Energy storage and methods for manufacturing an energy storage device

Abstract

Method for manufacturing an energy storage device (100), comprising the following steps: screen printing, on a printing surface (210) which is designed to support a cell element (102, 102') of the energy storage device (100), a housing side wall (502, 502') of the energy storage device (100); screen printing, on at least one section of the housing side wall (502, 502'), a metallic conductive layer (117) for electrical contacting an upper electrode layer (114) of the cell element (102, 102'); and screen printing, on the metallic conductor layer (117), a lower electrode layer (111) of another cell element (102', 102") of the energy storage device (100), so that the lower electrode layer (111) of the other cell element (102', 102") is electrically connected to the upper electrode layer (114).

Description

Technical field

[0001] The invention relates to an energy storage device, in particular an energy storage device containing an electrochemical cell. From a further perspective, the invention relates to a manufacturing process for such an energy storage device. Technical background

[0002] An electrochemical cell comprises a cathode (positive electrode), an anode (negative electrode), and a separator that separates the positive and negative electrodes. In a conventional battery cell, the positive electrode, the negative electrode, the separator, and a liquid electrolyte are housed within a casing. The electrolyte is at least partially immersed in the electrolyte. In a solid-state battery cell, the separator consists of a solid electrolyte. The anode and cathode can be connected to a load via contacts. An electrochemical cell can be used for energy storage as a primary or secondary battery. A primary battery is a non-rechargeable battery intended for single use.A secondary battery or accumulator is a battery that can be recharged.

[0003] In a well-known roll-to-roll wet coating process for manufacturing battery cells, a low-viscosity slurry containing the respective electrode material for the anode and cathode is applied sequentially to both sides of a metallic conductor, and the solvent is then evaporated. For cell assembly, the resulting electrode rolls are cut and stacked alternately (anode, separator, cathode) with a separator until the desired capacity is achieved. The stack is then electrically connected and packaged in a housing, such as a foil bag. A liquid electrolyte is then added, and the housing is sealed. The resulting cell has a nominal voltage of approximately 3.2 V, depending on the cathode material.

[0004] US Patent 5,035,965 A discloses a manufacturing process for a flexible thin-film cell in which an electrolyte material and a positive-polarity material are applied to a lithium-aluminum foil (a negatively polarized material) and then to the electrolyte material, respectively, by a screen-printing process and dried in a UV calcining oven. The viscosity of the polymer used in the screen-printing device is adjusted to approximately 30 Pa s. Under the same conditions, a current collector is applied in a further screen-printing and drying process. The thin-film cell units are then laminated between housing materials with conductor connections, fusion-bonded under evacuation, and cut to predetermined sizes.A multilayer structure can be produced by fusion bonding lithium-aluminium foil to the positive polarity material prior to applying the current collector, and repeating the application and drying of the electrolyte material and the positive polarity material.

[0005] US Patent 2020 / 0 020 974 A1 discloses the fabrication of a solid-state battery in which processes for forming a cathode green film, an anode green film, and a laminate precursor are carried out sequentially. To form the cathode terminal and the anode terminal, a respective section of the laminate precursor is immersed in a cathode or anode terminal slurry, respectively. US Patent 2019 / 0 252 690 A1 discloses a method for fabricating a flexible battery in which a first and second substrate are printed onto separating films and current collector layers are printed onto the substrates using a conventional printing technique. An anode side of the battery is formed by forming an anode on the current collector of the first substrate, and a cathode side is formed by forming a cathode on the current collector of the second substrate.After electrolyte has been deposited on the anode and / or the cathode, the anode and cathode sides are glued together and sealed, and the battery is separated from the separating foils.

[0006] One disadvantage of the above manufacturing processes lies in the multitude of different production steps that must be performed using differently specialized manufacturing equipment. This necessitates not only a complex production facility but also time-consuming transfers of intermediate products from one manufacturing device to another during the production process. US 2014 / 0302373A1 discloses a printed battery, e.g., a zinc-manganese dioxide battery, comprising multiple layers. Current collector layers extend beyond a certain area of ​​electrode layers to facilitate coupling with an external circuit.

[0007] A polymer insulator layer forms a coating around the electrode layers, an intermediate layer and a separator layer to seal the layers of the printed battery.

