Redox flow battery apparatus for use in a marine vessel

Abstract

The present invention discloses a redox flow battery apparatus (100) for use in a marine vessel (200) comprising a pair of electrolyte storage tank modules (10, 12), a fuel stack module (22), a power converter module (50) configured to electrically connect the redox flow battery apparatus (100) to an electrical load or an electrical power source, a service storage tank (14) configured to allow storage of electrolytes in the event of servicing of the apparatus (100) and serve as a marine vessel (200) ballast to maintain stability of the marine vessel (200) when off-shore. The redox flow battery apparatus (!00) further includes an anti-corrosion tank (52) that takes on the shape of a hull of a marine vessel and is configured to house the pair of electrolyte storage tank modules (10, 12) the fuel stack module (20), the power converter module (50), the service storage tank (14), a first assembly of conduits (10a, 10b, 10c, 10d, 10e, 12a, 12b, 12c, 12d, 12e) and circulatory pumps (30, 32) and a second assembly of conduits (14a, 14b, 14c, 14d) and circulatory pumps (40, 42).

Description

[0001] REDOX FLOW BATTERY APPARATUS FOR USE IN A MARINE VESSEL

[0002] FIELD OF THE INVENTION

[0003] The present invention generally relates to an energy storage and power system for a marine vessel. More particularly, the present invention relates to the use of a flow battery as a marine vessel energy storage and power system.

[0004] BACKGROUND OF THE INVENTION

[0005] Off late, in view of global warming, there has been a push toward de-carbonization across many industries. The maritime industry is no exception. The International Maritime Organization^ (IMO’s) de-carbonization targets, make battery systems even more valuable. Reducing fuel consumption through the use of hybrid systems that employ a combination of battery systems and systems that employ the combustion of fuels can result in a significant reduction of emissions and would thus allow the maritime industry to meet environmental requirements related to decarbonization. However, for hybrid systems to be viable and effective options to realize significant emissions reduction and thus meet de-carbonization targets, efficient and sustainable battery technologies are required.

[0006] Lithium-ion (Li-ion) batteries are currently the most prominent battery technology in maritime applications. They have been shown to be useful for electrical energy storage and electricity distribution on vessels. Li-ion batteries are made of positive and negative electrodes (called the cathode and anode, respectively), an electrolyte and a separator. Despite many advantages over older battery technologies, Li-ion batteries have their own limitations. Li-ion systems require complex monitoring systems to keep them within the proper operating range for temperature and voltage. They are susceptible to thermal runaway, where a temperature rise can cause a self- sustaining chemical reaction and a further increase in temperature. This can lead to battery failure and potential ignition of the electrolyte separator and electrodes, causing a fire in the battery system. Battery management systems and fire protection systems must be in place to prevent this from happening and prevent further damage in the event of thermal runaway. Some research indicates Li-ion batteries have very nearly reached their theoretical limit in energy and power density. This limits their potential for maritime applications where higher power and energy levels are needed, as more space is needed for a larger battery system to accommodate increased electrical load requirements

[0007] In view of the abovementioned disadvantages and limitations associated with Lithium-Ion batteries, particularly the disadvantages and limitations in relation to fire safety and maximum limit of energy deliverable by conventional Lithium-Ion battery technology, alternative battery technologies are being sought after. Foremost of these alternative battery technologies, is redox flow battery technology, particularly Vanadium Redox Flow Batteries (VRFBs).

[0008] Advantages of Vanadium Redox Flow Batteries (VRFBs) include the possibility of storing an unlimited amount of energy, as the amount of energy stored is a direct function of the electrolyte storage capacity of the tanks of the redox flow battery and the greater stability as the electrolytes utilized in redox flow batteries have low flammability and inherently mitigate battery heating thus minimizing the need for employing external cooling systems.

[0009] The state of the art having regard to the use of redox flow batteries in maritime applications is evidenced by the following prior art documents:

[0010] Japanese Patent Application Publication JP 2011235674 A is directed to a redox flow battery apparatus housed within a marine vessel and utilized primarily for electrical energy storage and transportation. In one aspect, JP 2011235674 A discloses a redox flow battery ship that houses within its hull a redox flow battery that is configured to be electrically charged by a wave power electricity generation apparatus and transport the stored electrical energy as a result of being electrically charged by the electricity generation apparatus to an onshore facility. In another aspect, JP 20111235674 A discloses a method for energy storage and transportation of energy generated by a wave-power electricity generation apparatus.

