Electrochemical cell for the storage of electric energy

Abstract

An electrochemical cell (1) for the storage of electrical energy comprises an operating portion (10) in which there is an anodic body (21) with a section having a decreasing area along a development direction in a first direction (V1) of separation from the anodic connector (20) and the cathodic body (31) has a section having a decreasing area along the development direction in a second direction (V2) of separation from the cathodic connector (30). The anodic body (21) has an anodic conductive part (211) connected to the anodic connector (20) and the cathodic body (31) has a cathodic conductive part (311) and connected to the cathodic connector (30); wherein along the development direction, in the first direction (V1), the anodic conductive part (211) has a section with a decreasing area and the cathodic conductive part (311) has a section with an increasing area and the cross-sectional areas of the cathodic conductive part (311) and of the anodic conductive part (211) along the development direction vary respectively as a function of a foreseen or expected electric current, in use, in the cathodic conductive part (311), or of a design electric current of the cathodic conductive part (311), and of a foreseen or expected electric current, in use, in the anodic conductive part (211), or of a design electric current of the anodic conductive part (211).

Description

[0001] ELECTROCHEMICAL CELL FOR THE STORAGE OF ELECTRIC ENERGY

[0002] TECHNICAL FIELD

[0003] DESCRIPTION

[0004] This disclosure relates to an electrochemical cell for the storage of electrical energy.

[0005] This solution finds a preferred, although not exclusive, application in the field of solid- state electrolyte electrochemical cells.

[0006] In particular, but not limited to, the application of this solution is advantageous in the field of electrochemical cells made by three-dimensional additive printing.

[0007] In this description as well as in the claims attached thereto, some terms and expressions are deemed to assume, unless otherwise explicitly indicated, the meaning expressed in the definitions that follow.

[0008] The expression "electrochemical cell" means a device capable of reversibly converting electrical energy into chemical energy so as to store and make electrical energy available respectively through charging and discharging processes.

[0009] In this text the expression "electrochemical cell" is used interchangeably with the expressions "cell", "secondary battery” or, more generally, "battery" or "product".

[0010] The terms “anode connector” and “cathode connector” mean parts of the anode and cathode of the electrochemical cell that are intended to be electrically connected to the outside of the electrochemical cell for charging and discharging it and do not necessarily take part in the mutual electrochemical interaction between the anode and cathode.

[0011] The terms “anodic body ” and “cathodic body” mean electrically conductive parts of the anode and cathode that are electrically connected to the anode connector and cathode connector, respectively, and that are intended for mutual interaction during the charging or discharging process of the electrochemical cell. The terms “cathode active part” and “anode active part” mean coverings of the anodic body and cathodic body, respectively, that are intended for mutual electrochemical interaction during the charging or discharging process of the electrochemical cell.

[0012] The "cathodic active part” and the “anodic active part” are designed to induce an increase or decrease in the electrical charge in the anodic body and in the cathodic body depending on an increase or decrease in the ions accumulating on them during battery operation.

[0013] The expression "section" of the anodic body or cathodic body means a geometric figure obtained from the intersection of an imaginary plane with the anodic body or cathodic body where such plane intersects substantially perpendicularly, for example with an angle between 75° and 105°, a line defined by the geometric centers of gravity of the anodic body and the cathodic body or along which line they develop.

[0014] The “area" of the section of the anodic body or cathodic body means the area of the surface of the geometric figure defined by said section.

[0015] The expression "interpenetrated structure" or the adjective "interpenetrated" referring to the structure or to a part of the battery with respect to another part or other parts of the battery, means that the mutually interpenetrated parts each occupy an autonomous space of a volume of the battery.

[0016] Preferably, by interpenetrated structure, which is used in this text interchangeably with the expression “interlaced” or “interlaced structure”, it is meant that the parts of the battery that form the interpenetrated structure develop in space with continuity according to a linear, not necessarily rectilinear, or reticulated scheme that leaves a space free where a first of the parts that is interpenetrated or interlaced with a second of the parts occupies the space, or part of such space, that is free from the first.

[0017] The expression “interpenetrated” or “interlaced”, referring to the structure, or “interpenetrated” or “interlaced” referring to the parts that form such structure, in this text excludes that parts interfere spatially or that they intersect or penetrate each other; in other words, such expressions imply that the interpenetrated or interlaced parts are in any case physically mutually distanced and physically separated from each other in the volume affected by their “interpenetration” or their “interlacing”.

