Battery cell structure and method for manufacturing a battery cell structure

Abstract

A battery cell structure (101, 201, 202) comprising a stack of at least : a first electrically insulating substrate (3), a cathode current collector (15), the first insulating substrate (3) being provided over the cathode current collector (15), a cathode active material layer (13), an electrolyte layer (9), a separator (7), an anode active material layer (17), an anode current collector (19), a second electrically insulating substrate (5) provided over the anode current collector (19). The stack is provided with at least one recess (33, 35, 37, 605) formed by a direct physical contact between the first electrically insulating substrate (3) and the second electrically insulating substrate (5) in at least one region of the stack. Alternatively, the stack is provided with at least one recess (33, 35, 37, 605) formed by a bonding of the first electrically insulating substrate (3) and the second electrically insulating substrate (5) by means of a bonding material (36).

Description

[0001] Battery cell structure and method for manufacturing a battery cell structure

[0002] Field of the Disclosure

[0003] The present disclosure relates to a battery cell structure, a battery cell and a method for forming such a battery cell structure. In particular, the present disclosure concerns the predominantly printed primary batteries. Some embodiments of the present disclosure also relate to a battery cell structure employing smart card technologies.

[0004] Technological Background

[0005] Batteries in a stack configuration have higher energy density, higher power density and longer service life than for example a battery in a co-planar or in a serial connection configuration. Due to these performances, batteries in a stack configuration are widely used in electric vehicles, smartphones, laptops and many other electronic devices.

[0006] In a typical stack configuration, wide layers or plates are stacked. This stack notably comprises a cathode layer, a cathode current collector layer, an anode layer, an anode current collector layer, electrolytes layers and a separator layer.

[0007] In many applications like smart Label or medical devices, a thickness limitation exists. To achieve a certain capacity of the battery that depends on the amount of active material confined within a limited thickness, in particular thicknesses comprised between 0.1 millimeter to 5 millimeters, a compensation by an increased cell area is necessary. However, larger area batteries are critical since the stack of layers is only held by the edge lamination. Thus, in case of torsion, deformation or bending forces, larger area batteries are subject to partial or total delamination of the layers of the stack. This leads to an increased impedance, a reduced electrical capacity of the battery and thus, to a reduced lifetime.

[0008] Summary of the Disclosure

[0009] The present invention aims to reduce and at least to partially resolve the above-mentioned problems and issues by providing a stacked battery cell structure that reduces the effects of bending forces on the battery cell. The aims of the invention are achieved by a first aspect of the present disclosure. The first aspect of the present disclosure provides a battery cell structure.

[0010] In the illustrative embodiments of the first aspect, the battery cell structure comprises a stack of at least: a first electrically insulating substrate, a cathode current collector, the first insulating substrate being provided over the cathode current collector, a cathode active material layer, an electrolyte layer, a separator, an anode active material layer, an anode current collector, a second electrically insulating substrate provided over the anode current collector. And the stack is either:

[0011] - provided with at least one recess formed by a direct physical contact between the first electrically insulating substrate and the second electrically insulating substrate in at least one region of the stack, or

[0012] - alternatively, the stack is provided with at least one recess formed by a bonding of the first electrically insulating substrate and the second electrically insulating substrate by means of a bonding material.

[0013] A battery device comprising the battery cell structure as described above provides the advantage to focus, divert and dissipate the bending and elastic deformation forces on the recesses during bending of the battery.

[0014] The invention provides the further advantage to increase the adhesion of the layers of the stack, stabilizing the layers of the stack. As a result, the cell structure integrity of the battery and the resistance to torsion, deformation or bending forces is increased. The invention permits to decrease the effect of the bending forces on the battery, as for example, delamination between the layers of the stack. Therefore, the electrical performances and the lifetime of the battery are increased

[0015] In various aspects of the present disclosure, the battery cell structure may comprise a housing, in particular the housing may be an electrically insulating substrate. The housing may be subjected to a final sealing process after having performed a one-time filling of the battery cell such that the housing is eventually sealed and no absorbing material is exposed to an outside of the housing. However, this does not impose any limitation and the battery cell structure may be periodically, temporarily or permanently contacting electrolyte reservoir(s).

[0016] The battery cell structure may be further improved according to various advantageous embodiments. The various embodiments of the invention may not be understood as being limitative. Any one or more of the features an embodiment the present invention may be combined with any one or more features of another embodiment of the present invention.

[0017] In various aspects of the present disclosure, a battery cell structure and a battery cell having at least two such battery cell structures are provided. Herein, the battery cell structure has a sequence of patterned or unpatterned sheets or rolls of thermoplastics (e.g., PVC, PC, PLA, PS, PET, or similar) which are laminated together into a laminated structure, cavities provided within the sheets being filled with redox active materials to form the battery cell structure. Herein, individual layers of the sequence of sheets may have predefined functionalities, for example outer layers having etched or printed or wire embedded contacts, current collectors, interior layers interposed between outer layers having and / or acting as a membrane. Some layers may be redox active layers comprising redox active composites or materials so as to form battery half cells and, when combined into the laminated structure, the full battery cell structure functioning as a battery cell is provided.

