Galvanic cell having electrode element and production method

Abstract

The invention relates to an electrochemical galvanic cell comprising a first electrode element (10) having an electrode body comprising an electrode active material (11) and a first conductive carbon additive (12), the first conductive carbon additive (12) being a carbon black characterized by a Brunauer-Emmet-Teller (BET) specific surface area of at least 100 m < 2 > g <-1 > and an average particle size of less than 1 [mu] m. The invention further relates to a method for producing a first electrode element for an electrochemical galvanic cell.

Description

[0001] The present invention relates to a primary cell having an electrode element, a method for producing such an electrode element and the use thereof.

[0002] Due to the significant growth in the distribution of consumer electronic products and the significant improvement in electromobility, the demand for electrode components characterized by desirable properties such as increased capacity, reduced resistance and optimized voltage curves is steadily increasing. At the same time, there is a constant need for improved manufacturing methods optimized in terms of efficiency and cost.

[0003] It is therefore an object of the present invention to provide improved electrodes and methods for their production.

[0004] This object is achieved by a primary electrochemical cell having the features of claim 1 and a process having the features of claim 10 .

[0005] According to claim 1, an electrochemical cell is provided comprising a first electrode element. The electrode element according to the invention comprises an electrode body comprising an electrode active material and a first conductive carbon additive. According to the invention, it is particularly contemplated that the first conductive carbon additive is a nanostructured carbon black characterized by a Brunauer-Emmet-Teller (BET) specific surface area of ​​at least 100 m 2 g -1 The average particle size is below 1 μm.

[0006] The use of nanostructured carbon or carbon black provides several advantages. When uniformly distributed in the electrode body, the nanostructured carbon or carbon black forms a percolating electronic network along which the electrode active material of the electrode body is supplied with an electrolyte, wherein the electrolyte is adsorbed in the micropores and high specific surface of the nanostructured carbon or carbon black. As a result, the fraction of the first conductive carbon additive can be reduced, and the fraction of the electrode active material can be increased, which leads to an increased energy density and / or power density. As a further result, the pulse voltage value increases from mid-life (MOL) to end-of-life (EOL).

[0007] The term "Brunauer-Emmet-Teller (BET) specific surface area" is used in the sense known to the skilled person. It relates in particular to the surface area of ​​a solid or porous material. It can be determined by measuring the amount of gas required for monolayer loading and the resulting determination of the accessible outer and inner surfaces of the porous solid. In order to remove all gas and water molecules, the sample is typically baked in a vacuum at T = 100 ° C for one hour. The measurement is then usually carried out at a constant temperature of -196 ° C (liquid nitrogen in a Dewar vessel) with nitrogen as the adsorption gas after determining the sample mass.

[0008] The term "average particle size" is used in a sense known to the skilled person. It particularly refers to the median value of the particle size distribution of particles (e.g., particles of the first conductive carbon additive). This value is also referred to as D50. Suitable methods for determining particle size or particle size distribution include laser diffraction analysis or small-angle scattering (e.g., using X-ray or neutron radiation).

[0009] In one embodiment of the electrochemical cell according to the invention, the electrode body of the first electrode element comprises the first conductive carbon additive (11) in a mass fraction in the range of 1% (weight / weight) to 5% (weight / weight) relative to the mass of the electrode element. In one embodiment, the electrode body comprises the first conductive carbon additive (11) in a mass fraction in the range of 1% (weight / weight) to 2.5% (weight / weight).

[0010] In one embodiment of the electrochemical cell according to the invention, the electrode active material of the first electrode element is selected from manganese dioxide or carbon monofluoride. In one embodiment, the electrode active material is present in the electrode body in a mass fraction in the range of 87% (weight / weight) to 97% (weight / weight) relative to the mass of the electrode element. In one embodiment, the electrode active material consists essentially of or comprises manganese dioxide and is present in the electrode body in a mass fraction in the range of 90% (weight / weight) to 93.5% (weight / weight) relative to the mass of the electrode element. In one embodiment, the electrode active material consists essentially of or comprises carbon monofluoride and is present in the electrode body in a mass fraction in the range of 87% (weight / weight) to 97% (weight / weight) relative to the mass of the electrode element. In one embodiment, the electrode element contains a first carbon additive in a mass fraction in the range of 1% (weight / weight) to 2.5% (weight / weight), in particular about 2.5% (weight / weight), relative to the total mass of the electrode element.

