Pressurized electrochemical battery and process for manufacturing the same

Abstract

A pressurized electrochemical battery and process for manufacturing the same, which comprises several connectors to at least one electrochemical cell with several electrical energy collectors that are connected to the connectors, with the electrochemical cell comprising several electrode sheets and several solid electrolyte sheets inserted between the electrode sheets, and at least one deformable chamber arranged in contact with the electrochemical cell, with the deformable chamber supplied with a fluid that deforms the chamber to apply pressure to the electrochemical cell.

Claims

1. A pressurized electrochemical battery comprising: anode and cathode connectors, a plurality of electrochemical cells, each electrochemical cell comprising electrical energy collectors connected to the anode and cathode connectors, the electrochemical cell further comprising: a plurality of electrode sheets, and a plurality of solid electrolyte sheets inserted between the electrode sheets, and deformable chambers, wherein each deformable chamber is arranged in contact with each one the plurality of electrochemical cells and is supplied with a fluid that deforms the chamber to apply pressure to the plurality of electrochemical cells, wherein the electrochemical cells and the deformable chambers are assembled concentrically around each other.

2. The pressurized electrochemical battery according to claim 1, wherein each electrochemical cell is arranged pressed between two deformable chambers.

3. The pressurized electrochemical battery according to claim 2, wherein the electrochemical cells have a cylindrical configuration.

4. The pressurized electrochemical battery according to claim 1, wherein each electrochemical cell is installed in a housing defined between two deformable chambers that are closed at their ends by several lateral covers that have several expansion seals.

5. The pressurized electrochemical battery according to claim 1, wherein the deformable chambers are connected to a system of fluid supply collectors.

6. The pressurized electrochemical battery according to claim 5, wherein the system of fluid supply collectors comprises a delivery system to control the intake flow to the system of fluid supply collectors and a pressure regulator to adjust the pressure inside the deformable chambers.

7. The pressurized electrochemical battery according to claim 1, wherein each electrode sheet comprises two layers of active material and one layer of conductive material, wherein the layers of active material partially cover both sides of the layer of conductive material, with the ends of the layer of conductive material protruding with respect to the layers of active material.

8. The pressurized electrochemical battery according to claim 1, wherein the electrode sheets are formed by anode sheets and cathode sheets of a same active material.

9. The pressurized electrochemical battery according to claim 1, wherein the electrode sheets are formed by anode sheets and cathode sheets of different active materials.

10. The pressurized electrochemical battery according to claim 1, wherein the solid electrolyte is made of a polymer, ceramic or composite material.

11. The pressurized electrochemical battery according to claim 1, further comprising electrical conductors, wherein the electrical conductors are flexible.

12. The pressurized electrochemical battery according to claim 1, wherein the plurality of electrode sheets and the plurality of solid electrolyte sheets are equipped with several conduits of an additional fluid with cooling properties.

13. A manufacturing process of a pressurized electrochemical battery according to claim 1 comprising: using a first roll that has an electrode sheet overlaid on a solid electrolyte sheet, using a second roll that has another electrode sheet overlaid on another solid electrolyte sheet, using a rotating spindle on which a deformable chamber is positioned, alternately winding on the deformable chamber the electrode sheet with the solid electrolyte sheet and the other electrode sheet with the other solid electrolyte sheet, encapsulating the assembly formed by the electrode sheets, solid electrolyte and the deformable chamber.

14. The manufacturing process according to claim 13, wherein prior to encapsulation, several assemblies formed by electrode sheets, solid electrolyte, and deformable chamber are wound, winding said assemblies around each other according to a concentric distribution.

15. The manufacturing process according to claim 13, wherein several rotating cutting dies are used to partially cut the ends of the electrode sheets to obtain several electrical energy collectors.

Description

DESCRIPTION OF THE FIGURES

(1) FIG. 1 shows a perspective view of a pressurized electrochemical battery according to a preferred embodiment of the invention.

(2) FIG. 2 shows a longitudinal cross-section view of a part of the pressurized electrochemical battery in the previous figure.

(3) FIG. 3 shows a schematic view of the layers that form an electrode sheet that is arranged on a solid electrolyte sheet.

(4) FIG. 4 shows a partial view of the electrode sheet of the previous figure.

(5) FIG. 5 shows a cross-section view of a part of the pressurized electrochemical battery in FIGS. 1 and 2 with continuous electrode sheets.

