Metallization mixture, metallization method using said mixture, and thermo-electrochemical generator cell according to the method
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- HEIONIT GMBH
- Filing Date
- 2024-08-22
- Publication Date
- 2026-07-01
Smart Images
Figure EP2024073592_27022025_PF_FP_ABST
Abstract
Description
[0001] Metallization mixture, metallization process with said mixture and thermo-electro-chemical generator cell according to the process
[0002] TECHNICAL BACKGROUND
[0003] The present invention originates in the field of conditioning hydrocarbons and / or hydrocarbon substitute compounds. For example, WO 2020 / 098984 A1 discloses a reactor with which additives such as water, hydrogen, oxygen, nitrogen, CO2, methane, and methanol can be chemically introduced into a hydrocarbon or a hydrocarbon substitute compound in a particularly gentle and efficient manner. For example, conditioning with oxygen and water can produce a diesel fuel with improved combustion behavior. Conditioned and chemically stabilized mixtures and emulsions, or bio-based substitute fuels through the acid-catalyzed transesterification of natural oils with methanol, catalyzed with sulfuric acid, are also accessible.
[0004] Parallel processes for the synthesis of bio-based substitute fuels are known, for example, in US2010 / 0175312 A1, US 8,545,702 B1 or WO 2014 / 111598 A2.
[0005] When conditioning the cheapest possible unsaturated oils with oxygen and / or water, hydrophilic phases were obtained as a byproduct, which could be used to construct thermo-electrochemical generator cells. Such a cell was disclosed and claimed in application PCT / EP2023 / 073100; PCT / EP2023 / 073100 forms the basis of this application, and priority is claimed. Additional searches and testing of possible product concepts led to the underlying mixtures and processes claimed here. More on this below.
[0006] SCIENTIFIC AREA
[0007] Fats (in this case also including oils):
[0008] Natural fats / oils range from medium-chain fatty acids with 6 to 12 carbon atoms to long-chain fatty acids with up to 24 carbon atoms, as well as their derivatives. Storage of the corresponding harvest in conditions of excessive humidity and oxygenation is problematic during extraction (UFOP Practical Information Bfa for Nutrition and Food, Münster, Dr. Bertrand Matthäus, Dr. Ludger Brühl, 'Quality Assurance in the Production of Native Rapeseed Oil', 2005; storage humidity above 7% quickly leads to the formation of musty and pungent aroma components). Fats and oils that are no longer marketable are also referred to as 'rancid'; storage in conditions of excessive humidity and / or oxygenation at elevated temperatures can cause seeds, fats, and oils to degrade and become rancid. Unmarketable fats and oils are then available at a reasonable price for technical purposes.
[0009] When testing cheap, rancid fats and oils for their suitability for technical applications, it was found, contrary to established information, that rancid oils can be used as the basis for a metallization mixture and also for the production of a thermo-electro-chemical generator cell, abbreviated to TEC-G cell.
[0010] TEC-G cells
[0011] Thermo-electrochemical generator cells have been known for some time. These cells generate a usable electrical current in a thermal flow through the corresponding flow of a redox couple and its reduction / oxidation. The article 'design and optimisation of thermo-electrochemical cells' (Salazar, Kuma, Cola; journal of applied electrochemistry; (2014) 44: 325-336; J Appl Electrochem (2014) 44: 325; DOI 10.1007 / s10800-013-0638-y) explains in general terms, and using the redox couple K3Fe(CN)6 / K4Fe(CN)6 as a concrete example, which factors go into suitable equations and how, based on the equation, a TEC generator cell can be optimized in terms of dimensions, concentrations, and operating parameters. Burmistrov et al.additionally report a voltage difference per degree Kelvin of 2 to 4 mV / K for a NiOOH / Ni(OH)2-TEC-G cell (Renewable Energy 157 (2020) 1-8; 'High Seebeck coefficient thermo-electrochemical cell using nickel hollow microspheres electrodes'; https: / / doi.Org / 10.1016 / j.renene.2020.04.001).