[0008] FR 2 690 567 A1 proposes a manufacturing process for a thin electrochemical generator (between 10 µm and 100 µm) in which a cathode current collector, a cathode, an electrolyte separator, an anode, an anode current collector, and an encapsulation material are applied sequentially and superimposed on a glass-epoxy composite substrate using a screen-printing process, followed by three hours of drying at 100 °C under primary vacuum after each layer. The electrolyte separator, the anode current collector, and the encapsulation material are extended obliquely from the side of the cathode and anode down to the glass-epoxy composite substrate, with the outer sections of the current collectors remaining uncovered by the encapsulation material.

[0009] In this process, the manufacturing process involves a sequence of similar steps. However, a problem arises: with a greater height of the anode top above the glass-epoxy composite support, the downwardly sloping anode current not only requires more metal and lateral space, but also loses stability due to its increasingly free-floating design. The resulting limitation of the anode top height above the glass-epoxy composite support, given a specific lateral space, also limits the achievable energy storage capacity, which is typically proportional to the thickness, particularly of the cathode. Therefore, an object of the invention is to increase the achievable energy storage capacity for a given lateral dimension while minimizing the complexity of the manufacturing process. Disclosure of the invention

[0010] The problem is solved by a method for manufacturing an energy storage device according to claim 1 as well as by an energy storage device according to claim 7.

[0011] The method according to the invention comprises a screen printing step on a printing surface designed to support a cell element of the energy storage device, specifically on a housing side wall of the energy storage device. A further process step consists of screen printing on at least a section of the housing side wall, specifically on a metallic conductive layer for electrical contacting an upper electrode layer of the cell element. The method further comprises a screen printing step on the metallic conductive layer, specifically on a lower electrode layer of another cell element of the energy storage device, such that the lower electrode layer of the further cell element is electrically connected to the upper electrode layer.

[0012] The terms "on," "upper," and "support" in this description and the claims consistently refer to a printing direction of the screen printing process, which preferably, but not necessarily, coincides with the direction of gravity during the screen printing steps. Thus, the upper electrode layer refers to an electrode layer of the cell element that is positioned higher than any other electrode layer of the cell element. Similarly, terms generally used in language that refer to the direction of gravity, such as "above," "below," "top," "height," or "next to," always refer to the printing direction in this context. Accordingly, the term "housing side wall" refers to a housing wall that has a laterally pointing surface normal and thus extends parallel to the printing direction. "Print support" refers to a support opposite to the printing direction, e.g., in the form of a flat tabletop.In the present description and the claims, screen printing on an element does not necessarily mean that the screen-printed material is applied directly to said element, but can also mean that one or more further elements are arranged between said element and the screen-printed material, which are supported by said element against the direction of printing. For example, screen printing the housing side wall on the printing surface can also mean that the housing side wall is screen-printed on a housing base that rests on the printing surface and is supported by it against the direction of printing.

[0013] The screen printing of the housing side wall in the first process step allows for the creation of a top surface of the housing side wall at the same height as, or only slightly different from, the upper electrode layer of the cell element, in addition to the cell element to be electrically contacted. This enables the upper electrode layer to be electrically contacted by means of the metallic conductive layer screen-printed onto the top surface of the housing side wall in the second process step. This eliminates the need for the metallic conductive layer to extend over a height difference corresponding to the thickness of the cell element to a lower end, such as a support plate, of the energy storage device. This allows for a thicker cell element without compromising the stability of the contact, thus achieving a higher energy storage capacity.

[0014] Since this also eliminates the need for an inclined guide of the metallic conductor layer over the aforementioned height difference, not only the required material for the metallic conductor layer but also the required lateral installation space can be reduced.

[0015] Screen printing of the lower electrode layer of the additional cell element makes it possible to manufacture the energy storage device with a cell stack comprising multiple electrically connected cell elements in series, thus providing a higher electrical voltage for the energy storage device. Since the process steps are screen printing operations, they are performed with a device that can also be used to form other elements of the energy storage device, such as electrodes. This allows the process effort to be kept to a minimum.

[0016] From another perspective, the invention provides an energy storage device comprising a cell element with an upper electrode layer, a housing side wall surrounding the cell element, a metallic conductor layer printed on at least a section of the housing side wall and electrically contacting the upper electrode layer of the cell element, and a further cell element with a lower electrode layer printed on the metallic conductor layer in such a way that the lower electrode layer of the further cell element is electrically connected to the upper electrode layer.

