE grade designated HDPE EX (Dowlex 2388, a HDPE grade for extrusion manufactured by Dow), an injection molding HDPE grade designated HDPE IM (Lupolen 5038GX, a HDPE grade for injection molding manufactured by LyondellBasell), the same injection molding HDPE grade with added Li salt designated HDPE IM LB, and two HDPE blow molding grades designated BM1 (Lupolen 4261AG, a blow molding HDPE grade manufactured by LyondellBasell) and BM2 (SABIC 5411, a blow molding grade manufactured by Sabic), respectively. For all sample types, pure samples without graphene were prepared, as well as samples containing different amounts of graphene, which can be obtained, for example, in Figure 6 It can be seen in.

[0166] Blow-molded samples were prepared by blending pellets of HDPE EX with pellets of a specified blow-molding grade to obtain a given corresponding rGO concentration. The pellet mixture was then processed using a blow-molding process known in the art, such as heating the pellet mixture and feeding the heated mixture into a blow-molding apparatus to form a parison, clamping the parison into a mold and blowing pressurized air or any other gas into the parison so that the parison conforms to the mold. Two different sizes of blow-molded liners were prepared, 10 L and 52 L. An industrial blow-molding apparatus, ST ASTI 200, was used. The conditions used included a pressure of 20 bar and a temperature of 50°C.

[0167] Blow molding test 1

[0168] Three sets of liners were prepared based on BM1, including a BM1 reference without rGO, and BM1 containing 15 wt% and 30 wt% HDPE EX masterbatch, resulting in rGO concentrations of 1.2 wt% and 2.4 wt%, respectively, relative to the total weight of the polymer composite. The hydrogen permeability and mechanical properties of the produced liners were evaluated.

[0169] During blow molding, it was noted that the parison drop time (PDT) was slightly longer due to the higher swell ratio. The use of extrusion grade masterbatch did not affect the parison strength and remained within the standard range for the polyolefin grade.

[0170] The linings produced had a matte and uniform appearance that met the usual standards for industrial components. No defects were found on either the inside or outside of the linings.

[0171] Blow molding test 2

[0172] Two sets of liners were prepared based on BM2, including a BM2 reference without rGO, and a BM2 containing 30 wt% HDPE EX masterbatch, resulting in an rGO concentration of 2.4 wt% relative to the total weight of the polymer composite. The hydrogen permeability and mechanical properties of the produced liners were evaluated.

[0173] Melt flow rate

[0174] The melt flow properties of a dilution of an HDPE EX masterbatch having a total rGO content of 10.4 ± 0.4 wt% relative to the total weight of the polymer composite with pure HDPE EX were determined using a Tinius Olsen MP 1200 according to ISO 1183-1:2019 Proc. B. The test was performed according to ISO 1183-1:2019 Proc. B. The as-received samples were tested at 190°C with a load of 2.16 kg.

[0175] The melt flow rate (MFR), melt volume rate (MVR) and melt density of pure HDPE EX and 5-30 wt% dilutions of specific HDPE EX masterbatches are given in Table 2.

[0176] It can be observed from Table 2 that the addition of HDPE EX masterbatch to neat HDPE EX reduces the melt flow rate. This is beneficial during blow molding as the parison stiffness will increase, leading to an increase in the parison drop time (PDT).

[0177] Table 2: Melt flow rate (MFR), melt volume rate (MVR) and melt density of neat HDPE EX and 5-30 wt% dilutions of HDPE EX masterbatch containing 10.4 ± 0.4 wt% rGO relative to the total weight of the polymer composite with neat HDPE EX.

[0178]

[0179]

[0180] Gas permeability test results

[0181] The permeability of hydrogen through pure and reduced graphene oxide-containing HDPE materials was measured at 20 bar and 50° C. The permeation experiments were performed in a permeation apparatus according to standard ASTM D1434-82 (manometer, procedure M). Prior to testing, all samples were degassed in a vacuum oven at 60° C. and 5 mbar for a minimum of 2 days. The test lasted 1 day for each sample and was performed as follows:

[0182] The sample is mounted in a cell. At the desired temperature (50°C), vacuum is applied overnight to allow the sample to be further degassed. Subsequently, a vacuum test of approximately 1 hour is performed to ensure a sufficiently low degassing rate, otherwise this would be mistakenly assessed as a permeating substance. Subsequently, the upstream side of the sample is exposed to approximately 20 bars of hydrogen and the downstream side is monitored until steady-state conditions are achieved. The test provides direct measurements of permeability (stable permeation) and diffusivity (via penetration / permeation curves). The solubility coefficient can then be calculated based on the dissolution / diffusion mechanism principle. The change in sample thickness is taken into account in the calculation.