[0011] In one embodiment of the electrochemical cell according to the invention, the manganese dioxide is a mixture of at least a first and a second powdery part, wherein the first powdery part is characterized by a smaller average particle size than the second powdery part. In one embodiment, the first powdery part is characterized by an average particle size in the range of 20 μm to 40 μm. In one embodiment, the second powdery part has an average particle size in the range of 40 μm to 80 μm. In one embodiment, the mass fraction of the first powdery part relative to the total mass of the manganese dioxide is in the range of 35% to 50%, in particular 42%. In one embodiment, the mass fraction of the second powdery part relative to the total mass of the manganese dioxide is in the range of 50% to 65%, in particular 58%. In one embodiment, the electrode body contains manganese dioxide in a mass fraction in the range of 90% to 93.5% relative to the total mass of the electrode body.

[0012] In a further embodiment of the electrochemical cell according to the present invention, the electrode body of the first electrode element further comprises a second conductive carbon additive. In one embodiment, the second conductive carbon additive is selected from graphite, for example, GNP6 (RMC Remacon GmbH) or KS6 (Imerys Graphite & Carbon). In one embodiment, the electrode body comprises the second conductive carbon additive in a mass fraction in the range of 0.5% to 5% relative to the total mass of the electrode body. In one embodiment, the electrode body comprises the second conductive carbon additive in a mass fraction in the range of 0.5% to 1.5% relative to the total mass of the electrode body.

[0013] In a further embodiment of the electrochemical cell according to the invention, the electrode body further comprises a binder. In one embodiment, the binder is selected from polytetrafluoroethylene (PTFE), carboxymethylcellulose (CMC), in particular the sodium salt of carboxymethylcellulose (Na-CMC), styrene-butadiene rubber (SBR), or a mixture of carboxymethylcellulose and styrene-butadiene rubber (CMC:SBR). In one embodiment, the electrode element comprises manganese dioxide (as the electrode active material) and a binder (in particular PTFE) (in a mass fraction ranging from 1% to 4%, in particular about 2.5%, relative to the total mass of the electrode body). In another embodiment, the electrode element comprises carbon monofluoride (as the electrode active material) and a binder (in particular carboxymethylcellulose (CMC), styrene-butadiene rubber (SBR), or a mixture of carboxymethylcellulose and styrene-butadiene rubber (CMC:SBR)) (in a mass fraction ranging from 2% (weight / weight) to 6% (weight / weight), in particular about 4.5% (weight / weight), relative to the total mass of the electrode body).

[0014] In an embodiment, the electrochemical cell according to the invention comprises a second electrode element, wherein the second electrode element comprises an alkali metal as electrode active material. In one embodiment, the alkali metal is selected from lithium, sodium and potassium, with lithium being preferred.

[0015] In a further embodiment, the electrochemical cell according to the invention further comprises an electrolyte, preferably a non-aqueous electrolyte, wherein in particular the first electrode comprises an alkali metal as electrode active material, in particular selected from lithium, sodium or potassium. Suitable electrolytes include, but are not limited to, non-aqueous, preferably aprotic solvents such as esters, ethers and dialkyl carbonates, in particular tetrahydrofuran, methyl acetate, diglyme (bis(2-methoxyethyl) ether), triglyme (tris(2-methoxyethyl) ether), tetraglyme (tetrakis(2-methoxyethyl) ether), 1,2-dimethoxyethane, 1,2-diethoxyethane, 1-ethoxy-2-methoxyethane, dimethyl carbonate, diethyl carbonate, dipropyl carbonate, ethyl methyl carbonate, methylpropyl carbonate, ethylpropyl carbonate or mixtures thereof, or cyclic carbonates, cyclic esters, cyclic amides, in particular propylene carbonate, ethylene carbonate, butylene carbonate, γ-butyrolactone, N-methylpyrrolidone or mixtures thereof. Suitable electrolytes also include polar non-aqueous solvents such as acetonitrile, dimethyl sulfoxide, dimethylformamide, dimethylacetamide or mixtures thereof.

