WO2023143942A1 - Système d'électrolyse et procédé d'exfoliation de graphite - Google Patents

Système d'électrolyse et procédé d'exfoliation de graphite Download PDF

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Publication number
WO2023143942A1
WO2023143942A1 PCT/EP2023/050826 EP2023050826W WO2023143942A1 WO 2023143942 A1 WO2023143942 A1 WO 2023143942A1 EP 2023050826 W EP2023050826 W EP 2023050826W WO 2023143942 A1 WO2023143942 A1 WO 2023143942A1
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Prior art keywords
electrode
electrolysis system
electrodes
water
liquid
Prior art date
Application number
PCT/EP2023/050826
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English (en)
Inventor
Paul Francis Geary
Original Assignee
Green Graphene Limited
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from GB2200933.6A external-priority patent/GB2614920A/en
Application filed by Green Graphene Limited filed Critical Green Graphene Limited
Publication of WO2023143942A1 publication Critical patent/WO2023143942A1/fr

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    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B9/00—Cells or assemblies of cells; Constructional parts of cells; Assemblies of constructional parts, e.g. electrode-diaphragm assemblies; Process-related cell features
    • C25B9/17—Cells comprising dimensionally-stable non-movable electrodes; Assemblies of constructional parts thereof
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/15—Nano-sized carbon materials
    • C01B32/182—Graphene
    • C01B32/184—Preparation
    • C01B32/19—Preparation by exfoliation
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B1/00—Electrolytic production of inorganic compounds or non-metals
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B1/00—Electrolytic production of inorganic compounds or non-metals
    • C25B1/50—Processes

Definitions

  • the present disclosure relates to an electrolysis system for generating graphite oxide and/or graphene oxide.
  • Other aspects of the present disclosure relate to a method for generating graphite oxide and/or graphene oxide.
  • graphene is a two-dimensional layer of carbon atoms which form hexagonal rings and is expected to transform a range of sectors such as microelectronics, energy creation and storage, as well as health and construction.
  • This single atom layer of carbon exhibits remarkable properties, such as an electric conductivity that is higher than copper and a strength that is 200 times the strength of steel.
  • Pure graphene is also highly transparent making it a particularly non-intrusive alternative to many other electric conductors.
  • an electrolysis system for generating graphite oxide and/or graphene oxide, said system, comprising:
  • the liquid supply is configured for supplying electrolyte-free water.
  • the electrolyte-free water is purified water, preferably deionised or distilled water.
  • the liquid chamber comprises a gap located between the two electrodes, wherein the gap has a width smaller than a Debye-length of purified water.
  • the graphite part of the flow-through electrode has a porosity that will allow the electrolyte-free water to permeate through said electrode.
  • both electrodes comprise graphite.
  • both electrodes are flow-through electrodes.
  • the electrolysis system comprises an electric supply circuit for supplying electric power to the electrodes.
  • the electric supply circuit is configured to supply electric power at a voltage that enables current to flow through electrolyte-free water between the anode-electrode and the cathode-electrode.
  • the electric supply circuit comprises a rectifier for supplying the electric power as a pulsed direct current, preferably by full-wave rectification of an alternating current supply.
  • the electric supply circuit comprises a transformer comprising primary windings and center tapped secondary windings connected to the rectifier.
  • the electrolysis system comprises a control unit for controlling a pressure within the liquid chamber.
  • control unit is configured to control a pressure drop across the flow-through anode-electrode.
  • the system comprises means for moving one or both of the two electrodes with respect to each other for adjusting and/or maintaining the gap size.
  • the system is transferable between a productions state, in which the electric supply circuit is configured to supply electric power at a first voltage, and an enrichment state, in which the electric supply circuit is configured to supply electric power at a second voltage, the first voltage being higher than the second voltage.
  • liquid penetrating the anode-electrode is returned to the liquid chamber.
  • liquid penetrating the cathode-electrode is removed from the system, preferably stored in a tank.
  • the second voltage is sufficient that graphene is repelled and does not flow through the Cathode.
  • the control unit is configured to transfer the electrolysis system between its production state and its enrichment state and vice versa, at regular intervals.
  • control unit is configured to transfer the electrolysis system between its production state and its enrichment state and vice versa, based on a level of graphene and/or graphite in a storage chamber.
  • At least the anode-electrode comprises additives, such as N-Methyl-2-pyrrolidone, for improving exfoliation of graphite by means of the liquid.
  • the electrolysis system comprises means for introducing additives into the liquid for doping graphite and/or graphene generated by the system.
  • the electrolysis system comprises a gas injector for injecting gases other than oxygen, preferably hydrogen, into the reaction liquid to reduce an amount of oxygen generated at the anode-electrode.
  • the gas injector is configured to inject the gases within or around the anode-electrode.
  • a method of generating graphite oxide and/or graphene oxide by electrolysis comprising:
  • the method comprises supplying electrolyte-free water to the electrodes.
  • the electrolyte free water comprises purified water, particularly deionized water or distilled water.
  • the flow-through electrode has a porosity that will allow the water or electrolyte water to permeate through the electrode.
  • the method comprises supplying the electric power at a voltage that enables current to flow through electrolyte -free water between the two electrodes.
  • the method comprises supplying the electric power as a pulsed direct current, preferably by full-wave rectification of an alternating current supply.
  • the method comprises supplying the water or electrolyte water to the electrodes at a pressure, preferably at a pressure of more than 1 bar.
  • Figure 1 shows a schematic illustration of an electrolysis system according to an embodiment of the present invention
  • Figure 2 shows a schematic cross-section of an electrode structure
  • Figure 3 shows a schematic cross-section of an electrode stack
  • Figure 4 shows a schematic illustration of an electric power supply
  • Figure 5 shows a flow diagram of a method according to an embodiment of the present disclosure.
  • Figure 6 shows a schematic illustration of an electrolysis system according to an embodiment of the present invention.
  • FIG. 1 shows an electrolysis system 100 according to an embodiment of the present disclosure.
  • an electrolysis system 100 for generating graphite, particularly by electrolysis of water or electrolyte water.
  • the electrolysis system 100 shown in FIG. 1 may also be suitable for generating graphite via electrolysis utilising other substances.
  • the term “water” may encompass tap water including that with no added electrolytes.
  • the term “electrolyte water” may encompass water including any added electrolyte suitable for water electrolysis.
  • electrolyte water may also be referred to as electrolyte solution.