[0183] from Figure 6As can be seen in the graphene graphite ...

[0184] The maximum reduction in hydrogen permeability is 47% for extruded HDPE EX (at 4.2 wt% rGO) and 63% for extruded HDPE IM (at 7% rGO).

[0185] For all the extruded samples, the extruded sample HDPE 1 M LB showed the lowest hydrogen permeability, thus showing the beneficial effect of Li salt on hydrogen permeability.

[0186] In addition, from Figure 6 It can be observed that the extruded HDPE IM grade with the highest rGO content (7.0 wt% per total weight of the polymer composite) has a -1 ·s -1 MPa -1 or 6.6E-18m 3 m / m 2 Pa·s or 6.0E-14 kg / m·s·bar of hydrogen permeability. This is close to the measured literature value of hydrogen permeability of polyamides of 2.6-3.2E-10 mol·m -1 ·s -1 MPa -1 or 1.4-1.8E-18m 3 m / m 2Pa·s or 1.3-1.6E-14 kg / m·s·bar (Dennis Krieg, Knowledge and Construction of Pipeline Systems from the Verification of Deutschen Straßenverkehrs with Wasserstoff, Dissertation 2012, Research Center Jülich GmbH Zentralbibliothek, Publishing House Jülich ISBN: 978-3-89336-800-6). Advantageously, therefore, by using HDPE with rGO, as shown in this patent disclosure, the hydrogen permeability of HDPE grades can be reduced to levels approaching those of polyamide grades. This is particularly advantageous because HDPE is known to be more straightforward to process than PA (such as PA6). Furthermore, the composite polymer materials according to this patent application can be used in higher pressure applications, such as those currently using PA, i.e., up to 700 bar hydrogen pressure.

[0187] Mechanical properties

[0188] Tensile properties of extruded pellets were measured according to ISO 527:2019 using a Tinius Olsen H10ST. Test plaques approximately 4 mm thick were produced using a Fontijne LabEcon press with an overflow die at 180°C and a forming pressure of 5 MPa. Tensile specimens were punched from these test plaques using an Elastocon EP 02 pneumatic cutter. The specimens were heat-conditioned at 23°C for 3 hours prior to testing.

[0189] To prepare dog bones from blow-molded parts, some parisons were cut in half and stretched immediately after blow molding. Dog bones were milled vertically and transversely from flat blow-molded cylinders of pure HDPE and HDPE with rGO. Prior to testing, the dog bones were heat-conditioned at 23°C for 3 hours. The tensile properties of the dog bones were determined according to ISO 527:2019 using a Tinius Olsen H10ST.

[0190] The results are shown in Table 3 below.

[0191] Table 3: Mechanical properties measured on various BM1-based samples from the second set of samples

[0192]

[0193]

[0194] The masterbatch contained 8 wt% rGO, so the sample with 15% MB contained 1.2 wt% rGO and the sample with 30% MB contained 2.4 wt% rGO, relative to the total weight of the polymer composite. The measurements were carried out in two directions (longitudinal and transverse) because blow molded parts of these grades can be anisotropic. The longitudinal direction is the direction parallel to the longest dimension of the blow molded part, and the transverse direction is the direction perpendicular to the longitudinal direction. It is apparent from Table 2 that the samples with graphene have a tensile modulus comparable to that of the neat resin. In addition, the samples with graphene show an increase of 14-28% in ultimate strength, while the elongation at break is comparable to that of neat BM1. In addition, the samples show smaller differences between the two directions (longitudinal and transverse), so the anisotropy is reduced, which is beneficial for parts, especially when used to contain pressurized fluids as disclosed in this patent.