[0016] In a further embodiment, the electrolyte comprises at least one conductive salt. The conductive salt is preferably an inorganic alkali metal salt, wherein the alkali metal cation is the same as the active anode material. Suitable anions are in particular PF6 - 、BF4 - 、AsF6 - 、SbF6 - 、ClO4 - 、O2 - 、AlCl4 - 、GaCl4 - 、SCN - 、SO3(C6F5) - 、C(SO2CF3)3 - 、N(SO2CF3)2 - and SO3CF3. In a preferred embodiment, the concentration of the conductive salt is 1 mol / l.

[0017] In a further embodiment, the electrochemical cell according to the invention further comprises at least one separator arranged between the first electrode element and the second electrode element. Suitable separators comprise non-metallic materials, in particular polymers such as polyethylene or polypropylene, polyamides such as nylon, or fluoropolymers such as ethylene tetrafluoroethylene copolymer (ETFE) or polytetrafluoroethylene (PTFE). Preferably, the separator is designed in the form of a film or a pouch and can be moistened with an electrolyte, in particular one of the electrolytes described in the above embodiments, before the separator is arranged between the first and second electrodes.

[0018] According to claim 10, a process for manufacturing an electrode element is provided. The process comprises the following steps:

[0019] - providing a first electrode active material, a first conductive carbon additive and optionally a second conductive material,

[0020] - mixing the first electrode active material, the first conductive carbon additive and optionally a second conductive carbon additive to produce a (homogeneous) dry mixture, in particular a homogeneous dry mixture,

[0021] - providing a binder suspension comprising a solvent and at least a first binder, wherein in particular the solvent is an aqueous solvent or water,

[0022] - mixing the binder suspension into the dry mixture to produce a wet granulate,

[0023] - drying the wet granular matter to produce dried granular matter, and

[0024] - forming the dried particles into an electrode body.

[0025] When the binder suspension is added to the dry mixture, the particles of the dry mixture become wet and spontaneously form aggregates (i.e., grains). The average particle size of the wet granules can advantageously be adjusted by using a predetermined ratio of dry mixture and binder suspension. In this case, it may be advantageous to first add a first predetermined amount of aqueous solvent to the dry mixture, then add a predetermined amount of binder suspension, and then optionally add a second predetermined amount of aqueous solvent.

[0026] In one embodiment of the process according to the invention, the first conductive carbon additive (12) is characterized by a Brunauer-Emmet-Teller (BET) specific surface area of ​​at least 100 m 2 g -1 And the average diameter of carbon (black) is less than 1 μm.

[0027] Thus, in one embodiment of the process according to the invention, the step of mixing the binder suspension and the dry mix to produce the wet granulate comprises the steps of adding a first predetermined amount of solvent to the dry mix, then adding the binder suspension, and / or adding a second predetermined amount of solvent after adding the binder suspension. In a preferred embodiment, the first predetermined amount of solvent is added to the dry mix, then the binder suspension is added, and then the predetermined second amount is added to produce the wet granulate.

[0028] Furthermore, the dry mixture can advantageously be mixed with agitation (e.g. stirring or shaking) before the addition of the aqueous solvent and / or the binder suspension, in particular in order to produce a homogeneous dry mixture, in particular in a mixing device. Furthermore, the aqueous solvent and / or the binder suspension can advantageously be added with agitation (e.g. stirring or shaking) of the dry mixture, preferably in a mixing device for providing the dry mixture.

[0029] Thus, in one embodiment of the process according to the invention, mixing the first electrode active material, the first conductive carbon additive and the optional second conductive carbon additive, and / or mixing the binder suspension and the dry mixture is performed under agitation with the aid of a mixing device, thereby producing wet granules.