[0012] In a complementary article, Burmistrov et al. provide an overview of established and well-known TEC-G cells (Sustainability 2022, 14, 9483. https: / / doi.org / 10.3390 / su14159483; 'Advances in Thermo-Electrochemical (TEC) Cell Performances for Harvesting Low-Grade Heat Energy: A Review').
[0013] As property rights, which illustrate thermochemically activatable / usable systems, the following can be mentioned: JP000S57170081A, WÖ002010120652A1 ,
[0014] WÖ002015164907A1 , KR000101747165B1 , WÖ002017155046A1 , WÖ002020146361 A1 and CN000114738719A.
[0015] STATE OF THE ART Metallizing mixtures based on reducing mineral oils were discovered at the beginning of the 20th century. In 1903, GB 190324148A proposed producing alloys from oxide mixtures by adding a suitable reducing agent, which can also be mineral oil, and heating the mixture. In 1909, US 924,077 proposed extracting Cu from CuSO4 by adding a component and / or a mixture of hydrogen, hydrocarbon, illuminating gas, or a hydrocarbon and reacting them under high pressure and heating. Further developments of this basic idea involve heating thermally decomposable salts or carbonyl compounds, as described in documents DE 825 192 A, DE 1 914 046 A, and JP 62 130 823 A.
[0016] In this case, the goal was to condition a low-cost, natural fat and use the resulting hydrophilic phase as an electrolyte. US Pat. No. 1,329,322 A discloses the production of finely dispersed nickel in a hydrocarbon directly from a salt by heating. The active nickel is capable of catalytically activating hydrogen and then transferring it to double bonds and also to available oxygen compounds, releasing water. However, the use of rancid fat is discouraged, as this contaminates and deactivates the nickel metal.
[0017] TASK
[0018] Therefore, the task arose to specify a metallization mixture for cheap, rancid fat available in industrial quantities as well as a process for said mixture, whereby hydrogen is still available for a redox equilibrium, which can produce water, in order to equip a TEC generator cell with a suitable electrolyte.
[0019] SOLUTION
[0020] This object is achieved according to the features of the independent claims. Advantageous embodiments emerge from the dependent claims and the following description.
[0021] SUMMARY OF THE INVENTION
[0022] A metallization mixture according to the invention comprises a fat with unsaturated fatty acids, wherein the fat has been conditioned with oxygen and / or water and further contains at least one metal salt and at least one sulfate-containing compound.
[0023] In the metallization process, to deposit a metal from an oil-metal salt mixture at elevated temperature with a water content of 0.1 to 10 weight percent, the metallization mixture is applied to a target surface and heated to up to 150 °C. For the TEC generator cell, a thickened, hydrophilic phase is separated after phase separation and used as the electrolyte layer (4).
[0024] The cell 1, which as a thermo-electro-chemical generator - abbreviated as TECG - converts heat energy into electrical energy on the basis of at least one temperature-dependent redox equilibrium, has a first electrode 2, a second electrode 3 and at least the electrolyte layer 4 according to the method.
[0025] DESCRIPTION OF THE INVENTION AND ADVANTAGEOUS FEATURES
[0026] The metallization mixture according to the invention comprises a fat with unsaturated fatty acids, wherein the fat has been conditioned with oxygen and / or water. The inventors assume that upon conditioning with oxygen, CC multiple bonds can react to form epoxy structures, which can crosslink over time or form vicinal or geminal diols with moisture. Conditioning with water can directly generate alcohols in CC multiple bonds through an addition reaction and also cleave ester and, in general, ROR bonds to generate two OH groups. Furthermore, the metallization mixture comprises at least one metal salt and at least one sulfate-containing compound. Metal sulfates such as iron(III) sulfate, molecular formula Fe2(SO4)3, are known to release SO3 when heated. A sulfate-containing compound can therefore provide SO3.As a result, at least SO3 / SO2 as well as metal / metal cation - possibly equilibria between different oxidation states of a metal - and H2 / C=C / C=O / COC / COO-C / C-OH / H2O are available in the metallization mixture as redox participants and can be combined in complex ways, which explains the surprisingly effective reactivities of a metallization mixture.
