Description:FIELD OF THE INVENTION
[001] Present invention relates to an energy storage system. More particularly, the present invention relates to an energy storage system for a vehicle.

BACKGROUND OF THE INVENTION
[002] Vehicles, such as electric vehicles, are typically provided with solid-state batteries such as Lithium-ion (Li-ion) batteries for energy storage, primarily due to their high energy density. However, such solid-state batteries suffer from numerous drawbacks including long charging periods to fully charge the batteries, susceptibility to thermal runaway and fires, and degradation over time due to electrode wear during charging and discharging cycles. Further, altering battery capacity of a solid-state battery pack requires complete disassembling of the battery pack, which is not ideal. Accordingly, solid-state batteries lack design flexibility for adaptation in high-power applications (for e.g., rapid discharge) or high-energy applications (for e.g., long duration discharge). Further, solid-state battery packs cannot be frequently discharged to very low states of charge without causing damage to the battery packs. Additionally, repair and maintenance of solid-state battery packs is cumbersome as it requires disassembling of the battery packs.
[003] Accordingly, there is a need for an energy storage system for a vehicle that can overcome one or more of the aforementioned problems of solid-state batteries.

SUMMARY OF THE INVENTION
[004] In one aspect, an energy storage system is disclosed. The energy storage system comprises a first tank configured to store a first electrolyte and a second tank configured to store a second electrolyte. One or more cells are fluidically connected to the first tank and the second tank. Each cell is being adapted to receive the first electrolyte from the first tank and the second electrolyte from the second tank to generate and store energy. Each cell comprises a first end plate adapted to support one end of the cell, a first current collector, a positive electrode, a membrane, a negative electrode, a second current collector and a second end plate. The first current collector is disposed on a first surface of the first end plate, wherein the first surface is facing the positive electrode. The positive electrode is disposed on the first current collector. The membrane comprises a first surface and a second surface, wherein the positive electrode is disposed on the first surface and a negative electrode is disposed on the second surface. The second current collector is disposed on a first surface of a second end plate, wherein the first surface is facing the negative electrode. The second end plate is adapted to support another end of each cell.
[005] In an embodiment, the energy storage system comprises a housing, the housing being adapted to accommodate the first tank and the second tank. The housing comprises an inlet port that comprises a first inlet and a second inlet, the first inlet being adapted to enable refilling of the first electrolyte in the first tank and the second inlet being adapted to enable refilling of the second electrolyte in the second tank.
[006] In an exemplary embodiment, the positive electrolyte is a first vanadium mixture with oxidation state being one of 2+ and 3+ and the negative electrolyte is a second vanadium mixture with oxidation state being one of 4+ and 5+.
[007] In the exemplary embodiment, the first vanadium mixture and the second vanadium mixture comprise a sulfuric acid solution.
