Method for producing a negative electrode, negative electrode, galvanic cell, and uses of the galvanic cell

Abstract

The invention relates to a method for producing a negative electrode, to a negative electrode, to a galvanic cell, and to uses of the galvanic cell. According to the method, a coating which contains or consists of a polymer and / or ceramic particles is applied onto the upper face of a flat metal structure which does not consist of lithium, and a metal arrester is applied onto the lower face of the flat metal structure, said arrester having a plurality of openings in the direction of the metal structure. The metal arrester is then pressed into the metal structure by exerting a mechanical pressure, whereby the openings of the metal arrester are filled with metal of the metal structure at least in some regions. The method is simple and inexpensive to carry out and facilitates the production of a negative electrode which has a high energy density at the cell level and a high degree of chemical, electrochemical, and mechanical stability, and thus a high degree of cycle stability, and which allows high operating currents.

Description

[0001] Process for producing a negative electrode, negative electrode, galvanic cell and uses of the galvanic cell

[0002] A method for producing a negative electrode, a negative electrode, a galvanic cell, and uses of the galvanic cell are presented. In the method, a coating containing or consisting of a polymer and / or ceramic particles is applied to the upper side of a flat metal structure that is not made of lithium, and a metallic conductor is applied to the underside of the flat metal structure. The metallic conductor has a plurality of openings in the direction of the metal structure. The metallic conductor is then pressed into the metal structure by exerting mechanical pressure, whereby the openings of the metallic conductor are at least partially filled with metal from the metal structure.The process is simple and cost-effective and enables the production of a negative electrode with high energy density at the cell level as well as high chemical, electrochemical, and mechanical stability, thus achieving high cycling stability and enabling high operating currents. Commercial alkaline batteries (e.g., lithium-ion batteries with a graphite anode) have reached a material limit regarding their potential energy density. In addition to increasing performance requirements, high process- and delivery-related material costs are driving the need for alternative anode approaches.

[0003] To improve the energy density of alkaline batteries, the use of metallic lithium, Li-metal alloys, or Na-metal alloys (e.g., a LiAl alloy or a NaAl alloy) instead of a graphite-based negative electrode (anode) has been proposed in the literature. However, the use of pure lithium or metal alloys results in insufficient cycle stability and is associated with high manufacturing and material costs.

[0004] CN 109244374 A discloses a method for producing a (negative) electrode for an alkaline battery. In this method, a nitrogen-doped stainless steel mesh and a metal foil made of lithium are mechanically pressed together in a tablet press to produce an electrode comprising a three-dimensional, porous lithium-metal composite material. A problem with the use of the metal foil made of lithium is that the production of the electrode is costly due to the challenging handling of lithium metal and the high material costs. Furthermore, the cycling stability of this electrode requires improvement.

[0005] JP S62 139276 A discloses a method for producing an alkaline battery in which a lithium-aluminum alloy is used in the negative electrode, wherein the lithium content in the lithium-aluminum alloy is set to 35-45 mol%. In this method, lithium metal is processed directly, i.e., lithium metal is alloyed with aluminum during a hot pressing process. Direct processing of lithium metal is challenging and cost-intensive. Furthermore, the cycle stability of the negative electrode of the produced alkaline battery is in need of improvement. Based on this, the object of the present invention was to provide a method for producing a negative electrode for a galvanic cell, a negative electrode for a galvanic cell, and a galvanic cell that do not have the disadvantages of the prior art.In particular, the process should be simple and cost-effective, providing a negative electrode that, when used in a galvanic cell, exhibits high energy density at the cell level, high chemical, electrochemical, and mechanical stability, and thus exhibits high cycling stability and enables high operating currents. Furthermore, applications of the galvanic cell should be proposed.

[0006] The object is achieved by the method having the features of claim 1, the negative electrode having the features of claim 8, the galvanic cell having the features of claim 15 and the use having the features of claim 16. The dependent claims show advantageous developments.

[0007] According to the invention, a method for producing a negative electrode for a galvanic cell is provided, comprising a) providing a flat metal structure selected from the group consisting of metal foil, expanded metal, perforated sheet, metal mesh, and combinations thereof, wherein the flat metal structure has a flat top side and a flat bottom side and has a specific height in a direction perpendicular to the top side and bottom side, wherein the metal structure is not made of lithium metal; b) applying a coating to the top side of the metal structure, wherein the coating contains or consists of a polymer and / or ceramic particles;c) applying a flat upper side of a flat metallic conductor to the underside of the metal structure, wherein the metallic conductor has a flat underside and has a specific height in a direction perpendicular to the upper side and underside, which height is at most as great as the height of the metal structure, wherein the metallic conductor has a multiplicity of openings at least on the upper side; and d) pressing the metallic conductor over a specific distance, which corresponds at least partially to the height of the metallic conductor, into the metal structure by exerting mechanical pressure on the underside of the metallic conductor, whereby the openings of the metallic conductor are filled with metal of the metal structure at least along the specific distance.

[0008] The process according to the invention can be carried out in a simple and cost-effective manner. The process can be used to produce a negative electrode that exhibits high energy density at the cell level, high chemical, electrochemical, and mechanical stability, and thus exhibits high cycling stability and enables high operating currents.