(6) FIG. 6 shows a cross-section view of a part of the pressurized electrochemical battery in FIGS. 1 and 2 with discontinuous electrode sheets.

(7) FIG. 7 shows a perspective view of a machine for carrying out the manufacture of a pressurized electrochemical battery like the one represented in the exemplary embodiment in FIGS. 1 and 2.

DETAILED DESCRIPTION OF THE INVENTION

(8) FIG. 1 shows a pressurized electrochemical battery according to a preferred embodiment of the invention, wherein the battery has a cylindrical configuration, although it is not limited to this configuration and the battery may adopt other shapes with this not altering the concept of the invention.

(9) The cross-section view of FIG. 2 shows the interior configuration of the preferred embodiment of the battery in FIG. 1. The battery comprises several connectors (1,2) or terminals, wherein said connectors are an anode connector (1) and a cathode connector (2), through which electrical energy that is stored in the battery is charged and discharged.

(10) In the preferred exemplary embodiment in FIG. 2, the battery comprises a set of electrochemical cells (3), wherein each one of the cells (3) is arranged between two deformable chambers (4) that receive a fluid, such that said fluid makes it possible to modify the size of the chambers (4), deforming them, and therefore pressing the elements that make up the electrochemical cell (3) to ensure adequate contact between them.

(11) The vertical black arrows shown on the electrochemical cells (3) in FIG. 2 indicate the direction in which the deformable chambers (4) exert pressure on the cells (3). The other black arrows in FIG. 2 indicate the direction of the fluid that is received by the chambers (4).

(12) In the preferred embodiment in FIGS. 1 and 2, the electrochemical cells (3) have a cylindrical configuration and are arranged according to a concentric distribution, making it possible to optimize the occupied space.

(13) Optionally, each one of the electrochemical cells (3), individually or the set all of them collectively, may be covered by a sealing material or be arranged in a sealing encapsulation.

(14) Also optionally, there may be internal structural components separating each one of the electrochemical cells (3) of the battery.

(15) In any case, it its most simplified configuration, the battery would have a single electrochemical cell (3) that on one of its long sides would be arranged in contact with a deformable chamber (4) and on its opposite long side would be arranged in contact with a fixed part of the battery. Preferably, said single cell (3) would be arranged between two deformable chambers (4).

(16) The electrochemical cells (3) have several collectors (5) at each one of their ends. The collectors (5) are secured by several flanges (6) and are connected to the connectors (1,2) by means of several electrical conductors (7). The collectors (5) of one of the ends of the cell (3) are connected electrically to the anode connector (1) and the collectors (5) of the other end of the cell (3) are connected electrically to the connector of the cathode (2).

(17) Each one of the deformable chambers (4) has a fluid intake and outlet that are connected to a system of collectors (8) through which the fluid that is supplied to the chambers (4) circulates.

(18) Preferably, the fluid that is supplied to the chambers (4) is a cooling fluid, such that the deformable chambers have a dual function; on one hand, regulating the pressure applied to the electrochemical cells (3), and on the other, cooling the battery.

(19) Thus, the chambers (4) have both adjustable temperature and pressure, both of which may be adjusted depending on the specific operating conditions of the battery. The pressure and temperature may be different depending on the battery process state: charging, discharging or at rest.

(20) Since the pressure can be modified based on the operating conditions, in addition to improving the contact between the elements that make up the electrochemical cells (3), the battery conform to the volume variations in the cell (3) in response to the ion exchanges that they undergo during the charging and discharging processes.

(21) Preferably, the system of collectors (8) has a delivery system (9) and a pressure regulator (10). The delivery system (9) is located at the intake of the system of collectors (8) and makes it possible to control the intake flow to the system of collectors (8), and with this, the battery temperature, while the pressure regulator (10) makes it possible to adjust the pressure inside the deformable chambers (4), and with this, the contact between the elements that make up the cells (3).

(22) The electrochemical cells (3) are arranged under conditions of a vacuum and controlled atmosphere inside the battery. Thus, the electrochemical cells (3) are installed in a housing defined between two deformable chambers (4) that are closed at their ends by several lateral covers (11). Said lateral covers (11) have several expansion seals (12) that make it possible to absorb the contractions experienced by the housings of the electrochemical cells (3) when the fluid of the chambers (4) deforms them.

(23) The electrochemical cells (3) are made up of several electrode sheets (13) and several solid electrolyte sheets (14), with the electrode sheets (13) being inserted between the solid electrolyte sheets (14).