[0011] Chinese Patent Application Publication CN115056958 A discloses a Vanadium Redox Flow Battery (VRFB) apparatus which comprises a positive electrolyte tank group and a negative electrolyte tank group, implying the use of more than a single electrolyte storage tank for both the positive electrolyte and the negative electrolyte. The apparatus disclosed therein appears to be capable of switching between one electrolyte storage tank to another electrolyte storage tank in a given electrolyte tank group to ensure extended continuous operation of the VRFB apparatus therein, in relation to powering all electrical loads of the ship incorporating said VRFB apparatus. Additionally, the apparatus disclosed further provides a device to facilitate the replacement of electrolytes disposed in the electrolyte tanks of the positive electrolyte tank and negative electrolyte tank groups respectively from a remote electrolyte charging facility.

[0012] Chinese Patent Application Publication CN 201810401042 A discloses the use of a Vanadium Redox Flow Battery (VRFB) for use in a marine vessel as a primary power source. The configuration of the VRFB disclosed therein is directed at overcoming the problems associated with storing large volumes of positive and negative electrolytes as well as long charging times for charging the electrolytes.

[0013] It is evident from the above-listed citations, that to date many attempts have been made to incorporate redox flow batteries either as a primary power source for marine vessel propulsion or as a secondary power source to power electrical loads other than those configured to effect propulsion of the marine vessel or even yet further as a means of storing and transporting energy. However, none of the citations above, appear to provide for easy maintenance and servicing of a redox flow battery apparatus while either onshore or offshore. To date a marine vessel utilizing a redox flow battery, whether for storage of energy or for supply of electrical power to electrical loads within the vessel would have to be docked onshore to enable the draining of electrolytes to enable maintenance and servicing. Thus it would be advantageous if a redox flow battery apparatus for use in marine vessels be it for energy storage or even the supply of power to electrical loads that allow for offshore maintenance and servicing, be conceived.

[0014] SUMMARY OF THE INVENTION

[0015] The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the invention. It is, not intended to identify key / critical elements of the invention. Its sole purpose is to present some concepts of the invention in a simplified form as a prelude to the more detailed description that is, presented later. The present invention provides a redox flow battery apparatus for use in a marine vessel as either a primary source of electrical power or a secondary source of electrical power, or for use as an apparatus for storage of energy, the apparatus comprises: a pair of electrolyte storage tank modules, a first storage tank module for storage of a positive electrolyte and a second storage tank module for storage of a negative electrolyte; a fuel stack module including an arrangement of one or more fuel stacks, each fuel stack including a positive electrode and a negative electrode spatially displaced from one another within the fuel stack, and a selectively permeable membrane positioned between said positive electrode and said negative electrode to thereby delineate a positive half-cell and a negative half-cell within the fuel stack; and a power converter module configured to electrically connect the redox flow battery apparatus to an electrical load or an electrical power source.

[0016] The first electrolyte storage tank module and the second electrolyte storage tank module are respectively rendered in fluid communication with a positive half-cell and a negative half-cell of each fuel stack of the fuel stack module via a first assembly of fluid conduits and circulatory pumps.

[0017] The redox flow battery apparatus of the present invention is characterized by a service storage tank configured to receive and store electrolytes from the first electrolyte storage tank module, the second electrolyte storage tank module, as well as the positive and negative half cells of each fuel stack of the fuel stack module to thus facilitate the draining of electrolytes from the redox flow battery of the redox flow battery apparatus, the service storage tank rendered in fluid communication with each fuel stack of the fuel stack module and the pair of electrolyte storage tanks modules by a pair of valves via the first assembly of conduits and circulatory pumps.

[0018] In an embodiment of the redox flow battery apparatus of the present invention, the service storage tank is further rendered in fluid communication with the pair of electrolyte storage tank modules via a second assembly of conduits and circulatory pumps. In an embodiment, the redox flow battery apparatus includes an anti-corrosion steel tank that takes on the shape of a hull of a marine vessel. The anti-corrosion steel tank is configured to house the pair of electrolyte storage tanks, the fuel stack module, the power converter module, the service storage tank, the first assembly of conduits and circulatory pumps and the second assembly of conduits and circulatory pumps. The anti-corrosion steel tank is configured to prevent any leakage of electrolytes into the ocean in the event of damage to the hull of the marine vessel.