[0009] These advantages arise from pressing the metallic conductor into the metal structure over a specific distance, which corresponds at least partially to the height of the metallic conductor, while filling the openings of the metallic conductor with metal from the metal structure. This creates very close mechanical contact and electrically conductive contact between the metal structure and the metallic conductor on its underside. If the electrically conductive contact and / or the metal structure has a metal oxide layer on its surface before pressing in (e.g. aluminium oxide in the case of aluminium), the pressing in causes the metal oxide layer to mechanically tear open, which improves the electrical contact between the metal structure and the metallic conductor. In addition, this eliminates the voltage loss caused by the oxide layer breaking through during the initial charging.The large number of openings that the metallic conductor has, at least on the upper side, also cause material of the metal structure to be pressed into these openings, allowing a more homogeneous distribution of the current density during operation of the electrode.

[0010] During the indentation process according to the invention, a force is inevitably exerted on the coating on the upper side of the metal structure, which presses the coating applied to the surface of the metal structure onto the surface of the metal structure or even at least partially into it. Consequently, intimate mechanical contact is also created between the metal structure and the coating on the upper side of the metal structure, which increases the mechanical load-bearing capacity and, due to the resulting concentration gradient, promotes the electrolyte distribution at the interface. The homogeneous electrolyte distribution has the advantage of homogeneous alloy formation, which leads to increased cycle stability and optimized capacity utilization.During cell operation, a stable, immobilized, ion-conducting, and electrically insulating passivation film formed in the pores of the coating consists of decomposition products of the liquid electrolyte (solid electrolyte interface, SEI). The coating acts as an "SEI precursor." The SEI stabilized by the coating serves as an additional protective layer for the metal structure. However, the coating may already contain material that transforms the coating into a solid electrolyte. In this case, the solid electrolyte is present in concentrated form at the surface of the metal structure, meaning the ionic conductivity at this interface is high. This minimizes polarization effects. The energy density of the electrode produced using this process is very high due to the feasibility of high-capacity anode materials such as lithium-aluminum alloy.

[0011] The cycle stability of the electrode produced using this process is high because the structure of the electrode suppresses dendrite growth. This also increases the safety of the electrode during operation, as dendrite-induced short circuits can be avoided.

[0012] The production of the electrode using the method according to the invention is also simple and cost-effective since no metal structure made of lithium metal is used.

[0013] The numerous openings that the metallic arrester has, at least on its top side, can be continuous openings. Consequently, the metallic arrester can also have a multitude of openings on its underside. The advantage of this is that the homogeneity of the current density during electrode operation is further increased by the three-dimensionality of the arrester structure. This results in uniform material loading and thus increased cycling stability.

[0014] The metal structure used in the process can contain or consist of aluminum, where the aluminum is optionally alloyed with a metal other than aluminum, preferably in a proportion of 0.1 to 20.0 wt.%, particularly preferably 0.5 to 5.0 wt.%, based on the total weight of the metal structure. Such a metal structure has the advantage that its specific weight is very low (e.g., the specific density is only approximately 30% of that of copper) and its specific electrical conductivity is relatively high (e.g., the electrical conductivity is approximately 65% ​​of that of copper). Consequently, aluminum, for example, has a better ratio of electrical conductivity to specific weight than copper, which makes it more powerful and attractive than a metal structure made of copper, especially for mobile applications.Another advantage of aluminum is that it forms an alloy with lithium, which leads to a potential-related reduction in the risk of dendrite formation compared to lithium metal. Furthermore, aluminum can provide a low anode potential (U_anode) (U of LiAl alloy is approximately 0.3V vs. Li / Li). + , which is only slightly higher than the anode potential of commercially used graphite). In addition, aluminum can provide a high specific capacity (e.g., as LiAl 993 Ah / kg, which is three times the capacity of graphite). Due to the high resulting total capacity C and the high resulting cell voltage U (U = U_cathode - U_anode), aluminum enables a high energy density E = C * U at the cell level and is more cost-effective than other suitable alloying materials such as indium or silicon.

[0015] Furthermore, the metal structure used in the process can contain at least one element selected from the II. main group of the periodic table, the III. main group of the periodic table, the IV. main group of the periodic table, a subgroup of the periodic table and combinations thereof, wherein the at least one element is preferably selected from the group consisting of magnesium, indium, zinc, tin, silicon, manganese and combinations thereof.

[0016] Furthermore, the metal structure used in the method can have a height, in a direction perpendicular to a surface of the metal structure, in the range of 1 to 100 μm, preferably 5 to 50 μm, particularly preferably 10 to 40 μm. Furthermore, the Meta II structure used in the method can have a top and / or bottom surface with a surface structure. The surface structure can be selected from the group consisting of brushed surface structure, grooved surface structure, embossed surface structure, and combinations thereof.

[0017] The ceramic particles of the coating used in the process can contain or consist of a material selected from the group consisting of ceramic oxide, ceramic sulfide, ceramic sulfate, ceramic phosphide, ceramic phosphate, ceramic silicate, ceramic nitride, ceramic nitrate, and combinations thereof. The material used in the process is particularly preferably selected from the group consisting of lithium phosphorus sulfide (U3PS4), lithium germanium phosphorus sulfide (LiioGePzS), lithium silicon phosphorus sulfide (LinSi2PS), LiePSsCl, Li8PSsBr, aluminum oxide, aluminum silicate, lithium aluminum silicate, and combinations thereof, wherein the material is in particular aluminum oxide (Al2O3). Al2O3 has the advantage of being cost-effective compared to solid electrolyte salts such as lithium phosphorus sulfide. Furthermore, AI2O3 forms an inert protective layer so that no undesirable side reactions occur.In addition, the incorporation of A Os particles into the coating creates porous structures, which results in an optimized electrolyte distribution, i.e., a SEI-P re cursor effect.