[0018] A chemistry for the battery cell structure may depend on the intended use and requirements for the battery cell structure, e.g., use as primary or secondary cells. For example, the chemistry may be determined by Leclanche, alkaline, Ag2<3, Lilon, LiPolymer etc... The redox active materials can be either dispensed during fabrication of the battery cell structure in a respective receptacle formed by a respective cavity in a layer provided on another layer closing the cavity on one side, e.g., the redox active material being provided as a slurry. Alternatively, the redox active material may be inserted into a cavity when provided as a prepatterned film adapted for insertion into the cavity or receptacle, or it may be laminated as a prepatterned film or printed onto an outer layer. Furthermore, half cells in the battery cell structure may be separated by a membrane for only allowing conductive ions passing among the half cells in the battery cell structure. Ideally, the membrane may be laminated to the receptacles and is chemically inert to electrolyte material in the battery cell structure, where the electrolyte may be applied onto the membrane by dispensing and / or it may be of a gel type to prevent unintentional leakage. For example, wires of the current collectors may be bare wires or coated with different metals (e.g., Sn, Ag, Ni, Au, bi or ternary alloys, or alloys comprising at least one of these listed metals) before embedding into the outer layers to increase chemical resistance to the anode and cathode materials or for injection reasons. The laminated structure may be obtained by pressing (hot or cold) during lamination. The process for fabricating the battery cell structure may employ smart card manufacturing processes.

[0019] The present disclosure provides for substrates which may be provided in accordance with smart card technologies (e.g., lamination, cutouts, hot embossing, milling, wire embedding, etc.), therefore these substrates being compatible with smart card techniques and battery cell structures fabricated on the basis of these substrates being compatible with smart card technologies. On the other hand, advantages of smart card fabrication techniques may be employed in the fabrication of battery cells such that battery cells may be fabricated with high fabrication volume and under high reproducibility. Furthermore, very flat or planar battery cells may be provided, e.g., planar and / or flexible battery cells, and / or battery cells may be easily integrated into the fabrication of smart cards such that it becomes possible to integrate battery cells into a smart card and equip a smart card with one or more battery cells as part of a card body of the smart card. In other words, the battery cell(s) may be part of prelam and / or card body structures without having to integrate a prefabricated battery cell as a module of a smart card into the card body of the smart card. Thereby, constraints imposed by smart card technologies onto a configuration of a battery cell are avoided as the battery cell is quite naturally embedded into smart card fabrication because of representing a smart card technology element.

[0020] In the illustrative embodiments of the first aspect, optionally at least one of the cathode current collector and the anode current collector may comprise a wire routing embedded into or onto the electrically insulating substrate, the wire routing having a space filling routing portion over a respective active material in which a wire routing is routed in a shape of a space filling curve.

[0021] Cathode and / or anode current collector comprising a wire routing embedded into or onto the electrically insulating substrate as described above allow the effective extraction of the charge carriers out of the respective active materials with low resistance due to the high conductivity of the wires. Wires can be made of pure metals like Co, Ni, Ag or other metals or copper plated with corrosion-inhibiting materials like Ni, Au or other combinations. It also permits to design patterns of the stack repartition adapted to the battery cell structure for optimal mechanical and electrical performances. The use of embedded wires for as current collectors requires less material and is thus less expensive. The use of embedded wires for current collectors also needs less processing time. Wire embedding is a simpler process. Solderability of the wires allows decreasing manufacturing complexity and manufacture costs, in particular of assembly with standard Printed Circuit Board Assembly (PCBA) technology.

[0022] Herein, wire embedding into or onto the electrically insulating substrate is understood as representing a wire at most partially embedded into the electrically insulating substrate or routed on a surface of the substrate by fixing the wire to the surface. Notably, the wire is fixed to the surface in such a way that the wire is arranged on the surface, e.g., by ultrasonic excitation (with pressure and / or adhesion and the like for achieving mechanical attachment of the wire to the surface. In particular, the wire may be partially buried into the surface. For example, the wire may be buried at 50 percent into the surface of the electrically insulating substrate. Wire embedding into the insulating substrate may be understood as inserting a wire into one or more grooves formed in the surface of the electrically insulating substrate. Alternatively, wire embedding into the insulating substrate may be understood as partially burying the wire into the material of the substrate, e.g., by employing local heat to the substrate such that the material of the substrate locally melts and the wire is partially buried into the substrate. The local heat may be, for example, generated by ultrasonic excitation. The current collector wire is bonded onto or into the substrate by ultrasonic excitation heating in the desired shape and pattern. The wire may be formed of copper (Cu) or aluminum (Al) and others, usually pure metals or allows are used. The wire may be coated with at least one of tin (Sn), silver (Ag), nickel (Ni), gold (Au), and bi or ternary alloys. Alternatively, the wire may be uncoated. A coated wire may represent a wire which is so as to increase chemical resistance of the wire to the anode and cathode active materials, while using an uncoated wire may decrease fabrication and product costs and result in easier fabrication.

[0023] After wire embedding, wires may be coated with a material, like for example carbon. The coating may be obtained by printing the material onto the wires. This coating may permit to increase the conductivity and efficiency of the current collectors.

[0024] An active material is understood as a material being capable of undergoing electrochemical oxidation or reduction and delivering electrical charges in the anode or cathode. Preferably, the active material of the anode (or active anode material) is selected with at least one property of efficiency as a reducing agent, high Coulombic output (Ah / g), good conductivity, stability, ease of fabrication, and low cost in mind. In special illustrative examples, the active anode material may comprise metals such as Zinc (Zn) or Lithium (Li) or Magnesium (Mg). Furthermore, the active material of the cathode (or active cathode material) is an efficient oxidizing agent, preferably stable when in contact with the electrolyte and having the combination of the materials providing an open circuit voltage high enough to operate electronic circuits. Although Oxygen can be used directly from ambient air when drawn into the cell as in a zinc / air battery, common active cathode materials are metallic oxides or halogens and oxyhalides or sulfur and its oxides.