[008] In an exemplary embodiment, the first electrolyte and the second electrolyte comprise one of vanadium with oxidation state being 2+/3+ and 4+/5+, iron-chromium with oxidation state being 2+/3+ and 2+/3+ or zinc-bromine with oxidation state being 2+/1+ and 2+/1-.
[009] In an embodiment, the membrane is an ion-exchange membrane comprising Nafion.
[010] In an embodiment, the positive electrode and the negative electrode comprise one of graphite felt or carbon paper.
[011] In an embodiment, the energy storage system comprises one or more gaskets adapted to seal the first end plate, the first current collector, the positive electrode, the membrane, the negative electrode, the second current collector and the second end plate.
[012] In an embodiment, the energy storage system comprises one or more pumps configured to circulate the first electrolyte and the second electrolyte between the first tank, the second tank and the one or more cells.
[013] In an embodiment, the energy storage system comprises an inverter configured to convert direct current (DC) generated in the energy storage system to alternating current (AC).
[014] In an embodiment, the one or more cells are arranged in at least one of series or parallel configuration in a stack arrangement.
[015] In an embodiment, the energy storage system comprises one or more flow connectors adapted to enable flow of the first electrolyte and the second electrolyte to the positive electrode and the negative electrode respectively in each cell in a stack arrangement.
[016] In another aspect, a two-wheeled vehicle is disclosed. The two-wheeled vehicle comprises an energy storage system. The energy storage system comprises a first tank configured to store a first electrolyte and a second tank configured to store a second electrolyte. One or more cells are fluidically connected to the first tank and the second tank. Each cell is being adapted to receive the first electrolyte from the first tank and the second electrolyte from the second tank to generate and store energy. Each cell comprises a first end plate adapted to support one end of the cell, a first current collector, a positive electrode, a membrane, a negative electrode, a second current collector and a second end plate. The first current collector is disposed on a first surface of the first end plate, wherein the first surface is facing the positive electrode. The positive electrode is disposed on the first current collector. The membrane comprises a first surface and a second surface, wherein the positive electrode is disposed on the first surface and a negative electrode is disposed on the second surface. The second current collector is disposed on a first surface of a second end plate, wherein the first surface is facing the negative electrode. The second end plate is adapted to support another end of each cell.
[017] In an embodiment, the first tank and the second tank are disposed on a floorboard of the two-wheeled vehicle and the one or more cells are disposed on a rear portion of the two-wheeled vehicle.
[018] In an embodiment, the two-wheeled vehicle comprises a housing, the housing being adapted to accommodate the first tank and the second tank. The housing comprises an inlet port that comprises a first inlet and a second inlet, the first inlet being adapted to enable refilling of the first electrolyte in the first tank and the second inlet being adapted to enable refilling of the second electrolyte in the second tank.
[019] In an embodiment, the membrane is an ion-exchange membrane comprising Nafion.
[020] In an embodiment, the one or more cells are arranged in at least one of a series or parallel configuration in a stack arrangement.