[0018] Furthermore, the material used in the process can have an average particle diameter dso in the range from 0.05 to 30 pm, preferably in the range from 0.1 to 1 pm, wherein the average particle diameter refers to a particle diameter determined by dynamic light scattering.

[0019] The polymer of the coating used in the process can contain or consist of a plastic selected from the group consisting of acrylonitrile-butadiene rubber, hydrogenated acrylonitrile-butadiene rubber, polyisobutylene, and combinations thereof. The plastics selected from this group have the advantage that the coating bonds to the (top side of the) metal structure with a high bonding force (i.e., they are polymeric binders). The bonding force is higher than, for example, with polyolefins (such as polypropylene). If the coating also contains ceramic particles, the bonding force to the ceramic particles is also high, as a result of which they are stably present in the coating. The plastic is particularly preferably polyisobutylene. Polyisobutylene has the advantage of ensuring good adhesion, i.e.ensures good adhesion of the coating, and the sustainability and environmental compatibility of polyisobutylene is higher compared to fluorinated compounds.

[0020] Furthermore, the polymer used in the process can contain or consist of a fluorinated plastic, wherein the fluorinated plastic is in particular selected from the group consisting of PVDF, PVDF-HFP, and combinations thereof. The plastics selected from this group also have the advantage that the coating bonds to the (top side of the) metal structure with a high bonding force (i.e., they are polymeric binders). This bonding force is higher than, for example, with polyolefins (such as polypropylene). If the coating also contains ceramic particles, the bonding force to the ceramic particles is also high, ensuring that they are stably present in the coating.

[0021] In this process, the coating can be rolled on mechanically.

[0022] Furthermore, the coating can be applied in the process via wet coating and / or dry coating.

[0023] In addition, the coating can be applied in the process by applying a mechanical pressure on the coating in the direction of the metal structure of at least 2000 kg / cm 2 , preferably a mechanical pressure in the range of 2500 to 6000 kg / cm 2 , onto, and preferably into, the metal structure. The mechanical pressure is particularly preferably applied using a cold lever press for a duration of 10 to 20 seconds at a temperature in the range of 20 to 30 °C.

[0024] Furthermore, the coating applied in the process can have a height in a direction perpendicular to the top surface of the metal structure in the range of 0.05 to 200 pm, preferably 0.1 to 100 pm. Furthermore, the coating applied in the process can be a porous coating.

[0025] In addition, the coating applied in the process can be contacted with a liquid electrolyte and / or gel electrolyte for a galvanic cell.

[0026] The liquid electrolyte and / or gel electrolyte can contain a liquid selected from the group consisting of EC, PC, DMC, EMC, DEC, VEC, VC, FEC, TBAC (acetyltributylcitrate), GTB (glycerol tributyrate), GTA (glycerol triacetate), γ-buthyrolactone, ionic liquid, and combinations thereof, particularly preferably containing a liquid selected from the group consisting of PC, FEC, EC, VEC, TBAC, GTB, GTA, ionic liquid, and combinations thereof. PC, FEC, EC, VEC, TBAC, GTB, GTA, and ionic liquids have the advantage of being high-boiling liquids with high temperature stability, which reduces the risk of fire and increases operational safety.

[0027] Furthermore, the liquid electrolyte and / or gel electrolyte can contain a lithium conducting salt and / or a sodium conducting salt, wherein the lithium conducting salt is in particular selected from the group consisting of LiPFe, LiClC, LiNO3, CßHisLiNSiz, FzLiNCSz, CzFßLiNCSz, LiBfCzC h, LiBF4 and combinations thereof and / or the sodium conducting salt is in particular selected from the group consisting of NaPFe, NaBF4, NaTF, NaTFSI, NaClC and combinations thereof.

[0028] In addition, the coating applied in the process can assume a quasi-solid state or a gel-like state by contacting it with a liquid electrolyte.

[0029] The metallic conductor used in the process can contain or consist of a metal that has a higher Vickers hardness than the metal of the metal structure. Furthermore, the metallic conductor used in the process can contain or consist of a metal selected from the group consisting of stainless steel, copper, nickel, and combinations and alloys thereof, with the metal preferably being stainless steel, in particular stainless steel 1.4301. Stainless steel has the advantage of having a high Vickers hardness and not forming an alloy with lithium. Furthermore, it is available as a cost-effective, commercial material in all shapes and structures.

[0030] In addition, the metallic arrester used in the process can be made to resist mechanical stress by applying a mechanical pressure of at least 2000 kg / cm on the underside of the metallic arrester in the direction of the metal structure. 2 , preferably a mechanical pressure in the range of 2500 to 6000 kg / cm2 , are pressed into the metal structure, wherein the mechanical pressure is particularly preferably applied via a cold lever press for a period of 10 to 20 seconds at a temperature in the range of 20 to 30 °C.

[0031] Apart from that, the metallic conductor used in the method may have a plurality of through openings from the top to the bottom.

[0032] Furthermore, the metallic arrester used in the method can contribute to the mechanical resistance to volumetric expansion during cycling when the electrode is operated in a galvanic cell, in particular can be mechanically resistant to volumetric expansion during cycling when the electrode is operated in a galvanic cell.

[0033] Furthermore, the metallic conductor used in the method can have a height in a direction perpendicular to the underside of the metal structure in the range of 1 to 100 pm, preferably 5 to 50 pm, particularly preferably 10 to 40 pm, optionally 10 to 20 pm.