  • Electrolyte water may contain any type of electrolyte additive, such as sulphuric acid, sulphate, potassium hydroxide, sodium hydroxide, etc.
  • electrolyte-free water refers to tap water with reduced electrolyte content. As will be appreciated, even tap water will typically include natural levels of electrolytes.
  • Electrode-free water therefore, relates to treated tap water that has a reduced, and preferably (to the extent possible) no electrolyte content. Although electrolyte will be removed from “electrolyte-free water” it should be understood that “electrolyte-free water” may still include various other non-water impurities, such as organic molecules. Examples of “electrolyte-free water” include purified water, such as deionised water and distilled water.
  • the electrolysis system 100 comprises a housing 102.
  • the housing 102 comprises a liquid chamber 104.
  • the liquid chamber is configured to hold water or electrolyte water (hereinafter collectively referred to as reaction liquid) under pressure as will be described in more detail below.
  • the housing 102 comprises a first gas collection chamber 106.
  • the first gas collection chamber 106 is separated from the liquid chamber 104 by a first electrode 108.
  • the housing 102 comprises a second gas collection chamber 110.
  • the second gas collection chamber 110 is separated from the liquid chamber 104 by a second electrode 112.
  • the liquid chamber 104 is located between the first and second electrodes 108, 112.
  • the liquid chamber 104 is a membrane-less chamber.
  • the electrolyser may comprise more than two electrodes, e.g. arranged in parallel to each other to form a stack of electrodes.
  • the pair of electrodes 108, 112 of Figure 1 are thus exemplary for any number of electrodes used in a stack.
  • One possible arrangement of electrodes in a stack will be described in more detail with reference to Fig. 3.
  • the housing 102 of Figure 1 is a multi-part housing.
  • the housing 102 comprises at least two parts: a first housing part includes the first gas collection chamber 106 and the first electrode 108; a second housing part includes the second gas collection chamber 110 and the second electrode 112.
  • the at least two housing parts are connected to each other such that a gap is formed between first surfaces 114, 118 of the first and second electrodes 108, 112. This gap defines the liquid chamber 104, which is thus arranged between the electrodes 108, 112.
  • the housing 102 is substantially H-shaped as will be described in more detail below.
  • the first electrode 108 is permeable to gases produced by decomposition of reaction liquid.
  • the first electrode 108 is also permeable to the reaction liquid.
  • the first electrode 108 is a so-called "flow-through" electrode in which gases produced by decomposition of water (and the reaction liquid) within the liquid chamber 104 are able to penetrate the first electrode 108 and thus move from the liquid chamber 104 towards the first gas collection chamber 106.
  • the first electrode 108 is a permeable electrode including a plurality of pores sized to allow permeation of the respective gas, e.g. hydrogen, through the first electrode 108.
  • the first electrode 108 has a first surface 114 facing the liquid chamber and a second, opposite surface 116 facing the first gas collection chamber 106.
  • the first electrode 108 may be made of graphite.
  • the second electrode 112 may also be made of graphite.
  • the first electrode 108 may be made of a different as the second electrode 108.
  • the second electrode may be made of titanium, nickel, steel, or any other suitable metal.
  • Gases produced by the first electrode 108 may flow into the first gas collection chamber 106.
  • the first gas collection chamber 106 comprises a first gas outlet 122 for extraction of the gas within the first gas collection chamber 106.
  • the first gas outlet 122 may include a pressure control valve, such as a pressure relief valve, configured to set a gas pressure within the first gas collection chamber 106.
  • the second electrode 112 of Figure 1 is also permeable to gases produced by the decomposition of reaction liquid.
  • the second electrode 112 is also generally permeable to reaction liquid depending on a pressure within the liquid chamber 104 as will be explained in more detail below.
  • the second electrode 112 is also a "flow-through" electrode in which gases produced by decomposition of the reaction liquid within the liquid chamber 104 are able to penetrate the second electrode 112 and thus move from the liquid chamber 104 towards the second gas collection chamber 110.
  • the second electrode 112 has a first surface 118 facing the liquid chamber 104 and a second, opposite surface 120 facing the second gas collection chamber 110.
  • Gases produced by the second electrode 112 may flow into the second gas collection chamber 110.
  • the second gas collection chamber 110 comprises a second gas outlet 124 for extraction of the gas within the second gas collection chamber 110.
  • the second gas outlet 124 may include a pressure control valve, such as a pressure relief valve, configured to determine the pressure within the second gas collection chamber 110.
  • the electrolysis system 100 comprises a liquid supply, particularly a liquid supply circuit 130, for supplying the liquid chamber 104 with reaction liquid.
  • the liquid supply circuit 130 of Figure 1 is a semi-closed system. "Semi-closed system” refers to the supply circuit 130 being closed via a drain port 142 of the first gas collection chamber 106, but open a second drain port 144 of the second gas collection chamber 144, as will be described in more detail below.
  • the liquid supply circuit may be an open system including a reaction liquid reservoir.
  • the liquid supply circuit 130 comprises a pump 134 arranged upstream of an inlet port 126 of the liquid chamber 104.
  • the pump 134 may be configured to move reaction liquid through the system and in the direction of the liquid chamber 104 at a selectable pressure.
  • the electrolyte supply circuit 130 comprises a liquid supply line 162 for topping up reaction liquid turned into gas by the electrolysis process.
  • the liquid supply line 162 may be connected to the pump 134 via a manually or automatically controlled shut off valve 164.
  • the liquid supply line 162 may be connected to either a water supply line, a reaction liquid tank or any other suitable reaction liquid source.
  • An expansion vessel 132 is a pressure storage device arranged within the reaction liquid supply circuit 130.
  • the expansion vessel 132 is configured to provide expansion derived pressure into the system and to enable pump 134 to have a lower cycle time and maintain a desired pressure range within the circuit 130/protect the circuit 130 from excessive pressures.
  • the liquid chamber 104 may comprise a vent port connected to a vent line 105.
  • the vent line 105 is configured to be used to drain back flushed electrolyte and any associated media. Additionally, the vent line 105 may be instrumental in sampling and even comprise a collection well for removal of electrolyte in the circulation system either with or without pressure. Additionally, the vent may or may not be instrumental in the purging of air from the system prior to current being applied to the electrodes. Finally, the vent pipe may allow electrolyte flow and recycling from 104 via 105 to 162, the water inlet line or it may discharged/collected.
  • the electrolyte supply circuit 130 may comprise a pressure gauge 136 for monitoring the pressure within the liquid chamber 104.