BRIEF DESCRIPTION OF THE DRAWINGS
[021] Reference will be made to embodiments of the invention, examples of which may be illustrated in accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
Figure 1 is a schematic view of an energy storage system, in accordance with an exemplary embodiment of the present invention.
Figure 2 is an exploded view of a cell of the energy storage system, in accordance with an exemplary embodiment of the present invention.
Figure 3 is a schematic view of a housing of the energy storage system enclosing a first tank and a second tank, in accordance with an exemplary embodiment of the present invention.
Figure 4 is a side perspective view of a vehicle comprising the energy storage system, in accordance with an exemplary embodiment of the present invention.
Figure 5 is a perspective view of the vehicle illustrating an open position of an inlet port of the housing, in accordance with an exemplary embodiment of the present invention.
Figure 6 is a perspective view of a vehicle illustrating a closed position of the inlet port of the housing mounted on a floorboard of the vehicle.
DETAILED DESCRIPTION OF THE INVENTION
[022] Present invention relates to an energy storage system. Particularly, the present invention relates to an energy storage system for a vehicle. The energy storage system is adapted to overcome the limitations posed in conventional solid-state batteries. The energy storage system of the present invention has design flexibility for adaptation in high-power applications (for e.g., rapid discharge) or high-energy applications (for e.g., long duration discharge). Further, the energy storage system of the present invention can be safely discharged to very low states of charge, while being relatively easy to maintain and repair compared to conventional solid-state battery packs.
[023] Figure 1 is a schematic view of an energy storage system 100 in accordance with an exemplary embodiment of the present invention. The energy storage system 100 has a first tank 108a adapted to store a first electrolyte and a second tank 108b adapted to store a second electrolyte. A stack arrangement 102 comprises one or more cells 106 that is fluidically connected to the first tank 108a and the second tank 108b. In an embodiment, each of the one or more cells 106 is fluidically connected to the first tank 108a and the second tank 108b through tubes. The one or more cells 106 may be arranged in a series configuration or a parallel configuration in the stack arrangement 102. Each cell 106 is adapted to receive the first electrolyte from the first tank 108a and the second electrolyte from the second tank 108b to generate and store energy.
[024] In an embodiment, the first tank 108a and the second tank 108b are accommodated in a housing 104 (as shown in Figure 3). The housing 104 has an inlet port 118 fluidically coupled to the first tank 108a and the second tank 108b. In an embodiment, the inlet port 118 is fluidically connected to the first tank 108a through a first conduit 128a, and to the second tank 108b through a second conduit 128b. The inlet port 118 enables refilling of the first electrolyte in the first tank 108a and the second electrolyte in the second tank 108b.
[025] In an embodiment, the housing 104 comprises a cap member 122 (as shown in Figure 6) provided over the inlet port 118. The cap member 122 is operable between a closed position 134 (shown in Figure 6) and an open position 132 (shown in Figure 5). The cap member 122 in the closed position 134 is adapted to provide ingress protection to the inlet port 118. The cap member 122 in the open position 132 enables refilling of the first electrolyte in the first tank 108a and the second electrolyte in the second tank 108b.
[026] Further, the energy storage system 100 has one or more pumps 126, 136 adapted to circulate the first electrolyte and the second electrolyte between the first tank 108a, the second tank 108b and the one or more cells 106. The one or more pumps 126, 136 comprises a first pump 126 and a second pump 136. The first pump 126 is fluidically coupled between the first tank 108a and the one or more cells 106, to circulate the first electrolyte from the first tank 108a to the one or more cells 106. The second pump 136 is fluidically coupled between the second tank 108b and the one or more cells 106, to circulate the second electrolyte to the one or more cells 106. In an embodiment, each of the first pump 126 and the second pump 136 may be one of a gear pump, a hydraulic pump, a centrifugal pump and the like as per fluid transfer requirement in the energy storage system 100.
[027] In an embodiment, the energy storage system 100 is a vanadium redox flow system in which vanadium ions are used as both positive and negative redox couples. In the embodiment, the first electrolyte is a first vanadium mixture with oxidation state being one of 2+ and 3+, and the negative electrolyte is a second vanadium mixture with oxidation state being one of 4+ and 5+. The first vanadium mixture and the second vanadium mixture comprise a sulfuric acid solution. That is, the first electrolyte and the second electrolyte are water-based, using sulfuric acid as a supporting electrolyte to enhance ion conductivity through one or more ion selective membranes in the stack arrangement 102. The vanadium mixtures as both the first electrolyte and the second electrolyte simplify the design and chemistry of the energy storage system 100.