[0034] The metallic conductor used in the process can be designed as a perforated foil, perforated expanded metal, or wire mesh. The metallic conductor is preferably designed as a wire mesh. The advantage of a wire mesh is that finely distributed heterogeneities can be introduced through a fine-mesh mesh, which results in a homogeneous, three-dimensional current density distribution over the entire negative electrode (anode). The wire mesh particularly preferably has a mesh size in the range of 0.01 to 0.1 mm, in particular in the range of 0.04 to 0.063 μm. Furthermore, it is particularly preferred that the wire mesh contains or consists of wires having a diameter in the range of 0.020 to 0.050 mm, preferably in the range of 0.028 to 0.040 mm.

[0035] According to the invention, a negative electrode for a galvanic cell is further provided, containing or consisting of i) a flat Meta II structure selected from the group consisting of metal foil, expanded metal, perforated sheet, metal mesh and combinations thereof, wherein the metal structure has a flat top side and a flat bottom side and has a certain height in a direction perpendicular to the top side and bottom side, wherein the metal structure does not consist of lithium metal; ii) a coating applied to the top side of the metal structure, wherein the coating contains or consists of a polymer and / or ceramic particles;and iii) a flat metallic conductor, wherein the metallic conductor has a flat top side and a flat bottom side and has a specific height in a direction perpendicular to the top side and bottom side, which height is at most as great as the height of the metal structure, wherein the metallic conductor has a plurality of openings at least on the top side; wherein the metallic conductor is embedded in the metal structure over a specific distance from the bottom side of the metal structure towards the top side of the metal structure, wherein the specific distance corresponds at least partially to the height of the metallic conductor and wherein openings of the metallic conductor are filled with metal of the metal structure at least along the specific distance.

[0036] The negative electrode according to the invention is simple and cost-effective to produce. It exhibits high energy density at the cell level as well as high chemical, electrochemical, and mechanical stability, thus providing high cycling stability. It also enables high operating currents.

[0037] The metal structure of the electrode can contain or consist of aluminum, wherein the aluminum is optionally alloyed with a metal other than aluminum, preferably in a proportion of 0.1 to 20.0 wt.%, particularly preferably 0.5 to 5.0 wt.%, based on the total weight of the metal structure. Such a metal structure has the advantage that its specific weight is very low (e.g., the specific density is only approximately 30% of that of copper) and its specific electrical conductivity is relatively high (e.g., the electrical conductivity is approximately 65% ​​of that of copper). Consequently, aluminum, for example, has a better ratio of electrical conductivity to specific weight than copper, which makes it more powerful and attractive than a metal structure made of copper, especially for mobile applications.Another advantage of aluminum is that it forms an alloy with lithium, which contributes to a potential-related reduction in dendrite hazard compared to lithium metal. Furthermore, aluminum can provide a low anode potential U (U of LiAl alloy is approximately 0.3V vs. Li / Li). + , which is comparable to graphite). In addition, aluminum can provide a high specific capacity (e.g., as LiAl 993 Ah / kg, which is three times the capacity of graphite). Furthermore, aluminum enables a high energy density E = C * U and is more cost-effective than other suitable alloying materials such as indium or silicon.

[0038] Furthermore, the metal structure of the electrode can contain at least one element selected from the II. main group of the periodic table, the III. main group of the periodic table, the IV. main group of the periodic table, a subgroup of the periodic table and combinations thereof, wherein the at least one element is preferably selected from the group consisting of magnesium, indium, zinc, tin, silicon, manganese and combinations thereof.

[0039] Apart from that, the metal structure of the electrode can have a height, in a direction perpendicular to the top side of the metal structure, in the range of 1 to 100 pm, preferably 5 to 50 pm, particularly preferably 10 to 40 pm. Furthermore, the Meta II structure of the electrode can have a top side and / or bottom side that has a surface structuring. The surface structuring can be selected from the group consisting of brushed surface structuring, grooved surface structuring, embossed surface structuring, and combinations thereof.

[0040] The ceramic particles of the coating may contain or consist of a material selected from the group consisting of ceramic oxide, ceramic sulfide, ceramic sulfate, ceramic phosphide, ceramic phosphate, ceramic silicate, ceramic nitride, ceramic nitrate, and combinations thereof. Particularly preferably, the material is selected from the group consisting of lithium phosphorus sulfide (U3PS4), lithium germanium phosphorus sulfide (LiioGePzS), lithium silicon phosphorus sulfide (LinSi2PSiz), LiePSsCl, Li8PSsBr, aluminum oxide, aluminum silicate, lithium aluminum silicate, and combinations thereof, wherein the material is, in particular, aluminum oxide (Al2O3). Al2O3 has the advantage of being cost-effective compared to solid electrolyte salts such as lithium phosphorus sulfide. Furthermore, AI2O3 forms an inert protective layer so that no undesirable side reactions occur.In addition, processing of A Os particles in coating provides porous structure, which results in an optimized electrolyte distribution, i.e., an SEI precursor effect.

[0041] Furthermore, the ceramic particles of the coating can have an average particle diameter dso in the range from 0.05 to 30 pm, preferably in the range from 0.1 to 1 pm, wherein the average particle diameter refers to a particle diameter determined by dynamic light scattering.

[0042] The polymer of the coating can contain or consist of a plastic selected from the group consisting of acrylonitrile butadiene rubber, hydrogenated acrylonitrile butadiene rubber, polyisobutylene, and combinations thereof. The plastic is particularly preferably polyisobutylene. Polyisobutylene has the advantage of providing good adhesion, i.e., ensuring the coating adheres well. Furthermore, polyisobutylene is more sustainable and environmentally friendly than fluorinated compounds. Furthermore, the polymer of the coating can contain or consist of a fluorinated plastic, with the fluorinated plastic being selected, in particular, from the group consisting of PVDF, PVDF-HFP, and combinations thereof.