[0027] The fat is preferably a rancid, natural fat. In direct contradiction to the state of the art, a metallization mixture based on an inexpensive, rancid, natural triglyceride has proven to be directly usable; depositable metal layers made from combined alkali, alkaline earth, and transition metal salts have always been metallically lustrous and surprisingly stable in the presence of a hydrophilic phase. X-ray fluorescence analysis (XRF) of the metal layers indicates, in addition to metal mixtures, deposited and / or passivating sulfur-containing compounds that also stabilize the respective layer. Metal deposition is particularly successful even when using technical reagents and salts, which, with 95% to 98% purity, contain 2 to 5 percent by weight of manufacturing-related impurities and are particularly inexpensive.The inventors assume that small amounts of hydrophilic byproducts and decomposition products of the rancid oil can stabilize and chemically actively enter the metal layers, similar to biomineralization, and account for the improved stability. Preferably, the fat has been thoroughly enriched and conditioned with oxygen and / or hydroxyl functions using cavitating water, water, and / or oxygen, either individually or in combination, with optional cavitation of the entire liquid. Such conditioning—preferably with oxygen and water—can be carried out particularly efficiently in a reactor according to WO 2020 / 098984 A1 and introduces additional intermediates of the RCH2OH / R2COH / RCHO / R2CO / RCOOR / R-HC=CH-R7H2O / O2 system and additional derivatives into the mixture.
[0028] The fat is preferably rapeseed oil. Rapeseed, in particular, deteriorates rapidly when stored in humid and / or excessively warm conditions, and can then no longer produce a marketable, flavorful oil. This very inexpensive oil proved to be widely combinable with the metallization mixtures claimed here, from which stable, nickel-containing metal layers could be produced, even when combined with nickel salts. Nickel, in particular, is capable of catalyzing the exchange of hydrogen between various hydrogenated hydrocarbons and / or other hydroxides / oxides, which can further stabilize and enhance redox activity in a mixture.
[0029] Preferably, the at least one metal salt comprises at least iron. Iron offers two known and well-studied oxidation states, Fe(II) and Fe(III), which are used, for example, in the potassium hexacyanoferrates in conventional TEC generator cells. In this case, a passivated, metallically lustrous layer, stable in the hydrophilic phase, was initially deposited using technical iron salts and / or technical iron powders dissolved in sulfuric acid. This layer could subsequently be used as part of a long-term stable TEC generator cell.
[0030] Preferably, the at least one metal salt contains, in addition to iron, at least one further metal salt of another metal, wherein the further metal is selected from the group consisting of cobalt, chromium, nickel, manganese, copper, lithium, sodium, potassium, calcium, magnesium, aluminum, vanadium, and titanium. Using the specified metals, metal mixtures could be deposited that provided increased redox activity and improved performance parameters as an electrode covering layer in a TEC generator cell while maintaining at least the same longevity of the system.
[0031] The metallization mixture preferably consists of hydrous, rancid rapeseed oil, technical-grade sulfuric acid, and technical-grade sulfate salts of the metals iron, chromium, nickel, and manganese. The inventors assume that iron and manganese provide several, closely spaced oxidation states, while chromium builds a stable hydrate matrix via aqua complexes and nickel catalytically integrates hydrogen-based redox equilibria. This may explain why, after initial metal deposition, a hydrophilic phase forms as a green, elastic mass, which in turn can be used for several years as the electrolyte of a TEC generator cell. The sulfate salts are particularly preferably produced by dissolving a technical alloy with the weight proportions 70% iron, 18% chromium, 8% nickel, and 1.5% manganese.