[0025] In the illustrative embodiments of the first aspect, at least one of the cathode current collector and the anode current collector may optionally comprise an electrode cladded onto the electrically insulating substrate bound by the roughness of the substrate and metal or by using an special adhesive. The current collectors may be partially exposed in the electrically insulating substrate for allowing physical contacting by material(s) arranged on the current collectors, e.g., active material.

[0026] The electrode cladded onto the electrically insulating substrate permits to overcome issues related to conventional battery cells having current collectors made of Ag-paste. It also overcomes any limitations imposed by the conventional current collectors. Standard PCBA manufacturing equipment can be used to manufacture the assembly. Furthermore, costs are reduced in avoiding current collectors made of silver. Also, the electrical conductivity may be increased upon using a material for current collectors having better electrical conductivity than silver. Accordingly, a battery cell structure with low impedance (inner resistance) with high peak current capability is provided at low fabrication cost and with simplified fabrication processes.

[0027] Furthermore, an electrode cladded onto the electrically insulating substrate is understood as attaching a current collector material onto the electrically insulating substrate. Attaching the conductive material (e.g. copper) may be followed by patterning it to a desired shape. Patterning may be notably performed by continuous lithographic methods. The desired shape representing at least partly a target shape of the current collector in the battery cell structure.

[0028] In the illustrative embodiments of the first aspect, the battery cell structure may be provided with a plurality of recesses.

[0029] A battery cell provided with a plurality of recesses reduces the stress on the stack by enhancing the dissipation of the bending forces. It also permits to reduce the size of the layers of the stack between two recesses. In particular, the total surface of each layer of the stack is reduced because of the presence of the plurality of recesses, resulting in a reduction of the delamination of the layers of the stack, which improves the lifetime and the electrical performances of the battery cell. Notably, the plurality of recesses permits to avoid the negative effects of the torsion, deformation and bending wherever it is applied on the battery cell.

[0030] Depending on the size of a battery comprising the battery cell structure according to the invention, the battery may have a different number of recesses. In particular, the battery may be provided with only one recess. The surface density of recess of a battery notably depends, for example, on the substrate material, size, required bending radius, material and application. Preferably, the recess density may be comprised between 0,005 recess per square centimeter and 0,25 recess per square centimeter. High recess densities may lead in too high capacity losses due to decrease of the total active battery area. Low recess densities may lead to stability issues of the battery cell.

[0031] In the illustrative embodiments of the first aspect, the recesses of the plurality of recesses may be at least partially aligned along one direction, in particular along two distinct directions, more in particular along two directions perpendicular to one another. Directions along which the recesses are aligned are to be taken parallel to the plane defined by the surface of the stack. The recesses are orthogonal to this said plane.

[0032] Having recesses at least partially aligned along one direction permits to better divert the bending forces in case of torsion or deformation of the battery cell. Indeed, it guides the bending of the battery cell along the direction of alignment of the recesses. Consequently, it permits to increase the dissipation of the negative bending effects. Increasing the number of different alignment directions of the recesses permits to better dissipate the bending forces. Especially, when a torsion or deformation in several directions are applied on the battery cell, in particular in different locations of the battery cell, having several alignment directions of the recesses permits to better avoid delamination of the layers of the stack. Thus, it permits to improve the lifetime and electrical performances of the battery cell.

[0033] Moreover, in alternative embodiments of the first aspect of the invention, the stack of the battery cell may comprise only one recess. It may also comprise a plurality of recesses. In particular, the plurality of recesses may be disposed following certain patterns. For example, the recesses may be disposed so as to form a grid, or concentric circles, or any other pattern.

[0034] In the illustrative embodiments of the first aspect, a cross-section parallel to the layers of the stack of the at least one recess may be substantially circular, oval or oblong.

[0035] To have a cross-section parallel to the layers of the stack of the at least one recess substantially circular, oval or oblong permits to increase the dissipation of the negative bending effects, which also allows to reduce manufacturing complexity, thus reducing the manufacturing costs

[0036] In the illustrative embodiments of the first aspect, a cross-section parallel to the layers of the stack of the at least one recess may be substantially rectangular. In particular, the cross-section may be a square.

[0037] A cross-section parallel to the layers of the stack of the at least one recess substantially rectangular permits to increase the dissipation of the negative bending effects, which also allows to reduce manufacturing complexity, thus reducing the manufacturing costs.

[0038] In the illustrative embodiments of the first aspect, a cross-section parallel to the layers of the stack of the at least one recess is substantially cross-shaped. In particular, the cross shape of recess may be formed with walls that have ninety degrees angles between two consecutive walls. Alternatively, the walls of the cross shape of the recess may be curved. In particular, the curves may be quarters of circle arcs.

[0039] A cross-section parallel to the layers of the stack of the at least one recess substantially crossshaped permits to increase the flexibility of the battery cell. It permits the dissipation of the bending forces, which are the cause of the delamination of the layers of the stack. This results in an increase of the sealing forces that keep the integrity of the stack. Consequently, it keeps the layers of the stack laminated and connected between one another. Indeed, it permits to facilitate the torsion of the battery cell in two directions. In the illustrative embodiments of the first aspect, a dimension of a cross-section of the at least one recess decreases along a direction extended towards the direct physical contact between the first electrically insulating substrate and the second electrically insulating substrate.