[0018] The applicant is now aware of the need to increase the specific energy density and improve the environmental compatibility of batteries by allowing the use of more efficient production techniques and / or the use of alternative materials and / or to allow greater recycling of batteries.

[0019] For example, lithium-ion batteries today represent one of the most promising technologies to meet the energy needs deriving from energy storage.

[0020] Especially in this sector, therefore, there is a need to optimize the energy density by reducing the amount of electrochemically inactive materials used in the production of such batteries.

[0021] The applicant is also aware that, in addition to the density of the active materials, the structure of the electrodes also plays a decisive role in the performance of electrochemical cells.

[0022] In particular, the thickness of the coating, the porosity and the active material loading of the coating are critical parameters in defining the energy performance of the electrochemical cell.

[0023] The applicant is aware of making a battery having the anodic body and the cathodic body that form two non-planar layers that develop according to mutually interpenetrating shapes between which a separator is placed.

[0024] The applicant has however observed that such known solutions have room for improvement especially with regard to the performances relating to the speed of accumulation and delivery of the charge.

[0025] SUMMARY OF THE INVENTION An electrochemical cell according to the present solution comprises

[0026] - an anode connector and a cathode connector;

[0027] - at least one anodic body extending from the anode connector towards the cathode connector;

[0028] - at least one cathodic body extending from the cathode connector towards the anode connector;

[0029] - an electrolyte medium placed between the anodic body and the cathodic body.

[0030] Geometrically, a development direction extends between the anode connector and the cathode connector.

[0031] According to an aspect of the present solution, the electrochemical ceil may comprise an operating portion in which the anodic body may have a section having a decreasing area along the development direction in a first direction of separation from the anode connector.

[0032] According to another aspect of the present solution, in the operative portion of the electrochemical cell the cathodic body can have a section having a decreasing area along the development direction in a second direction of separation from the cathode connector.

[0033] Structurally, according to an aspect of the present solution, the anodic body can have an anodic conductive part, electrically conductive, and electrically connected to the anode connector.

[0034] The cathodic body can have an electrically conductive cathodic conductive part and electrically connected to the cathode connector where - along the development direction

[0035] - in the first direction, the anodic conductive part has a section having a decreasing area and the cathodic conductive part has a section having an increasing area.

[0036] According to a further aspect of the present solution, the section area of the anodic conductive part, along the development direction, can vary spatially as a function of a foreseen or expected electric current, in use, in the anodic conductive part. In other words, the cross-sectional area of the anodic conductive part, along the development direction, can be sized as a function of a design electric current of the anodic conductive part, i.e. of a predefined electric current which, in use, is expected to flow in the anodic conductive part.

[0037] Differently stated, the cross-sectional area of the anodic conductive part may be variable, along the development direction of the anodic conductive part, depending on the amount of charge that, during use of the battery, is expected to flow inside the anodic conductive part itself.

[0038] According to another aspect of the present solution, the cross-sectional area of the cathodic conductive part may be sized according to a planned or expected electric current, in use, in the cathodic conductive part. In other words, the cross-sectional area of the cathodic conductive part, along the development direction, may be sized according to a design electric current of the cathodic conductive part, i.e. a predefined electric current that, in use, is expected to flow in the cathodic conductive part.

[0039] In other words, the cross-sectional area of the cathodic conductive part may be variable, along the development direction, depending on the amount of charge that, during charging or discharging of the battery, is expected to flow through it

[0040] In other words, the cathode and / or anodic conductive part may have a section that varies depending on the amount of charge expected to flow in that section during battery charging or discharging.

[0041] In particular, the section of the cathode and / or anodic conductive part may be increased where a greater amount of charge is expected to flow in that section during battery charging or discharging.

[0042] In other words, the cathodic conductive part and / or the anodic conductive part may be configured so as to have a greater electrical conductance in sections where, during battery charging or discharging, a greater flow of charge or intensity of flowing current is expected.

[0043] In this way, an electrolytic cell according to the present solution can have a cathodic conductive part and / or an anodic conductive part having an electrical conductance that gradually increases as the cathode connector and / or the anode connector are approached along the cathodic conductive part and / or along the anodic conductive part, respectively.