  • the pressure gauge 136 may be arranged anywhere downstream of the pump 134. In some embodiments, the pressure gauge 136 may be an integral part of the pump 134. In other embodiments, the pressure gauge may be arranged within the liquid chamber 104.
  • the reaction liquid supply circuit 130 may comprise a pressure storage device, such as an accumulator 138.
  • the accumulator 138 shown in FIG. 1 is arranged downstream of the pump 134.
  • the accumulator 138 may be connected to the pump 134 via a check valve, which, during normal operation of the electrolysis system 100, allows fluid to be pumped into the accumulator 138.
  • the check valve will stop fluid from leaving the accumulator 138.
  • the accumulator 138 may also comprise a separate outlet valve for selectively connecting an outlet of the accumulator 138 with the liquid chamber 104.
  • the accumulator 138 may thus comprise a normally-open outlet valve, which is closed during normal operation of the electrolyser.
  • pressurized reaction liquid may be pumped into the accumulator 138 but may not leave the accumulator 138, until the outlet valve is opened.
  • using a normally-open outlet valve enables the accumulator 138 to be used as a safety measure, e.g. during power cuts.
  • the first gas collection chamber 106 comprises a first drain port 142.
  • the second gas collection chamber 110 comprises a second drain port 144.
  • the first drain port 142 is connected to the pump 134 of the reaction liquid supply circuit 130 via a first drain line 146.
  • the second drain port 144 is connected to a gaphite solution tank 166 via a second drain line 148.
  • Reaction liquid permeating the first electrode 108 during operation of the electrolysis system 100 may be drained from the first gas collection chamber 106 via the first drain port 142 and the first drain line 146 respectively.
  • reaction liquid permeating the second electrode 112 during operation of the electrolysis system 100 may be drained from the second gas collection chamber 110 via the second drain port 144 and the second drain line 148 respectively.
  • any drain port can act for one or more of the cells rather than being required by each cell.
  • the first and second drain ports 142, 144 are arranged typically at a bottom end of the first and second gas collection chambers 106, 110.
  • the drain ports 142, 144 are arranged below the first and second gas outlets 122, 124 of the first and second gas collection chambers 106, 110.
  • the drain ports 142, 144 are also arranged below the first and second electrodes 108, 112 but this may not always be the case.
  • both the first and the second gas collection chambers 106, 110 comprise drain wells 141, 143 arranged typically at a bottom end of the gas collection chambers 106, 110.
  • the housing 102 is thus substantially H-shaped but does not need to be, it can be a multicell or arranged similar to a plate heat exchanger design.
  • the device can be made of multiple electrodes usually arranged in parallel to each other to form a stack of electrodes as will be described with reference to Figures 2 and 3.
  • reaction liquid that has permeated the first electrode 108 will collect within the drain well 141 at the bottom of the first gas collection chamber 106, whereas the gases produced during the electrolysis, will rise and pressurize the first gas collection chamber 106.
  • Reaction liquid that is drained via the first drain port 142 will be returned into the semi-closed liquid supply circuit 130 via first drain line 146, e.g. upstream of pump 134, and may thus be redirected towards the liquid chamber 104.
  • Reaction liquid that has permeated the second electrode 112 will collect within the drain well 143 at the bottom of the second gas collection chamber 110, whereas the gases produced during the electrolysis, will rise and pressurize the second gas collection chamber 112. Reaction liquid that is drained via the second drain port 144 will be directed towards the graphite solution tank 166.
  • the reaction liquid that penetrated the first electrode 108 may be collected for use and not recycled back to the liquid chamber 104, depending on the properties it has acquired by passing through the Cathode.
  • the first and second gas collection chambers 106, 110 both comprise gas pressure gauges 150, 152.
  • a first gas pressure gauge 150 is configured to determine the gas pressure within the first gas collection chamber 106.
  • a second gas pressure gauge 152 is configured to determine a second gas pressure within the second gas collection chamber 110.
  • the first and second gas gauges may be incorporated into a single device.
  • the electrolysis system 100 comprises a first electrical terminal 154 and a second electrical terminal 156.
  • the first terminal 154 is a negative terminal
  • the second terminal 156 is a positive terminal.
  • the polarity of the first and second terminals may be swapped, such that the first terminal 154 is a positive terminal and the second terminal 156 is negative.
  • the electrolyser is symmetrical on either side of the liquid chamber 104.
  • the first and the second electrodes 108, 112 are flow-through graphite electrodes.
  • the terminals may be swapped to change the polarity after some time. This swap will turn the first electrode 108 into an anode-electrode and the second electrode into a cathode-electrode.
  • This embodiment is beneficial in that both graphite electrodes may be exfoliated by simply swapping the polarity of the terminals 154, 156.
  • the terminals 154, 156 are connected to the housing 102 of the electrolysis system 100.
  • the first terminal 154 is connected to the first gas collection chamber 106.
  • the second terminal is connected to the second gas collection chamber 110.
  • the first terminal 154 is electrically connected to the first electrode 108, which is electrically connected to the first gas collection chamber 106 via its second surface 116.
  • the second terminal 156 is connected to the second gas collection chamber 110, which in turn is connected to the second electrode 112 via the second surface 120 of the second electrode 112.
  • the terminals 154, 156 may also be connected to the electrodes 108, 112 directly, rather than via the housing 102 of the electrolysis system 100.
  • the terminals 154, 156 are connectable to a power source, e.g. a direct current power source, to apply a current across the electrodes 108, 112. If the terminals 154, 156 are connected to the power source, current will flow between the first and second electrode 108, 112 via the reaction liquid within the liquid chamber 104, thereby activating the electrolysis process for decomposition and separation of reaction liquid into oxygen and hydrogen, as will be explained in more detail below.
  • a power source e.g. a direct current power source
  • the first terminal 154 is a negative terminal and the second terminal 156 is a positive terminal.
  • the first electrode 108 of the embodiment in Figure 1 is the cathode of the electrolysis system 100
  • the second electrode 112 is the anode of the electrolysis system 100.
  • the first electrode 108 is permeable to gas, particularly hydrogen.
  • the second electrode 112 is permeable to gas, particularly oxygen.
  • the first and second electrodes 108, 112 comprise different porosities.
  • the porosity of the first electrode 108 may be about half of the second electrode 112.
  • the first gas collection chamber 106 is configured to receive hydrogen gas
  • the second gas collection chamber 110 is configured to receive oxygen gas.