[0032] In a metallization process for depositing a metal from an oil-metal salt mixture at elevated temperature, the metallization mixture according to the invention with a water content of 0.1 to 10 weight percent is applied to a target surface and heated to up to 150°C. The metal is deposited on the underside; in parallel, a hydrophilic phase forms, which develops a higher viscosity during cooling. Heating is preferably carried out to 50°C to 130°C, which can prevent severe boiling delays. Heating is particularly preferred to 70°C to 100°C, which can prevent coloring / clouding decomposition processes. Metallization preferably takes place directly on a first electrode 2, so that after cooling, only a lipophilic phase needs to be separated to obtain the hydrophilic phase as a viscous electrolyte.
[0033] The pH of the metallization mixture is preferably adjusted to 0 to 6, preferably 1 to 5, and particularly preferably 2.5 to 4.5, before heating with sulfuric acid. Very acidic pH values of around 0 to 2 are recommended for mixtures in which metals are to be preliminarily dissolved. Moderately acidic mixtures with pH values of around 2 to 3 are recommended for mixtures in which metals are to be deposited from metal salts during heating. Weakly acidic mixtures with pH values of around 3.5 are recommended for mixtures and hydrophilic phases that are to be combined with aluminum electrodes and / or aluminum layers.
[0034] Preferably, the pH is finally adjusted to a value between 3 and 9, particularly preferably between 3 and 4. Furthermore, the pH is preferably adjusted using an alcoholate / alcohol mixture, preferably lithium glycerate.
[0035] The mixture preferably contains at least 60% natural fat by weight as the main component and is kept warm under metal deposition until a lower, hydrophilic phase and an upper, lipophilic phase have formed. Combined with metallization directly on a first electrode 2, only the supernatant, lipophilic phase needs to be separated, while the hydrophilic phase remains as a viscous electrolyte directly on the electrode 2. Therefore, the electrolyte layer 4 is preferably applied directly to a first electrode 2 under metal deposition.
[0036] Preferably, the metallization mixture and / or the hydrophilic phase are heated until a viscoelastic, hydrophilic phase is present. A viscoelastic mass is easier to handle and reduces the risk of accidentally causing a short circuit in flexible electrodes. Particularly preferably, the viscosity is finally adjusted using a setting agent such as a framework silicate, sand, activated carbon, conductive carbon black, graphite, an inert additive based on porous, inert particles such as glass spheres, oxide particles, or porous glass sponge spheres, or combinations of the above. This allows the viscosity to be increased to such an extent that quasi-solid, less elastic bodies can be obtained.
[0037] Preferably, after phase separation, the lipophilic phase is separated and reused.
[0038] Preferably, after phase separation, a thickened, hydrophilic phase is separated and used as electrolyte layer 4.
[0039] The electrolyte layer 4 is used in a cell 1 as the electrolyte of a thermo-electro-chemical generator (TECG). Thermal energy is converted into electrical energy based on at least one temperature-dependent redox equilibrium. The cell 1 comprises a first electrode 2, a second electrode 3, and at least one electrolyte layer 4, produced with the metallization mixture according to the invention.
[0040] Further advantages emerge from the exemplary embodiments. The features and advantages described above and the following exemplary embodiments are not to be construed as limiting combinations of features, unless explicitly described as such. Additional advantageous features and additional combinations of features, as explained in the description and established in the documents cited in the application, can be implemented individually or in different combinations as additions within the scope of the independent claims in the claimed subject matter, without departing from the scope of the invention.
[0041] SHORT DESCRIPTION OF THE CHARACTERS
[0042] The figures - abbreviated to Fig. - illustrate in principle sketches:
[0043] Figure 1: Cross section of a cell 1 with first electrode 2, a first main surface 12, a second main surface 14, electrolyte layer 4, second electrode 3 with first main surface 13 and second main surface 15;
[0044] Figure 2: Cell 1 according to Figure 1 with layer 5 formed for operational reasons;
[0045] Figures 3 to 14: Current-time diagrams (current measured during discharge in a short circuit) with zero voltage noted at different temperatures; Figure 15: Current-time diagrams of the discharge in a comparative overview.