[0044] It is therefore clear how a battery according to the present solution allows, with the same overall capacity, to safely manage higher charging or discharging current flows compared to a traditional battery.

[0045] Therefore, an electrochemical cell according to the present solution has a high flexibility of construction while guaranteeing the ability to obtain high energy densities and increased charging and power delivery speed compared to traditional solutions.

[0046] An electrochemical cell according to the present solution allows for the creation of a permeated electrode conformation, independent of the shape and format of the ceil and guarantees a high scalability of the same.

[0047] The flexibility of shape of the electrodes of a cell according to the present solution is particularly suitable to be obtained by additive manufacturing, allowing a high level of customization of the shape and size of the battery with the same desired energy performance.

[0048] According to a further aspect of the present solution, the anodic body can have an active anodic part that covers the conductive anodic part and that is able to induce an accumulation of electric charge in the conductive anodic part following an ionic accumulation on it. The cathodic body may have a cathode active part that covers the cathodic conductive part and that is capable of inducing an accumulation of electric charge in the cathodic conductive part following an ionic accumulation on it.

[0049] The cross-sectional areas of the anodic active part and / or the cathode active part may vary while maintaining a constant stoichiometric ratio between a chemical composition of the cathodic active part and a chemical composition of the anodic active part.

[0050] Where the chemical compositions of the cathodic active part and of the anodic active part, during the operation of the electrolytic cell, are involved in an oxidation-reduction reaction functional to the operation of the battery.

[0051] In particular, the cross-sectional areas of the anodic active part and / or the cathode active part may vary along the development direction while maintaining a constant stoichiometric ratio.

[0052] In other words, the cross-sectional areas of the anodic active part and / or the cathodic active part can vary along the development direction depending on the amount of ionic contribution that - with respect to their chemical composition - they give to the oxidationreduction reaction that develops on their surface during the activity of the battery.

[0053] Differently stated, the anodic active part and / or the cathodic active part are configured in such a way that their capacity for ionic contribution to the chemical reaction that corresponds to the movement of electric charges in the anodic conductive part and in the cathodic conductive part, which they can respectively cover, is proportional to the flow of charges - i.e. the intensity of current - that develops in the anodic conductive part and in the cathodic conductive part during the charging and discharging of the battery.

[0054] Therefore, even more so, a battery according to the present solution allows to achieve better performances than the batteries known today with the same storage capacity and size. Furthermore, the distribution of the material constituting the anodic active part and the cathodic active part is optimized in a battery according to the present solution.

[0055] Indeed, the material constituting the anodic active part and the cathodic active part in a battery according to the present solution is distributed according to the ionic contribution required from it as a function of its position in the battery itself, i.e. with respect to the direction of development.

[0056] According to one aspect of the present solution, in the operating portion, at a height X along an operating direction that extends between the anode connector and the cathode connector, the electrochemical cell can have an electrode section whose overall area is given by the sum of a first area, not zero, and a second area, not zero, where:

[0057] - the first area is the area of the section of the anodic body at height X and

[0058] - the second area is the area of the section of the cathodic body at height X.

[0059] The value of the overall area of the electrode section can be constant along the operating direction as the height X varies so that - along the operating direction - an increase in the first area corresponds to a decrease in the second area and vice versa.

[0060] In this way, the use of the material used to make the anodic body and the cathodic body is particularly optimized, with respect to the charge flows that pass through them and to the involvement of their chemical components in the chemical reaction of the electrolytic cell, during its operation.

[0061] According to one aspect of the present solution, the electrochemical cell comprises an electrolyte medium and, in the operating portion, the anodic body can define a plurality of first interstices.

[0062] In the operating portion, the cathodic body can define a plurality of second interstices. Each interstice of the first interstices can be occupied by the electrolyte medium and by a portion of the cathodic body. Each interstice of the second interstices can be occupied by the electrolyte medium and by a portion of the anodic body .

[0063] This allows to obtain a highly efficient interpenetrated structure in optimizing the material constituting the anodic body , the cathodic body and the electrolyte medium, which preferably can be in a solid state.

[0064] Such an interpenetrated structure can especially be obtained by additive manufacturing or by three-dimensional additive printing.

[0065] A separator can be present in the interstices depending on contingent needs of implementing the present solution.

[0066] According to one aspect of the present solution, the electrolyte medium may comprise or consist of a liquid or gel electrolyte or a solid state electrolyte.