  • the electrolysis system 100 further comprises a control unit 160, schematically represented in Figure 1.
  • the control unit may be connected to the first and/or second gas pressure gauges 150, 152 to receive gas-pressure-data representative of a gas pressure within the first and/or second gas collection chamber 106, 110.
  • the control unit 160 may be connected to the first and second drain valves 142, 144 for controlling operation of the first and second drain valves 142, 144.
  • the control unit may be connected to the first and second gas outlets 122, 124 for controlling the operation of the first and second gas outlets 122, 124.
  • the control unit 160 may be connected to a power source (not shown) for controlling the supply of electrical power to the first and second electrodes 108, 112.
  • the control unit 160 may be connected to an outlet valve of the accumulator 138.
  • the control unit 160 may be connected to the pump 134 and the reaction liquid pressure gauge 136.
  • the control unit may be connected to any of the above devices via control wires or wirelessly as is well known in the art.
  • the control unit may either be locally arranged together with the housing 102 of the electrolyser or remotely, e.g. in a centralised control office.
  • the control unit 160 is configured to control a pressure drop across at least one of the permeable electrodes 108, 112. In one embodiment, the control unit 160 is configured to control the electrolyte pressure in the liquid chamber 104 relative to a gas pressure in the first or second gas collection chamber 106, 110. The control unit 160 may be configured to control the reaction liquid pressure in the liquid chamber 104 to be higher than a gas pressure in the first and/or second gas collection chambers 106, 110. In other words, the control unit 160 is configured to maintain a pressure drop between the liquid chamber 104 and the gas collection chambers 106, 110.
  • control unit 160 is configured to control the reaction liquid pressure in the liquid chamber 104 to be at least 1 bar higher than a gas pressure in the first and/or second gas collection chamber 106, 110. Maintaining a pressure drop of at least 1 bar between the liquid chamber 104 and the first and/or second gas collection chamber 106, 110 may increase the amount of reaction liquid permeating the first electrode 108 and/or the second electrode 112 and thus causes flow between the liquid chamber 104 and the first and/or second gas collection chamber 106, 110. As will be described in more detail below, it may be beneficial to increase reaction liquid flow through the second electrode 112 to increase production of graphite solution.
  • the control unit 160 may be configured to maintain a pressure drop of at least 1 bar, preferably at least 5 bar, across the second electrode 112 to increase flow of reaction liquid through the second electrode 112.
  • control unit 160 of Figure 1 is configured to receive gas- pressure-data representative of a gas pressure within the first or second gas collection chambers 106, 110 respectively.
  • the gas- pressure-data may be pressure readings supplied by the first and/or second gas pressure gauges 150, 152.
  • the control unit On the basis of the gas-pressure-data, the control unit will determine a desired reaction liquid pressure within the liquid chamber 104. In some examples, the control unit may add a preselected amount of pressure to the gas pressure indicated by the gas-pressure-data in order to determine the desired reaction liquid pressure. In some embodiments, the control unit 160 may determine a desired reaction liquid pressure that is at least 1 bar higher than the gas pressure within the second gas collection chamber 110.
  • the control unit may then control the reaction liquid supply circuit 130 to supply reaction liquid to the liquid chamber 104 until the desired reaction liquid pressure is reached.
  • the control unit 160 may be configured to activate the pump 134 to supply reaction liquid to the control chamber 104 until the desired reaction liquid pressure has been reached.
  • the control unit may receive liquid-pressure-data representative of a pressure of reaction liquid within the liquid chamber 104.
  • the liquid- pressure-data comprises pressure readings supplied by the pressure gauge 136 arranged downstream of the pump 134.
  • the control unit may control activation of the pump 134 via a control loop, based on the liquid-pressure-data provided by the pressure gauge 136.
  • the control unit may control the reaction liquid pressure within the control chamber 104, represented by the pressure readings of the pressure gauge 136, via a PID control loop.
  • a pressure drop between the liquid chamber 104 and the gas collection chambers 106, 110 will vary continuously as the electrolysis system 100 is operated. This is because, during operation of the electrolysis system, i.e. when pressurised reaction liquid is available in the liquid chamber 104 and a current is applied across the two electrodes 108, 112, hydrogen and oxygen gases are produced and added to the first and second gas collection chambers 106, 110 continuously. Accordingly, in this example, as long as the first and second gas outlets 122, 124 remain closed, the gas pressure within the gas collection chambers 106, 110 will continue to rise. This exemplary rise in gas pressure will be determined by the control unit 160 on the basis of the gas-pressure-data.
  • the control unit 160 will then determine a new, higher, desired reaction liquid pressure and control the pump 134 to increase the reaction liquid pressure within the liquid chamber 104 and match said increased desired reaction liquid pressure.
  • the control unit 160 may continuously adjust the pressure within the liquid chamber 104 as long as the gas pressure within the first or second gas collection chamber 106, 110 rises.
  • the control unit 160 may also control the gas pressure within the first and/or second gas collection chamber 106, 110.
  • the control unit may be configured to control an operation of the first and/or second gas outlet 122, 124.
  • the control unit 160 may open and close the first gas outlet 122 to control the (hydrogen) gas pressure within the first gas collection chamber 106.
  • the control unit 160 may open and close the second gas outlet 124 to control the (oxygen) gas pressure within the second gas collection chamber 110.
  • the control unit 160 may receive a first desired gas pressure for the first gas collection chamber 106 and a second desired gas pressure for the second gas collection chamber 110. The first and second desired gas pressures may be selected by an operator.
  • the desired gas pressures may be determined directly by apparatus using the hydrogen and oxygen gases provided by the electrolysis system 100.
  • one or both of the gas outlets may comprise pressure relief valves configured to open automatically once the gas pressure in the first or second gas collection chamber 106, 110 exceeds a set pressure.
  • the pressure within the gas collection chambers will be determined by the set pressure of the pressure relief valves of the first and second gas outlets 122, 124 respectively.
  • the set pressure of the pressure relief valves may be adjustable, e.g. via the control unit 160.
  • control unit 160 may be configured to maintain a gas pressure in the first and second gas collection chamber 106, 110 at lOObar to lOOObar. If the gas pressure within the gas collection chambers 106, 110 is maintained at 100 bar, the control unit may set a desired reaction liquid pressure of 101 bar or more to allow for some reaction liquid to pass through the first and/or second electrode 108, 112 as has been described above.