[0030] In a preferred embodiment, the mixing device comprises a rotatable mixing container and a rotatable mixing tool. In one embodiment, the directions of rotation of the mixing container and the mixing tool are opposite to each other, wherein the mixing container and the mixing tool can rotate essentially around the same rotation axis or around different rotation axes. In one embodiment, the electrode active material, the first conductive carbon additive and the optional second conductive carbon additive are mixed in the mixing device at an rpm (revolutions per minute) ratio between the container and the tool in the range of 1:55 to 1:65, in particular about 1:60. In one embodiment, the solvent and / or binder suspension is added to the dry mixture to produce wet granules at an rpm (revolutions per minute) ratio between the container and the tool in the range of 1:100 to 1:50, in particular about 1:78. In one embodiment, during mixing the electrode active material, the first conductive carbon additive and the optional second conductive carbon additive to produce the dry mixture and / or during adding the solvent and / or binder suspension to the dry mixture to produce the wet granules, the mixing tool is rotated at 2000 min -1 Up to 5000 minutes -1and rotating at an rpm within a range of 3750 to 4000 rpm, in particular, rotating at an rpm within a range of 3750 to 4000 rpm during mixing the electrode active material, the first conductive carbon additive, and the optional second conductive carbon additive to produce a dry mixture. -1 The dry mixture is rotated at 4500 rpm and / or at about 4500 rpm during the addition of solvent and / or binder suspension to the dry mixture to produce the wet granules. -1 In one embodiment, the mixing vessel is rotated at 50 minutes. -1 Up to 65 minutes -1 In the range, especially about 58 minutes -1 In one embodiment, the electrode active material, the first conductive carbon additive, and the optional second conductive carbon additive are mixed to produce a dry mixture within a period of time ranging from 30 seconds to 120 seconds, preferably about 80 seconds, in particular in the aforementioned mixing apparatus, in particular with the aforementioned rpm for the mixing vessel and / or mixing tool. In one embodiment, after the addition of the solvent and / or binder suspension, the wet granules are agitated within a period of time ranging from 100 seconds to 300 seconds, in particular about 200 seconds, in particular in the aforementioned mixing apparatus, in particular with the aforementioned rpm for the mixing vessel and / or mixing tool.

[0031] However, it may be desirable to adjust the average particle size of the dried granules. This can be achieved, for example, by sieving the dried granules to the desired average particle size.

[0032] Preferably, the step of mixing the electrode active material, the first conductive carbon additive and the optional second conductive carbon additive to produce a dry mixture and / or the step of adding the solvent and / or binder suspension to the dry mixture to produce wet granules is performed at room temperature.

[0033] One advantage of the process according to the invention is that the electrode material is provided in granular form, which is easier to handle than ungranulated powder, in particular with regard to dust development and flowability. This is particularly important for the production of electrode elements according to the invention, since the first conductive carbon additive can be handled only poorly due to its very small particle size.

[0034] In one embodiment of the process according to the invention, the first electrode active material comprises or consists essentially of carbon monofluoride.

[0035] In one embodiment, the manganese dioxide is provided as a powder having an average particle size in the range of 10 μm to 100 μm. In one embodiment, the manganese dioxide is a mixture of at least a first and a second powdered portion, wherein the first powdered portion is characterized by a smaller average particle size than the second powdered portion. In one embodiment, the first powdered portion is characterized by an average particle size in the range of 20 μm to 40 μm. In one embodiment, the second powdered portion has an average particle size in the range of 40 μm to 80 μm. In one embodiment, the mass fraction of the first powdered portion relative to the total mass of the manganese dioxide is in the range of 35% to 50%, particularly approximately 42%. In one embodiment, the mass fraction of the second powdered portion relative to the total mass of the manganese dioxide is in the range of 50% to 65%, particularly approximately 58%. In one embodiment, the dry mixture contains a mass fraction of manganese dioxide in the range of 90% to 93.5% relative to the total mass of the electrode body.