[0195] Hydrogen carrier

[0196] 5 , there is shown a hydrogen carrier 500 according to the present disclosure, which includes a hollow body capable of withstanding mechanical stresses, thereby providing load-bearing support for the hydrogen carrier 500. The hollow body may, for example, have a thickness in the cm size range and is therefore typically the main portion, or one of the main portions, of the hydrogen carrier 100.

[0197] A hydrogen carrier 500 for hydrogen storage and / or transport is provided. The hydrogen carrier 500 includes a hollow body 501 that contains or consists of a polymer-based graphene composite material 200. The polymer-based composite material 200 includes a polyethylene-based polymer matrix 202 and reduced graphene oxide 201 in an amount ranging from 0.1% to 15% by weight per weight of the polyethylene-based polymer matrix 202.

[0198] In the polymer-based composite material 200 , reduced graphene oxide 201 may be distributed in a polymer matrix 202 . The polymer-based composite material 200 may also be referred to as a polymer-graphene composite material 200 .

[0199] Figure 5a shows a schematic diagram of a hydrogen storage container 500 according to one embodiment of a hydrogen carrier disclosed herein. This container 500 can be used to store and / or transport hydrogen. Figure 5a shows a schematic longitudinal cross-section of the hydrogen storage container 500, which is open, such as in the form of a tube or pipe. Figure 5b shows a cross-section of the hydrogen storage container 500 shown in Figure 5a along line AA.

[0200] In certain embodiments, the hydrogen carrier 500 may have more parts or layers, such as additional outer or inner layers separated from the hollow body 501. In the hydrogen carrier 500, at least the hollow body 501 comprises a polymer-graphene composite material 501. As will be discussed in more detail further below, the hollow body 501 may be formed, for example, by extrusion.

[0201] As described above, hydrogen carrier 500 can include other components, such as, but not limited to, additional cross-sectional portions as schematically illustrated in Figures 5c and 5d. In Figure 5c, an outer portion 502, or a second hollow body 502 arranged concentrically with hollow body 501, is provided to, for example, provide increased mechanical stability or impact protection. This outer portion 502 can comprise or consist of a carbon fiber polymer composite material or steel. A portion similar to outer portion 502 can be disposed inside hollow body 501.

[0202] Another alternative is to provide reinforcement in the polymer-graphene composite material 200, for example the polymer-graphene composite material may further comprise carbon fibers. Figure 5d shows another alternative, in which the hydrogen carrier comprises, from the outside inward, a first hollow body 501', a hollow mechanical reinforcement body 503 and a second hollow body arranged within the mechanical reinforcement body 503. At least one of the first hollow body 501' and the second hollow body 501" comprises or consists of the polymer-graphene composite material 200. The first hollow body 501' and the second hollow body 501" may have a thickness in the cm size range and are typically thicker than the hollow mechanical reinforcement body 503 (for example having a thickness in the mm size range). The mechanical reinforcement body 503 may, for example, be made of stainless steel, or made by winding carbon fibers.

[0203] The hydrogen carrier 500 beneficially increases the amount of hydrogen retained in the container 500 and reduces the amount of hydrogen permeating through the hollow body 501. Additional improved properties of the hydrogen carrier 500 according to the present invention include increased electrical conductivity, increased carrying capacity, and reduced electrostatic effects.

[0204] As previously discussed, the hydrogen carrier 500 as discussed herein can be any type of container for storing and / or transporting hydrogen in liquid and / or gaseous form. Examples include tanks, vessels, pipes, fittings, bottles, boxes, and the like.

[0205] The hydrogen carrier 500 is typically configured to withstand a wide range of temperatures and high pressures. For example, in hydrogen transportation, hydrogen may be transported at pressures ranging from 1 bar to 100 bar (e.g., 2 to 30 bar). Consequently, the associated components will be subject to considerable mechanical loads. The hollow body 501 may be configured to withstand pressures within these ranges. Polyethylene-based pipes may preferably be used in lower hydrogen pressure ranges (e.g., 2-10 bar or 2-5 bar).

[0206] Another benefit of the hydrogen carrier 500 is that it can have low volume or resistivity, see above Figure 4 Description.