  • the control unit may also be configured to control a power source (not shown) attached to the electrodes 108, 112 via the terminals 154, 156.
  • the operator or controller can alter the voltage according to the type of electrolysis and the type of electrode used and other variables such as cell gap.
  • the control unit may be configured to set the voltage provided by the power source to be at a desired voltage.
  • the desired voltage may be designated by the operator.
  • the amperage and voltage can be fixed, manually set or variably controlled by the control unit 160.
  • control unit may be configured to supply electrical power to the electrodes 108, 112 only once the desired pressure drop across the electrodes 108, 112 has been achieved.
  • control unit 160 may monitor a pressure difference between one of the gas collection chambers 106, 110 and the liquid chamber 104. Once the pressure difference exceeds a selectable first pressure-threshold, the control unit may activate the power supply to apply a DC current across the electrodes 108, 112 and the reaction liquid within the liquid chamber 104 to start operation of the electrolysis system 100.
  • the control unit 160 may be configured to de-activate the power supply whenever the pressure difference falls below a second pressure-threshold.
  • the second pressure threshold may be the same as or lower than the first pressurethreshold.
  • the application is not limited to the electrolysis system comprising an H-shaped housing shown in FIG. 1. Rather, the present invention is applicable to any type of electrolysis system, in which at least the anode-electrode is constructed as a graphite flow-through electrode. At least the anode-electrode(s), and preferably also the cathode-electrode(s), may comprise any type of graphite that can be exfoliated.
  • FIG. 2 shows a flow-through electrode 200.
  • the flow-through electrode 200 is made of a porous structure that is permeable to gases produced during electrolysis and reaction liquids.
  • the electrode layout shown in FIG. 2 may be used for both an anode-electrode and a cathode-electrode in an electrolysis system for exfoliating graphite.
  • the anodeelectrode will be constructed of porous graphite
  • the cathode-electrode may be constructed of any suitable porous structure that is electrically conductive, such as graphite, titanium, nickel, or steel.
  • the porous electrode 200 shown in FIG. 2 may be sintered into the structure shown, so as to provide suitable pore sizes.
  • the electrode 200 comprises a first surface 202 and an opposite second surface 204. Both the first and second surfaces 202, 204 are made of the flow-through material (e.g., graphite, titanium, nickel, or steel).
  • a gas collection chamber 206 is located between the first and second surfaces 202, 204 of the electrode 200.
  • the electrode 200 comprises a first porous wall 203 comprising the first surface 202 and a second porous wall 205 comprising the second surface 204.
  • the gas collection chamber 206 extends between the first and second walls 203, 205.
  • the electrode shown in FIG. 2 differs from the electrodes shown in the embodiment of FIG. 1 in that the electrode 200 includes an integral gas collection chamber.
  • the gas collection chamber 206 is arranged on the inside of the electrode 200.
  • the gas collection chambers of FIG. 1 were provided as a part of the housing 102 and are thus separate parts that may be disconnected from the electrodes.
  • the electrode 200 Due to the arrangement of the gas collection chamber 206 on the inside of the electrode 200, the electrode 200 comprises two flow-through surfaces, namely the first and the second surfaces 202, 204.
  • the electrode 200 of FIG. 2 may be provided with reaction liquid on both sides of the electrode, i.e., on both surfaces 202, 204, such that electrolysis may occur when reaction liquid penetrates the first wall 203 and/or the second wall 205.
  • reaction liquid and gases produced by the decomposition of the reaction liquid will penetrate the flow-through electrode 200 and flow into the gas collection chamber 206.
  • the electrode 200 is provided with electrical power of a positive polarity, the electrode will be an anode-electrode and reaction liquid penetrating the first and/or second walls 203, 205 will act to exfoliate graphite from the porous graphite structure of the walls 203, 205 during electrolysis.
  • the anode-electrode will decompose some of the reaction liquid into oxygen. Accordingly, during the electrolysis process, oxygen and a graphite solution will enter the gas collection chamber 206 of the electrode 200.
  • the so collected oxygen and graphite solution may be extracted from the electrode 200 via corresponding extraction openings.
  • the oxygen gas may be extracted via a gas collection opening 208
  • the graphite solution may be extracted via a liquid collection opening 210.
  • the functionality of the gas collection opening 208 is comparable to the gas outlet 124 of FIG. 1, whereas the functionality of the liquid collection opening 210 is comparable to the drain port 144 of FIG. 1.
  • the way in which the gases and liquid are removed from the gas collection chamber 206 is, however, not the subject of this invention.
  • the electrode 200 is provided with electrical power of a negative polarity, it will act as a cathode-electrode for the production of hydrogen.
  • the cathode-electrode may be made of any conductive material, such as graphite or steel.
  • the structure of the cathode-electrode may, however, be identical to the structure of the anode-electrode, i.e., the structure of the electrode 200 shown in FIG. 2.
  • no exfoliation of graphite occurs at the cathode-electrode, even if the cathode-electrode is a graphite flow- through electrode.
  • an electrode stack 300 comprising three electrodes of FIG. 2 arranged adjacent to each other.
  • a first electrode 300a is a first anode-electrode. The first electrode 300a is connected to a positive pole of an electric power supply.
  • a second electrode 300b is arranged in parallel and adjacent to the first electrode 300a. The second electrode 300b is connected to a negative pole of the electric power supply of the electrolysis system.
  • a third electrode 300c is arranged in parallel and adjacent to the second electrode 300b. The third electrode 300c is connected to a positive terminal of the electric power supply of the electrolysis system.
  • Each of the electrodes 300a, 300b, 300c of the electrode stack 300 has a structure that is identical to the structure of the electrode 200 discussed with reference to FIG. 2. Accordingly, the first electrode 300a has a first surface 302 defined by a first porous wall and a second surface 304, which is arranged opposite to the first surface 302 and defined by a second porous wall. A gas collection chamber 306 is arranged between the first and second surfaces 302, 304 of the first and third electrodes 300a, 300c.
  • the first and third electrodes 300a, 300c comprise gas collection openings 308 and reaction liquid collection openings 310.
  • the gas collection openings 308 are preferably arranged at an upper region of the electrodes, whereas the reaction liquid collection openings 310 are arranged at a bottom end of the electrodes.
  • the second electrode 300b of the electrode stack 300 shown in FIG. 3 is arranged between the first and third electrodes 300a, 300c.
  • the second electrode 300b comprises a first surface 314 and an opposite second surface 316.
  • a gas collection chamber 318 is arranged between the first surface 314 and the second surface 316 of the second electrode 300b.