(24) As shown in FIG. 3, each electrode sheet (13) comprises two layers of active material (131) and one layer of conductive material (132). The layers of active material (131) are arranged on both sides of the layer of conductive material (132), partially covering them, such that the layer of conductive material (132) protrudes with respect to the layers of active material (131) at its ends, with said ends acting as electrical energy collectors (5) that will be connected to the connectors or terminals (1,2) to extract and generate the voltages and currents expected in the design of the battery.

(25) Also as shown in FIG. 3, the electrode sheet (13) is arranged on the solid electrolyte sheet (14), with the ends of the sheet of conductive material (132), in other words, the collectors (5) protruding with respect to the solid electrolyte sheet (14).

(26) The material of the electrode sheets (13) will depend on the final chemistry of the battery; in the case of lithium, the active material of the anode could be graphite and the active material of the cathode a lithium oxide (LCO, LNO, NMO, NMC, . . . ), while, in the case of sodium, the electrode sheets (13) could use active materials such as hard carbons in the anode and sodium oxide, Prussian blue, or even organic-based materials as the active material in the cathode. In both cases, lithium or sodium metal could also be considered for the active material of the anode. The solid electrolyte (14) could be made of a polymer material, a ceramic material, or even a composite.

(27) In addition, the deformable chambers (4) are made of deformable materials, which include elastomers or even metals, such as aluminum in films with a limited thickness.

(28) The electrode sheets (13) may be continuous, as shown in FIG. 5, or discontinuous, as shown in FIG. 6, such that there is a separation between sheets (13). This will provide a certain degree of flexibility in the deformation of the sheets (13), such that they can slide between them in response to the application of interior pressure without experiencing mechanical stresses that could damage them.

(29) Likewise, when the electrode sheets (13) that are connected to the anode connector (1) and the electrode sheets (13) that are connected to the cathode connector (2) are made of the same active material, said separation between sheets (13) is favorable to prevent short-circuits.

(30) In regard to the solid electrolyte sheets (14), depending on the type of material of the electrolyte, they may have an arrangement of sheets with a limited length, as shown in FIG. 6, or if their mechanical properties allow it, they may be continuous and deform in response to the pressure exerted, as shown in FIG. 5.

(31) Preferably, the sheets (13,14) have several cavities in the radial direction of the battery through which they are equipped with several conduits for an additional fluid with cooling properties. Said cavities can be connected to an additional system to supply a liquid or gaseous fluid, such that it allows the delivery of said fluid through said conduits, in addition to the fluid that is circulating through the deformable chambers (4). Using a tempered fluid with controlled temperature throughout all of the cavities and chambers (4) achieves thermal management that improves the performance of the battery, avoiding the problems associated with overheating and even allowing the generation of batteries that are thicker than the set of sheets (13,14), thus increasing their storage capacity.

(32) According to the embodiment shown in FIG. 2, the collectors (5) are interconnected, preferably by means of a soldering process, and grouped by the flanges (6), so that by means of the collectors (5), the set of electrode sheets (13) that make up the electrochemical cells (3) are grouped together. This means that there will be one contact zone in each cell (3) for each connector (1,2). In another alternative configuration (not shown in the figures), there may be a contact zone at each one of the lateral ends of the layer of conductive material (132) for each one of the connectors (1,2).

(33) Preferably, the electrical conductors (7) that connect the collectors (5) to the connectors (1,2) are made of a flexible material, such that said material tolerates and adapts to the different deformations that the battery experiences during its operation.

(34) The battery has been designed to have an exterior encapsulation (15), which acts as a barrier between different batteries that may be arranged in series, such that said encapsulation (15) prevents a battery from coming into direct contact with adjacent batteries.

(35) The following section describes the procedure for the manufacture of the battery with a cylindrical configuration in the preferred embodiment shown in FIGS. 1 and 2, although it is evident for a person skilled in the art that batteries with configurations other than a cylindrical configuration can be obtained using the described procedure, with this not altering the concept of the invention.

(36) As shown in FIG. 7, the battery is manufactured by means of a winding process, wherein electrode sheets (13) and solid electrolyte sheets (14) are progressively overlaid on a deformable chamber (4).

(37) To do this, a first roll (16) that has an electrode sheet (13), a first sheet, overlaid on a solid electrolyte sheet (14), and a second roll (17) that has another electrode sheet (13), a second sheet, overlaid on another sheet of solid electrolyte (14) are used. The sheet (13) of the first roll (16) will be connected to the anode connector (1) and the other sheet (13) of the second roll (17) will be connected to the connector of the cathode (2), as will be explained below.