[0067] The electrolyte medium may, in particular, comprise an open-cell foam and a liquid electrolyte contained in the foam or in the cells thereof.

[0068] According to one aspect of the present solution, the anodic body may have a reticular shape, preferably extending in three spatial directions in a three-dimensional manner, and may comprise a first plurality of meshes arranged reciprocally to form a first lattice. This first lattice may define the first interstices into which the cathodic body may extend, an electrolyte medium may be present and possibly a separator depending on the contingent embodiment of the present solution.

[0069] The cathodic body may have a reticular shape and may comprise a second plurality of meshes arranged reciprocally to form a second lattice which may define the second interstices.

[0070] The first lattice and the second lattice can be interlaced with the first lattice engaging the second interstices and the second lattice engaging the first interstices.

[0071] The electrolyte medium and possibly a separator can be arranged to separate the first lattice and the second lattice. The first lattice and the second lattice can be configured in such a way that they are composed of branches so that each branch of the branches of the first lattice is surrounded by six branches of the second lattice, skewed with respect to it, likewise, each of the branches of the second lattice is surrounded by six branches of the first lattice, skewed with respect to it, coplanar to each other, as shown in the sectional view. The electrolyte medium can be in the solid state.

[0072] Thus, a battery according to the present solution can be easily obtained by additive manufacturing and can achieve high energy densities with a significant optimization of the materials constituting the anode and cathode bodies as well as the electrolyte medium.

[0073] According to a particular aspect of the present solution, each mesh of the first plurality of meshes and each mesh of the second plurality of meshes can have a tetragonal shape and the first meshes and the second meshes can be interlaced.

[0074] At least in the operating portion, the anodic body and the cathodic body may be intertwined with each other in such a way that mutual separation is prevented following a translation or rotation of the anodic body or of the cathodic body with respect to the other.

[0075] BRIEF DESCRIPTION OF THE DRAWINGS

[0076] The features and advantages of the present solution will be better understood from the detailed description of a preferred embodiment thereof, shown for illustrative and non- limitative purposes with reference to the attached drawings, in which:

[0077] - Figure 1 is a partial schematic and perspective view from above, not to scale, of an electrochemical cell according to the present solution;

[0078] - Figure 2 is a partial schematic and perspective view, not to scale, of a cathodic body and of an anodic body of an electrochemical cell according to the present solution; - Figure 3 is a partial schematic and plan view from above, not to scale, of an electrochemical cell according to the present solution;

[0079] - Figures 4a and 4b are simplified schematic views of sections of an operating part of an electrochemical cell according to the present invention.

[0080] DETAILED DESCRIPTION

[0081] Making reference to the cited figures, an electrochemical cell 1 according to the present solution comprises:

[0082] - an external anodic connector 20 and an external cathodic connector 30;

[0083] - at least one anodic body 21 extending from the anodic connector 20 towards the cathodic connector 30;

[0084] - at least one cathodic body 31 extending from the cathodic connector 30 towards the anode connector 20;

[0085] - an electrolyte medium, not shown in the attached figures 1-3, placed between the anodic body 21 and the cathodic body 31 .

[0086] In figures 1 , 2 and 3 an aspect of the electrolytic cell according to the present solution is exemplified in which the anodic body 21 has a reticular shape and comprises a first plurality of meshes 211 arranged reciprocally to form a first lattice and the cathodic body 31 has a reticular shape and comprises a second plurality of meshes 311 arranged reciprocally to form a second lattice.

[0087] For example, in figure 2 a portion of the anodic body 21 and a portion of the cathodic body 31 are shown separated from each other in order to better highlight their shape characteristics.

[0088] In each of these portions a sequence of meshes 211 and 311 , respectively, is shown.

[0089] In the non-limiting example of figures 1 to 3, the meshes 211 and 311 are tetragonal in shape. The meshes 211 and 311 that form the first lattice of the anodic body 21 and the second lattice of the cathodic body 31 are dimensionally corresponding so that they can be made, for example by additive manufacturing, in an interpenetrated or interlaced structure, for example as shown in figures 1 and 3.

[0090] According to one aspect, the first lattice and the second lattice are cubic lattices.

[0091] In the embodiment shown in the attached figures 1-3 by way of a non limiting example, the anodic body 21 has a section Sa with a decreasing area along its own development direction A in a first direction V1 of separation from the anode connector 20.