[0019] In an embodiment of the redox flow battery apparatus of the present invention, the first storage tank module comprises a plurality of storage tanks configured to store a positive electrolyte and the second storage tank module comprises a plurality of storage tanks configured to store a negative electrolyte. The plurality of storage tanks of each of said first and second storage tank modules can be selectively rendered in fluid communication with the positive and negative halfcells of each fuel stack of fuel stack module.

[0020] Preferably, the selectively permeable membrane of each fuel stack of the fuel stack module that is positioned between the positive electrode and negative electrode is an ion exchange membrane. Exemplarily, the ion exchange membrane is a proton exchange membrane, which is preferably a sulfonated tetra-fluoro-ethylene-based fluoropolymer-copolymer (NA ION®) membrane.

[0021] Exemplarily, the positive and negative electrodes of each fuel stack of the fuel stack module are porous carbon-based electrodes. Preferably, the positive and negative electrodes of each fuel stack of the fuel stack module are carbon nanotube-based electrodes.

[0022] In a preferred embodiment, the redox flow battery apparatus is a Vanadium redox flow battery (VRFB) apparatus. Preferably, in said preferred embodiment, the negative electrolyte is an electrolyte containing V2+ / V3+ions and the positive electrolyte is an electrolyte containing V4+ / V5+ions. Preferably the electrolytes are produced by electrolytically dissolving vanadium pentoxide (V2O5) in sulphuric acid (H2SO4).

[0023] It is an advantage of the present invention to provide an environmentally friendly energy storage and power system apparatus for use in a marine vessel. It is another advantage of the present invention to provide an energy storage and power system apparatus that is safe for use in a marine vessel.

[0024] It is also another advantage of the present invention to provide an energy storage and power system apparatus for use in a marine vessel that has a long service life.

[0025] It is yet another advantage of the present invention to provide an energy storage and power system apparatus for use in a marine vessel that has low life-cycle cost.

[0026] It is a further advantage of the present invention to provide an energy storage and power system for a marine vessel that can be easily maintained and inspected.

[0027] It is an advantage of the present invention to provide an energy storage and power system for a marine vessel that improves the stability of the marine vessel when offshore.

[0028] BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and other objects, features and other advantages of the present invention will be more clearly understood from the detailed description taken in conjunction with the accompanying drawings, in which:

[0030] Figure 1 is a simplified schematic diagram of a vanadium redox flow battery apparatus in an embodiment of the present invention, operating in a discharging mode of operation (i.e. supplying electrical power to an electrical load).

[0031] Figure 2 is a simplified schematic diagram of a vanadium redox flow battery apparatus in an embodiment of the present invention, operating in a charging mode of operation (i.e. receiving electrical power from an electrical supply source).

[0032] Figure 3 illustrates a general positioning of a vanadium redox flow battery apparatus in an embodiment of the present invention within a marine vessel; and Figure 4 illustrates an exemplary use of a vanadium redox flow battery apparatus in an embodiment of the present invention for effective transportation of energy from an offshore facility to an onshore facility.

[0033] DETAILED DESCRIPTION OF THE INVENTION

[0034] The detailed description set forth below in connection with the appended drawings is intended as a description of an exemplary embodiment and is not intended to represent the only form in which the embodiment may be constructed and / or utilized. The description sets forth the functions and the sequence for constructing the exemplary embodiment. However, it is to be understood, that the same or equivalent functions and sequences may be accomplished by different embodiments that are also intended to be encompassed within the scope of this disclosure.

[0035] With reference to Figures 1 to 3, there is shown a preferred embodiment of a redox flow battery apparatus 100 for use in a marine vessel 200 as either a primary source of electrical power, or a secondary source of electrical power, or for use as an apparatus for storage of energy that includes a service storage tank 14 configured to receive and store electrolytes from an electrolyte storage tank module 10, 12 of the apparatus 100 and each half cell of a fuel stack 22 within a fuel stack module 20 of the apparatus 100.