[0040] To have a cross-section parallel to the layers of the stack of the at least one recess decreasing along a direction extended towards the direct physical contact between the first electrically insulating substrate and the second electrically insulating substrate permits to simplify the manufacturing of the recesses.

[0041] In the illustrative embodiments of the first aspect, one or more of the at least one recess provided in the stack may be filled with a material. In particular, the recess may be filled with a hot melt adhesive material, more particularly polyurethane, or polyacrylate, or temperature activated epoxy systems.

[0042] To fill the recess with a material permits to keep the integrity of the stack during use or bending of the device. Indeed, it locally seals the stack. It permits to strengthen the lamination and connection between the layers of the stack. Thus, it permits to avoid delamination of the layers of the stack. It therefore improves the lifetime and electrical performances of the battery cell.

[0043] In the illustrative embodiments of the first aspect, each current collector may be covered by a carbon comprising material or a conductive material not being redox active relative to overlying the active materials.

[0044] Herein, the conductive material not being redox active relative to the overlying active material may be understood as a material of an electrode potential in the galvanic series higher than an electrode potential of the uncoated wire in the galvanic series such that the wire may be accordingly passivated by such a coating. It may also concern cladded current collectors. Thus, it permits to avoid a decrease of the electrical performances and efficiency of the battery cell. Additionally or alternatively, the wire may be coated by a material of higher electrical conductivity compared to aluminum and / or copper such that an internal electrical resistance of the battery cell structure may be reduced. The material may be in particular carbon.

[0045] In the illustrative embodiments of the first aspect, the anode active material layer may be made of a material comprising Zn, or Mg or Al.

[0046] The anode active material layer may be made of a material comprising Zn, or Mg or Al. The redox couple of the anode material defines the potential of the anodic part of the cell battery structure. The metal may be in the form of a solid layer or as grains in a printable paste. The metallic nature of the anode provides low resistance and low ohmic losses in the cell. In the illustrative embodiments of the first aspect, the cathode active material layer may be made of a material comprising MnC>2.

[0047] The cathode active material layer may be made of a material comprising MnC>2 defining the potential of the cathodic part of the cell. Cathode made of a material comprising MnC>2 permits to decrease costs and provide a better battery stability. In particular, it increases thermal stability.

[0048] In the illustrative embodiments of the first aspect, the cathode current collector and / or the anode current collector may be made of metal or carbon or coated with metal.

[0049] In the illustrative embodiments of the first aspect, the first and / or the second electrically insulating substrate may be made of PVC, PC, PET or PS or similar.

[0050] In the illustrative embodiments of the first aspect, the electrically insulating substrate may be a monolithic substrate or the electrically insulating substrate may be coated to at least one other substrate, e.g., a carrier substrate and / or a handle substrate, supporting the substrate at least during fabrication, possibly in a final product. In case of the electrically insulating substrate being coated to at least one other substrate, the electrically insulating substrate may be of a material softer than the at least one other substrate. Alternatively, the electrically insulating substrate may be coated with a hot-melt material as disclosed herein, the disclosure of which is incorporated by reference in its entirety. Accordingly, current collector(s) may be easily embedded into the substrate and at least one other substrate may be easily equipped with the current collector(s) via attaching the electrically insulating substrate with embedded current collector(s) to the at least one other substrate.

[0051] Moreover, electrically insulating substrate made of PVC, PC, PET or PS permits to us hot- lamination process without using a supplementary bonding and / or adhesive material disposed between the two electrically insulating substrates layers to be bonded. The hot-lamination process may be used for laminating the layers of the stack and / or for creating the recesses of the battery cell structure.

[0052] In the illustrative embodiments of the first aspect, the separator layer may be made of a membrane or a fiber-based material comprising an ion-conducting liquid or gel forming an electrolyte source for the ionic conduction path of the battery.

[0053] Having a separator layer comprising hydrogels, gels or liquid acting as electrolyte source, permits to counterforce the force applied to the layers by the delamination. In particular, the gels and hydrogels may be compressible gels and hydrogels storing electrolyte. The separator layer separates the active material layers from each other. The use of a separator layer comprising a liquid, gel or hydrogel increases the flexibility of the separator layer. Thus, it also increases the flexibility of the battery cell structure. The hydrogel or the gel can be made of Polyacrylic acid or comparable materials. The hydrogel or the gel can be made of particles or as a crosslinked patterned layer.

[0054] The electrolyte layer comprises an electrolyte preferably having good ionic conductivity without being electronically conductive (as this would cause internal short-circuiting). The electrolyte is nonreactive with active materials besides the exchange of charges and preferably has little change in properties with change in temperature. Often, electrolytes are aqueous solutions, but there may be solid electrolytes or gel form electrolytes. As described above, the anode and cathode are physically isolated in the cell to prevent internal short-circuiting, but are surrounded by the electrolyte.

[0055] In the illustrative embodiments of the first aspect, the wire routing of the anode current collector may be formed of a copper or aluminum or nickel wire. The wire routing of the cathode current collector may also be formed of a copper or aluminum wire or a nickel wire coated with carbon. The copper or aluminum or nickel wire of the anode current collector may be partially exposed to the anode active material layer. The copper or aluminum wire of the cathode current collector may be covered by a metal material of an electrode potential in the galvanic series higher than an electrode potential of copper in the galvanic series. The copper or aluminum wire of the anode current collector may be covered by a metal material of an electrode potential in the galvanic series lower than an electrode potential of copper in the galvanic series.