[0092] The development direction A extends between the anode connector 20 and the cathode connector 30.

[0093] Particularly in the example of the attached figures, it is possible to appreciate that the cathodic body 31 also has a section Sc with a decreasing area along its own development direction A in a second direction V2 of separation from the cathode connector 30.

[0094] With reference to the example schematized in figures 4a and 4b, the anodic body 21 has an electrically conductive anodic conductive part 211 , electrically connected to the anode connector 20, not shown in the figure, and an active anodic part 212 that covers the anodic conductive part 211 and is capable of inducing an accumulation of electrical charge in the anodic conductive part 211 following an ionic accumulation thereon.

[0095] The cathodic body 31 has a cathodic conductive part 311 which is electrically conductive and is electrically connected to the cathodic connector 30, not shown in figure 4a, and an active cathodic part 312 that covers the cathodic conductive part 311 and that is capable of inducing an accumulation of electrical charge in the cathodic conductive part 311 following an ionic accumulation thereon.

[0096] The active anodic part 212 and the active cathodic part 312 are configured to be involved in an oxidation-reduction reaction during the operation of the electrolytic cell for the storage of electrical energy, functional to the operation of the latter. Differently, the conductive anodic part 211 and the conductive cathodic part 311 are configured to transport an electronic current (therefore a flow of electrons) between the respective active anodic part 212 or cathodic part 312 and the respective anode connector 20 or cathodic connector 30, without participating in the chemical oxidation-reduction reaction that occurs during the normal operation of the electrolytic cell for the storage of electrical energy.

[0097] With particular reference to the diagrams shown by way of non limiting example in figures 4a and 4b, along the development direction A, in the first direction V1 , the anodic conductive part 211 has a section Sea with a decreasing area and the cathodic conductive part 311 has a section See with an increasing area, and vice versa in the direction V2. According to one aspect, the ratio between the areas of the anodic conductive part 211 and the cathodic conductive part 311 can remain constant along the various sections in the directions V1 and V2.

[0098] Figures 4a and 4b show an embodiment of the present solution in which the cathodic body 31 and the anodic body 21 are interdigitated so as to allow an easier appreciation of the structural characteristics of the electrochemical cell, compared to an interlaced structure; however, what is described for this embodiment is applicable mutatis mutandis to an interlaced structure of embodiments of the present solution.

[0099] It is exemplified in figures 4a and 4b that the cross-sectional areas of the cathodic conductive part 311 and of the anodic conductive part 211 along the development direction A can be sized as a function, respectively, of a predicted or expected electric current, in use, in the cathodic conductive part 311 or of a design electric current for the cathodic conductive part 311 and / or of a predicted or expected electric current, in use, in the anodic conductive part 211 or of a design electric current for the anodic conductive part 211. According to one aspect, the cross-sectional areas of the anodic conductive part 211 and of the cathodic conductive part 311 along the development direction A vary as a function of a foreseen design current that passes through these sections along the development direction A. A part of the current flow that passes through a generic section - for example of the anodic conductive part 211 - along the development direction A will still move in the anodic conductive part 211 , while another part will pass through the anodic active part 212, the electrolyte and the cathodic active layer, in the direction of their thickness, to reach the cathodic conductive part 311 and arrive along it up to the external cathodic connector (cathodic terminal). For this reason, the areas of the sections of the anodic conductive part 211 are conveniently larger the closer the sections are to the external anodic connector (anodic terminal) since, during operation, the current flowing through a first section along the development direction A of the anodic conductive part 211 closest to the anodic connector is greater than the current flowing through a second section along the development direction A of the anodic conductive part 211 furthest from the anodic connector.

[0100] According to one aspect illustrated in figures 4a and 4b, the sections along the development direction A of the anodic conductive part 21 1 (respectively, cathodic 311) are circular and have a decreasing radius the further the sections are from the anodic connector (respectively, cathodic). According to one aspect, the sections along the development direction A of the anodic conductive part 211 (respectively, cathodic 311) have a radius that for example decreases linearly the greater the distance of the section from the anodic connector (respectively, cathodic).