[0036] The redox flow battery apparatus 100 further comprises: a pair of electrolyte storage tank modules 10, 12, a first storage tank module 10 for storage of positive electrolyte and a second storage tank module 12 for storage of negative electrolyte; a fuel stack module 20 including an arrangement of one or more fuel stacks 22, each fuel stack 22 including a positive electrode 26 and a negative electrode 28 spatially displaced from one another within the fuel stack 22, and a selectively permeable membrane 24, positioned between said positive electrode 26 and said negative electrode 28 to thereby delineate a positive half-cell 25a and a negative half-cell 25b within the fuel stack 22; and a power converter module 50 configured to electrically connect the redox flow battery apparatus 100 to an electrical load or an electrical power source and allow transfer of electricity from the redox flow battery apparatus 100 to an electrical load or allow the transfer of electricity from an electrical power source to the redox flow battery apparatus 100.

[0037] In said preferred embodiment of the present invention as alluded to in Figures 1 and 2 appended herewith, the first electrolyte storage tank module 10 and the second electrolyte storage tank module 12 are respectively rendered in fluid communication with a positive half-cell 25a and a negative half-cell 25a of each fuel stack 22 of the fuel stack module 20 via a first assembly of fluid conduits 10a, 10b, 10c, lOd, lOe, 12a, 12b, 12c, 12d, 12e and circulatory pumps 30, 32.

[0038] The combination of the electrolyte storage tank modules 10, 12, the fuel stack module 20 including one or more fuel stacks 22, the power converter module 50 and the first assembly of conduits and circulatory pumps 30, 32, effectively form the redox flow battery of the redox flow battery apparatus 100.

[0039] The redox flow battery apparatus 100 shown in aforementioned Figures 1 to 3, is characterized in part by a service storage tank 14 configured to receive and store electrolytes from the first electrolyte storage tank 10, the second electrolyte storage tank 12, as well as the positive and negative half cells 25a, 25b of each fuel stack 22 of the fuel stack module 20 to thus facilitate the draining of electrolytes from the redox blow battery of the redox flow battery apparatus 100. Aforementioned service storage tank 14 is rendered in fluid communication with each fuel cell stack 22 of the fuel cell stack module 20 and the pair of electrolyte storage tanks 10, 12 by a pair of valves 34, 36 via the first assembly of conduits 10a, 10b, 10c, lOd, lOe, 12a, 12b, 12c, 12d, 12e and circulatory pumps 30, 32. In the preferred embodiment of the redox flow battery apparatus 100 for use in a marine vessel 200 as alluded to in Figures 1 to 3, the service storage tank 14 is further rendered in fluid communication with the pair of electrolyte storage tank modules 10,12 via a second assembly of conduits 14a, 14b, 14c, 14d and circulatory pumps 40, 42.

[0040] The aforementioned second assembly of conduits 14a, 14b, 14c, 14d and circulatory pumps 40, 42 are configured to allow the pumping back or recirculating of electrolytes stored in the service storage tank 14, into the electrolyte storage tank modules 10, 12. Exemplarily, in the preferred embodiment of the redox flow battery apparatus 100, valves 34, and 38 are control valves that are actuated by a remote controller (not specifically indicated and shown in the list of figures appended herewith).

[0041] Preferably, the redox flow battery apparatus 100 includes an anti-corrosion steel tank 52 that takes on the shape of a hull 202 of a marine vessel 200. The anti-corrosion steel tank 52 is configured to house the pair of electrolyte storage tank modules 10, 12, the fuel stack module 20, the power converter module 50, the service storage tank 14, the first assembly of conduits 10a, 10b, 10c, lOd, lOe, 12a, 12b, 12c, 12d, 12e and circulatory pumps 30, 32 and the second assembly of conduits 14a, 14b, 14c, 14d and circulatory pumps 40, 42. The anti-corrosion steel tank 52 is also configured to prevent any leakage of electrolytes into the ocean in the event of damage to the hull 202 of the marine vessel 200.

[0042] In an exemplarily embodiment of the redox flow battery apparatus 100 of the present invention which is not specifically alluded to by the list of figures appended herewith, the first storage tank module 10 comprises a plurality of storage tanks configured to store a positive electrolyte (anolyte) and the second storage tank module 12 comprises a plurality of storage tanks configured to store a negative electrolyte (catholyte). The plurality of storage tanks of each of said first and second storage tank modules 10, 12 can be selectively rendered in fluid communication with the positive and negative half-cells 25a, 25b of each fuel stack 22 of the fuel stack module 20.

