ES2911761B2 - ELECTRICAL ENERGY ACCUMULATOR WITH INTERNAL REFRIGERATION - Google Patents

Description

DESCRIPTION

ELECTRICAL ENERGY ACCUMULATOR WITH INTERNAL COOLING

OBJECTIVE AND FIELD OF THE INVENTION

The present invention consists of having an internal heat exchange system for accumulators of electrical energy, such as batteries and condensers, with the main objective of avoiding or reducing heating due to the transformation of chemical energy into electricity, typical of these accumulation systems. energy, cooling its interior. In this way, the problems caused by heating are reduced, improving the performance of the accumulators and increasing their useful life.

The technical field of the invention focuses on electrical energy accumulators, such as cells or batteries, and more specifically on cooling systems or means for said electrical energy accumulators.

BACKGROUND

Energy accumulators are devices where chemical energy is transformed into electrical energy. Said chemical transformation generates an exothermic process, giving off heat that can affect the operation of the device, reducing the number of hours of use of said device.

Among the energy accumulators where electrical energy is stored in the form of chemical energy, electric batteries, capacitors and batteries stand out, which consist of portable devices configured to store and provide electricity in places with difficult access to the electrical network.

These types of devices can be reused and recharged a limited number of times, or they can have a single use, so that once their useful life has ended, their activity ceases and the elements that constitute them have to be renewed, since that its characteristics are altered during it.

The use of the electrical energy of these accumulators is accessible through two terminals that the electrical accumulator has, called poles, electrodes or terminals.

One of them is the positive pole or cathode and the other is the negative pole or anode.

These elements for accumulating electrical energy can present different inconveniences related to their operation, such as their capacity or speed of loading and unloading, specific maintenance conditions, or a very common problem such as the tendency to overheat, thus making it difficult to use them in said situations. .

There are devices, mechanisms or systems configured on the market to avoid or reduce this heating, most of them being external systems that consist of cooling the accumulator cells from the outside.

Document CN209993704U describes a cooling system for a cylindrical battery that cannot be applied to batteries with electrodes arranged in groups of superimposed layers, stacked or stacked. The way to cool the battery comprises an internal conduit that stores a static gel, located in the core of the battery, that is, in the axis of its cylindrical shape, so that it can extract the heat generated in said core, dissipating it through fins arranged inside the battery.

In this configuration, the electrodes are not perforated or spaced, so there is no rapid and efficient exchange of heat between the inside of the accumulator and the outside. In addition, the cooling system described in CN209993704U comprises a static thermoconductive gel material that transmits heat between the internal coil of the battery and the conduit, said gel being an element that is difficult to incorporate and contain inside an energy accumulator. Due to this gel, the conduit through which the coolant flows cannot be electrically conductive, that is, it is only configured to cool the battery core.

On the other hand, document CN104993183 defines a cooling system that surrounds the edge of the battery. It is made up of perforated dissipation plates placed on the sides of the electrolytes, these plates being where the cooling tubes are located. In other words, the dissipation plates are the ones with perforations and not the electrodes. In addition, the cooling tubes used, as they are not connected to the electrodes, do not conduct electric current at any time, being elements only configured for cooling.

Document W02017150012 defines an energy accumulator that comprises a battery pack made up of different cells that are cooled by an external ventilation system that generates a current that circulates between them. At no time does this refrigeration enter the interior of the cell, producing heat exchange by convection.

Of all the refrigeration systems found for electrical energy accumulators, none has been found in which a refrigerant fluid is conducted through a conduit that is in contact with all the electrodes of said accumulator, directly capturing the heat generated, said conduit also being in charge of the electrical connection between said electrodes and therefore, of the accumulator.

DESCRIPTION OF THE INVENTION

In order to solve the indicated problems of heating in electric energy accumulators, the present invention consists of an electric energy accumulator with internal cooling. That is, you can reduce its temperature from the inside instead of externally cooling the accumulator.

This accumulator comprises at least one cell comprising a plurality of electrodes stacked in the form of superimposed layers, said electrodes being separated into two groups, one being anodes and the other cathodes, and the number of electrodes in said cell being dependent on the desired charge density.

In a preferred embodiment, each electrode comprises a metal surface or sheet, such that said surfaces or sheets are stacked in the form of superimposed layers. In the same preferred way, the cell also comprises a separating film arranged between each layer of electrodes with different charges, so that the electrodes with different charges are not in contact, to avoid short circuits. The separation, in this case, between the anodes and the cathodes occurs due to said film and a displacement towards each end depending on the charge of the electrode, in such a way that the plates of the anodes displaced towards one end or side of the stack of superimposed layers and the cathodes towards the other end.