[0101] In the detail of the proposed examples, the cathodic body 31 has a cathodic active part 312 that covers the cathodic conductive part 311 capable of inducing an accumulation of electric charge in the cathodic conductive part 311 following an ionic accumulation on it. The cross-sectional areas Sa and Sc of the anodic active part 212 and the cathodic active part 312 along the development direction A, vary while maintaining constant the stoichiometric ratio between a chemical composition of the cathodic active part 312 and a chemical composition of the anodic active part 211.

[0102] The chemical compositions of the cathodic active part 312 and of the anodic active part 211 are involved in an oxidation-reduction reaction during the operation of the electrolytic cell, functional to the operation of the latter.

[0103] In the operating portion, at a height X along an operating direction that extends between the anode connector 20 and the cathode connector 30, the electrochemical cell 1 has an electrode section S whose overall area is given by the sum of a first non-zero area and a second non-zero area, wherein:

[0104] - the first area is the area of the section Sa of the anodic body 21 at height X and

[0105] - the second area is the area of the section Sc of the cathodic body 31 at height X.

[0106] At height X, we have S=Sa+Sc.

[0107] According to one aspect of the present solution, the value of the overall area of the electrode section S is constant along the operating direction as the height X varies.

[0108] In other words, at two heights X1 and X2 -not illustrated in the attached figures- we have S=(Sa+Sc)|x2=(Sa+Sc)|xi.

[0109] An electrolyte medium is present between the cathodic body 31 and the anodic body 21 and in the operating portion 10, the anodic body 21 defines a plurality of first interstices 11 and the cathodic body 31 defines a plurality of second interstices I2, and wherein each interstice of the first interstices 11 is occupied by the electrolyte medium and a portion of the cathodic body 31 and each interstice of the second interstices I2 is occupied by the electrolyte medium and a portion of the anodic body 21.

[0110] The electrolyte medium comprises or is constituted by an electrolyte liquid or gel or by a solid state electrolyte. In a possible embodiment of the present solution, the electrolyte medium comprises an open-cell foam and an electrolyte liquid that soaks the foam, for example contained in the open cells.

[0111] In particular, between the anodic body 21 and the cathodic body 31 there may be an open-cell insulating micro-grid 40 capable of accommodating a liquid electrolyte medium or, preferably, a solid-state or gel electrolyte.

[0112] According to an aspect illustrated in figure 4b, the shape of the electrolytic layer 40 (which for example can be an insulating micro-grid or a permeable material to be soaked with liquid electrolyte, or alternatively with solid state electrolyte) in the plane of a generic section along the development direction A at a generic height X will not be the same in all areas of the cell, but this shape will change with the height X depending on the areas of the sections of the anodic conductive part 211 and the cathodic conductive part 311 : indeed it constitutes a boundary layer between the active anodic and cathodic parts, whose sections have different shapes in different areas as a consequence of the different respective conductive substrates. According to an aspect illustrated in figure 4b, the shape of the insulating micro-grid 40 will be square in correspondence with the section B or B1 in which the radii of the anodic conductive part 211 and of the cathodic conductive part 311 are equal.

[0113] According to an aspect illustrated in figure 4b, in the plane of a generic section C along the development direction in which the radius of the anodic conductive part 211 is different from the radius of the cathodic conductive part 311 , the insulating micro-grid 40 will define a closed concave star shape with four cusps arranged in a cross and oriented radially with respect to that anodic conductive part 211 or cathodic part 311 of smaller radius.

[0114] According to one aspect illustrated in figure 4b, in the plane of a generic section A along the development direction in which the radius of the anodic conductive part 211 is different from the radius of the cathodic conductive part 311 , the insulating micro-grid 40 will define a closed convex shape centered with respect to either the anodic conductive part 211 or cathodic part 311 that has the greatest radius.

[0115] As illustrated in figures 4a and 4b, the shape of the insulating micro-grid 40 in a section at the generic level X along the development direction A changes continuously as the level X varies from a closed convex shape centered with respect to the anodic conductive part 211 (section A), to a square (section B, B1). According to an aspect illustrated in figure 4b, in the plane of a generic section C along the development direction in which the radius of the anodic conductive part 211 is different from the radius of the cathodic conductive part 311 , the insulating micro-grid 40 will define a closed concave star shape with four cusps arranged in a cross.