[0036] In a further embodiment of the process according to the invention, the second conductive carbon additive is selected from graphite, for example GNP 6 (RMC Remacon GmbH) or KS6 (Imerys Graphite & Carbon). In one embodiment, the dry mixture comprises the second conductive carbon additive in a mass fraction in the range of 0.5% to 5%, in particular in the range of 0.5% to 1.5%, relative to the total mass of the dry mixture.

[0037] In a further embodiment of the process according to the invention, the binder suspension comprises a binder selected from polytetrafluoroethylene (PTFE), carboxymethylcellulose (in particular the sodium salt of carboxymethylcellulose (Na-CMC)), styrene-butadiene rubber (SBR), or a mixture of carboxymethylcellulose and styrene-butadiene rubber (SBR:CMC) (in particular, when the electrode active material comprises manganese dioxide or consists essentially of manganese dioxide), or the binder is selected from polyvinylidene fluoride (PVDF), carboxymethylcellulose, styrene-butadiene rubber (SBR), or a mixture of carboxymethylcellulose and styrene-butadiene rubber (CMC:SBR) (in particular, when the electrode active material comprises carbon monofluoride or consists essentially of carbon monofluoride). In one embodiment, the binder suspension comprises polytetrafluoroethylene (PTFE) as a binder, the mass concentration of polytetrafluoroethylene (PTFE) being in the range of 50% to 70%, in particular about 60%, in particular when the electrode active material comprises manganese dioxide or consists essentially of manganese dioxide. In one embodiment, the aqueous solvent is water. In another embodiment, the binder suspension comprises carboxymethyl cellulose, styrene butadiene rubber (SBR), or a mixture of carboxymethyl cellulose and styrene butadiene rubber (SBR:CMC) as a binder in a mass concentration ranging from 2% to 6%, in particular about 4.5%.

[0038] In a further embodiment of the process according to the invention, the dried granulate is characterized by an average particle size in the range of 200 μm to 600 μm, in particular in the range of 300 μm to 350 μm, more in particular about 318 μm.

[0039] According to another aspect of the present invention, a medical device is provided, in particular an implantable medical device, wherein the medical device comprises an electrode element according to claim 1 or one of its embodiments described above, an electrode element manufactured by a process according to claim 9 or an embodiment thereof, or an electrochemical cell according to claim 15 or one of its embodiments.

[0040] Further details of various aspects of the present invention will be explained with reference to the embodiments and the accompanying drawings. In the drawings:

[0041] Figure 1 shows a schematic diagram of an electrode element according to the prior art,

[0042] Figure 2 A schematic diagram of an electrode element according to the present invention is shown.

[0043] Figure 3 A schematic diagram of a granulation process according to the present invention is shown.

[0044] Figures 4 to 7 A comparison of the voltage curve of an electrode element according to the prior art and the voltage curve of an electrode element according to the present invention is shown.

[0045] Figure 1 A schematically illustrates the structure of a cathode element according to the prior art, which comprises an electrode body in electrical communication with a current collector 15. Typically, the electrode body is a mixture of an electrode active material 11 (e.g., carbon monofluoride or manganese oxide) and a conductive carbon additive (e.g., carbon black 16 and graphite 13) to enhance the electrical conductivity of the electrode body. However, the carbon black used is typically characterized by a relatively low BET, so more graphite 13 must be added to achieve the desired conductivity.

[0046] In contrast to the above-described prior art cathode elements, the electrode element 10 according to the present invention utilizes an improved design and composition. Figure 2 According to the present invention, it is particularly contemplated to use in the electrode body 16 a conductive nanostructured carbon additive 12, which is particularly characterized by an average particle size below 1 μm and at least 100 μm. 2 g -1 Advantageously, the conductive nanostructured carbon additive 12 according to the present invention combines high electrical conductivity with high electrolyte absorption and forms a percolated electron network 12 ( Figure 2 ). In addition, when compared to conductive additives according to the prior art, the conductive nanostructured carbon additive 12 can be effectively used at a reduced concentration. As a result, the amount of electrode active material 11 (e.g., manganese dioxide or carbon monofluoride) can be increased, and thus the energy / power density can be increased.