The accumulator cell comprises at least a first and a second current collector, made of an electrically conductive material, which comprise a tube shape, and are configured to conduct a fluid through the interior of said collectors, that is, as a conduit that, in addition to conducting a fluid through its interior, also allows the passage of electricity .

The first current collector is embedded in some through holes of the anodes and the second current collector is embedded in some through holes of the cathodes, that is, each electrode of the cell comprises a through hole crossed by the corresponding collector. In this way, the fluid conducted inside the conduit is configured to exchange heat with said electrodes.

With this configuration, in the event that the cell or cells of the accumulator need to be cooled due to overheating of the electrolytes, a cold fluid can be passed through the interior of the current collectors, which subtracts the heat generated inside each cell and transfer it to an outside of the accumulator, through a device configured for it, such as a radiator, or a coil connected to a natural or forced ventilation system. On the other hand, if it is required to heat the interior of the energy accumulator, because the temperature at which it is found is too cold to allow correct operation, the current collector can also be used for this purpose, conducting a hot fluid through its interior, transferring heat from the collector to the electrodes.

In order for there to be a passage of heat by conduction between the electrodes and the current collectors, said collectors must be tight to the holes of the electrodes, that is, without looseness in the fit. In addition, to facilitate said adjustment, in one embodiment, all the holes of the electrodes are concentric, that is, they have the same axis, so that the current collector crosses them following a single straight direction of said axis, crossing them perpendicularly.

In one embodiment, the through holes of the plurality of electrodes, in addition to being concentric, are located at a displaced end of said electrodes.

In one embodiment, each cell comprises a casing configured to contain inside the plurality of electrodes contained in said cell, where said casing comprises at least four holes, two of said holes being crossed by the first collector and the other two holes through the second current collector. In this way, the passage of each current collector is allowed between the outside and the inside of each cell, being able to connect said collector with the outside of the accumulator or with other cells included in said accumulator. In a preferred embodiment, the casing also contains conductive organic coatings inside it, in the form of flat plates, arranged on each flat side of each electrode, as well as a separating film or separating film located between each electrode.

In one embodiment, the accumulator comprises insulating bushings fitted snugly between the current collectors and the casing holes. More precisely, said bushings isolate the temperature and the electricity conducted by the electrical collectors to prevent it from being conducted to the casing of each cell.

In one embodiment, the current collector is made of a conductive material that varies depending on the specifications of the cells, said materials being suitable for the exchange of heat and electricity as they have a high thermal and electrical transmission rate. Specifically, the current collector is made of a material selected from the group consisting of stainless steel, copper, aluminum, nickel, silver, gold, bronze, titanium, and alloys derived from these materials.

In one embodiment, the fluid conducted inside the first and second current collectors is a gas or a liquid, since both states of the fluid allow a rapid flow that facilitates an adequate exchange of temperatures between said fluid and the electrodes.

In fact, in one embodiment, the first and second current collectors are configured to direct the fluid conducted inside them towards a heat exchange system external to the accumulator, so that said system may be capable of both heating and cooling the fluid.

In other embodiments, the energy accumulator can be connected to an energy utilization system, that is, a system that can absorb the heat generated inside the cells and use it for another use, such as heating, or in industrial processes.

In one embodiment, the accumulator comprises a plurality of cells connected through current collectors, depending on the load transmitted by the electrodes to which said collectors are fitted in each cell, where said collectors are configured to electrically connect the cells included in the accumulator and to communicate the fluid conducted through its interior. In a preferred embodiment, the plurality of cells of said accumulator are stacked in rows and columns so that the space occupied by them is as compact as possible.

In one embodiment, the current collectors of the cells are connected in series, in parallel, or in a combination of the above. If necessary, depending on the selected connection between the cells, the energy accumulator can include ducts that allow the passage of fluid between the cells but do not transmit electrical energy between them.

DESCRIPTION OF THE FIGURES

Figure 1A: shows a perspective view of an electric energy accumulator comprising a cell sectioned along a longitudinal plane, in which it is possible to see the outer casing of said cell as well as the insulating bushings attached to the current collectors.

Figure 1B: shows a rear perspective view of an electric energy accumulator comprising a cell cut along a longitudinal plane, similar to that of figure 1A, in which it is possible to visualize the plurality of electrodes, anodes or cathodes, arranged stacked in superimposed layers, in parallel, separated by a separating film, and displaced towards each side of the battery depending on the charge, said electrodes being traversed by the first and second current collectors, for the anodes and cathodes, correspondingly.