  • the second electrode 300b comprises a gas collection opening 320, which is arranged at an upper end of the electrode 300b.
  • the second electrode 300b further comprises a reaction fluid collection opening 320, which is arranged at a lower end of the second electrode 300b.
  • the electrode stack 300 comprises a first liquid chamber 330 arranged between the first electrode 300a and the second electrode 300b.
  • the electrode stack 300 also comprises a second liquid chamber 332 arranged between the second electrode 300b and the third electrode 300c.
  • the first liquid chamber 330 is arranged between the second surface 304 of the first electrode 300a and the first surface 314 of the second electrode 300b.
  • the second liquid chamber 332 is arranged between the second surface 316 of the second electrode 300b and the first surface 302 of the third electrode 300c.
  • the first and second liquid chambers 330, 332 are connected to each other via a reaction liquid channel 324 extending through the second electrode 300b, i.e., between the first surface 314 and the second surface 316. Accordingly, in the electrode stack 300 shown in FIG.
  • reaction liquid within the first and second liquid chambers 330, 332 will have the same pressure, which is then applied to the second surface 304 of the first electrode 300a, the first and second surfaces 314, 316 of the second electrode 300b, and the first surface 302 of the third electrode 300c.
  • the first and third electrodes 300a, 300c are anode-electrodes, such that, during the electrolysis process, oxygen is generated at the first and third electrodes 300a, 300c. At the same time, reaction liquid in the first and second liquid chambers 330, 332 will enter the gas collection chambers 306 of the first and third electrodes 300a, 300c.
  • the reaction liquid permeating the porous structure of the first and third electrodes 300a, 300c will act to exfoliate some of the graphite of the flow-through electrodes, such that a graphite solution will be received within the gas collection chambers 306 of the anode-electrodes.
  • This graphite solution may be drained from the gas collection chambers 306 of the anode-electrodes 300a, 300c via their respective liquid collection openings 310.
  • Reaction liquid within the first and second liquid chambers 330, 332 will be decomposed into hydrogen gases at the cathode-electrode, i.e., the second electrode 300b of FIG. 3. Accordingly, hydrogen produced via the flow-through porous structure of the second electrode 300b will enter the gas collection chamber 318 of the second electrode 300b. Since the porous walls of the second electrode 300b may also be permeable to reaction liquid, the gas collection chamber 318 may receive some of the reaction liquid of both liquid chambers 330, 332 during the electrolysis process. Such reaction liquid may be drained from the second electrode 300b via the liquid collection opening, whereas hydrogen gas may be collected via the gas collection opening 320.
  • the electrode stack 300 may extend further on either side of the first and third electrodes 300a, 300c.
  • further electrodes would be arranged adjacent to each other in an alternating fashion.
  • another cathode-electrode would be arranged next to the first electrode 300a (i.e., on the left of the first electrode 300a).
  • a third cathode-electrode would be arranged in parallel with and adjacent to the third electrode 300c (i.e., on the right side of the third electrode 300c).
  • additional liquid chambers would be connected to the first and second liquid chambers 330, 332 via channels 312 extending through the first and third electrodes 300a, 300b.
  • FIGs. 1 to 3 describe various ways of arranging flow-through electrodes in an electrolysis system.
  • the present invention is, however, not restricted to any particular type of electrode arrangement. Rather, it has been found that using graphite flow-through electrodes, at least on the anode side of the electrolysis system, leads to a significant production of graphite solution as reaction liquid flows through the anode-electrode.
  • the electrolysis process on the cathode side i.e., at the cathode-electrodes, produces hydrogen, which may conventionally be used to power various different machines.
  • the present invention provides an electrolysis system and electrolysis method, which provides a dual functionality, i.e. to produce hydrogen gas at the cathode side and, at the same time, produce graphite solution at the anode side.
  • the graphite solution may be stored until graphite or graphene is extracted from the graphite solution in a subsequent step.
  • the reaction liquid supply discussed above will provide electrolyte-free water to the one or more liquid chambers of the electrolysis system.
  • the electrolyte-free water may be any type of water from which naturally occurring electrolytes have substantially been removed.
  • the electrolyte-free water may be purified water, preferably deionized or distilled water.
  • Using electrolyte-free water within the electrolysis system of the present invention further increases the amount of graphite solution produced at the anode side. This is particularly the case if the liquid chamber comprises a gap between the adjacent surfaces of the cathode and anode-electrodes, that has a width smaller than a Debye-length of purified water.
  • the electrolyte- free water will be decomposed without the need for electrolyte additives typically used for electrolysis.
  • Such small gap sizes ensure that OH- ions may travel from the cathode-electrode to the anode-electrode.
  • some of the OH- ions will be converted to oxygen, which will penetrate the anodeelectrodes.
  • Other parts of the OH- ions will combine with graphite exfoliated by the reaction liquid when permeating through the porous structure of the flow- through anode-electrodes.
  • the so created graphite particles surrounded by OH- ions may in some circumstances be two-dimensional layers, i.e. graphene flakes that are collected within the gas collection chambers of the anode-electrodes.
  • these flow-through electrodes should have a pore size that allows the electrolyte -free water to permeate through the anodeelectrodes.
  • the pore size of the anode-electrode flow- through structures may be larger than the pore size of the cathode-electrodes, such that more reaction liquid will penetrate the anode-electrodes more than the cathode-electrodes. Increasing the size of the pores of the anode-electrodes, will increase the amount of graphite solution harvested at the anode-electrodes.
  • the electrolysis system of the present invention comprises an electric supply circuit for supplying electric power to the electrodes, e.g., via the terminals 154, 156 shown in FIG. 1.
  • An embodiment of an electric supply circuit 400 is shown schematically in FIG. 4.
  • the electric supply circuit 400 is configured to supply electric power at a voltage that enables current to flow through electrolyte-free water between the anode electrode and the cathode electrode.
  • electrolyte-free water has a very low electrical conductivity due to the absence of electrolytes.
  • the electric supply circuit comprises a transformer 403 connected to a rectifier for supplying electric power as pulsed direct current to the electrodes 416, 418 of the electrolysis system.
  • the transformer 403 is connected to the full-wave rectifier.
  • the transformer comprises primary windings 404 and secondary windings 406.
  • the secondary windings 406 are connected to the rectifier.
  • the secondary windings are center tapped secondary windings connected to the rectifier.