[0017] According to a preferred embodiment of the method, the metallic conductive layer is screen-printed across the entire upper electrode layer. This ensures particularly good electrical contact and simultaneously protects the upper electrode layer, which may, for example, consist of an alkali metal such as lithium or sodium, from corrosion. Preferably, the screen-printed metallic conductive layer extends to a section of the housing side wall that surrounds the upper electrode layer in a ring-like fashion. This allows for a particularly tight seal with the housing side wall to minimize losses and suppress ionic current between the cell element and, for example, another cell element of the energy storage device.

[0018] According to a preferred embodiment, the method further comprises a screen-printing step on the housing side wall of another housing side wall of the energy storage device. This makes it possible to easily produce an energy storage device with any desired number of cell elements by repeating the same steps.

[0019] According to a preferred embodiment, the method further comprises a screen-printing step on at least one section of the further housing side wall of an additional metallic conductive layer for electrical contacting an upper electrode layer of the further cell element, as well as a screen-printing step on the further metallic conductive layer of a housing cover of the energy storage device such that a contacting section of the further metallic conductive layer is exposed next to the housing cover. This makes it possible to electrically connect the energy storage device to external circuits at the contacting section, whereby, due to the design of the further metallic conductive layer on the further housing side wall, potentially harmful pressure on the further cell element can be avoided.

[0020] According to a preferred embodiment, the process further comprises a screen printing step on the printing surface of a housing base for the energy storage device. This enables particularly efficient manufacturing of the energy storage device, as, for example, process steps and corresponding devices for cutting a carrier plate can be eliminated. Brief description of the drawings

[0021] The inventive method and energy storage device are described below using several exemplary embodiments. The figures shown are: Fig. 1 a schematic cross-sectional view of an energy storage device, Fig. 2 A schematic, cutaway front view of a screen printing device during the screen printing of a first electrode sublayer of the energy storage device. Fig. 1, Fig. 2A a partial magnification of the electrode layer made of Fig. 2, Fig. 3 the device from Fig. 2 during the formation of a second electrode layer of the energy storage device, Fig. 4. A flowchart of a process for manufacturing an energy storage device. Fig. 5A-S schematic cross-sectional views of steps in a process for manufacturing an energy storage device, as seen in Fig. 5R, and Fig. 6 A schematic cross-sectional view of an energy storage device according to one embodiment. Detailed description of the drawings

[0022] Unless explicitly stated otherwise, identical or equivalent elements in the drawings are designated with the same reference numerals.

[0023] Fig. Figure 1 shows a schematic cross-sectional view of an energy storage device 100, which can be configured, for example, as a primary or secondary battery. The energy storage device 100 comprises an electrochemical cell element 102. The cell element 102 is a sheet-like structure consisting of several layers 110, 111, 112, 114, comprising a first electrode layer 101 and a second electrode layer 114. A separator layer 110 made of a solid electrolyte material is located between the first electrode layer 101 and the second electrode layer 114.

[0024] The first electrode layer 101 consists of a second electrode sublayer 112 adjacent to the separator layer 110 and a first electrode sublayer 111 adjacent to the side of the second electrode sublayer 112 facing away from the separator layer 110. The second electrode sublayer 112 is thinner than the first electrode sublayer 111. For example, the first electrode sublayer 111 has a thickness of 150 µm, while the second electrode sublayer 112 also has a thickness of 150 µm. Both electrode sublayers 111 and 112 contain an active material suitable for acting as an electron donor or ion donor, or as an electron receptor or ion receptor. In particular, electrons can be released during the discharge process of the energy storage device 100 by a chemical reaction in the active material.In particular, during a charging process of the energy storage device, 100 electrons or ions can be bound in the active material by a chemical reaction. These chemical reactions can be electrochemical reactions. The chemical reactions can be reversible, depending on whether the energy storage device is being discharged to provide electrical energy or charged for later provision of electrical energy. The second electrode sublayer 112 contains an admixture of the solid electrolyte material used in the separator layer 110, giving it a higher ionic conductivity than the first electrode sublayer 111, but a lower conductivity than the separator layer 110.This results in a decreasing concentration gradient of ionic conductor from the separator layer 110 via the second electrode sublayer 112 to the first electrode sublayer 111, simultaneously with a reversed concentration gradient of electrical conductor.