[0207] The hydrogen carrier 500 according to the present patent disclosure can generally be manufactured by standard techniques such as injection molding, rotational molding, blow molding, or spraying.

[0208] In one aspect, a method for manufacturing a hydrogen carrier 500 according to the present patent disclosure is provided, wherein the hydrogen carrier 500 is manufactured using extrusion or injection molding.

[0209] Polymer extrusion is a processing technique in which a polymer is melted and formed into a desired profile. The polymer is melted by a heater and mechanical energy generated by a screw used in the process. The polymer-graphene composite material 200 can be manufactured by mixing the polymer with rGO using, for example, an extruder.

[0210] More embodiments of the present disclosure

[0211] The present disclosure includes the following embodiments:

[0212] 1. A polymer-based composite material (200) comprising a polyethylene-based polymer matrix (202) and reduced graphene oxide (201) in an amount of 0.1% to 15% by weight per weight of the polyethylene-based polymer matrix (202).

[0213] 2. The polymer-based composite material (200) according to embodiment 1, wherein the reduced graphene oxide (201) is distributed in the polyethylene-based polymer matrix (202).

[0214] 3. The polymer-based composite material (200) according to embodiment 1 or 2, comprising reduced graphene oxide (201) in an amount of 0.5% to 9% by weight per weight of the polyethylene-based polymer matrix (202).

[0215] 4. The polymer-based composite material (200) according to embodiment 1, 2 or 3, wherein the amount of reduced graphene oxide (201) in the polymer-based composite material (200) is 0.5% to 5% by weight per weight of the polyethylene-based polymer matrix (202).

[0216] 5. The polymer-based composite material (200) according to any one of the preceding embodiments, wherein the amount of reduced graphene oxide (201) in the polymer-based composite material (200) is 2.5% to 5% by weight per weight of the polyethylene-based polymer matrix (202), preferably 3% to 5% by weight per weight of the polyethylene-based polymer matrix (202).

[0217] 6. The polymer-based composite material (200) according to any one of the preceding embodiments, wherein the polymer-based composite material further comprises nanoclay.

[0218] 7. The polymer-graphene composite material (200) according to embodiment 6, wherein the polymer-based composite material comprises nanoclay in an amount equal to 90 to 110 weight percent per weight of reduced graphene oxide.

[0219] 8. The polymer-graphene composite material (200) according to embodiment 6 or 7, wherein the nanoclay comprises nanoparticles based on layered mineral silicates.

[0220] 9. The polymer-graphene composite material (200) according to embodiment 8, wherein the layered mineral silicate-based nanoparticles comprise one or more selected from montmorillonite nanoparticles, bentonite nanoparticles, kaolinite nanoparticles, hectorite nanoparticles, and halloysite nanoparticles.

[0221] 10. The polymer-based composite material (200) according to any one of the preceding embodiments, wherein the reduced graphene oxide (201) in the polymer-based composite material (200) comprises a Li salt, preferably lithium bis(salicylate)borate; and / or

[0222] The polyethylene-based polymer matrix comprises a mixture of extrusion-grade high-density polyethylene and blow molding-grade high-density polyethylene.

[0223] 11. An assembly (100) for hydrogen storage and / or transportation, the assembly comprising:

[0224] - a hollow body (101); and

[0225] - at least one hydrogen barrier lining (102) arranged along a surface of said hollow body (101);

[0226] wherein the at least one hydrogen barrier liner (102) comprises a polymer-based composite material (200) according to any one of the preceding embodiments.

[0227] 12. The assembly (100) according to embodiment 11, wherein the surface of the hollow body is an inner surface (101a) of the hollow body (101).

[0228] 13. The assembly (100) of embodiment 11 or 12, wherein the body is a tank, a vessel, a pipe, a fitting or a bottle.

[0229] 14. The assembly (100) of embodiment 11, 12 or 13, wherein the assembly is a hydrogen storage container or a hydrogen transport container,

[0230] Preferably, the hydrogen storage container is a hydrogen storage tank, a hydrogen storage vessel or a hydrogen bottle, wherein optionally, the hydrogen bottle is a hydrogen gas cylinder; and / or the hydrogen transport container is a hydrogen transport pipeline or a connector for connecting a hydrogen transport pipeline.