[0043] The coating can be applied mechanically.

[0044] Furthermore, the coating can be applied via wet coating and / or dry coating.

[0045] In addition, the coating can be deformed by applying a mechanical pressure on the coating in the direction of the Meta II structure of at least 2000 kg / cm 2 , preferably a mechanical pressure in the range of 2500 to 6000 kg / cm 2 , onto, and preferably into, the metal structure, wherein the mechanical pressure was particularly preferably applied via a cold lever press for a period of 10 to 20 seconds at a temperature in the range of 20 to 30 °C.

[0046] Apart from that, the coating may have a height in a direction perpendicular to the top side of the metal structure in the range of 0.05 to 2 pm, preferably 0.1 to 1 pm.

[0047] The coating may be a porous coating.

[0048] Furthermore, the coating may comprise a liquid electrolyte and / or gel electrolyte for a galvanic cell.

[0049] The liquid electrolyte and / or gel electrolyte can contain a liquid selected from the group consisting of EC, PC, DMC, EMC, DEC, VEC, VC, FEC, TBAC (acetyltributylcitrate), GTB (glycerol tributyrate), GTA (glycerol triacetate), γ-buthyrolactone, ionic liquid, and combinations thereof. Particularly preferably, the liquid electrolyte and / or gel electrolyte contains a liquid selected from the group consisting of PC, FEC, EC, VEC, TBAC, GTB, GTA, ionic liquid, and combinations thereof. PC, FEC, EC, VEC, TBAC, GTB, GTA, and ionic liquids have the advantage of being high-boiling liquids with high temperature stability, which reduces the risk of fire and increases operational safety.

[0050] Furthermore, the liquid electrolyte and / or gel electrolyte can contain a lithium conducting salt and / or a sodium conducting salt, wherein the lithium conducting salt is in particular selected from the group consisting of LiPFe, LiClC, LiNO3, CßHisLiNSiz, FzLiNCSz, CzFßLiNCSz, LiBfCzC h, LiBF4 and combinations thereof and / or the sodium conducting salt is in particular selected from the group consisting of NaPFe, NaBF4, NaTF, NaTFSI, NaClC and combinations thereof.

[0051] Furthermore, the liquid electrolyte and / or gel electrolyte (by having a liquid electrolyte) may be in a quasi-solid state or a gel state.

[0052] The metallic conductor may contain or consist of a metal that has a higher Vickers hardness than the metal of the metal structure.

[0053] Furthermore, the metallic conductor can contain or consist of a metal selected from the group consisting of stainless steel, copper, nickel, and combinations and alloys thereof, with the metal preferably being stainless steel, in particular stainless steel 1.4301. Stainless steel has the advantage of having a high Vickers hardness and not forming an alloy with lithium. Furthermore, it is available as a cost-effective, commercial material in all shapes and structures.

[0054] In addition, the metallic arrester can be de-energised by applying a mechanical pressure on the underside of the metallic arrester in the direction of the metal structure of at least 2000 kg / cm 2 , preferably a mechanical pressure in the range of 2500 to 6000 kg / cm 2, have been pressed into the metal structure, wherein the mechanical pressure was particularly preferably applied via a cold lever press for a duration of 10 to 20 seconds at a temperature in the range of 20 to 30 °C.

[0055] Furthermore, the metallic conductor can have a plurality of through openings from the top to the bottom. It is preferred that the metallic conductor contribute to the mechanical resistance to volumetric expansion during cycling when the electrode is operated in a galvanic cell, and in particular, that it be mechanically resistant to volumetric expansion during cycling when the electrode is operated in a galvanic cell.

[0056] The metallic conductor can have, in a direction perpendicular to the underside of the Meta II structure, a height in the range of 1 to 100 µm, preferably 5 to 50 µm, particularly preferably 10 to 40 µm, optionally 10 to 20 µm.

[0057] The metallic conductor can be designed as a perforated foil, perforated expanded metal, or wire mesh. The metallic conductor is preferably designed as a wire mesh. The advantage of a wire mesh is that finely distributed heterogeneities can be introduced through a fine-mesh mesh, which results in a homogeneous, three-dimensional current density distribution across the entire negative electrode (anode). The wire mesh particularly preferably has a mesh size in the range of 0.01 to 0.1 mm, in particular in the range of 0.04 to 0.063 pm. Furthermore, the wire mesh particularly preferably contains or consists of wires having a diameter in the range of 0.020 to 0.050 mm, preferably in the range of 0.028 to 0.040 mm.

[0058] In a preferred embodiment, the negative electrode according to the invention is produced using the method according to the invention. In this case, the negative electrode according to the invention has features that are necessarily caused by the implementation of the method according to the invention in the negative electrode.

[0059] The invention further provides a galvanic cell containing a negative electrode (anode) according to the invention, a cathode, and an electrolyte. The electrolyte is preferably a liquid electrolyte, which, due to diffusion into the coating, can be present in a gel formed by the coating and the liquid electrolyte. Furthermore, the use of the galvanic cell according to the invention for supplying energy to i) a mobile device, preferably a mobile phone, a vehicle, an aircraft, and / or a ship; and / or ii) a stationary device, preferably a building, is proposed.

[0060] The subject matter of the invention will be explained in more detail with reference to the following figure and the following example, without wishing to restrict it to the specific embodiments shown here.