[0046] EXAMPLES OF IMPLEMENTATION
[0047] In an advantageous embodiment, a TECG cell 1 according to the invention comprises the electrolyte layer 4, a first electrode 2, and a second electrode 3, wherein the electrolyte layer 4 is arranged between the two electrodes and was produced using the metallization mixture according to the invention. The first electrode 2 consists of carbon, the second electrode 3 of aluminum foil, and the TECG cell 1 with electrolyte layer 4 was obtained by: applying a metallization mixture made acidic with sulfuric acid and containing 0.1 to 10 percent by weight of water to the first electrode 2, the metallization mixture consisting of rancid, natural rapeseed oil, sulfuric acid, and immediately previously formed metal sulfates of the technical metals Fe, Cr, Ni, and Mn;
[0048] Heating up to 100 °C with metal deposition until a lower, thickened, viscoelastic, hydrophilic phase and an upper, lipophilic phase have formed;
[0049] Separation of the lipophilic phase; optional purification of the hydrophilic phase; optional addition of stabilizers and auxiliary substances including SiO2 spheres, framework silicates, inert builders, gelling aids, humectants, buffers, carrier fibers, paper carrier fibers, pyrogenic silica, salts, carrier fabrics, random fiber nonwovens;
[0050] Application of the second electrode 3 in the form of aluminum foil; optionally, the electrodes can be connected with electrical leads and the cell sealed. The cell produced in this way proves to be stable over years in climate chamber tests, generating energy from approximately 10 °C, and exhibiting decreasing internal resistance with increasing age / charge state: With an initial internal resistance of 800 ohms, the same cell showed an initially rapidly decreasing and then stable internal resistance of 8 to 10 ohms after 4 years. The potential coefficient in mV per K remained surprisingly stable, consistently ranging between 2 and 4 mV / K.
[0051] In a further advantageous embodiment, natural triglycerides (source: rapeseed) were stirred with 0.1% to 1.5%, preferably 0.5% to 1%, technical sulfuric acid (99%); the reaction process could be accelerated by cavitation. Subsequently, 1 to 3% water was added and left to stand until water settled as a hydrophilic phase. This hydrophilic, strongly acidic phase was heated in a metal container with a suitable alloy (Fe, Cr, Ni, Mn with 70% iron, 18% chromium, 8% nickel and 1.5% manganese), boiled briefly at 80 °C, heated further to just under 100 °C until the evolution of steam subsided, and then held at this temperature until decomposition was audibly initiated. The material shows increasing viscosity. The heat supply was then stopped. A green, modeling clay-like mass was obtained, which was mixed with porous, inert glass beads and used as an electrolyte layer.Optionally, impurities can be washed out with oil, methyl ester, or paraffin oil at 80 to 100 °C until the mass clumps. The resulting mass was applied to a carbon electrode; it was then covered with an aluminum foil as a second electrode to create a cell. The inventors assume that in this configuration, the carbon electrode has an overvoltage against some redox processes, which is provided by the metal deposition in similar electrodes. In any case, the initial heating of a carbon-based electrode is accompanied by metal deposition, which polarizes a cell with a metal counterelectrode, especially with an aluminum foil electrode as the counterelectrode, accordingly, and establishes a current flow. Such a cell can be provided in any size and format. For example, it can have a base area of 45 by 70 mm and then delivers a voltage of just under 1 V at a sufficiently high temperature.If the circuit is closed, a current of a few milliamperes flows for a few seconds, for example 20 seconds. The cell is then almost discharged (but cannot be fully discharged because ambient heat > 10°C is always converted directly into electrical energy and released straight away without being stored). If the cell is heated, for example for 30 minutes at a temperature of 25 degrees, the cell is fully charged again, i.e. it is able to provide the previously mentioned electrical voltage. It has been found that such cells can be charged by staying at an ambient temperature of at least between 9.5°C and 40°C, but also, for example, by exposure to sunlight or contact with a warm object. It has been shown that longer charging times and / or higher charging temperatures lead to higher cell voltages until a saturation effect occurs. The heating of the cell orof the electrolyte can, for example, be effected