(38) In addition, the deformable chamber (4) is arranged on a rotating spindle (18), and the sheets (13,14) of the first and second rolls (16,17) are wound in an alternating manner on said deformable chamber (4) until an electrochemical cell (3) with a desired thickness is obtained on the chamber (4).

(39) The electrode sheet (13) overlaid on a solid electrolyte sheet (14) has a configuration like the one shown in FIG. 3 and that was described above. Thus, the electrode sheet (13) comprises two layers of active material (131) between which a layer of conductive material (132) is positioned and which protrudes with respect to the layers of active material (131).

(40) By means of several rotating cutting dies (19) the ends of the electrode sheets (13) are partially cut to obtain several electrical energy collectors (5). To do this, the electrode sheets (13) are passed through the dies (19), partially cutting the layer of conductive material (132), which protrudes with respect to the layers of active material (131).

(41) As shown in detail in FIG. 7, the layer of conductive material (132) that protrudes with respect to the layers of active material (131) of the sheet (13) of the first roll (16), is only trimmed on one side, such that collectors (5) are defined for the connection to the anode connector (1). In addition, the layer of conductive material (132) that protrudes with respect to the layers of active material (131) of the sheet (13) of the second roll (17), is only trimmed on one the other side, such that collectors (5) are defined for the connection to the cathode connector (2).

(42) After obtaining the electrochemical cell (3), the collectors (5) are flanged and soldered to each other, and are then interconnected electrically to the collectors (5) by means of several electrical conductors (7) and the collectors (5) of one of the ends of the cell (3) are connected electrically to the anode connector (1) and the collectors (5) of the other end of the cell (3) are connected electrically to the cathode connector (2). Lastly, the assembly formed by the electrode sheets (13), solid electrolyte (14) and the deformable chamber (4) is placed in an encapsulation (15).

(43) To obtain a battery with several electrochemical cells (3), like the one shown in FIG. 2, prior to encapsulation and the electrical connection of the collectors (5), several assemblies of electrode sheets (13), solid electrolyte (14), and deformable chambers (4) are wound, winding said assemblies around each other according to a concentric distribution.

(44) To obtain the rolls (16,17), first, a layer of conductive material (132), such as aluminum, copper or another more advanced material, such as lithium-aluminum alloys, is automatically unrolled and sent to a system for the application of a coating to cover the layer of conductive material (132) with layers of active material (131).

(45) Said layers of active material (131) may be applied by means of printing systems, electrostatic adhesion, or by any other method for coating or priming layers, and it may even consist of a layer of active material (131) such as lithium or sodium metal. The electrode sheet (13) will be obtained in this manner.

(46) A solid electrolytic coating is then applied on the electrode sheet (13), with said coating applied on one or both sides of the electrode sheet (13). The electrode sheet (13) with the solid electrolyte sheet (14) is obtained in this manner. Preferably, the solid electrolyte sheet (14) is applied from a roll of solid electrolytic material.

(47) In one configuration of the invention, the electrode sheets (13) and solid electrolyte sheets (14) are cut before being wound onto the deformable chamber (4). In another configuration of the invention, the electrode sheet (13) is cut, but leaving the solid electrolyte sheet (14) uncut. In another configuration, cuts are not made in the sheets (13,14), so that the sheets wound onto the deformable chamber (4) are continuous, instead of having limited lengths.

(48) The process described for the manufacture of the rolls (16,17) will be executed in installations with a controlled atmosphere, preferably with a relative humidity below 0.01%, and preferably with a pressurized atmosphere that prevents leaks towards the interior, with the consequent possibility that moisture may enter the enclosure. In an alternative configuration, the described process will be executed in installations with a strong vacuum to achieve the proper working conditions.

(49) The application of the solid electrolyte mainly isolates the active materials from the external atmosphere and therefore, this process must be carried out in an atmosphere with no special requirements that are demanding as controlled atmosphere as in the case of the active materials.

(50) The rotating spindle (18) is expandable, or with variable dimensions, so that it can accommodate the different concentric deformable chambers (4) optimally. This means that using one spindle (18), it is possible to manufacture batteries with cells (3) with different internal diameters.

(51) In a preferred configuration of the manufacturing process, the temperature of the spindle (18) and material is managed in a controlled manner, so that, by means of controlled thermal expansion, the final adjustments and contacts between components can be more precise.