[0061] The figure schematically shows the method according to the invention and an electrode according to the invention. A coating 2 (e.g., an aluminum silicate coating) is applied to the upper side of a metal structure 3 (e.g., an aluminum foil), and a metallic conductor 4 (e.g., a stainless steel wire mesh) is applied to the underside. This metal structure is placed between an upper press die 1 of a cold lever press and a lower press die

[0062] 5 of a cold lever press and the cold lever press exerts a pressing force on the coating 2 of the metal structure 3 in the direction of the metal structure 3 on the one hand and on the metallic conductor 4 of the metal structure 3 in the direction of the metal structure 3 on the other hand. As a result, the coating 2 is pressed onto or into the upper side of the metal structure 3, so that an upper section

[0063] 6 of the metal structure 3, onto or into which the coating 2 is pressed. Furthermore, the metallic conductor 4 is pressed into the underside of the metal structure 3, so that a lower section 7 of the metal structure 3 is formed, into which the metallic conductor 4 is pressed.

[0064] Example - Manufacturing a negative electrode for a galvanic cell

[0065] On an aluminum foil as a metal structure (foil thickness: 10 pm), a coating of aluminum silicate is first applied to the first side (top side) by doctor blade, so that an aluminum silicate coating with a wet film thickness of 300 pm is created on the top side of the aluminum foil.

[0066] On a second side of the coated aluminum foil (underside), a stainless steel wire mesh (made of stainless steel 1.4301 with a mesh size of 0.04 mm, a wire diameter of 0.028 mm and a thickness of 10 µm) is applied as a metallic conductor.

[0067] Then, using a cold lever press at a pressure of 3500 kg / cm 2 At room temperature (25 °C) for a period of 15 seconds, the aluminum silicate coating is pressed onto or into the top side of the aluminum foil, and the stainless steel wire mesh is pressed into the underside of the aluminum foil. This creates an aluminum foil with the aluminum silicate coating pressed onto or into the top side and the stainless steel wire mesh pressed into the underside. In this case, the stainless steel wire mesh is pressed into the underside of the aluminum foil over its entire height.

[0068] 1: upper press ram of a cold lever press;

[0069] 2: Coating on top of the Meta II structure (e.g. aluminum silicate coating);

[0070] 3: Metal structure (e.g. aluminum foil);

[0071] 4: metallic arrester (e.g. stainless steel wire mesh);

[0072] 5: lower press ram of a cold lever press;

[0073] 6: Upper section of the metal structure onto or into which the coating is pressed; and

[0074] 7: Lower section of the metal structure into which the metallic conductor is pressed.

Claims

Patent claims Method for producing a negative electrode for a galvanic cell, comprising a) providing a flat metal structure which is selected from the group consisting of metal foil, expanded metal, perforated sheet, metal mesh and combinations thereof, wherein the flat metal structure has a flat top side and a flat bottom side and has a certain height in a direction perpendicular to the top side and bottom side, wherein the metal structure does not consist of lithium metal; b) applying a coating to the top side of the metal structure, wherein the coating contains or consists of a polymer and / or ceramic particles;c) applying a flat upper side of a flat metallic conductor to the underside of the metal structure, wherein the metallic conductor has a flat underside and, in a direction perpendicular to the upper side and underside, has a specific height which is at most as great as the height of the metal structure, wherein the metallic conductor has a plurality of openings at least on the upper side; d) pressing the metallic conductor over a specific distance, which corresponds at least partially to the height of the metallic conductor, into the metal structure by exerting mechanical pressure on the underside of the metallic conductor, whereby the openings of the metallic conductor are filled with metal of the metal structure at least along the specific distance. Method according to the preceding claim, characterized in that the metal structure; i) contains or consists of aluminum, wherein the aluminum is optionally alloyed with a metal other than aluminum, preferably in a proportion of 0.1 to 20.0 wt.%, particularly preferably 0.5 to 5.0 wt.%, based on the total weight of the metal structure; and / or ii) at least one element selected from the II. main group of the Periodic Table, the III. main group of the Periodic Table, the IV.Main group of the periodic table, a subgroup of the periodic table and combinations thereof, wherein the at least one element is preferably selected from the group consisting of magnesium, indium, zinc, tin, silicon, manganese and combinations thereof; and / or iii) has a height, in a direction perpendicular to a surface of the metal structure, in the range from 1 to 100 pm, preferably 5 to 50 pm, particularly preferably 10 to 40 pm; and / or iv) has a top side and / or bottom side which has a surface structuring which is preferably selected from the group consisting of brushed surface structuring, grooved surface structuring, embossed surface structuring and combinations thereof.Method according to one of the preceding claims, characterized in that the ceramic particles of the coating i) contain or consist of a material selected from the group consisting of ceramic oxide, ceramic sulfide, ceramic sulfate, ceramic phosphide, ceramic phosphate, ceramic silicate, ceramic nitride, ceramic nitrate and combinations thereof, wherein the material is particularly preferably selected from the group consisting of lithium phosphorus sulfide, lithium germanium phosphorus sulfide, lithium silicon phosphorus sulfide, LiβPSsCl, LiβPSsBr, aluminum oxide, aluminum silicate, lithium aluminum silicate and combinations thereof, wherein the material is in particular aluminum oxide; and / or. ii) have an average particle diameter dso in the range from 0.05 to 30 µm, preferably in the range from 0.1 to 1 µm, wherein the average particle diameter refers to a particle diameter determined by dynamic light scattering.