[0025] The cell element 102 is surrounded by a housing side wall 502 made of polyethylene or another suitable electrical insulator, extending laterally around the cell element 102. A first metallic current collector layer 115 is formed on the side of the first electrode sublayer 111 facing away from the second electrode sublayer 112. This first metallic current collector layer extends over the entire lower surface of the first electrode sublayer 111 and the housing side wall 502. The second electrode layer 114 comprises a metallic material, e.g., an alkali metal such as lithium or sodium. A second metallic current collector layer 116 is formed on the side of the second electrode layer 114 facing away from the separator layer 110. This second metallic current collector layer extends over the entire upper surface of the second electrode layer 114 and the housing side wall 502.The externally accessible sides of the metallic conductive layers 115, 116 form electrical connections of the energy storage device 100 in order to extract electrical energy from the energy storage device 100 or, depending on the type, to supply it for charging. In particular, within a first contact area 512 and a second contact area 510, which are arranged on a section of the housing side wall 502 thickened for this purpose, the first metallic conductive layer 115 and the second metallic conductive layer 116 can be electrically contacted from above and below without affecting the cell element 102, since mechanical loads are dissipated into the housing side wall 502.

[0026] Fig. Figure 2 shows a screen printing device 212 for producing the first electrode layer 101 of an energy storage device 100 according to Fig. 1. The screen printing device 212 comprises a printing plate 210, wherein the printing plate 210 is for the support of a cell element 102 (see Fig. 1) or a cell stack 104 comprising several cell elements 102 (cf. Fig. 6) of the energy storage device 100. The screen printing device 212 comprises a printing screen 200, which has a plurality of screen openings 202. The screen printing device 212 further comprises a first application device 221 containing a first paste 121 and a second application device 222 containing a second paste 122, by means of which the pastes 121, 122 can be applied to the printing screen 200. A spreading device 214 with a squeegee 215 that can be spread over the printing screen 200 is designed for spreading the pastes 121, 122 over the printing screen 200 and through the screen openings 202 in the direction of the printing surface 210.

[0027] The first paste 121 and the second paste 122 both contain an identical active material suitable for acting as an electron donor or ion donor, or as an electron receptor or ion receptor. The second paste 122 is additionally supplemented with, for example, 10% porous separator material. Both pastes contain a binder with an epoxy resin and diethylene glycol monobutyl ether ester as a solvent. The composition of the first paste 121 is selected such that its resting viscosity is 250 Pa s and its shear viscosity is 50 Pa s. The solvent content of the second paste 122 is higher than that of the first paste 121 and is selected such that the second paste 122 has a resting viscosity of 100 Pa s.

[0028] The following will be based on the Fig. 4 flowchart shown with reference to Fig. 1 to 3 a method for manufacturing an energy storage device 100 according to Fig. 1 using the screen printing device 212 from Fig. 2 will be explained. The process begins with step 400, in which a first metallic conductive layer 115, which consists, for example, of nickel, is placed on the printing surface 210 of the screen printing device 212. This step can optionally be carried out by means of a screen printing process or in another way, e.g., by providing a commercially available nickel foil.

[0029] In step 401, the first electrode sublayer 111 of the energy storage device 100 is formed by screen printing with the first paste 121 onto the first metallic conductive layer 115. For this purpose, a suitable quantity of the first paste 121 is applied to the printing screen 200 using the first application device 221. Subsequently, as in Fig. 2 shown, using the squeegee 215 of the coating device 214, the applied first paste 121 is spread horizontally over the printing screen 200 and simultaneously vertically through the screen openings 202 in the direction of the printing surface 210, such that the first electrode sublayer 111 is formed on the first metallic conductor layer 115.

[0030] In step 402, the first electrode partial layer 111 is dried by heat irradiation for 6 minutes. Due to the high viscosity of the first paste 121, the first electrode partial layer 111 has an almost cuboid shape after drying 402, with a raised edge 301 of less than 1 µm and an edge angle 300 of less than 1°.