by solar radiation or thermal conduction, i.e. in particular by bringing it into contact with a warm material or by the influence of the ambient temperature. The cell produced in this way proves to be long-term stable; its properties and measured values are illustrated in the figures: Figure 1 shows a schematic cross-section of a galvanic cell 1 according to a first embodiment of the invention. The cell 1 has a first electrode 2 with a first main surface 12 and a second main surface 14. Adjacent to the second main surface 14 of the first electrode 2 is a layer 4 made of an electrolyte. The electrolyte in the form of a viscous mass is the material also referred to as material 2 and produced as described above. On the side facing away from the first electrode 2, a second electrode 3 is connected to the layer 4 made of the electrolyte.The second electrode 3 also has a first main surface 13 and a second main surface 15 and is arranged such that the layer 4 made of electrolyte is arranged between the second main surface 14 of the first electrode 2 and the first main surface 13 of the second electrode 3. In the illustrated embodiment, the first electrode 2 comprises carbon and small amounts of copper. The second electrode 3 is made of aluminum foil. The cell 1 is able to absorb thermal energy from its surroundings and store it in the form of chemical energy. If the first electrode 2 is connected to the second electrode 3 via a consumer, an electric current flows until the galvanic cell 1 is almost discharged. Figure 2 shows the cell 1 according to Figure 1 after it has been in operation for a while, i.e. after it has been charged and discharged several times.In the process, a layer 5 formed in layer 4 of the electrolyte adjacent to the first main surface 13 of the second electrode 3. This layer 5 is visually distinct from layer 4 and is no longer greenish, but rather gray. The inventors assume that the complex, interacting redox systems reach an energetic minimum over time, in which the formerly dispersed metal complexes are replaced by a more stable, conductive, and evenly distributed, homogeneous structure. This is supported by the internal resistance of cell 1 decreasing to a minimum while simultaneously providing stable power. Mass spectroscopic analyses revealed more sulfur in layer 5 than in layer 4, but less sulfur than layer 4 in the charged state. During charging and discharging of cell 1, sulfur-containing compounds move between layers 4, 5, and electrode 3.It was further shown that the sulfur content of a used second electrode 3 made of aluminum foil is lower than in the initial state, i.e. of an unused electrode. Furthermore, with the help of mass spectroscopic investigations, it was shown that copper, particularly in the form of copper(II) oxide, is mobile between the first electrode 2 and layer 4 during the charging and discharging process. In particular, copper migrates more intensively from the electrolyte into layer 5 during the discharging process and into the first electrode 2 during the charging process. Both of these indicate complex interwoven redox equilibria in which anions and cations provide thermal energy as electrical energy in accordance with local overvoltages or a superimposed thermal flow. Figures 3 to 10 show diagrams illustrating the charging and discharging of the cell 1, in which the measured current intensity is plotted as a function of the charging and discharging current.Discharge time is plotted and supplemented with the zero voltage, i.e. the voltage without any significant current flow. Figures 3 and 4 refer to cell 1 with an area of 45 mm by 70 mm, where cell 1 was charged at a temperature of 9.5 °C, i.e. was exposed to a temperature of 9.5 °C for 30 minutes after it had initially been (almost) discharged. Starting from a cell voltage of approximately 0.05 V, which delivered a current of 0.98 mA, the cell voltage after a charging time of 30 minutes was 0.782 V, which delivered a current of 1.1 mA. During the discharge process, which is shown in Figure 4, the cell voltage fell back to its initial value within 7 seconds. However, as other studies have shown, the cell voltage rises back to a voltage close to the initial voltage within a few seconds solely due to the influence of the ambient temperature.Figures 5 and 6 show a similar charging and discharging process of the same cell at 9.5°C, but with a doubled charging time. In this case, as can be seen from Figure 6, the cell is discharged again after approximately 10 seconds. Figures 7 and 8 show a charging and discharging process of the same cell, also at a temperature of 