[0056] In a second aspect of the present disclosure, a method for forming a battery cell structure is provided. In the illustrative embodiments herein, the method comprises a step for forming a stack of at least a first electrically insulating substrate, a cathode current collector, the first insulating substrate being provided over the cathode current collector, a cathode active material layer, an electrolyte layer, a separator, an anode active material layer, an anode current collector, a second electrically insulating substrate provided over the anode current collector, and a step for providing the stack with at least one recess either formed by a direct physical contact between the first electrically insulating substrate and the second electrically insulating substrate. Or, alternatively, during the step for providing the stack with at least one recess, the recess is formed by a bonding of the first electrically insulating substrate and the second electrically insulating substrate by means of a bonding material.

[0057] In the illustrative embodiments of the second aspect herein, the method may comprise providing an electrically insulating substrate with at least two wire routing portions embedded into or onto a main surface of the electrically insulating substrate or cladded onto the electrically insulating substrate. The at least two wire routing portions each having a space filling curve-shaped routing portion. The method may further comprise a step of printing a first active material having a first electrode potential in the galvanic series on a first wire routing portion of the at least two wire routing portions. The method may also comprise a step of printing a second active material having a different second electrode potential in the galvanic series on a second wire routing portion of the at least two wire routing portions embedded into the main surface of the electrically insulating substrate or embedded into a main surface of another electrically insulating substrate. The method may also comprise a step of printing an electrolyte layer over at least one of the first and second active materials. The method may also comprise a step for providing the stack with at least one recess. In particular, the step for providing the recess may use hot-lamination process.

[0058] The recesses may be manufactured during a patterning process. To do so, areas are left blank, i.e. with no active material nor metal. Then, either the electrically insulating substrates are directly laminated or an adhesive is applied locally, between electrically insulating substrates, for bonding. In particular, when the electrically insulating substrates are made of PVC, PC, PLA, PS, the recess is formed due to the pressure lamination process. Otherwise, if the electrically insulating substrates cannot be laminated by hot or pressure lamination process, an adhesive is applied locally, between electrically insulating substrates, for bonding with a pressure or hot lamination process.

[0059] In the illustrative embodiments of the second aspect, the method may further comprise a step for providing a wire routing embedded into or onto the first electrically insulating substrate and the second electrically insulating substrate, the wire routing having a space filling routing portion over a respective active material in which a wire routing is routed in a shape of a space filling curve.

[0060] The step for providing a wire routing embedded into or onto the electrically insulating substrates permits to obtain all the technical effects and advantages of the wire routing embedded into or onto the electrically insulating substrates already described herein above.

[0061] In the illustrative embodiments of the second aspect, further comprising a step for providing the current collector of the cathode and / or the current collector of the anode with an electrode cladded onto the respective electrically insulating substrate.

[0062] The step for providing the current collector of the cathode and / or the current collector of the anode with an electrode cladded onto the respective electrically insulating substrate permits to obtain all the technical effects and advantages of same feature already described herein above in the first aspect of the invention. In the illustrative embodiments of the second aspect, the step for forming a stack may comprise printing the first active material having a first electrode potential in the galvanic series on a first wire routing portion of the at least two wire routing portions. It may also comprise printing the second active material having a different second electrode potential in the galvanic series on a second wire routing portion of the at least two wire routing portions embedded into the main surface of the electrically insulating substrate or embedded into a main surface of another electrically insulating substrate. The step for forming a stack may further comprise printing the electrolyte layer over at least one of the first and second active materials layers.

[0063] In the illustrative embodiments of the second aspect, the method may comprise a step for folding the electrically insulating substrate so as to flap a substrate surface portion of the main surface onto the electrolyte layer so as to completely cover the electrolyte layer and to obtain a stacked arrangement, the substrate surface portion being free of any embedded wiring. The method may further comprise a step for laminating the stacked arrangement in a lamination process, preferably a hot lamination process. In particular, during the hot lamination process the at least one recess may be formed.

[0064] In the present context, a battery comprises several components and, may further comprise components not described herein. In the present context, each battery comprises a battery cell which comprises several battery cell structures depending on, for example, the number of recess in the battery cell. In particular, according to the invention, each battery cell comprises at least one recess and two battery cell structures.

[0065] The accompanying drawings are incorporated into the specification and form a part of the specification to illustrate several embodiments of the present invention. These drawings, together with the description serve to explain the principles of the invention. The drawings are merely for the purpose of illustrating the preferred and alternative examples of how the invention can be made and used, and are not to be construed as limiting the invention to only the illustrated and described embodiments. Furthermore, several aspects of the embodiments may form, individually or in different combinations, solutions according to the present invention. The following described embodiments thus can be considered either alone or in an arbitrary combination thereof. Further features and advantages will become apparent from the following more particular description of the various embodiments of the invention, as illustrated in the accompanying drawings, in which like references refer to like elements, and wherein:

[0066] Fig. 1 schematically shows a cross-section a of battery cell with a battery cell structure in accordance with some illustrative embodiments of the present disclosure. Fig. 2 schematically shows a cross-section of a battery cell with two battery cell structures in accordance with some illustrative embodiments of the present disclosure before forming the recesses by lamination.

[0067] Fig. 3 schematically shows a cross-section of a battery cell with two battery cell structures in accordance with some same illustrative embodiments of the present disclosure than the ones of Fig. 2 after forming the recesses by lamination.