[0031] In branching step 403, it is determined whether another electrode sublayer should be screen-printed. Since this is the case here (“J”), the process branches back to step 401. In step 401, the second electrode sublayer 112 of the energy storage device 100 is now formed by screen printing with the second paste 122 onto the first electrode sublayer 111. For this purpose, a suitable amount of the second paste 122 is applied to the printing screen 200 using the second application device 222. Subsequently, as in Fig. 3 shown, using the squeegee 215 of the spreading device 214, the applied second paste 122 is spread horizontally over the printing screen 200 and simultaneously vertically through the screen openings 202 in the direction of the printing surface 210, such that the second electrode partial layer 112 is formed on the first electrode partial layer 111.

[0032] Subsequently, in step 402, the second electrode sublayer 112 is dried by heat irradiation for 6 minutes. After drying 402, the resulting first electrode layer 101 also has an almost cuboid shape with an edge height 301 of less than 5 µm and an edge angle 300 of less than 5°.

[0033] In branching step 403, it is checked again whether another electrode sublayer should be screen-printed. Since this is no longer the case (“N”), the process continues with step 404. In step 404, the separator layer 110 of the energy storage device 100 is screen-printed onto the second electrode sublayer 112 using a third paste. For this purpose, the third paste is prepared from the porous separator material and binder with an epoxy resin and diethylene glycol monobutyl ether ester as a solvent, the composition of the binder and the solvent content being adjusted so that the third paste has a rest viscosity of 200 Pa s and a shear viscosity of 50 Pa s. This screen-printing process is preferably also carried out using the screen-printing device 212. Fig. 2 carried out.

[0034] Subsequently, in step 405, the separator layer 110 is dried by heat irradiation for 6 minutes. After drying in step 405, the separator layer 110 produced in this way also has an almost cuboid shape with an edge height 301 of less than 5 µm and an edge angle 300 of less than 5°.

[0035] In step 406, the second electrode layer 114 of the energy storage device 100 is formed on the separator layer 110 by screen printing with a fourth paste. For this purpose, the fourth paste is prepared from the intended metallic material, such as lithium or sodium, and a binder. This screen printing process is preferably also carried out using the screen printing device 212. Fig. 2. Then, in step 409, the second electrode layer 114 is dried by heat irradiation for 6 minutes.

[0036] In step 410, the second metallic conductive layer 116 of the energy storage device 100 is formed on the second electrode layer 114 by screen printing with a fifth paste. The fifth paste is prepared for this purpose from the intended metallic material, such as nickel and binder. This screen printing process is preferably also carried out using the screen printing device 212. Fig. 2. Then, in step 411, the second metallic conductor layer 116 is dried by heat irradiation for 6 minutes.

[0037] Next, the production of another energy storage device 100 will be carried out according to a further process based on Fig. Sections 5A to 5S are described, in which the corresponding steps AS of the process are schematically illustrated. If the steps are screen printing steps, they can be described, for example, using the diagram in Fig. The screen printing device 212 shown in section 2 is used.

[0038] In a Fig. In step A, shown in Figure 5A, a housing base 501 of the energy storage device 100 is screen-printed onto a printing plate (not shown), which can be the printing plate 210 of the screen printing device 212. For this purpose, a paste that polymerizes by thermal radiation to an electrically non-conductive material, which will be assumed to be polyethylene in the following, is used. The resulting housing base 501 is a substantially cuboid layer approximately 200 µm to 500 µm thick.

[0039] In step B - shown in Fig. 5B - the base of the housing 501 is treated with heat radiation 599 for a period of approximately 6 minutes to carry out the polymerization of the polyethylene.

[0040] In step C - shown in Fig. 5C - A 10 µm thick first metallic conductive layer 115 made of nickel is applied to the base of the housing 501 by laying or screen printing with a suitable paste. Near the edge of the base of the housing 501, a strip-shaped circumferential area of ​​the housing side wall remains uncovered, in which a first contact area 512 and, opposite it, a second contact area 510 for contacting the energy storage device 100 are located, except for the first contact area 512, in which the first metallic conductive layer 115 extends essentially to the edge of the base of the housing 501.

[0041] In step D - shown in Fig. 5D - the first metallic conductive layer 115 is dried with thermal radiation 599. The duration of the irradiation, as in subsequent irradiation steps, is also approximately 6 minutes.

[0042] In step E - shown in Fig. 5E - a first electrode sublayer 111 with a thickness of approximately 100 µm is applied to the first metallic current collector layer 115 by screen printing, leaving the first contact area 512 unprinted. The paste used for this purpose has the same composition and properties as that used with regard to Fig. The first paste 121, already described in steps 1 to 3, is used here, so a further explanation of its composition is omitted. In step F - shown in Fig. 5F - the first electrode sublayer 111 is dried with thermal radiation 599.