[0116] According to one aspect, such different closed shapes can be described by a parametric equation of the Cartesian variables (x,y) of a two-dimensional space, such as (but not necessarily) in the case of the so-called Lame curve or superellipse, in which by varying the parameter of the parametric equation a closed curve is obtained that varies continuously in the manner indicated above. Conveniently, such parameter of the parametric equation will vary continuously depending on the elevation X of the generic section along the development direction A.

[0117] By defining the shape of the micro-grid in a section at a generic height X, the surface area of the section surrounded by the shape itself, and therefore the area of the section of the active anodic part 212 and of the active cathodic part 312, is also determined.

[0118] As illustrated by way of non limiting example in figure 1 , at least in the operating portion, the anodic body 21 and the cathodic body 31 are intertwined with each other in such a way that mutual separation is prevented following a translation or rotation of the anodic body 21 or the cathodic body 31 with respect to the other, so as to obtain an interlaced or interpenetrated structure, that can have the anodic body 21 and / or the cathodic body 31 , the possible solid electrolyte medium and the possible separator, made through an additive manufacturing process.

[0119] With particular reference to figure 4b, three section diagrams of the battery sector boxed in a dotted line in figure 4a are shown, respectively carried out according to the section lines A, B and C of figure 4a.

[0120] In particular, the sections Sa and Sc of the anodic body 21 and the cathodic body 31 respectively, in sections A, B and C are configured according to a sizing criterion aimed at obtaining an equi-volume or an equi-stoichiometric ratio between the two electrodes. In the alternative B1 of section B, a variant is shown in which, instead, the sizing criterion was directed to obtain an equi-thickness between the two electrodes.

[0121] It is therefore clear how the present solution achieves the task and the intended purposes.

[0122] The implementation of the present solution, in fact, allows to optimize the use of space and materials, in particular of electrically conductive material, compared to the conventional production of electrodes, allowing to achieve higher energy densities compared to traditional batteries.

[0123] A battery according to the present solution is achievable, for example through three- dimensional printing technologies, optimizing the energy performance of the battery allowing to selectively adjust the thickness of the electrodes, create layers through multiple printing and allowing to obtain good properties in terms of spatial configuration, ionic and electronic conductivity.

[0124] A battery according to this solution, moreover, can be made with high definition 3D inkjet printing allowing to obtain the particular microstructures described above that are optimized from an electrochemical point of view, at the same time allowing to obtain through a single production phase an already complete and sealed electrochemical cell, starting from the individual materials in liquid form. This solution also allows to significantly increase the production logistics of electrochemical cells for example by providing a honeycomb arrangement that could in fact significantly reduce the volume of the production plant.

Claims

CLAIMS1. An electrochemical cell (1) for the storage of electric energy, comprising- an anodic connector (20) and a cathodic connector (30);- at least one anodic body (21) extending from the anodic connector (20) towards the cathodic connector (30);- at least one cathodic body (31) extending from the cathodic connector (30) towards the anodic connector (20);- an electrolyte medium placed between the anodic body (21) and the cathodic body (31); the electrochemical cell (1) includes an operative portion (10) wherein: the anodic body (21) has a section with a decreasing area along a development direction in a first direction (V1) of separation from the anodic connector (20); wherein the development direction extends between the anodic connector (20) and the cathodic connector (30); the cathodic body (31) has a section with a decreasing area along the development direction in a second direction (V2) of separation from the cathodic connector (30); wherein the anodic body (21) has an anodic conductive part (211) capable of conducting an electric current, and electrically connected to the anodic connector (20), wherein said anodic conductive part (211) has a section having a decreasing area along said development direction in the first direction (V1) of separation from the anodic connector (20); wherein the cathodic body (31) has a cathodic conductive part (311) capable of conducting an electric current and electrically connected to the cathodic connector (30), wherein said cathodic conductive part (311) has a section having an area decreasing along said development direction in the second direction (V2) of separation from the cathodic connector (30); wherein the anodic body (21) has an anodic active part (212) which covers the anodicconductive part (211) suitable for inducing an accumulation of electric charge in the anodic conductive part (211) following an ionic accumulation thereon; wherein the cathodic body (31) has an active cathodic part (312) which covers the cathodic conductive part (311) suitable for inducing an accumulation of electric charge in the cathodic conductive part (311) following an ionic accumulation thereon; wherein said active anodic part (212) and said active cathodic part (312) are configured to be involved in an oxidation-reduction reaction during a functioning of the electrolytic cell, functional to the operation of the electrolytic cell itself; wherein said anodic conductive part (211) is configured to conduct an electronic current between the anodic active part (212) and the anodic connector (20) without participating in the oxidation-reduction chemical reaction of the electrolytic cell; wherein said cathodic conductive part (311) is configured to conduct an electronic current between the cathodic active part (312) and the cathodic connector (30) without participating in the chemical oxidation-reduction reaction of the electrolytic cell.