[0068] Fig. 4 schematically shows a cross-section of a battery cell with two battery cell structures in accordance with some other illustrative embodiments of the present disclosure than the ones of Fig. 2 and 3 before forming the recesses by lamination.

[0069] Fig. 5 schematically shows a cross-section of a battery cell with two battery cell structures in accordance with some same illustrative embodiments of the present disclosure than the ones of Fig. 4 after forming the recesses by lamination.

[0070] Fig. 6 schematically shows a top view of a battery comprising a battery cell with a battery cell structure in accordance with some illustrative embodiments of the present disclosure.

[0071] Fig. 7 represents schematically a top view of three battery cells having three different sizes and provided respectively with recesses having three different shapes of cross-section.

[0072] Fig. 1 shows a cross-section taken along a line crossing recesses 37, 35 of a battery cell structure 100. The cross-section represented in Fig. 1 may correspond to a cross-section obtained along a lineout as represented in Fig. 6 under reference 609. The battery cell structure 100 comprises a battery cell structure 101. The battery cell structure 101 is provided with an electrically insulating substrate 3 and 5. The electrically insulating substrates 3 and 5 may be the same electrically insulating substrate layer which is sandwiched. Alternatively, the electrically insulating substrates 3 and 5 may be two distinct and different layers. The battery cell structure 101 is further provided with a separator layer 7. The separator layer 7 is provided between two electrolyte layers 9, 11. The electrolyte layers 9, 11 are in complete alignment. The battery cell structure 101 is also provided with a first active material layer 13 that may be an anode active material layer of a redox pair, e.g., Zn, or a cathode active material layer, e.g., MnC>2. The first active material layer 13 may be formed by screenprinting. The first active material layer 13 is formed over a wire routing portion 15. A second active material layer 17 is also formed over a wire routing portion 19. The second active material layer 17 is complementary to the first active material layer 13 in a redox pair. The second active material layer 17 may be formed by screenprinting. Accordingly, the second active material layer 17 may be an anode active material layer for the first active material layer 13 being a cathode material layer. For example, the second active material layer 17 comprises Zn. Alternatively, the second active material layer 17 may be a cathode active material layer for the first active material layer 13 being an anode material layer. In that case, the second active material layer 17 may comprise MnC>2.

[0073] In the battery cell structure 101 , the current collectors 15, 19 may optionally and respectively be coated with a layer 25, 27. At least one of the layers 25, 27 is optional and may not be present in the subsequently described structures, although Fig. 1 and following may comprise the layers 25, 27. The layers 25, 27 may be deposited by printing. In particular, layers 25 and 27 may be printed after embedding of wires 15, 19. The layers 25, 27 are passivation layers and may be screenprinted carbon. Carbon is electrically inactive with both active materials of active material layer 13, 17 and permits to protect the current collector materials to prevent oxidation or reduction of the surface layer.

[0074] Optionally, the stack of layers respectively comprising the current collector 15, the coating layer 25, and the current collector 19, the coating layer 27 may be laterally separated from the sidewalls of the electrically insulating substrate 3, 5 by respectively insulating separators 21 , 23 surrounding. The current collectors 15, 19 may be wire embedded current collectors or cladded current collectors. The insulating separator 21 may further partially cover from both sides the interface between the stack of layers comprising the current collector 15, the coating layer 25 and the active material layer 13. Similarly, the insulating separator 23 may further partially cover from both sides the interface between the stack of layers comprising the current collector 19, the coating layer 27 and the active material layer 17. In particular, the insulating separators 21 , 23 may cover these interfaces from both sides on a distance, more particularly on 100 to 200 micrometers. In particular, the insulating separators 21 , 23 respectively cover edges of the stack of layers respectively comprising the current collector 15, the coating layer 25, and the current collector 19, the coating layer 27. This overlapping of the interfaces by the insulating separators 21 , 23 permits to have an easier manufacture and to prevent from negative effects of possible sharp edges of the stack of layers 15, 25 and 19, 27.

[0075] The battery cell 100 is further provided with a recess 37, 35 on each side of the battery cell structure 101 .

[0076] In illustrative embodiments, the layers 25, 27 may be provided by a carbon comprising material. Alternatively or additionally, the layers 25, 27 may be provided by a conductive material which is not redox active relative to a material to be formed on layer(s) 25 and / or 27 for avoiding an redox active contact of layer(s) 15 and / or 19 and any subsequently formed overlying material. For example, a carbon coating may passivate copper or aluminum or nickel wires against Manganese (Mn) comprising material on cathode side of a final battery cell structure, such as Manganese dioxide (MnC>2), while tin (Sn) may be used for plating copper wires at anode of the final battery cell structure. At the anode, a noble metal passivation or plating of anode wire routings may lead to H2 generation during operation in a Mn+3 / Zn configuration for the final battery cell structure, while Sn or noble metal coating on a cathode-side wire routing of the Mn02 / Zn configuration for the final battery cell structure may be advantageous.

[0077] Subsequently, the folded battery cell 100 may be subjected to a lamination process, e.g., a hot lamination process.

[0078] Fig. 2 shows a cross-section taken along a line crossing recesses of a battery cell 200. Fig. 2 shows the battery cell 200 during a first phase of the method of the invention prior to recess lamination processing step. Fig. 2 notably describes two adjacent battery cell structures 201 , 202 before formation of recesses. The reference signs designate the same features and layers than in Fig. 1. The battery cell structures 201 , 202 comprise the same layers than the ones in the battery cell structure 101 of the battery cell 100 in Fig. 1. In Fig. 2, the battery cell 200 is provided with two substrate surface portions 29, 31 being free of any embedded wiring. The two substrate surface portions 29, 31 are provided between the two battery cell structures 201 , 202.