[028] In an embodiment, the first electrolyte and the second electrolyte comprise one of vanadium with oxidation state being 2+/3+ and 4+/5+, iron-chromium with oxidation state being 2+/3+ and 2+/3+ or zinc-bromine with oxidation state being 2+/1+ and 2+/1-. In an exemplary embodiment where an iron mixture is the first electrolyte and a chromium mixture is the second electrolyte, the iron mixture may have an oxidation state of 2+/3+ and the chromium mixture may have an oxidation state of 2+/3+. In another exemplary embodiment where a zinc mixture is the first electrolyte and a bromine mixture is a second electrolyte, the zinc mixture may have an oxidation state of 2+/1+ and the bromine mixture may have an oxidation state of 2+/1-.
[029] In an embodiment, the energy storage system comprises an inverter configured to convert direct current (DC) generated in the energy storage system to alternating current (AC).
[030] Figure 2 is an exploded view of a cell of the one or more cells 106 in the energy storage system 100, in accordance with an exemplary embodiment of the present invention. Each cell 106 comprises a first end plate 110a, a first current collector 112a, a positive electrode 114a, a membrane 116, a negative electrode 114b, a second current collector 112b, and a second end plate 110b. The first end plate 110a supports one end of the cell 106 and acts as an outer surface on the one end of the cell 106. The first current collector 112a is disposed on a first surface (or an inner surface) of the first end plate 110a that is facing the positive electrode 114a. The first current collector 112a is placed or bonded on the first surface of the first end plate 110a through conventional bonding techniques known in the art. The positive electrode 114a is then disposed or bonded on the first current collector 112a.
[031] Further, the membrane 116 comprises a first surface and a second surface. The positive electrode 114a is disposed on the first surface of the membrane 116 and the negative electrode 114b is disposed on the second surface of the membrane 116. The negative electrode 114b is electrically coupled to the positive electrode 114a. In an embodiment, the negative electrode 114b is electrically coupled to the positive electrode 114a through a conducting wire. The membrane 116 enables a flow of plurality of ions between the positive electrode 114a and the negative electrode 114b. In other words, the membrane 116 is an ion-exchange membrane. The second current collector 112b is disposed on a first surface of the second end plate 110b that is facing the negative electrode 114b. The second current collector 112b is placed or bonded on the first surface of the second end plate 110b. The second end plate 110b is adapted to support another end of the cell 106 and acts as an opposing outer surface at the another end of the cell 106. Such an internal construction of the cells 106 in the stack arrangement 102 helps to achieve better energy density compared to conventional solid-state batteries.
[032] In an embodiment, shape of each of the first end plate 110a, the first current collector 112a, the positive electrode 114a, the membrane 116, the negative electrode 114b, the second current collector 112b, and the second end plate 114b is rectangular. However, in alternate embodiments, one or more of the first end plate 110a, the first current collector 112a, the positive electrode 114a, the membrane 116, the negative electrode 114b, the second current collector 112b, and the second end plate 114b may have a non-rectangular shape and the shape may be suitably selected based on design requirements of the cell 106 to satisfy energy storage requirement of the energy storage system 100. In an embodiment, dimensions of the first end plate 110a, the first current collector 112a, the positive electrode 114a, the membrane 116, the negative electrode 114b, the second current collector 112b, and the second end plate 114b is selected as per energy storage requirements in the energy storage system 100.
[033] In an exemplary embodiment, the membrane 116 is an ion-exchange membrane comprising Nafion. The positive electrode 114a and the negative electrode 114b comprise one of graphite felt or carbon paper.
[034] In an embodiment, each cell 106 of the energy storage system 100 includes one or more gaskets 120 adapted to seal the first end plate 110a, the first current collector 112a, the positive electrode 114a, the membrane 116, the negative electrode 114b, the second current collector 112b and the second end plate 110b. Each cell 106 includes one or more flow connectors 124 adapted to enable flow of the first electrolyte and the second electrolyte across the membrane 116. That is, the energy storage system 100 comprises one or more flow connectors 124 adapted to enable flow of the first electrolyte and the second electrolyte to the positive electrode 114a and the negative electrode 114b respectively in each cell 106 of the stack arrangement. In an embodiment, each of the one or more flow connectors 124 may be rectangular plate members provided with one or more slots that route the electrolytes.