  • the rectifier comprises a first diode 408 connected to a first (positive) terminal of the secondary windings 406 of the transformer 403.
  • the rectifier comprises a second diode 410 connected to a second (negative) terminal of the secondary windings 406 of the transformer 403.
  • the first and second diodes 408, 410 are connected in parallel and face the same direction.
  • both the first and second diodes 408, 410 are connected to the secondary windings 406 of the transformer 403 via their respective anode ends.
  • the two diodes are connected to each other and an anode electrode 416 of the electrolysis system via their opposite cathode end.
  • the cathode electrode 418 is connected to ground 420.
  • an AC input waveform 402 will be stepped down in voltage by the transformer 403 and rectified by the full-wave rectifier thereafter.
  • the result is a pulsed DC waveform 414, which is then applied across the electrodes of the electrolysis system.
  • FIG. 5 shows a schematic flow chart of a method of generating graphite oxide and/or graphene oxide by electrolysis according to the present disclosure.
  • the method comprises providing an electrolysis system with a flow-through graphite anode-electrode.
  • a flow-through anode-electrode may have a porosity that will allow the electrolyte water to permeate through the electrode.
  • water or electrolyte water is supplied to the electrodes of the electrolysis system 100, such system 100 described in FIG. 1.
  • the water supply to the electrodes may be electrolyte-free water, particularly purified water such as deionized water or distilled water.
  • this graphite solution will be obtained behind the porous graphite flow-through electrode structure.
  • this graphite solution may be stored for further use.
  • the reaction liquid may be removed from the solution to obtain high purity graphite, particularly in two-dimensional layers also known as graphene.
  • the water or electrolyte water may contain chemicals to enhance the graphene oxide, so that when it is processed to form a 2D-layer of carbon, it has been doped to have special properties.
  • FIG. 6 shows a schematic illustration of another embodiment of the electrolysis system according to the present disclosure.
  • the electrolysis system 600 shown in FIG. 6 is similar to the electrolysis system 100 of the embodiment shown in FIG.
  • the electrolysis system of FIG. 6 differs from the electrolysis system of FIG. 1 in that the first drain port 642 of the first gas collection chamber 606 may either be connected to a storage tank 645 or returned into the liquid supply circuit 630. Similarly, the second drain port 644 of the second gas collection chamber 610 of the embodiment shown in FIG. 6 is selectively connectable to either a storage tank 666 or the supply circuit 630.
  • the selective connection of the first and second drain ports 642, 644 is achieved by means of 3/2 way valves 643, 647 respectively.
  • first drain port 642 of the first gas collection chamber 606 is connected to an inlet of a first directional control valve 643.
  • the directional control valve 643 may be used to direct the fluid drain from the first gas collection chamber 606 via the first drain port 642 selectively either towards a water collection tank 645 (via fluid line 649) or towards the supply circuit 630 (via fluid line 646). It should be understood that the directional control valve 643 is only one option of selectively changing the direction of the fluid drained from the first gas collection chamber 606, and any other suitable means of redirecting the fluid flow may be implemented too.
  • the first directional control valve 643 may be controlled remotely or locally via the control unit 660.
  • the second drain port 644 of the second gas collection chamber 610 is selectively connectable to either a graphene solution tank 666 or to the supply circuit 630 via the second directional control valve 647. Similar to the first directional control valve 643, the second directional control valve 647 may be controlled by means of the control unit 660 depending on operational states of the electrolysis system, which will be described in more detail below.
  • the electrolysis system 600 shown in FIG. 6 comprises a production state and an enrichment state.
  • the electrolysis system 600 is operated substantially in the same way as has been described in connection with the electrolysis system 100 shown in FIG. 1.
  • liquid drained from the first (cathode) gas collection chamber 606 via the first drain port 642 will be diverted to the Cathode Liquid collection tank 645 or returned to the fluid supply circuit 630, e.g., upstream of the pump 644.
  • liquid drained from the second (anode) gas collection chamber 610 via the second drain port 644 will be collected in a graphene solution storage tank 666.
  • the first and second directional control valves 643, 647 will be set by the control unit 660 as shown in FIG. 6, i.e. connecting the first drain port 642 to the Cathode Liquid collection tank 645 and the second drain port 644 to the graphene solution storage tank 666.
  • liquid drained from the first gas collection chamber 606 via the first drain port 642 will be directed towards a Cathode Liquid collection tank 645 via a fluid line 649.
  • liquid drained from the second gas collection chamber 610 via the second drain port 644 will be returned to the fluid supply circuit 630 via return line 651.
  • both directional control valves 643, 647 are shifted into their second position (not shown) by the control unit 660.
  • the electrolysis system 600 of FIG. 6 works in substantially the same way as described with reference to FIG. 1, i.e. producing a graphene solution at the anode-electrode (second electrode 612 in Fig. 6) and storing the latter in a graphene solution storage tank 666.
  • liquid penetrating the anode-electrode (second electrode 612 in Fig. 6) is returned to the liquid chamber 604 of the electrolysis system 600 via the liquid supply circuit 630.
  • the liquid chamber 604 will not or only partially be provided with fresh liquid such as electrolyte-free water. Rather, in the enrichment state, the liquid chamber 604 will be provided with liquid that already contains graphene or graphite nanoparticles. This so re-circulated graphene solution may then be further enriched by exfoliation additional graphite as it penetrates through the second electrode 612 (here anode-electrode) once again, thereby exfoliating more of the graphite.
  • the graphene or graphite nanoparticles of the re-circulated graphene solution will not penetrate the first electrode 608 (cathode-electrode). Rather, the first electrode 608 will act to filter the electrolyte-free water from the graphene nanoparticles, thereby further increasing the concentration of the graphene solution that is recirculated within the electrolysis system 600.
  • the so-filtered electrolyte-free water that penetrates the first electrode 608 is then removed from the system, e.g. via the cathode Liquid collection tank 645. It will be appreciated that the graphene content within the graphene solution will increase more, the longer the electrolysis system is operated in its enrichment state.
  • the graphene solution may be directed towards the graphene solution tank 666 and the electrolysis system 600 may be returned into its production state to start a new graphene solution exfoliation cycle.
  • the control unit 660 may be configured to change between the production state and the enrichment state automatically at regular intervals. In other embodiments, the control unit may be configured to transfer the electrolysis system between its production state and its enrichment state automatically, based on a level of graphene and/or graphite within the graphene solution.
  • the electrolysis system 600 may include a graphene sensor (not shown) that is arranged, for example, anywhere within the liquid supply circuit 630 and or pipes 648, 649.