[0079] Fig. 3 shows a cross-section taken along a line crossing recesses of a battery cell structure 300. The cross-section represented in Fig. 3 may, for example, correspond to a cross-section obtained along a lineout as represented in Fig. 6 under reference 607. The same battery cell structures 201 , 202 than in Fig. 2 are pictured in Fig. 3 but in a phase of the method of the invention that is after the lamination of the two substrate surface portions 29, 31 for forming the recesses 33, 35. The substrate surface portions 29, 31 being free of any embedded wiring may be laminated after or simultaneously than laminating step of the stacked arrangement. The lamination process may be preferably a hot lamination process. In particular, PVC, PC, PLA or PS may be preferred as substrate materials for the substrate 3, 5, the substrate material itself can be hot laminated, more particularly, without using bonding or adhesive material disposed between the substrate 3, 5.

[0080] Due to the lamination of the substrate surface portions 29, 31 , two recesses 33, 35 are formed. Accordingly, the two substrate surface portions 29, 31 are in direct physical contact. Alternatively, only one recess may be formed. The size of the recesses 33, 35 may be equal or not. The recesses 33, 35 may have a conical shape. A cross-section of the recess 33, 35 parallel to one of the layers of the stack, for example the separator layer 7, may be circular, rectangular or crossshaped. Fig. 4 shows a cross-section taken along a line crossing recesses of a battery cell 400. The same two adjacent battery cell structures 201 , 202 than the ones in Fig. 2 and 3 are depicted in a phase of the method of the invention prior to lamination of the electrically insulating substrate 3, 5. In Fig. 4, the battery cell 400 is further provided with a material layer 36 disposed between the battery cell structures 201 , 202. The material layer 36 is disposed inside the battery cell structure, between the electrically insulating substrates 3,5. The material layer 36 is configured for bonding together the substrate surface portions 29, 31 . The material layer 36 may comprise a bonding or adhesive material. For example the material layer 36 may be polyurethane, or polyacrylate, or temperature activated epoxy systems. The bonding material layer 36 permits to use as material for substrate 3, 5 materials that are not hot-laminable together.

[0081] Fig. 5 shows a cross-section taken along a line crossing recesses of a battery cell 500. The crosssection represented in Fig. 5 may correspond to a cross-section obtained along a lineout as represented in Fig. 6 under reference 607. The same battery cell structures 201 , 202 than in Fig. 4 are pictured in Fig. 5 but in a phase of the method of the invention that is after the lamination of the two substrate surface portions 29, 31. The lamination of the two substrate surface portions 29, 31 is notably obtained by means of the bonding material layer 36. The two substrate surface portions 29, 31 are bonded.

[0082] Referring to Fig. 6, a battery 600 comprising a battery cell 611 with a structure in accordance with some illustrative embodiments of the present disclosure is shown from a top view. The battery 600 notably comprises two current collectors 601 , 602. Current collectors 601 , 602 may be for example wire embedded current collectors or cladded current collectors. The current collectors 601 , 602 may be of a rectangular shape, although any regular or irregular polygonal shape or a circular or elliptical shape may also be used. A shape of current collector is preferably congruent to a shape of active material to be formed over the current collector.

[0083] The current collectors 601 , 602 may be formed of an electrical conductor material. The electrical conductor material may be obtained by subjecting an electrically conductive material to punching or rolling processes or deposition-etching processes or printing processes for forming the electrical conductor material into a desired shape.

[0084] The battery 600 further comprises a sealing material 603, in particular a sealing adhesive material. The sealing material 603 seals the edges of the battery 600. It permits to avoid leak of current. It also permits to avoid degradation due to the environment like air, gas, water, moisture, dust, etc.

[0085] The battery 600 further comprises a plurality of recess 605. In the battery 600, the recesses 605 are disposed so as to form a grid made of lines and columns. On Fig. 6, a lineout 609 represents an example of lineout leading to a cross-section similar to the one of Fig. 1. Additionally, on Fig. 6, a lineout 607 represents an example of lineout leading to a cross-section similar to the ones of Fig. 3, 5.

[0086] Fig. 7 represents schematically a top view of three batteries 71 , 75, 78. The batteries 71 , 75, 78 have current collector that are not represented in Fig. 7. Moreover, the batteries 71 , 75, 78 have different sizes, in particular different total surface of active materials. The total surface of active materials respectively increases from the battery 71 , to 75, to 78. The battery 71 is provided with only one recess 73. The recess 73 has a cross-section parallel to the stack of layers crossshaped. The battery 75 is provided with a plurality of recess 77. Each of the plurality of recess 77 has a cross-section parallel to the stack of layers having a rectangular shape. The battery 78 is provided with a plurality of recess 79. Each of the plurality of recess 79 has a cross-section parallel to the stack of layers having a circular shape. In particular, the battery 78 having a size bigger than the battery 75, is provided with a higher number of recces 79 than the battery 75.

[0087] In particular, the battery 75, 78 may have its number of recess column different than its number of recess line.