[0043] Preferably, in the preferred embodiment of the redox flow battery apparatus 100 of the present invention as alluded to in Figures 1 to 3, the selectively permeable membrane 24 of each fuel stack 22 of the fuel stack module 20 that is positioned between the positive electrode 26 and negative electrode 28, is an ion exchange membrane. Exemplarily, the ion exchange membrane is selected from either a proton exchange membrane or a cation exchange membrane. Preferably, the selectively permeable membrane 24 is a sulfonated tetra-fluoro-ethylene-based fluoro-polymer- copolymer (NA ION®) membrane.

[0044] Exemplarily, the positive and negative electrodes 26, 28 of each fuel stack 22 of the fuel stack module 20 is a porous carbon-based electrode. Preferably, the positive and negative electrodes 26, In the preferred embodiment of the redox flow battery apparatus 100 for use in a marine vessel 200 as described herein, the redox flow battery apparatus 100 is a Vanadium Redox Flow battery apparatus 100 utilizing an electrolyte containing Vanadium ions of oxidation states of +2, +3, +4, +5. More particularly, the negative electrolyte is an electrolyte containing V2+ / V3+ions and the positive electrolyte is an electrolyte containing V4+ / V5+ions. Preferably, the electrolytes are produced by electrolytically dissolving vanadium pentoxide (V2O5) in sulphuric acid (H2SO4). It would be readily understood by one of ordinary skill in the art that the selectively permeably membrane 24 of the vanadium redox flow battery apparatus 100 as provided in the preferred embodiment of the present invention is configured to allow the passage of H+ions and electrons but is impervious to the passage of vanadium ions from one half-cell 25a, 25b to another half-cell 25a, 25b of a fuel stack 22 of the fuel stack module 20. It would be readily understood by one of ordinary skill in the art, that the vanadium redox flow battery of the vanadium redox flow battery apparatus 100 is formed by the combination of the electrolyte storage tank modules 10, 12, the fuel stack module 20, the power converter module 50 and the first assembly of conduits 10a, 10b, 10c, lOd, lOe, 12a, 12b, 12c, 12d, 12e and circulatory pumps 30, 32.

[0045] With reference to Figure 3, the redox flow battery apparatus 100 for use in a marine vessel 200 in the preferred embodiment of the present invention is positioned within a hull 202 of the marine vessel 200. Such positioning of the redox flow battery apparatus 100 within a marine vessel 200 is viable as it allows the large tanks configured for the storage of electrolytes, particularly the service storage tank 14 to serve as a ballast to maintain the stability of the marine vessel 200. Moreover, it will be appreciated by one of ordinary skill in the art, that the electrolyte storage tank modules 10, 12 of the redox flow battery apparatus 100 as provided in embodiments of the present invention are positioned above the service storage tank 14 within a hull 202 of a marine vessel 200. Such positioning would allow the electrolytes to be easily drained into the service storage tank 14 of the redox flow battery apparatus 100 during maintenance and servicing of the redox flow battery apparatus 100, thus facilitating the inspection of the electrolyte storage tank modules 10, 12.for leaks or damage by maintenance personnel. The positive and negative electrolytes of the redox flow battery apparatus 100 are drained from aforementioned electrolyte storage tank modules 10, 12 and the positive and negative half cells 25a, 25b of each fuel cell stack 22 of the fuel stack module 20 via the first assembly of conduits 10a, 10b, 10c, lOd, lOe, 12a, 12b, 12c, 12d, 12e and circulatory pumps 30, 32 by actuating opening of control valves 34, 36. Advantageously and surprisingly, the service storage tank 14 of the vanadium redox flow battery apparatus 100 as shown in Figures 1 to 3 allows for a rebalancing of the volume of electrolytes in the electrolyte tank modules 10, 12 in the event there is an imbalance of the volume electrolytes present in storage tank modules 10, 12. Exemplarily, rebalancing is done by actuating the control valves 34, 36 to regulate the flow of electrolytes from each electrolyte storage tank module 10, 12 via the first assembly of conduits 10a, 10b, 10c, lOd, lOe, 12a, 12b, 12c, 12d, 12e.