[0231] 15. The assembly (100) according to any one of embodiments 11 to 14, wherein the hollow body (101) is a hollow stainless steel body, a hollow carbon fiber wound body or a hollow polymer body.

[0232] 16. The assembly (100) according to any one of embodiments 11 to 15, wherein the hydrogen barrier liner (102) is attached to the hollow body (101) using an adhesive.

[0233] 17. The assembly (100) of any one of embodiments 11 to 15, wherein the hydrogen barrier liner (102) is attached to the hollow body in an adhesive-free manner.

[0234] 18. A method of manufacturing a component (100) for hydrogen storage and / or transport according to any one of embodiments 11 to 17, the method comprising lining a surface (101a) of the hollow body (101) with one of the at least one hydrogen barrier linings (102).

[0235] 19. Use of the polymer-graphene composite material (200) according to any one of embodiments 1 to 10 as a hydrogen barrier liner (102).

[0236] 20. A hydrogen carrier (500) for hydrogen storage and / or transport, comprising a hollow body (501) comprising the polymer-based graphene composite material (200) according to any one of embodiments 1 to 10.

[0237] 21. The hydrogen carrier (500) according to embodiment 20, wherein the hollow body is a tank, a vessel, a pipe, a joint or a bottle.

[0238] 22. The hydrogen carrier (500) according to embodiment 20 or 21, wherein the hydrogen carrier is a hydrogen storage container or a hydrogen transport carrier,

[0239] Preferably, the hydrogen storage container is a hydrogen storage tank, a hydrogen storage vessel or a hydrogen bottle, wherein optionally, the hydrogen bottle is a hydrogen gas cylinder; and / or the hydrogen transport carrier is a hydrogen transport pipeline or a connector for connecting a hydrogen transport pipeline.

[0240] 23. The hydrogen carrier (500) according to embodiment 20, 21 or 22, wherein the hollow body (501) is made of the polymer-based graphene composite material (200).

[0241] 24. The hydrogen carrier (500) according to any one of embodiments 20 to 23, wherein

[0242] The hollow body (501) is a first hollow body (501', 501"); and

[0243] The hydrogen carrier further includes a second hollow body (501', 501") concentrically arranged relative to the first hollow body (501', 501").

[0244] 25. The hydrogen carrier (500) according to embodiment 24, further comprising a hollow mechanical reinforcement body (503) arranged between the first hollow body (501', 501") and the second hollow body (501', 501").

[0245] 26. The hydrogen carrier (500) according to embodiment 24 or 25, wherein the second hollow body (501', 501") is made of the polymer-based composite material (200).

[0246] 27. The hydrogen carrier (500) according to embodiment 24, 25 or 26, wherein the second hollow body (501") is arranged inside the first hollow body (501').

[0247] 28. The hydrogen carrier (500) according to any one of embodiments 24 to 27, wherein the first hollow body (501") is arranged inside the second hollow body (501').

[0248] 29. A method for manufacturing the hydrogen carrier (500) according to any one of embodiments 20 to 28, wherein the hydrogen carrier (500) is manufactured using extrusion or injection molding.

[0249] 30. An extruded hydrogen carrier (500) comprising the polymer-graphene composite material (200) according to any one of embodiments 1 to 10.

[0250] Although the present invention has been described with reference to specific embodiments also shown in the accompanying drawings, it will be apparent to those skilled in the art that many changes and modifications are possible within the scope of the invention described in the specification and defined with reference to the following claims.

Claims

1. A polymer-based composite material (200) comprising a polyethylene-based polymer matrix (202) and reduced graphene oxide (201) in an amount of 1.2% to 15% by weight per weight of the polyethylene-based polymer matrix (202), wherein the polyethylene-based polymer matrix is ​​a high-density polyethylene-based polymer matrix.

2. The polymer-based composite material (200) according to claim 1, wherein the reduced graphene oxide (201) is distributed in the polyethylene-based polymer matrix (202).

3. The polymer-based composite material (200) according to claim 1 or 2, comprising reduced graphene oxide (201) in an amount of 2% to 9% by weight per weight of the polyethylene-based polymer matrix (202).