4. Method according to one of the preceding claims, characterized in that the polymer of the coating i) contains or consists of a plastic selected from the group consisting of acrylonitrile-butadiene rubber, hydrogenated acrylonitrile-butadiene rubber, polyisobutylene, and combinations thereof, wherein the plastic is in particular polyisobutylene; and / or ii) contains or consists of a fluorinated plastic, wherein the fluorinated plastic is in particular selected from the group consisting of PVDF, PVDF-HFP, and combinations thereof.

5. Method according to one of the preceding claims, characterized in that the coating is i) mechanically rolled on; and / or ii) applied via wet coating and / or dry coating; and / or iii) by exerting a mechanical pressure on the coating in the direction of the metal structure of at least 2000 kg / cm 2 , preferably a mechanical pressure in the range of 2500 to 6000 kg / cm 2 , onto, and preferably into, the metal structure, wherein the mechanical pressure is particularly preferably applied via a cold lever press for a period of 10 to 20 seconds at a temperature in the range of 20 to 30 °C; and / or iv) in a direction perpendicular to the top side of the metal structure, has a height in the range of 0.05 to 200 pm, preferably 0.1 to 100 pm; and / or v) is a porous coating; and / or vi) is contacted with a liquid electrolyte and / or gel electrolyte for a galvanic cell, which contains a liquid selected from the group consisting of EC, PC, DMC, EMC, DEC, VEC, VC, FEC, TBAC (acetyltributylcitrate), GTB (glycerol tributyrate), GTA (glycerol triacetate), γ-buthyrolactone, ionic liquid and combinations thereof, particularly preferably a liquid selected from the group consisting of PC, FEC, EC, VEC, TBAC, GTB, GTA, ionic liquid and combinations thereof, and / or a lithium conducting salt and / or a sodium conducting salt, wherein the lithium conducting salt is in particular selected from the group consisting of LiPFe, LiClC, LiNO3, CßHisLiNSiz, FzLiNCSz, CzFßLiNCSz, LiBfCzC h, LiBF4 and combinations thereof and / or the sodium conducting salt is in particular selected from the group consisting of NaPFe, NaBF4, NaTF, NaTFSI, NaClC and combinations thereof;and / or vii) assumes a quasi-solid state or a gel-like state by contacting with a liquid electrolyte. Method according to one of the preceding claims, characterized in that the metallic conductor i) contains or consists of a metal that has a higher Vickers hardness than the metal of the metal structure; and / or ii) contains or consists of a metal selected from the group consisting of stainless steel, copper, nickel, and combinations and alloys thereof, wherein the metal is preferably stainless steel, in particular stainless steel 1.4301; and / or iii) by exerting a mechanical pressure of at least 2000 kg / cm on the underside of the metallic conductor in the direction of the metal structure; 2 , preferably a mechanical pressure in the range of 2500 to 6000 kg / cm 2, is pressed into the metal structure, the mechanical pressure being particularly preferably applied via a cold lever press for a period of 10 to 20 seconds is applied at a temperature in the range of 20 to 30 °C; and / or iv) has a plurality of through openings from the top side to the bottom side; and / or v) when the electrode is operated in a galvanic cell, contributes to the mechanical resistance to volumetric expansion during cycling, in particular when the electrode is operated in a galvanic cell, is mechanically resistant to volumetric expansion during cycling; and / or vi) in a direction perpendicular to the bottom side of the metal structure, has a height in the range of 1 to 100 pm, preferably 5 to 50 pm, particularly preferably 10 to 40 pm, optionally 10 to 20 pm.Method according to one of the preceding claims, characterized in that the metallic conductor is designed as a perforated foil, perforated expanded metal or wire mesh, wherein the metallic conductor is preferably designed as a wire mesh, wherein the wire mesh particularly preferably i) has a mesh size in the range from 0.01 to 0.1 mm, in particular in the range from 0.04 to 0.063 pm; and / or ii) contains or consists of wires which have a diameter in the range from 0.020 to 0.050 mm, preferably in the range from 0.028 to 0.040 mm.A negative electrode for a galvanic cell, comprising or consisting of i) a flat metal structure selected from the group consisting of metal foil, expanded metal, perforated sheet, metal mesh and combinations thereof, wherein the metal structure has a flat top side and a flat bottom side and has a certain height in a direction perpendicular to the top side and bottom side, wherein the metal structure does not consist of lithium metal;. ii) a coating applied to the top side of the metal structure, wherein the coating contains or consists of a polymer and / or ceramic particles; and iii) a flat metallic conductor, wherein the metallic conductor has a flat top side and a flat bottom side and has a specific height in a direction perpendicular to the top side and bottom side, which height is at most as great as the height of the metal structure, wherein the metallic conductor has a multiplicity of openings at least on the top side; wherein the metallic conductor is embedded in the metal structure over a specific distance from the bottom side of the metal structure towards the top side of the metal structure, wherein the specific distance corresponds at least partially to the height of the metallic conductor, and wherein openings of the metallic conductor are filled with metal of the metal structure at least along the specific distance.Electrode according to claim 8, characterized in that the metal structure i) contains or consists of aluminum, wherein the aluminum is optionally alloyed with a metal other than aluminum, preferably in a proportion of 0.1 to 20.0 wt. %, particularly preferably 0.5 to 5.0 wt. %, based on the total weight of the metal structure; and / or ii) contains at least one element selected from the II. main group of the Periodic Table, the III. main group of the Periodic Table, the IV. main group of the Periodic Table, a subgroup of the Periodic Table and combinations thereof, wherein the at least one element is preferably selected from the group consisting of magnesium, indium, zinc, tin, silicon, manganese and combinations thereof; and / or iii) has a height, in a direction perpendicular to the top side of the metal structure, in the range of 1 to 100 pm, preferably 5 to 50 pm, particularly preferably 10 to 40 pm; and / or. v) metal structure has a top and / or bottom side which has a surface structuring which is preferably selected from the group consisting of brushed surface structuring, grooved surface structuring, embossed surface structuring and combinations thereof.Electrode according to one of claims 8 or 9, that the ceramic particles of the coating i) contain or consist of a material which is selected from the group consisting of ceramic oxide, ceramic sulfide, ceramic sulfate, ceramic phosphide, ceramic phosphate, ceramic silicate, ceramic nitride, ceramic nitrate and combinations thereof, wherein the material is particularly preferably selected from the group consisting of lithium phosphorus sulfide, lithium germanium phosphorus sulfide, lithium silicon phosphorus sulfide, LiβPSsCl, LiβPSsBr, aluminum oxide, aluminum silicate, lithium aluminum silicate and combinations thereof, wherein the material is in particular aluminum oxide; and / or ii) have an average particle diameter dso in the range from 0.05 to 30 pm, preferably in the range from 0.1 to 1 pm, wherein the average particle diameter refers to a particle diameter determined by dynamic light scattering.Electrode according to one of claims 8 to 10, characterized in that the polymer of the coating i) contains or consists of a plastic selected from the group consisting of acrylonitrile-butadiene rubber, hydrogenated acrylonitrile-butadiene rubber, polyisobutylene, and combinations thereof, wherein the plastic is in particular polyisobutylene; and / or ii) contains or consists of a fluorinated plastic, wherein the fluorinated plastic is in particular selected from the group consisting of PVDF, PVDF-HFP, and combinations thereof. Electrode according to one of claims 8 to 11, characterized in that the coating i) is mechanically rolled on; and / or ii) is applied via wet coating and / or dry coating; and / or iii) by exerting a mechanical pressure on the coating in the direction of the metal structure of at least 2000 kg / cm 2, preferably a mechanical pressure in the range of 2500 to 6000 kg / cm 2, onto, and preferably into, the metal structure, wherein the mechanical pressure was particularly preferably applied via a cold lever press for a duration of 10 to 20 seconds at a temperature in the range of 20 to 30 °C; and / or iv) in a direction perpendicular to the top side of the metal structure, has a height in the range of 0.05 to 2 pm, preferably 0.1 to 1 pm; and / or v) is a porous coating;and / or vi) a liquid electrolyte and / or gel electrolyte for a galvanic cell, which contains a liquid selected from the group consisting of EC, PC, DMC, EMC, DEC, VEC, VC, FEC, TBAC (acetyltributylcitrate), GTB (glycerol tributyrate), GTA (glycerol triacetate), γ-buthyrolactone, ionic liquid and combinations thereof, particularly preferably a liquid selected from the group consisting of PC, FEC, EC, VEC, TBAC, GTB, GTA, ionic liquid and combinations thereof, and / or a lithium conducting salt and / or a sodium conducting salt, wherein the lithium conducting salt is in particular selected from the group consisting of LiPFe, LiCl, LiNO3, CßHisLiNSiz, F2LiNO4S2, C2FeLiNO4S2, LiB[C2O4]2, LiBF4 and combinations thereof thereof and / or the sodium conducting salt is in particular selected from the; Group consisting of NaPFe, NaBF4, NaTF, NaTFSI, NaClC and combinations thereof; and / or vii) by having a liquid electrolyte in a quasi-solid state or a gel state.