[0043] In step G - shown in Fig. 5G - a second electrode sublayer 112 with a thickness of approximately 50 µm is applied to the first electrode sublayer 111 by screen printing. The paste used for this purpose has the same composition and properties as that used with regard to Fig. The second paste 122, already described in sections 1 to 3, contains, however, a corresponding proportion of an ionic conductor instead of an admixture of a porous separator material. The first and second electrode sublayers 111, 112 together form a first electrode layer 101 of the energy storage device 100. In step H - shown in Fig. 5H - the second electrode partial layer 112 is dried with thermal radiation 599.

[0044] In Step I - shown in Fig. 5I - A separator layer 110 made of a solid electrolyte material with a thickness of approximately 10 µm to 30 µm is applied to the second electrode sublayer 112 by screen printing. The solid electrolyte material contains the same proportion of ionic conductor as the second electrode sublayer 112, resulting in a concentration gradient of the ionic conductor from the second electrode sublayer 112 to the separator layer 110. In step J - shown in Fig. 5J - the second separator layer 110 is dried with heat radiation 599.

[0045] In step K - shown in Fig. In step 5K, a circumferential housing side wall 502 is applied to the housing base 501, or the first metallic separator layer 115, by screen printing with the same material used for the housing base 501 in step A, in the circumferential housing side wall area, including an inner section of the first contact area 512. The first metallic separator layer 115 remains exposed in the outer section of the first contact area 512. The upper edge of the housing side wall 502 is flush with the upper edge of the separator layer 110 in an inner section of the second contact area 510, while in the remaining sections it is approximately 10 µm higher than the upper edge of the separator layer 110. In step L - shown in Fig. 5L - the housing side wall 502 is dried with heat radiation 599.

[0046] In step M - shown in Fig. 5M - a second electrode layer 114 is applied to the separator layer 110 and the inner section of the second contact area 510 by screen printing a metallic material, which may be lithium, sodium, or another alkali metal. The second electrode layer 114 is approximately 10 µm thick, so that it is flush with the top edge of the housing side wall 502. In step N - shown in Fig. 5N - the second electrode layer 114 is dried with thermal radiation 599. As an alternative to producing the second electrode layer 114 by screen printing in steps M and N, the second electrode layer 114 can also be applied by spraying.

[0047] In step O - shown in Fig. In step 50, a second metallic discharge layer 116, approximately 10 µm thick and made of nickel, is applied to the second contact area 510 by screen printing with a suitable paste. In the outer section of the second contact area 510, the second metallic discharge layer 116 lies directly on the housing side wall 502, while in the inner section of the second contact area 510 it lies on the second electrode layer 114. However, it is mechanically supported by the housing side wall 502 throughout the entire second contact area 510. In step P – shown in Fig. 5P - A height compensation layer 503 with a thickness of 10 µm, made of the same material used for the housing base 501 and the housing side wall 502, is screen-printed onto the still exposed sections of the second electrode layer 114 and the housing side wall 502. In step Q - shown in Fig. 5Q - the second metallic conductor layer 116 and the height compensation layer 503 are dried or polymerized with thermal radiation 599.

[0048] In step R - shown in Fig. 5R - a cuboid housing cover 504 with a thickness of approximately 200 µm is screen-printed onto the height compensation layer 503 and - leaving the outer section of the second contact area 510 uncovered - the second metallic conductive layer 116 by screen printing with the same material used for the housing base 501, the housing side wall 502 and the height compensation layer 503. In step S - shown in Fig. 5S - the housing cover 504 is dried or polymerized using heat radiation 599.

[0049] The manufactured energy storage device 100 can be electrically contacted from above through the exposed ends of the first metallic conductor layer 115 and the second metallic conductor layer 116 in the outer sections of the first contacting area 512 and the second contacting area 510, whereby mechanical loads are transferred into the housing without affecting the cell element 102.

[0050] Fig. Figure 6 shows another energy storage device 100, which has a similar structure, but instead of a single cell element 102, it has a cell stack 104 with several cell elements 102, 102', 102" connected electrically in series. The energy storage device 100 can be manufactured using a manufacturing process that is largely based on the one described in Fig. The descriptions in sections 5A to 5S are consistent. To avoid repetition, only the differences are presented below.