Claims

CLAIMS1 . A battery cell structure (101 , 201 , 202) comprising: a stack of at least : a first electrically insulating substrate (3), a cathode current collector (15), the first insulating substrate (3) being provided over the cathode current collector (15), a cathode active material layer (13), an electrolyte layer (9, 11 ), a separator (7), an anode active material layer (17), an anode current collector (19), a second electrically insulating substrate (5) provided over the anode current collector (19), and the stack is provided with at least one recess (33, 35, 37, 605) formed by a direct physical contact between the first electrically insulating substrate (3) and the second electrically insulating substrate (5) in at least one region of the stack, or the stack is provided with at least one recess (33, 35, 37, 605) formed by a bonding of the first electrically insulating substrate (3) and the second electrically insulating substrate (5) by means of a bonding material (36).

2. The battery cell structure (101 , 201 , 202) according to claim 1 , wherein a wire routing is embedded into or onto the first electrically insulating substrate (3) and the second electrically insulating substrate (5), the wire routing having a space filling routing portion over a respective active material in which a wire routing is routed in a shape of a space filling curve.

3. The battery cell structure (101 , 201 , 202) according to claims 1 or 2, wherein the current collector (15) of the cathode and / or the current collector (19) of the anode comprises an electrode cladded onto the electrically insulating substrate (3, 5).

4. The battery cell structure (101 , 201 , 202) according to any one of claims 1 to 3, wherein one of the at least one recess (33, 35, 37, 605) provided in the stack is filled with a material, in particular filled with a hot melt adhesive material, more particularly polyurethane, or polyacrylate, or temperature activated epoxy systems.

5. The battery cell structure (101 , 201 , 202) according to any one of the preceding claims, wherein the battery cell structure (101 , 201 , 202) is provided with a plurality of recesses (33, 35, 37, 605).

6. The battery cell structure (101 , 201 , 202) according to claim 5, wherein the recesses of the plurality of recesses (33, 35, 37, 605) are at least partially aligned along one direction, in particular along two distinct directions, more in particular along two directions perpendicular to one another.

7. The battery cell structure (101 , 201 , 202) according to any one of the preceding claims, wherein a cross-section parallel to the layers of the stack of the at least one recess (33, 35, 37, 605) is substantially circular, oval or oblong.

8. The battery cell structure (101 , 201 , 202) according to any one of the preceding claims, wherein a cross-section parallel to the layers of the stack of the at least one recess (33, 35, 37, 605) is substantially rectangular.

9. The battery cell structure (101 , 201 , 202) according to any one of the preceding claims, wherein a cross-section parallel to the layers of the stack of the at least one recess (33, 35, 37, 605) is substantially cross-shaped.

10. The battery cell structure (101 , 201 , 202) according to any one of the preceding claims, wherein the dimension of a cross-section of the at least one recess (33, 35, 37, 605) decreases along a direction extended towards the direct physical contact between the first electrically insulating substrate (3) and the second electrically insulating substrate (5).

11. The battery cell structure (101 , 201 , 202) according to any one of the preceding claims, wherein each current collector (15, 19) is covered by a carbon comprising material or a conductive material (25, 27) not being redox active relative to overlying the active materials.

12. The battery cell structure (101 , 201 , 202) according to any one of the preceding claims, wherein the anode active material layer (17) is made of a material comprising Zn, or Mg or Al.

13. The battery cell structure (101 , 201 , 202) according to any one of the preceding claims, wherein the cathode active material layer (13) is made of a material comprising MnC>2.

14. The battery cell structure (101 , 201 , 202) according to any one of the preceding claims, wherein the cathode current collector (15) and / or the anode current collector (19) is made of metal or coated with metal.

15. The battery cell structure (101 , 201 , 202) according to any one of the preceding claims, wherein the first and second electrically insulating substrate (3, 5) are made of PVC, PC, PLA, PET or PS.

16. The battery cell structure (101 , 201 , 202) according any one of the preceding claims, wherein the separator layer (7) is made of a membrane or a fiber-based material comprising an ion-conducting liquid or gel forming an electrolyte source.

17. The battery cell structure (101 , 201 , 202) according to any one of the preceding claims, wherein the wire routing of the anode current collector (19) is formed of a copper or aluminum or nickel wire and the wire routing of the cathode current collector (15) is formed of a copper or aluminum wire or a nickel wire coated with carbon, wherein the copper or aluminum or nickel wire of the anode current collector (19) is partially exposed to the anode active material layer (17) and the copper or aluminum wire of the cathode current collector (15) is covered by a metal material of an electrode potential in the galvanic series higher than an electrode potential of copper in the galvanic series.

18. A method for forming a battery cell structure (101 , 201 , 202) comprising: a step for forming a stack of at least a first electrically insulating substrate (3), a cathode current collector (15), the first insulating substrate (3) being provided over the cathode current collector (15), a cathode active material layer (13), an electrolyte layer (9, 11 ), a separator (7), an anode active material layer (17), an anode current collector (19), a second electrically insulating substrate (5) provided over the anode current collector (19), and a step for providing the stack with at least one recess (33, 35, 37, 605) either formed by a direct physical contact between the first electrically insulating substrate (3) and the second electrically insulating substrate (5), or formed by a bonding of the first electrically insulating substrate (3) and the second electrically insulating substrate (5) by means of a bonding material (36).

19. The method according to claim 18, further comprising a step for providing a wire routing embedded into or onto the first electrically insulating substrate (3) and the second electrically insulating substrate (5), the wire routing having a space filling routing portion over a respective active material in which a wire routing is routed in a shape of a space filling curve.

20. The method according to claim 18 or 19, further comprising a step for provided the current collector (15) of the cathode and / or the current collector (19) of the anode with an electrode cladded onto the respective electrically insulating substrate (3, 5).

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