13. Electrode according to one of claims 8 to 12, characterized in that the metallic conductor i) contains or consists of a metal that has a higher Vickers hardness than the metal of the metal structure; and / or ii) contains or consists of a metal that is selected from the group consisting of stainless steel, copper, nickel and combinations and alloys thereof, wherein the metal is preferably stainless steel, in particular stainless steel 1.4301; and / or iii) by exerting a mechanical pressure on the underside of the metallic conductor in the direction of the metal structure of at least 2000 kg / cm 2 , preferably a mechanical pressure in the range of 2500 to 6000 kg / cm 2, was pressed into the metal structure, wherein the mechanical pressure was particularly preferably applied via a cold lever press for a duration of 10 to 20 seconds at a temperature in the range of 20 to 30 °C; and / or iv) has a multiplicity of through openings from the top side to the bottom side; and / or v) when the electrode is operated in a galvanic cell, contributes to the mechanical resistance to volumetric expansion during cycling, in particular when the electrode is operated in a galvanic cell, is mechanically resistant to volumetric expansion during cycling; and / or vi) in a direction perpendicular to the bottom side of the metal structure, has a height in the range of 1 to 100 pm, preferably 5 to 50 pm, particularly preferably 10 to 40 pm, optionally 10 to 20 pm. Electrode according to one of claims 8 to 13, characterized in that the metallic conductor is designed as a perforated foil, perforated expanded metal or wire mesh, wherein the metallic conductor is preferably designed as a wire mesh, wherein the wire mesh particularly preferably i) has a mesh size in the range from 0.01 to 0.1 mm, in particular in the range from 0.04 to 0.063 pm; and / or ii) contains or consists of wires which have a diameter in the range from 0.020 to 0.050 mm, preferably in the range from 0.028 to 0.040 mm. Galvanic cell containing a negative electrode according to one of claims 8 to 14, a cathode and an electrolyte. Use of the galvanic cell according to claim 15 for supplying energy to i) a mobile device, preferably a mobile phone, a vehicle, an aircraft and / or a ship; and / or ii) a stationary device, preferably a building.

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