4. The polymer-based composite material (200) according to claim 1, 2 or 3, wherein the amount of reduced graphene oxide (201) in the polymer-based composite material (200) is 2% to 7% by weight per weight of the polyethylene-based polymer matrix (202).

5. The polymer-based composite material (200) according to any one of the preceding claims, wherein the amount of reduced graphene oxide (201) in the polymer-based composite material (200) is 2.3%-7% by weight per weight of the polyethylene-based polymer matrix (202), preferably 2.3%-5% by weight per weight of the polyethylene-based polymer matrix (202), such as 2.5%-5% and 3%-5% by weight per weight of the polyethylene-based polymer matrix (202).

6. The polymer-based composite material (200) according to any one of the preceding claims, wherein the polymer-based composite material further comprises nanoclay.

7. The polymer-graphene composite material (200) according to claim 6, wherein the polymer-based composite material comprises nanoclay in an amount equal to 90 to 110 weight % per weight of reduced graphene oxide.

8. The polymer-graphene composite material (200) according to claim 6 or 7, wherein the nanoclay comprises nanoparticles based on layered mineral silicates.

9. The polymer-based composite material (200) according to any one of the preceding claims, wherein the reduced graphene oxide (201) in the polymer-based composite material (200) comprises a Li salt, preferably lithium bis(salicylate)borate.

10. The polymer-based composite material (200) according to any one of the preceding claims, wherein the polyethylene-based polymer matrix comprises a mixture of extrusion-grade high-density polyethylene and blow molding-grade high-density polyethylene.

11. An assembly (100) for hydrogen storage and / or transportation, the assembly comprising: - a hollow body (101); and - at least one hydrogen barrier lining (102) arranged along a surface of said hollow body (101); wherein the at least one hydrogen barrier liner (102) comprises a polymer-based composite material (200) comprising a polyethylene-based polymer matrix (202) and reduced graphene oxide (201) in an amount of 0.1% to 15% by weight per weight of the polyethylene-based polymer matrix (202).

12. The assembly (100) according to claim 11, wherein the surface of the hollow body is an inner surface (101a) of the hollow body (101).

13. The assembly (100) of claim 11 or 12, wherein the body is a can, a vessel, a pipe, a fitting or a bottle.

14. The assembly (100) according to claim 11, 12 or 13, wherein the assembly is a hydrogen storage container or a hydrogen transport container, Preferably, the hydrogen storage container is a hydrogen storage tank, a hydrogen storage vessel or a hydrogen bottle, wherein optionally, the hydrogen bottle is a hydrogen gas cylinder; and / or the hydrogen transport container is a hydrogen transport pipeline or a connector for connecting a hydrogen transport pipeline.

15. The assembly (100) according to any one of claims 11 to 14, wherein the hollow body (101) is a hollow stainless steel body, a hollow carbon fiber wound body or a hollow polymer body.

16. The assembly (100) according to any one of claims 11 to 15, wherein the hydrogen barrier liner (102) is attached to the hollow body (101) using an adhesive.

17. The assembly (100) according to any one of claims 11 to 15, wherein the hydrogen barrier liner (102) is attached to the hollow body in an adhesive-free manner.

18. The assembly (100) according to any one of claims 11 to 17, wherein the polymer-based composite material (200) is the polymer-based composite material (200) according to any one of claims 1 to 10.

19. The assembly (100) according to any one of claims 11 to 17, wherein the polyethylene-based polymer matrix is ​​a high-density polyethylene-based polymer matrix.

20. The assembly (100) according to any one of claims 11 to 19, wherein the hydrogen barrier liner (102) is made by blow molding.

21. The assembly (100) according to any one of claims 11 to 19, wherein the hydrogen barrier liner (102) is made by extrusion, such as coextrusion.

22. A method of manufacturing a component (100) for hydrogen storage and / or transport according to any one of claims 11 to 21, comprising lining a surface (101a) of the hollow body (101) with one of the at least one hydrogen barrier linings (102).

23. The method of claim 20, wherein the at least one hydrogen barrier liner (102) is made by blow molding.

24. Use of the polymer-graphene composite material (200) according to any one of claims 1 to 10 as a hydrogen barrier liner (102).

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