[0051] After procedural steps as in Fig. 5A to 5J were shown to be executed similarly to how in Fig. Figure 5K shows a housing side wall 502 formed, which, however, completely extends beyond the separator layer 110 by 10 µm. Subsequently, a second electrode layer 114 is formed similarly to the one shown in Figure 5K. Fig. 5M is shown applied to the separator layer 110, but not to the housing side wall 502, so that the housing side wall 502 and the separator layer 110 are flush with each other at the top.

[0052] Subsequently, a third metallic discharge layer 117 is applied to the second electrode layer 114 and an annularly adjacent inner section of the housing side wall 502, in the same manner as previously for the second metallic discharge layer 116 in the diagram based on Fig. The manufacturing process described in sections 5A to 5S can be carried out. To form a second cell element 102' of the cell stack, the following steps are then performed: Fig. The corresponding process steps from 5E to 5J are repeated, whereby the first electrode sublayer 111 of the second cell element 102' is applied to the third metallic current collector layer 117. In the manner described, as in Fig. Figure 6 shows three or more cell elements 102, 102', 102" are formed, which are electrically connected in series via intervening metallic conductor layers 117 and separated from each other with respect to ionic conductors.

Claims

[1] Method for producing an energy storage device (100), comprising the following steps: Screen printing, on a printing support (210), which is designed to support a cell element (102, 102') of the energy storage device (100), a housing side wall (502, 502') of the energy storage device (100); Screen printing, on at least a portion of the housing side wall (502, 502'), a metallic conductor layer (117) for electrically contacting an upper electrode layer (114) of the cell element (102, 102'); and Screen printing, on the metallic conductor layer (117), a lower electrode layer (111) of a further cell element (102', 102") of the energy storage device (100), so that the lower electrode layer (111) of the further cell element (102', 102") is electrically connected to the upper electrode layer (114). [2] The method of claim 1, wherein the screen printing of the metallic conductor layer (117) is performed on the entire upper electrode layer (114). [3] The method of claim 2, wherein the screen printing of the metallic conductor layer (117) extends to a portion of the housing side wall (502, 502') annularly surrounding the upper electrode layer (114). [4] Method according to one of the preceding claims, further comprising a step of screen printing, on the housing side wall (502, 502'), a further housing side wall (502', 502") of the energy storage device (100). [5] The method of claim 4, further comprising the following steps: Screen printing, on at least a portion of the further housing side wall (502"), a further metallic conductor layer (116) for electrically contacting an upper electrode layer (114) of the further cell element (102"); Screen printing, on the further metallic conductor layer (116), of a housing cover (504) of the energy storage device (100) such that a contacting section of the further metallic conductor layer (116) is exposed next to the housing cover (504). [6] Method according to one of the preceding claims, further comprising a step of screen printing, on the printing support (210), a housing base (501) of the energy storage device (100). [7] Energy storage device (100), comprising: a cell element (102, 102') having an upper electrode layer (114); a housing side wall (502, 502') surrounding the cell element (102, 102'); a metallic conductor layer (117) which is screen-printed onto at least a portion of the housing side wall (502, 502') and electrically contacts the upper electrode layer (114) of the cell element (102, 102'); and a further cell element (102', 102") having a lower electrode layer (111) which is screen-printed onto the metallic conductor layer (117) such that the lower electrode layer (111) of the further cell element (102', 102") is electrically connected to the upper electrode layer (114). [8] Energy storage device (100) according to claim 7, wherein the metallic conductor layer (117) extends over the entire upper electrode layer (114) and a portion of the housing side wall (502, 502') surrounding the upper electrode layer (114) in an annular manner. [9] Energy storage device (100) according to claim 7 or 8, further comprising a further housing side wall (502', 502") which is screen-printed onto the housing side wall (502, 502'). [10] Energy storage device (100) according to claim 9, further comprising: a further metallic conductor layer (116) which is screen-printed on at least a portion of the further housing side wall (502") and electrically contacts an upper electrode layer (114) of the further cell element (102"); and a housing cover (504) which is screen-printed onto the further metallic conductor layer (116) in such a way that a contacting section of the further metallic conductor layer (116) is exposed next to the housing cover (504).

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