Figure 2A: shows an elevation view of a cell sectioned by a longitudinal plane, similar to that of figure 1B, in which it is possible to visualize the plurality of electrodes, anodes or cathodes, arranged stacked in superimposed layers, in parallel and spaced by a separating film.

Figure 2B: Shows an elevation view of a cell cut through a cut similar to shown in figure 1A, in which it is possible to visualize the outer casing of a cell as well as the bushings attached to the current collectors.

Figure 3A: shows a sectioned and perspective detail view of a corner of a cell of an electric energy accumulator in which the arrangement of the electrodes can be seen. Said electrodes are arranged in the form of metal plates, and in this figure it can be seen how the anode plates are displaced towards one side of the stack of electrodes arranged stacked in superimposed layers, which comprise a through hole at one end of said electrodes. plate, all the holes of said plates being fitted with the first current collector, so that the exchange of heat and current flow between said collector and said plates occurs. It can also be seen how, surrounding each electrode on its two flat faces, there is a conductive organic coating, also in the form of a flat plate, and a separating film located between each electrode with a different charge.

Figure 3B: shows a detailed sectional view similar to the one shown in figure 3A but showing the arrangement of the cathodes.

Figure 4: shows a perspective view of an electric energy accumulator comprising four rows and six columns of cells, in a total of 24 cells. Said cells are connected through the current collectors, in sections of four cells connected in series (by columns) with the six columns connected in parallel. With this, a desired voltage and intensity is achieved based on said arrangement and that the input fluid to the accumulator is divided into six different conductions, each one directed to 4 cells connected in series to later be joined again in an outlet by collector. .

Figure 5: shows a perspective view of an electric energy accumulator comprising a plurality of cells connected in parallel, so that the fluid entering the accumulator is divided into said plurality of current collectors that pass through each cell.

Figure 6: shows a perspective view of an electric energy accumulator comprising six cells connected in series so that the positive terminals of one cell are connected to the negative terminals of the next, with only the conduits of the upper part collectors of electrical current, while those shown in the lower part are fluid conduits, but not of electrical energy as it is not necessary for said series connection.

PREFERRED EMBODIMENT OF THE INVENTION

As can be seen in the figures, the preferred embodiment of the invention consists of an accumulator (7) of electrical energy that can comprise a cell (1) as shown in figures 1 and 2, or a plurality of them arranged in series. , in parallel or in both arrangements as shown in figures 6, 5 and 4 respectively, which has an internal cooling system, in order to reduce the temperature that can be reached inside each accumulator (7).

As can be seen in figures 1B, 2A and 3A and 3B, the interior of each cell (1) comprises a plurality of electrodes (4) that have the shape of rectangular metal plates and are stacked in superimposed layers, one on top of the other. others in height, with the plates of the anodes and cathodes being displaced towards opposite sides. As can be seen in figures 3A and 3B, on each side of each metal sheet there is a conductive organic coating (3), and to avoid contact between electrodes (4) of different charge, a separating film (9) is also placed. electrical insulator, also in the form of a rectangular flat plate, arranged between each electrode (4), to prevent short circuits.

The ends of these electrodes (4) comprise a through hole at one end of the plate, all the holes of said anode plates being fitted with the first current collector (2a) and the holes of the cathode plates in the second collector (2b), so that the exchange of heat and current flow occurs between said collectors and said plates. The holes of all the electrodes (4) of the same load are concentric and of the same diameter, to have a good fit to the current collector (2a, 2b).

The collectors (2a, 2b) are configured to conduct a fluid through their interior, and to transmit the electrical current generated inside each cell (1). In other words, the collectors (2a, 2b) not only conduct a fluid to cool the internal accumulator (7), but also transmit the electrical charge of said accumulator (7).

In these figures 1 to 3, it can also be seen that each cell (1) comprises a casing (6) that contains in its interior the plurality of electrodes (4), said casing (6) being crossed by the first (2a) and the second current collector (2b). To prevent the current collectors (2a, 2b) from transmitting the electrical charge of the electrodes (4) to the casing (6), the accumulator (7) comprises bushings (5), insulating electricity and temperature, located a tight fit between the current collectors (2a, 2b) and the holes in the casing (6) crossed by the collectors (2a, 2b), as shown in figure 3.