9.5°C, with the charging time further increased to 6 hours. In this case, as can be seen from Figure 8, the cell is discharged again after 15 seconds (discharge due to maximum short circuit). Figures 9 and 10 show another charging and discharging process of the same cell at 9.5°C, with a increased charging time to 17 hours. In this case, as can be seen from Figure 10, the cell is discharged after 17 seconds. Figure 11 shows a diagram summarizing the charging processes of the cell at 9.5°C according to Figures 3 to 10.It can be seen that the cell voltage achieved by charging approaches the saturation value, which is reached after around 15 hours. Figure 12 shows a diagram for the same cell as Figure 11, but where the charging took place at 26.2 °C instead of 9.5 °C. As can be seen from Figure 12, under these conditions the saturation value for the cell voltage is reached earlier, namely after one to two hours. Figure 13 shows another diagram for charging the same cell, but where the charging process took place at 37 °C. Under these conditions the saturation value is reached after just half an hour of charging. Figure 14 shows another diagram for charging the same cell, but where the charging took place at 44.3 °C. A saturation value for the cell voltage or the supplied current is reached in less than half an hour. Figure 15 summarizes the results of various charging and discharging processes.Discharge processes of the same cell at different temperatures and durations. Curve A shows the discharge of the cell after a 30-minute charge at 9.5°C. Curve B shows the discharge of the cell after a 60-minute charge at 9.5°C. Curve C shows the discharge of the cell after a one-hour charge at 9.5°C. Curve D shows the discharge of the cell after a 17-hour charge at 9.5°C. Curve E shows the discharge of the.
[0052] Cell after a 30-minute charge at 26.2 °C. Curve F shows the discharge of the
[0053] Cell after a 40-minute charge at 26.2 °C. Curve G shows the discharge of the
[0054] Cell after a 60-minute charge at 26.2 °C. Curve H shows the discharge of the
[0055] Cell after a 15-minute charge at 37°C. Curve I shows the cell discharge after a 30-minute charge at 37°C. Curve J shows the cell discharge after a 60-minute charge at 37°C. Curve K shows the cell discharge after a 15-minute charge at 44.3°C, and curve L shows the cell discharge after a 30-minute charge at 44.3°C. Over the course of the tests, the internal resistance of cell 1 fell from approximately 800 ohms to 80 ohms; after several simulated years of aging testing in a climate chamber, the internal resistance fell by 10 to 20 ohms, with the potential in mV per degree K always being between 2 and 4 mV / K.
[0056] In a further advantageous embodiment, the mass for an electrolyte layer 4 is obtained by: natural triglycerides, preferably rapeseed oil, are stirred with 0.1 to 0.5% technical sulfuric acid (99%); • 1 to 3% water is added and the mixture is left to stand until a hydrophilic phase settles; the settled hydrophilic phase is heated after adding a powder of a technical, iron-containing alloy, for example an alloy comprising iron, nickel, chromium and manganese, in particular approx. 70% iron, 18% chromium, 8% nickel and 1.5% manganese; the mixture is boiled at 80 °C until the evolution of gas subsides, then heated to just under 100 °C until the evolution of steam subsides and kept at this temperature until the then present mass becomes viscous with the development of noise; the heat supply is then stopped and the cooled mass is removed.
[0057] INDUSTRIAL APPLICABILITY
[0058] Known TEC generator cells generally deliver energy in a thermal gradient; energy is unavailable at a uniform temperature. The challenge is to overcome this disadvantage. With the help of a metallization mixture, long-term stable electrodes can be provided for the first time. These electrodes, which determine the current direction for one of the redox reactions via a stable overvoltage and make energy accessible at a uniform temperature. A metallization process and a thermo-electrochemical generator cell based on this process can be manufactured and supplied particularly inexpensively using rancid, natural oils as the raw material and starting material for the metallization mixture, as well as inexpensive, technically pure chemicals.The direct utilization of undirected waste heat in the range 10°C to 70°C is thus commercially possible for the first time on an industrial scale with a cell 1 with electrode 2, first main surface 12, second main surface 14, electrolyte layer 4, second electrode 3, first main surface 13 and second main surface 15.