[035] Figure 4 illustrates a side perspective view of the vehicle 200, in which the energy storage system 100 is retrofitted at a side portion of the vehicle 200, in accordance with an exemplary embodiment of the invention. In an embodiment, the vehicle 200 can be a two-wheeled vehicle, a three-wheeled vehicle or a trike. In the present embodiment, the vehicle 200 is the two-wheeled vehicle. The first tank 108a and the second tank 108b are disposed adjacent to the floorboard of the vehicle 200. The stack arrangement 102 is fastened to the rear portion of the vehicle adjacent to a vehicle seat. The stack arrangement 102 is disposed below the vehicle seat 138 and positioned adjacent to a body panel 140 provided below the vehicle seat 138. In an embodiment, the body panel 140 may be a right-side body panel or a left-side body panel. In the present embodiment, the stack arrangement 102 is provided adjacent to the right-side body panel of the vehicle 200. The electrical energy generated by the energy storage system 100 is routed to a transmission component of the vehicle 200 for providing driving force to the vehicle 200.
[036] Referring Figure 5, the first tank 108a and the second tank 108b are disposed on a floorboard 202 of the vehicle 200 and the one or more cells 106 are disposed on a rear portion of the vehicle 200. Particularly, the housing 104 is provided at a middle portion of the floorboard 202 of the vehicle, for allowing space for a rider to place his feet on either side of the housing 104 on the floorboard 202. Such a placement enables the rider to comfortably place his feet while driving the vehicle 200.
[037] The housing 104 accommodates the first tank 108a and the second tank 108b. The housing also comprises the inlet port 118 having a first inlet 118a and a second inlet 118b. The first inlet 118a is fluidically connected to the first tank 108a and enables refilling of the first electrolyte in the first tank 108a. The second inlet 118b is fluidically connected to the second tank 108b and enables refilling of the second electrolyte in the second tank 108b. In an embodiment, the first inlet 118a is fluidically connected to the first tank 108a through a tube or a conduit. In an embodiment, the second inlet 118b is fluidically connected to the second tank 108b through a tube or a conduit.
[038] The claimed invention as disclosed above is not routine, conventional, or well understood in the art, as the claimed aspects enable the following solutions to the existing problems in conventional technologies. Specifically, the claimed aspect of providing one or more cells in the energy storage system, makes the system relatively easier to maintain and repair compared to conventional solid-state battery packs, as affected individual components such as cells or membranes can be replaced and serviced without replacing the entire stack arrangement. The energy storage system of the present disclosure is relatively safe from fire hazards as water-based electrolytes can be used as the first electrolyte and the second electrolyte. With the ability to quickly exchange or replenish electrolyte solutions in the tanks, the energy storage system of the present disclosure provides a modular approach to fueling thereby dispensing the need for long charging hours at a charging station. The energy storage system of the present disclosure has a long operational lifespan as the liquid electrolytes do not degrade during charging and discharging cycles. By adjusting the size of the stack arrangement and the capacity of the electrolyte tanks, the energy storage system of the present invention provides design flexibility for adaptation in high-power applications (for e.g., rapid discharge) or high-energy applications (for e.g., long duration discharge). Further, the energy storage system of the present invention can be safely discharged to very low states of charge without causing damage.
[039] While the present invention has been described with respect to certain embodiments, it will be apparent to those skilled in the art that various changes and modification may be made without departing from the scope of the invention as defined in the following claims.
, Claims:WE CLAIM:
1. An energy storage system (100) comprising:
a first tank (108a) configured to store a first electrolyte;
a second tank (108b) configured to store a second electrolyte; and
one or more cells (106) being fluidically connected to the first tank (108a) and the second tank (108b), wherein each cell (106) being adapted to receive the first electrolyte from the first tank (108a) and the second electrolyte from the second tank (108b) to generate and store energy, wherein each cell (106) comprises:
a first end plate (110a) adapted to support one end of the cell (106);
a first current collector (112a) being disposed on a first surface of the first end plate (110a), wherein the first surface is facing a positive electrode (114a);
the positive electrode (114a) being disposed on the first current collector (112a);
a membrane (116) comprising a first surface and a second surface, wherein the positive electrode (114a) being disposed on the first surface and a negative electrode (114b) being disposed on the second surface;
a second current collector (112b) being disposed on a first surface of a second end plate (110b), wherein the first surface is facing the negative electrode (114b); and
the second end plate (110b) adapted to support another end of each cell (106).