[0046] Making reference to Figure 1, during a discharging mode of operation (i.e. when the vanadium redox flow battery apparatus 100 as provided in the preferred embodiment is supplying electric power to an electrical load), the V5+ions of the electrolyte pumped into half-cell 25a of fuel stack 22 of the fuel stack module 20 by circulatory pump 30 accepts electrons transmitted from the negative half-cell 25b via electrode 26 and the external circuit comprising the power converter 50. The V5+ions are consequently converted into V4+ions which are pumped and re-circulated into the electrolyte storage tank module 10. Likewise, the V2+ions of the electrolyte pumped into halfcell 25b of fuel stack 22 of the fuel stack module 20 by circulatory pump 32 release an electron which is transmitted via electrode 28 and the external circuit comprising the power converter 50 to the positive half-cell 25a. The process continues indefinitely and is limited in time by the volume of the electrolytes stored in each storage tank module 10, 12. The vanadium redox flow battery apparatus 100 is completely discharged when all the V5+ions in the electrolyte storage tank module 10 are converted into V4+ions and when all the V2+ions in the electrolyte storage tank module 12 are converted into V3+ions.

[0047] The preferred embodiment of the vanadium redox flow battery apparatus 100 of the present invention can be utilized as either a primary power source for providing electrical power to an electric propulsion system of a marine vessel 200 which powers propeller 206 and rudder 204 of the marine vessel 200. Alternatively, the vanadium redox flow battery apparatus 100 of the preferred embodiment as shown in Figures 1 to 3 can be configured as a secondary power source or backup power source configured to supply electricity to lighting and critical electrical components of the marine vessel 200.

[0048] Making reference to Figure 2, during a charging mode of operation (i.e. when the vanadium redox flow battery apparatus 100 as provided in the preferred embodiment is charged by an external electric power source), the V4+ions of the spent electrolyte pumped from storage tank module 10 by circulatory pump 30 into the positive half-cell 25a of a fuel stack 22 of the fuel stack module 20, each release an electron and are converted into V5+ions. The released electrons are transmitted to the negative half-cell 25b of the fuel stack 22 of the fuel stack module 20 via the external circuit comprising the power converter 50 and the electrode 28. In the negative half-cell 25b, the V3+ions of the spent electrolyte pumped from storage tank module 12 by circulatory pump 32 into the negative half-cell 25b, receive the electrons and are converted into V2+ions. The process continues indefinitely and is limited in time by the volume of the electrolytes stored in each storage tank module 10, 12. The vanadium redox flow battery apparatus 100 is completely charged when all the V4+ions in the electrolyte storage tank module 10 are converted into V5+ions and when all the V3+ions in the electrolyte storage tank module 12 are converted into V2+ions.

[0049] In the preferred embodiment of the vanadium redox flow battery apparatus 100, the vanadium redox flow battery formed by the combination of the electrolyte storage tank modules 10, 12, the fuel stack module 20, the power converter module 50 and the first assembly of conduits 10a, 10b, 10c, lOd, lOe, 12a, 12b, 12c, 12d, 12e and circulatory pumps 30, 32, can be charged by an onboard renewable energy electrical power source such as an on-board wave power generation apparatus or an on-board solar power generation apparatus. Conversely, the vanadium redox flow battery can be charged by an on-board hydrogen fuel cell.

[0050] Referring Figure 4, the vanadium redox flow battery apparatus 100 according to the preferred embodiment of the present invention can be employed as an energy storage device. Specifically, it would readily be understood by one of ordinary skill in the art, that since the amount of energy that can be delivered by the redox flow battery apparatus 100 is a function of the volume of charged electrolytes stored in the storage tank modules 10, 12 of the redox flow battery apparatus 100, the volume of electrolytes stored in the storage tank modules 10, 12 represent energy stored and deliverable to a remote facility for redistribution to power various electrical loads. Accordingly, it would be appreciated by one of ordinary skill in the art that the redox flow battery apparatus 100 as provided in embodiments of the present invention can be employed as an energy storage device. More particularly, with reference to Figure 4, which is directed at illustrating a method 300 for off-shore -charging of electrolytes of the redox flow battery apparatus 100 as provided in embodiments of the present invention and consequently transportation of the charged electrolytes which represent stored energy, used or spent electrolyte stored in the electrolyte storage tank modules 10, 12 of the apparatus 100 can be charged by a designated remote off-shore location 302 containing a renewable energy facility 303 such as a remote offshore wind, wave or solar energy generation facility. The charged electrolytes of the redox flow battery apparatus 100 can then be transported to an onshore facility 301 for redistribution to various onshore customer facilities (presumably an onshore redox flow battery facility) for use in powering customer electrical loads.