  • vent line 605 may be opened by the control unit 660 to release concentrated graphene or graphite to the graphene solution tank 666.
  • the control unit 660 may be configured to compare the level of graphene and/or graphite within the liquid supply circuit to a desired threshold, which may be set by the operator according to their individual requirements. Once the levels of graphene have reached the desired threshold, the control unit 660 may drain the enriched graphene solution into the graphene solution tank 666 and return the electrolysis system 600 back into the production state as described above.
  • the electric power supplied to the electrodes of the electrolysis system 600 differs in the different states of the electrolysis system 600.
  • the control unit 660 may control the electric power supply in such a way that, in the production state, a first voltage is supplied to the electrodes 608, 612, whereas, in the enrichment state, a second voltage is supplied to the electrodes 608, 612.
  • the second voltage will be higher than zero and high enough such that the graphene does not flow through the cathode electrode.
  • the second voltage of the enrichment state is dependent on various parameters of the electrolysis system 600, such as the gap size between the electrodes 608, 612 and the type of reaction liquid used, etc. In some examples, the second voltage was determined to be between 10V and 20V.
  • the enrichment state may be carried out by a separate electrolysis system.
  • the electrolysis system for enrichment of the graphene solution may comprise two electrodes for decomposition of water or electrolyte water, wherein at least a cathode-electrode is a flow-through electrode comprising preferably graphite.
  • the anode-electrode may be of any other type.
  • the electrodes will be supplied with a graphene solution (e.g. the graphene solution stored in tank 166 of the system shown in Fig. 1). Once a voltage, i.e.
  • the flow through cathode-electrode will allow water to permeate, whereas graphene particles will be repelled and remain within the liquid chamber between the first and second electrodes or exit the cell gap via the anodeelectrode (if flow-through) or the vent line 605.
  • the water that permeated through the cathode-electrode may be removed from the system, e.g. via a water tank.
  • the electrolysis system of the present disclosure may comprise a gas injector for injecting gases other than oxygen into the reaction liquid to reduce an amount of oxygen generated at the anode-electrode.
  • the gas injector may be configured to inject the gases within or around the anode-electrode.
  • a gas injector nozzle may be provided that penetrates the porous material of the flow-through anode-electrode (e.g. second electrode 612) and allows gases to be introduced into the porous structure of the anode-electrode during the production state.
  • the gases injected may comprise any gas that can reduce the amount of oxygen generated at the anode-electrode.
  • the gas injector may inject hydrogen gas within or around the anode-electrode, which may reduce the amount of oxygen found in the liquid that has penetrated the anode-electrode. Reduction of the oxygen content may result in higher purity, i.e. less oxidized, graphene flake/particles dissolved in the graphene solution and drained from the second gas collection chamber of the electrolysis system.
  • the electrolysis system may comprise means for moving one or both of the two electrodes with respect to each other for adjusting or maintaining the gap size.
  • the thickness of at least the anode-electrode will reduce during exfoliation of graphite when the electrolysis system is in use. Such reduction in the thickness of the anode-electrode will automatically increase the gap between the electrodes 608, 612. This may be particularly problematic for embodiments in which the electrolysis system is fed with electrolyte-free water, because in such examples the gap size needs to be small (e.g. below the Debyelength) in order to allow flow of electricity between the electrodes.
  • the means for moving the two electrodes with respect to each other may be controlled by the control unit 660 in order to maintain an appropriate gap size between the electrodes.
  • the means for moving one or both of the electrodes may include actuators that can be controlled by the control unit 660 to adjust the gap size when required.
  • the means for moving one or both of the two electrodes with respect to each other may simply include a biasing means, such as a spring, which constantly pushes the electrodes against each other.
  • a spacer may be used to ensure that the gap is always maintained at the same size and avoids direct contact of the electrodes.
  • the anode-electrode will be consumed by exfoliation over time, requiring intermittent replacement of the graphite flow-through electrode. In the embodiments described above, this would mean regular replacement of the second electrode 112, 612. It should be understood, however, that, in embodiments where both the first and second electrodes 108, 608, 112, 612 are flow-through and comprise graphite, the polarity of the terminals 154, 654, 156, 656 may be swapped intermittently to exfoliate both electrodes rather than one. This method may double the running time of the electrolysis system, before the electrodes require replacement.
  • the electrolysis system may also include a plurality of control units controlling some of the aforementioned aspects and, preferably, communicating with each other.

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Abstract

La présente invention concerne un système d'électrolyse pour générer de l'oxyde de graphite et/ou de l'oxyde de graphène, ledit système comprenant un boîtier comprenant : une chambre à liquide ; deux électrodes pour la décomposition de l'eau ou de l'eau d'électrolyte, au moins une électrode d'anode étant une électrode de passage comprenant du graphite ; et une alimentation en liquide pour fournir de l'eau ou de l'eau d'électrolyte à la chambre à liquide.
PCT/EP2023/050826 2022-01-25 2023-01-16 Système d'électrolyse et procédé d'exfoliation de graphite WO2023143942A1 (fr)

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GB2200933.6 2022-01-25
GB2200933.6A GB2614920A (en) 2022-01-25 2022-01-25 Electrolysis system and method for exfoliating graphite
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GBGB2202636.3A GB202202636D0 (en) 2022-01-25 2022-02-25 Electrolysis system and method for exfoliating graphite

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Citations (6)

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US20090026086A1 (en) * 2007-07-27 2009-01-29 Aruna Zhamu Electrochemical method of producing nano-scaled graphene platelets
US20130161199A1 (en) * 2011-12-23 2013-06-27 Academia Sinica Production of Graphene
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US20090026086A1 (en) * 2007-07-27 2009-01-29 Aruna Zhamu Electrochemical method of producing nano-scaled graphene platelets
US9440866B2 (en) * 2011-06-06 2016-09-13 Axine Water Technologies Efficient treatment of wastewater using electrochemical cell
US20130161199A1 (en) * 2011-12-23 2013-06-27 Academia Sinica Production of Graphene
US20160017502A1 (en) * 2014-07-17 2016-01-21 Rochester Institute Of Technology Electrochemical Process for Producing Graphene, Graphene Oxide, Metal Composites, and Coated Substrates
WO2017100968A1 (fr) * 2015-12-14 2017-06-22 Baoshan Iron & Steel Co., Ltd. Oxyde de graphène et son procédé de production
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