Claims
PATENT CLAIMS 1. A metallization mixture comprising a fat with unsaturated fatty acids, wherein the fat has been conditioned with oxygen and / or water; at least one metal salt and at least one sulfate-containing compound.
2. Metallizing mixture according to the preceding claim, characterized in that the fat is a rancid, natural fat.
3. Metallizing mixture according to one of the preceding claims, characterized in that the grease has been thoroughly enriched and conditioned with cavitating water, water and / or oxygen.
4. Metallizing mixture according to one of the preceding claims, characterized in that the fat consists of rapeseed oil.
5. Metallization mixture according to one of the preceding claims, characterized in that the at least one metal salt comprises at least iron.
6. Metallization mixture according to one of the preceding claims, characterized in that the at least one metal salt contains, in addition to iron, at least one further metal salt of a further metal, wherein the further metal is selected from the group consisting of cobalt, chromium, nickel, manganese, copper, lithium, sodium, potassium, calcium, magnesium, aluminum, vanadium, titanium.
7. Metallizing mixture according to one of the preceding claims, consisting of water-containing, rancid rapeseed oil, technical sulfuric acid and technical sulfate salts of the metals iron, chromium, nickel and manganese.
8. Metallization process for depositing a metal from an oil-metal salt mixture at elevated temperature, characterized in that a metallization mixture according to one of the preceding claims with a water content of 0.1 to 10 percent by weight is applied to a target surface, preferably to a first electrode (2), and heated to up to 150 °C, preferably 50 °C to 130 °C, particularly preferably 70 °C to 100 °C.
9. Metallization process according to the preceding claim, characterized in that the pH value of the metallization mixture before heating with Sulphuric acid is adjusted to 0 to 6, preferably 1 to 5, particularly preferably 2.5 to 4.
5.
10. Metallization process according to one of the two preceding claims, characterized in that the mixture contains at least 60% by weight of natural fat as the main component and the mixture is kept warm with metal deposition until a lower, hydrophilic phase and an upper, lipophilic phase have formed.
11. Metallization process according to one of the three preceding claims, characterized in that the metallization mixture is heated until a visco-elastic, hydrophilic phase is present.
12. Metallization process according to one of the four preceding claims, characterized in that after phase separation a lipophilic phase is separated and reused.
13. Metallization process according to one of the five preceding claims, characterized in that after phase separation a thickened, hydrophilic phase is separated and used as electrolyte layer (4).
14. Metallization process according to the preceding claim, characterized in that the electrolyte layer (4) is applied to a first electrode (2) with metal deposition.
15. Cell (1) which, as a thermo-electro-chemical generator - abbreviated as TECG - converts heat energy into electrical energy on the basis of at least one temperature-dependent redox equilibrium, comprising a first electrode (2), a second electrode (3) and at least one electrolyte layer (4) according to claim 13.
16. TECG cell (1), preferably according to the preceding claim, comprising a first electrode (2), a second electrode (3) and an electrolyte layer (4), wherein the first electrode (2) consists of carbon, the second electrode (3) consists of aluminum foil and the TECG cell (1) with electrolyte layer (4) was obtained by: applying an acidic metallization mixture with a water content of 0.1 to 10 percent by weight to the first electrode (2), wherein the metallization mixture consists of rancid, natural rapeseed oil, sulfuric acid, immediately previously formed metal sulfates of the technical metals Fe, Cr, Ni, Mn; Heating up to 100 °C with metal deposition until a lower, thickened, visco-elastic, hydrophilic phase and an upper, lipophilic phase have formed; Separation of the lipophilic phase; optional purification of the hydrophilic phase; optional addition of stabilizers and auxiliary substances including SiO2 spheres, framework silicates, inert builders, gelling aids, humectants, buffers, carrier fibers, paper carrier fibers, pyrogenic silica, salts, carrier fabrics, random fiber nonwovens; Applying the second electrode (3); optionally connecting the electrodes with electrical leads and sealing the cell.