[0051] Alternative embodiments will become apparent to those skilled in the art to which the present invention pertains without departing from its scope. Accordingly, the scope of the present invention is defined by the appended claims rather than the foregoing description.

Claims

CLAIMS1. A redox flow battery apparatus (100) for use in a marine vessel (200) as a primary source of electrical power or a secondary source of electrical power, or as an apparatus for storage of energy; characterized in that the apparatus (100) comprises: a pair of electrolyte storage tank modules (10, 12), a first storage tank module (10) for storage of positive electrolyte and a second storage tank module (12) for storage of negative electrolyte; a fuel stack module (20) including an arrangement of one or more fuel stacks (22), each fuel stack (22) including a positive electrode (26) and a negative electrode (28) spatially displaced from one another within the fuel stack (22), and a selectively permeable membrane (24) positioned between said positive electrode (26) and said negative electrode (28), to thereby delineate a positive half-cell (25a) and a negative half-cell (25b) within the fuel stack (22); and a power converter module (50) configured to electrically connect the redox flow battery apparatus (100) to an electrical load or an electrical power source; wherein the first electrolyte storage tank module (10) and the second electrolyte storage tank module (12) are respectively rendered in fluid communication with a positive half-cell (25a) and a negative half-cell (25b) of each fuel stack (22) of the fuel stack module (20) via a first assembly of fluid conduits (10a, 10b, 10c, lOd, lOe, 12a, 12b, 12c, 12d, 12e) and circulatory pumps (34, 36); and wherein the redox flow battery apparatus (100) further includes a service storage tank (14) configured to receive and store electrolytes from the first electrolyte storage tank module (10), the second electrolyte storage tank module (12), as well as the positive and negative half cells (25a, 25b) of each fuel stack (22) of the fuel stack module (20) via the first assembly of fluid conduits (10a, 10b, 10c, lOd, lOe, 12a, 12b, 12c, 12d, 12e) and circulatory pumps (34, 36).

2. The redox flow battery apparatus (100) for use in a marine vessel (200) according to claim 1, wherein the service storage tank (14) is further rendered in fluid communication with the pair of electrolyte storage tank modules (10, 12) via a second assembly of conduits (14a, 14b, 14c, 14d) and circulatory pumps (34, 36).

3. The redox flow battery apparatus (100) according to claims 1 or 2, wherein the apparatus (100) includes an anti-corrosion steel tank (52) that takes on the shape of a hull (202) of a marine vessel (200); wherein the anti-corrosion steel tank (52) is configured to house the pair of electrolyte storage tank modules (10, 12), the fuel stack module (20), the power converter module (50), the service storage tank (14), the first assembly of conduits (10a, 10b, 10c, lOd, lOe, 12a, 12b, 12c, 12d, 12e) and circulatory pumps (30, 32) and the second assembly of conduits (14a, 14b, 14c, 14d) and circulatory pumps (40, 42).

4. The redox flow battery apparatus (100) for use in a marine vessel (200) according to claim 1, wherein the selectively permeable membrane (24) of each fuel stack (22) of the fuel stack module (20) that is positioned between the positive electrode (26) and negative electrode (28) is an ion exchange membrane.

5. The redox flow battery apparatus (100) for use in a marine vessel (200) according to claim4, wherein the ion exchange membrane is a proton exchange membrane.

6. The redox flow battery apparatus (100) for use in a marine vessel (200) according to claim5, wherein the proton exchange membrane is a sulfonated tetra- fluoro-ethylene- based fluoropolymer-copolymer membrane.

7. The redox flow battery apparatus (100) for use in a marine vessel (200) according to claim 1, wherein the positive and negative electrodes (26, 28) of each fuel stack (22) of the fuel stack module (20) are porous carbon-based electrodes.

8. The redox flow battery apparatus (100) for use in a marine vessel (200) according to claim 7, wherein the porous carbon-based electrodes are carbon nanotube based electrodes.

9. The redox flow battery apparatus (100) for use in a marine vessel (200) according to claim 1, wherein the redox flow battery apparatus (100) is a vanadium redox flow battery apparatus (100) utilizing a negative electrolyte containing V2+ / V3+ions and a positive electrolyte containing V4+ / V5+ions.

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