2. The electrochemical cell (1) according to claim 1 , wherein an area of a section of said areas of sections of the anodic conductive part (211) along the development direction, varies spatially along the development direction as a function of a predicted or expected electric current, in use, in the anodic conductive part (211) in said section of the anodic conductive part (211) and / or of a design electric current of the anodic conductive part (311) in said section of the anodic conductive part (211), said electric current in said section of the anodic conductive part (211) being given by a sum between an electric current entering the anodic conductive part (211) from edges of said section of the anodic conductive part (211) and an electric current flowing through the anodic conductive part (211) through said section of the anodic conductive part (211) along said development direction, and an area of a section of said areas of sections of the cathodic conductive part (311) along the development direction varies spatially along the directionof development as a function of a predicted or expected electric current, in use, in the cathodic conductive part (311) in said section of the cathodic conductive part (311) and / or of a design electric current of the cathodic conductive part (311) in said section of the cathodic conductive part (311).

3. The electrochemical cell (1) according to one of the previous claims, wherein said electric current in said section of the cathodic conductive part (311) is given by a sum between an electric current entering the cathodic conductive part (311) from edges of said section of the cathodic conductive part (311) and an electric current flowing through the cathodic conductive part (311) through said section of the cathodic conductive part (311) along said development direction.

4. The electrochemical cell (1) according to one of the previous claims, wherein said areas of sections of the anodic active part (212) and of the cathodic active part (312) along the development direction, vary while maintaining constant the stoichiometric ratio between a chemical composition of the cathodic active part (312) and a chemical composition of the anodic active part (211); wherein said chemical compositions are involved in an oxidation-reduction reaction during the operation of the electrolytic cell, functional to the operation of the latter.

5. The electrochemical cell (1) according to one of the preceding claims, wherein in the operative portion (10), at a height X along an operative direction which extends between the anodic connector (20) and the cathodic connector (30), the electrochemical cell (1) has an electrode section whose overall area is given by the sum of a first nonzero area and a second non-zero area wherein:- the first area is the area of the section of the anodic body (21) at said height X and- the second area is the area of the section of the cathodic body (31) in said height X; wherein the value of the overall area of the electrode section is constant along theoperative direction as the height X varies.

6. The electrochemical cell (1) according to any of the previous claims, which comprises an electrolyte medium and wherein, in the operative portion (10), the anodic body (21) defines a plurality of first interstices and the cathodic body (31) defines a plurality of second interstices, and wherein each interstice of the first interstices is occupied by the electrolyte medium and by a portion of the cathodic body (31) and each interstice of the second interstices is occupied by the electrolyte medium and by a portion of the anodic body (21).

7. The electrochemical cell (1) according to the previous claim, wherein the electrolyte medium comprises or consists of a electrolyte liquid or gel or of a solid state electrolyte.

8. The electrochemical cell (1) according to the previous claim, wherein the electrolyte medium comprises an open cell foam and an electrolyte liquid which imbibes the open cell foam.

9. The electrochemical cell (1) according to any one of the previous claims, wherein the anodic body (21) has a reticular shape and includes a first plurality of meshes mutually arranged to form a first lattice and the cathodic body (21) has a reticular shape and includes a second plurality of meshes arranged reciprocally to form a second lattice.

10. The electrochemical cell (1) according to any one of the preceding claims, wherein each mesh of the first plurality of meshes and each mesh of said second plurality of meshes has a tetragonal shape.

11. The electrochemical cell (1) according to any of the previous claims, wherein at least in the operative portion, the anodic body (21) and the cathodic body (31) are intertwined with each other in such a way that mutual separation is prevented following a translation or rotation of the anodic body (21) or of the cathodic body (31), with respect to the other, the anodic body (21) and the cathodic body (31).

12. The electrochemical cell (1) according to any one of the preceding claims, wherein each of the anodic body (21) and of the cathodic body (31) is made by an additive manufacturing process.

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