When the accumulator (7) is heated to a high temperature, the fluid conducted inside the collectors (2a, 2b) can extract said heat and conducts it to an exterior of the accumulator (7) where it is transferred in an exchange system external heat source, which may be a radiator, a finned heat sink, or a device comprising some means of generating current, such as a fan.

As can be seen in figures 4 to 6, the accumulators (7) can comprise a plurality of cells (1) arranged in parallel, as shown in figure 5, where the fluid entering the accumulator is divided into as many flows as Cells (1) comprise the accumulator (7), to later rejoin at the accumulator outlet (7), or can be in series and go through a sequence of cells (1), as shown in figure 6.

In fact, in said configuration of Figure 6, the connection of the terminals of each cell (1) changes from positive to negative, so to avoid connection problems, only one of the tubes coming out of each terminal of each cell (1) is a current collector (2a, 2b), while the other tube is a non-collector conduit (8), that is, it allows the passage of fluid but not electricity.

In figure 4, an accumulator (7) can be seen that comprises a plurality of cells (1) stacked in six columns of four rows, but unlike figure 6, the series connection of said cells (1) arranged in each column is made between terminals of the same electrical charge.

This configuration of the accumulator (7), allows to have desired voltage and intensity values without this affecting the way in which the accumulator (7) is cooled.

Claims (11)

1. Accumulator (7) of electrical energy with internal cooling, comprising at least one cell (1) comprising a plurality of electrodes (4) stacked in the form of superimposed layers, said electrodes (4) being separated into two groups, being one for anodes and the other for cathodes, characterized in that each electrode (4) comprises a through hole; where the cell (1) comprises a first (2a) and a second current collector (2b), made of an electrically conductive material, which comprise a tube shape and are configured to conduct a fluid inside said collectors (2a, 2b); where the first current collector (2a) is fitted in the through holes of the anodes and the second current collector (2b) is fitted in the through holes of the cathodes; and where the fluid is configured to exchange heat with said electrodes (4). 2. Accumulator (7) of electrical energy, according to the previous claim, where each electrode (4) comprises a metal sheet, where said sheets are stacked in the form of superimposed layers; where the cell (1) comprises a separating film (9) arranged between each layer of electrode (4) of different charge, said separating film (9) being configured so that the stacked electrodes (4) of different charge are electrically isolated avoiding short circuits , and where each end of each electrode (4) is displaced depending on the charge of said electrode (4), the plates of the anodes being displaced towards one end or side of the stack of superimposed layers of the electrodes (4) and cathodes to the opposite end. 3. Accumulator (7) of electrical energy, according to the preceding claim, wherein the through holes of the plurality of electrodes (4) are concentric and are located at a displaced end of said electrodes (4). 4. Accumulator (7) of electrical energy, according to any of the preceding claims, wherein each cell (1) comprises a casing (6) configured to contain inside the plurality of electrodes (4) contained in said cell (1), where said casing (6) comprises at least four holes, two of said holes being traversed by the first collector (2a) and the other two holes by the second current collector (2b). 5. Accumulator (7) of electrical energy, according to the previous claim, comprising insulating bushings (5) located snugly between the collectors (2a, 2b) of current and the holes of the casing (6). 6. Accumulator (7) of electrical energy, according to any of the preceding claims, where the current collector (2) is made of a material selected from the group consisting of stainless steel, copper, aluminum, nickel, silver, gold, bronze , titanium and alloys derived from these materials. 7. Accumulator (7) of electrical energy, according to any of the previous claims, where the fluid conducted inside the first (2a) and the second current collector (2b) is a gas or a liquid. 8. Accumulator (7) of electrical energy, according to any of the previous claims, where the first (2a) and the second current collector (2b) are configured to direct the fluid conducted through its interior towards an external heat exchange system to the accumulator (7). 9. Accumulator (7) of electrical energy, according to any of the preceding claims, comprising a plurality of cells (1) connected through the current collectors (2a, 2b) that pass through them, depending on the load they transmit the electrodes to which said collectors (2a, 2b) are fitted in each cell (1), where said collectors (2a, 2b) are configured to electrically connect the cells (1) included in the accumulator (7) and to communicate the fluid conducted through its interior. 10. Accumulator (7) of electrical energy, according to the previous claim, where the plurality of cells (1) are stacked in rows and columns. 11. Accumulator (7) of electrical energy, according to any of claims 8 or 9, where the current collectors (2a, 2b) of the cells (1) are connected in the selected way within the group consisting of series, in parallel, and in a combination of the above.