[0047] The electrode body can advantageously be Figure 3The granulation process shown in the figure and described below is formed. In a first step, a suspension containing a solvent 16 (preferably water) and an organic binder 17 (for example PTFE, CMC, SBR or SBR:CMC) is added to a powdered electrode composition containing an electrode active material 11 (for example manganese dioxide or carbon monofluoride) and a conductive carbon additive (in particular a nanostructured carbon additive 12 according to the present invention) and optionally graphite 13. When the suspension 16, 17 is added, the powdered composition 11, 12, 13 is wetted 20 by the suspension 16, 17, whereupon the particles of the powdered composition 11, 12, 13 spontaneously agglomerate 30 into larger particles 21. The larger particles 30 are now dried to produce dry granules of the electrode composition.

[0048] Comparative Example 1: Electrode element with manganese oxide according to prior art

[0049] In order to produce a first comparative electrode element according to the prior art, 200 g of a powdered composition comprising manganese dioxide 11 (180 g), carbon black P50uv 12 (5 g) and graphite GNP6 13 (10 g) was mixed at 3750 rpm for 80 seconds, in particular using a mixing device having a rotating container and mixing elements rotating in opposite directions, wherein the mixing tool rotates at approximately 3750 rpm. Then, 25 ml of water 15, 8.37 g of a binder suspension 16, 17 (60% PTFE in water) and 5 ml of water 15 were continuously added to the powdered compositions 11, 12, 13 while mixing at 4500 rpm, in particular in the above-mentioned mixing device. The wetted composition 20 was granulated at 4500 rpm for 200 seconds to form a wet granulate 21. The wet granulate 21 was dried 12 at 130 ° C and 200 mbar. Subsequently, particles larger than 500 μm were separated by sieving.

[0050] Example 1: Electrode element having manganese oxide according to the present invention:

[0051] To produce the first electrode element according to the invention, 200 g of a powdered composition comprising manganese dioxide 11 (187 g), nanostructured carbon black ENSACO 350G (5 g), and graphite GNP 6 12 (3 g) were mixed at 3750 rpm for 80 seconds, in particular using a mixing device with a rotating container and mixing elements rotating in opposite directions, the mixing tools rotating at approximately 3750 rpm. 25 ml of water 15, 8.37 g of a binder suspension 14, 15 (60% PTFE in water), and 5 ml of water 15 were then added successively to the powdered compositions 11, 12, 13 while mixing at 4500 rpm, in particular in the aforementioned mixing device. The moistened composition 20 was granulated for 200 seconds under agitation at 4500 rpm to form wet granules 21. The wet granules 21 were dried 12 at 130° C. and 200 mbar. Particles larger than 500 μm were subsequently separated by sieving. The final composition of the pellets was then manganese dioxide 11 (187 g), ENSACO 350G (5 g), graphite GNP 6 12 (3 g), and PTFE (5 g). This first example used nanostructured carbon black (ENSACO 350G) as the first conductive carbon additive, which is characterized by a high BET ratio and a small mean grain size. Advantageously, the second carbon additive (graphite) can be added in smaller amounts, thereby increasing the amount of active electrode material (manganese oxide) and thus improving the energy density of the electrochemical cell.

[0052] Comparative Example 2: Electrode element with carbon monofluoride according to prior art

[0053] To produce a second comparative electrode element according to the prior art, 100 g of a powdered composition comprising carbon monofluoride 11 (83 g), graphite BNB90 13 (10 g) and PVDF (7 g) as a binder were mixed to produce a dry electrode material mixture.