2. The energy storage system (100) as claimed in claim 1 comprising a housing (104), the housing (104) being adapted to accommodate the first tank (108a) and the second tank (108b), the housing (104) comprising an inlet port (118) that comprises a first inlet (118a) and a second inlet (118b), the first inlet (118a) being adapted to enable refilling of the first electrolyte in the first tank (108a) and the second inlet (118b) being adapted to enable refilling of the second electrolyte in the second tank (108b).

3. The energy storage system (100) as claimed in claim 1, wherein
the positive electrolyte being a first vanadium mixture with oxidation state being one of 2+ and 3+; and
the negative electrolyte being a second vanadium mixture with oxidation state being one of 4+ and 5+.

4. The energy storage system (100) as claimed in claim 1, wherein the first electrolyte and the second electrolyte comprise one of vanadium with oxidation state being 2+/3+ and 4+/5+, iron-chromium with oxidation state being 2+/3+ and 2+/3+ or zinc-bromine with oxidation state being 2+/1+ and 2+/1-.

5. The energy storage system (100) as claimed in claim 3, wherein the first vanadium mixture and the second vanadium mixture comprise a sulfuric acid solution.

6. The energy storage system (100) as claimed in claim 1, wherein the membrane (116) being an ion-exchange membrane comprising Nafion.

7. The energy storage system (100) as claimed in claim 1, wherein the positive electrode (114a) and the negative electrode (114b) comprise one of graphite felt or carbon paper.

8. The energy storage system (100) as claimed in claim 1 comprising one or more gaskets (120) adapted to seal the first end plate (110a), the first current collector (112a), the positive electrode (114a), the membrane (116), the negative electrode (114b) and the second current collector (112b) and the second end plate (110b).

9. The energy storage system (100) as claimed in claim 1 comprising one or more pumps (126, 136) configured to circulate the first electrolyte and the second electrolyte between the first tank (108a), the second tank (108b) and the one or more cells (106).

10. The energy storage system (100) as claimed in claim 1 comprising an inverter configured to convert direct current (DC) generated in the energy storage system (100) to alternating current (AC).

11. The energy storage system (100) as claimed in claim 1, wherein the one or more cells (106) being arranged in at least one of series or parallel configuration in a stack arrangement (102).

12. The energy storage system (100) as claimed in claim 1 comprising one or more flow connectors (124) adapted to enable flow of the first electrolyte and the second electrolyte to the positive electrode (114a) and the negative electrode (114b) respectively in each cell (106) in a stack arrangement (102).

13. A two-wheeled vehicle (200) comprising:
an energy storage system (100) comprising:
a first tank (108a) configured to store a first electrolyte and a second tank (108b) configured to store a second electrolyte; and
one or more cells (106) being fluidically connected to the first tank (108a) and the second tank (108b), each cell (106) being adapted to receive the first electrolyte from the first tank (108a) and the second electrolyte from the second tank (108b) to generate and store energy, wherein each cell (106) comprises:
a first end plate (110a) adapted to support one end of the cell (106);
a first current collector (112a) being disposed on a first surface of the first end plate (110a), wherein the first surface is facing a positive electrode (114a);
the positive electrode (114a) being disposed on the first current collector (112a);
a membrane (116) comprising a first surface and a second surface, wherein the positive electrode (114a) being disposed on the first surface and a negative electrode (114b) being disposed on the second surface;
a second current collector (112b) being disposed on a first surface of a second end plate (110b), wherein the first surface is facing the negative electrode (114b); and
the second end plate (110b) adapted to support another end of each cell (106).

14. The two-wheeled vehicle (200) as claimed in claim 13, wherein the first tank (108a) and the second tank (108b) are disposed on a floorboard (202) of the two-wheeled vehicle and the one or more cells (106) being disposed on a rear portion of the two wheeled-vehicle (200).

15. The two-wheeled vehicle (200) as claimed in claim 13 comprising a housing (104), the housing (104) being adapted to accommodate the first tank (108a) and the second tank (108b), the housing (104) comprising an inlet port (118) that comprises a first inlet (118a) and a second inlet (118b), the first inlet (118a) being adapted to enable refilling of the first electrolyte in the first tank (108a) and the second inlet (118b) being adapted to enable refilling of the second electrolyte in the second tank (108b).

16. The two-wheeled vehicle (200) as claimed in claim 13, wherein the membrane (116) being an ion-exchange membrane comprising Nafion.

17. The two-wheeled vehicle (200) as claimed in claim 13, wherein the one or more cells (106) being arranged in at least one of series or parallel configuration in a stack arrangement (102).

Dated this 02nd day of January 2024

TVS MOTOR COMPANY LIMITED
By their Agent & Attorney

(Nikhil Ranjan)
of Khaitan & Co
Reg No IN/PA-1471