[0054] Example 2: Electrode element with carbon monofluoride according to the present invention

[0055] To produce the second electrode element according to the invention, 100 g of a powdered composition comprising carbon 1.5 monofluoride 11 (93.5 g), carbon black LITX-200 12 (2.5 g) and graphite GNP6 13 (1.5 g) were mixed at 3750 rpm for 80 seconds, in particular using a mixing device having a rotating container and mixing elements rotating in opposite directions, wherein the mixing tools rotate at approximately 3750 rpm. 25 ml of ethanol and 50 ml of a binder suspension 16, 17 (6% SBR:CMC in water) were then added continuously to the powdered compositions 11, 12, 13 while mixing at 4500 rpm, in particular in the aforementioned mixing device. The moistened composition 20 was granulated at 4500 rpm for 200 seconds to form a wet granulate 21. The wet granulate 21 was dried 12 at 130° C. and 200 mbar. Subsequently, particles larger than 800 μm were separated by sieving. The final composition of the particulate matter of the second electrode element according to the present invention is thus: carbon monofluoride 11 (93.5 g), carbon black LITX-200 12 (2.5 g), graphite GNP6 13 (1.5 g), and CMC:SBR (2.5 g). Furthermore, this second example uses nanostructured carbon black (LITX-200) as the first conductive carbon additive, characterized by a high BET ratio and a small average particle size. Furthermore, in this case, the second carbon additive (graphite) can be added in a smaller amount, thereby increasing the amount of active electrode material (carbon monofluoride) and, therefore, the energy density of the electrochemical cell.

[0056] Figures 4 to 7 In particular, the advantageous effect of the conductive nanostructured carbon additive 12 is shown. Each of the figures shows the voltage curve of an electrode element 10 according to the prior art compared to an electrode element according to the invention, wherein both electrode elements (forming the cathode) are used in combination with lithium as the electrode active material of the counter electrode (anode).

[0057] In detail, Figure 4 The discharge curves of electrode elements (prior art and according to the invention) with respect to absolute capacity are shown, wherein both electrode elements use manganese dioxide as the electrode active material. The electrode element 10 according to the invention exhibits a higher voltage curve and an increased absolute capacity.

[0058] Figure 5The discharge curves of electrode elements (both according to the prior art and according to the present invention) are shown with respect to their specific capacity, with both electrode elements using manganese dioxide as the electrode active material. Furthermore, the electrode element 10 according to the present invention exhibits a higher voltage curve. Furthermore, the electrode element 10 according to the present invention demonstrates improved utilization or exploitation of the electrode active material 11.

[0059] Figure 6 The discharge curves of electrode elements (both according to the prior art and according to the present invention) with respect to absolute capacity are shown, wherein both electrode elements use carbon monofluoride as the electrode active material 11. Moreover, the electrode element 10 according to the present invention exhibits a higher voltage curve and an increased absolute capacity by using this electrode active material 11.

[0060] Figure 7 The discharge curves of electrode elements (according to the prior art and according to the present invention) are shown with respect to their specific capacity, with both electrode elements using carbon monofluoride as the electrode active material. Furthermore, the electrode element 10 according to the present invention exhibits a higher voltage curve. Furthermore, the electrode element 10 according to the present invention demonstrates improved utilization or development of the electrode active material 11.

Claims

1. Electrochemical primary cell, comprising: - a first electrode element (10) having an electrode body comprising an electrode active material (11) and a first conductive carbon additive (12), in, The first conductive carbon additive (12) is characterized by a Brunauer-Emmet-Teller (BET) specific surface area of ​​at least 100 m 2 g -1 And the average particle size of carbon black is less than 1 μm.

2. The electrochemical cell according to claim 1 , wherein the electrode body contains the first conductive carbon additive ( 11 ) in a mass fraction in the range of 1% (w / w) to 5% (w / w), in particular in the range of 1% (w / w) to 2.5% (w / w), relative to the total mass of the electrode body.

3. The electrochemical cell according to claim 1 , wherein the electrode active material ( 11 ) is manganese dioxide or carbon monofluoride, in particular in a mass fraction ranging from 87% (w / w) to 97% (w / w) relative to the total mass of the electrode body.

4. The electrochemical cell of claim 3, wherein the manganese dioxide is a mixture of at least a first powdered portion and a second powdered portion, wherein the first powdered portion is characterized by a smaller average particle size than the second powdered portion.

5. The electrochemical cell according to claim 4, wherein: - said first pulverulent portion is characterized by an average particle size in the range of 20 μm to 40 μm, and / or - the second powdery part has an average particle size in the range from 40 μm to 80 μm.

6. The electrochemical cell according to claim 4 or 5, wherein: - the mass fraction of the first pulverulent part is in the range of 35% to 50%, in particular about 42%, and / or - the mass fraction of the second powdery part is in the range of 50% to 65%, in particular about 58%.

7. Electrochemical cell according to any of the preceding claims, wherein the electrode body (16) contains a second conductive carbon additive (12), in particular in a mass fraction in the range of 0.5% (w / w) to 5% (w / w), in particular in the range of 0.5% (w / w) to 1.5% (w / w), relative to the total mass of the electrode body, the second conductive carbon additive (12) being in particular selected from graphite.

8. Electrochemical cell according to any of the preceding claims, wherein the electrode body contains an organic binder, in particular in a mass fraction in the range of 2% (w / w) to 6% (w / w), more particularly in the range of 2.5% (w / w) to 4.5% (w / w), relative to the mass of the electrode body, wherein the organic binder is in particular chosen from polytetrafluoroethylene, sodium salt of carboxymethylcellulose, styrene butadiene rubber, or polyvinylidene fluoride, or a mixture thereof.

9. The electrochemical cell according to any one of the preceding claims, comprising: - a second electrode element, Characteristically, the second electrode element contains an alkali metal, in particular lithium, sodium or potassium, as an electrode active material.

10. A process for producing an electrode element (10) for an electrochemical cell, comprising the following steps: - providing a first electrode active material (11), a first conductive carbon additive (12) and optionally a second conductive material (13), wherein the first conductive carbon additive (12) is characterized by a Brunauer-Emmet-Teller (BET) specific surface area of ​​at least 100 m 2 g -1 And the average diameter of carbon (black) is less than 1μm, - mixing the first electrode active material, the first conductive carbon additive and optionally a second conductive carbon additive to produce a dry mixture (20), - providing a binder suspension comprising at least a first binder (14) and a solvent (15), in particular an aqueous solvent or water, - mixing the binder suspension (14, 15) and the dry mixture (20) to produce a wet granulate (21), - drying the wet granules (21) to produce dried granules (22), and - forming the dried particles into an electrode body (16).

11. The process according to claim 10, wherein The step of mixing the binder suspension (14, 15) and the dry mixture (20) comprises: - adding a first predetermined amount of said solvent (15) to said dry mixture (20) and then said adding said binder suspension (14, 15), and / or - adding a second predetermined amount of said solvent (15) after adding said binder suspension.

12. The process according to claim 10 or 11, wherein The following is carried out under agitation, in particular by means of a mixing device, which in particular comprises a mixing container and a mixing tool, wherein in particular the mixing container and the mixing tool rotate in opposite directions: - said mixing of said first electrode active material, said first conductive carbon additive and optionally a second conductive carbon additive, and / or - said mixing of said binder suspension (14, 15) and said dry mixture to produce a wet granulate (21).

13. The process according to claims 10-12, wherein the first electrode active material (11) comprises carbon monofluoride (CF x ) or manganese dioxide (MnO2), or, alternatively, carbon monofluoride (CF x ) or manganese dioxide (MnO2).

14. The process according to claim 10 , wherein the binder ( 14 ) is selected from polytetrafluoroethylene, carboxymethyl cellulose, styrene butadiene rubber, a mixture of carboxymethyl cellulose and styrene butadiene rubber, or polyvinylidene fluoride, wherein in particular the binder is present in the binder suspension in a mass concentration in the range of 30% to 70%, wherein in particular the binder ( 14 ) is styrene butadiene rubber and is present in the binder suspension in a mass concentration in the range of 30% to 50%, preferably about 40%, or the binder ( 14 ) is polytetrafluoroethylene and is present in the binder suspension in a mass concentration in the range of 50% to 70%, preferably about 60%.

15. The process according to any one of claims 10 to 14, wherein the dried particulate matter (22) is characterized by an average particle size in the range of 200 to 600 μm, in particular in the range of 300 to 350 μm, more particularly about 318 μm.

Images