Systems and methods for producing electrochemical cells with multi-part anodes

Abstract

A nozzle for supplying anode material to an electrochemical cell and a method of using the same are provided. The nozzle includes: a hollow tubular body extending between an open upper end and an open lower end; a lower deflector spaced apart from the open lower end of the hollow tubular body, with an annular opening formed between a deflector surface of the lower deflector and the open lower end of the hollow tubular body; and a support rod connecting the lower deflector to the hollow tubular body, wherein the support rod is suspended inside the hollow tubular body by one or more support trusses.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims priority to U.S. Provisional Application Serial No. 62 / 964,374, filed January 22, 2020, which is incorporated herein by reference in its entirety.

[0003] background

[0004] Especially for spool-type electrochemical cells, common in alkaline batteries, the positional oxidation of the anode particles can affect the overall performance of the electrochemical cell. In these spool-type cells, the cathode (which typically contains manganese dioxide as the active material in alkaline galvanic cells) is formed as a generally hollow tube located within the battery container. The anode (usually comprising zinc or a zinc composite) is located inside the hollow cathode and is separated from it by a separator. The current collector (e.g., a nail) is located at the center of the anode. The entire composition is saturated in KOH electrolyte.

[0005] Recently, small-scale testing of electrochemical cells comprising multiple anode portions located at least substantially concentrically within the center of a spool-type alkaline battery has yielded promising results in improving overall battery performance. For example, as discussed in co-pending U.S. Patent Application No. 15 / 896,917, filed February 14, 2018, and U.S. Patent Application No. 16 / 145,830, filed September 28, 2018 (the contents of which are incorporated herein by reference in their entirety), certain battery configurations with dual anodes exhibit increased high-speed discharge performance with minimal trade-offs to low-rate service. While these small-scale laboratory tests have demonstrated the potential for improved performance in alkaline electrochemical cells, significant efforts have not yet been made to develop manufacturing techniques for the large-scale production of alkaline electrochemical cells with dual-anode configurations. Therefore, new alkaline electrochemical cell manufacturing techniques are needed to produce electrochemical cells with improved discharge performance. Summary of the Invention

[0006] Various embodiments provide systems and methods for constructing electrodes (e.g., anodes) for electrochemical cells to provide a characteristic gradient (e.g., providing at least two anode portions therein). Some embodiments relate to an extrusion nozzle configured to produce an anode ring within an electrochemical cell (e.g., within an opening formed by a cathode ring and a separator of the cell).

[0007] Various embodiments relate to a nozzle for supplying electrode material to an electrochemical cell, the nozzle comprising: a hollow tubular body extending between an open upper end and an open lower end; a lower deflector spaced apart from the open lower end of the hollow tubular body, an annular opening formed between a deflector surface of the lower deflector and the open lower end of the hollow tubular body; and a support rod connecting the lower deflector to the hollow tubular body, wherein the support rod is suspended inside the hollow tubular body by one or more support trusses.

[0008] In some embodiments, the support rod and the lower steering member define a through-passage. Furthermore, the diameter of the lower steering member is larger than the second outer diameter of the hollow tubular body. In some embodiments, the steering surface is concave. In various embodiments, the annular opening is adjustable. In some embodiments, the annular opening has a height of about 0.09 inches to about 0.125 inches. In many different embodiments, the steering member has a diameter of about 0.24 inches to about 0.275 inches. In some embodiments, the one or more support trusses are spaced apart at radially distributed locations at least substantially equidistant from the interior of the hollow tubular body. In many different embodiments, the one or more support trusses comprise multiple support trusses at each radial location.

[0009] Some embodiments relate to a method for forming an electrode in an electrochemical cell, the method comprising: positioning a nozzle within a central opening of the electrochemical cell; retracting the nozzle from the central opening of the electrochemical cell while continuously extruding a first anode material through an annular opening located near the lower end of the nozzle, to form a first anode portion having a central opening; and extruding a second anode material into the central opening of the first anode portion.

[0010] In various embodiments, extruding the second anode material into the central opening of the first anode portion includes: extruding the second anode material via a central channel within the nozzle while retracting the nozzle from the central opening of the electrochemical cell. In some embodiments, the nozzle includes: a hollow tubular body extending between an open upper end and an open lower end; a lower deflector spaced from the open lower end of the hollow tubular body, with an annular opening formed between a deflector surface of the lower deflector and the open lower end of the hollow tubular body; and a support rod connecting the lower deflector to the hollow tubular body, wherein the support rod is suspended inside the hollow tubular body by one or more support trusses; and wherein extruding the first anode material via the annular opening includes: extruding the first anode material along the length of the hollow tubular body from the open upper end to the open lower end and against the deflector surface of the lower deflector, wherein the deflector surface redirects the first anode material through the annular opening. In some embodiments, the method further includes adjusting the height of the annular opening. According to some embodiments, extruding the second anode material into the central opening of the first anode portion includes: extruding the second anode material into the central opening of the first anode portion after the nozzle has withdrawn from the central opening of the first anode portion. Attached Figure Description

[0011] Now refer to the accompanying drawings, which are not necessarily drawn to scale, and in which:

[0012] Figure 1 This is a front cross-sectional view of an alkaline electrochemical cell according to one embodiment;

[0013] Figure 2 This is a front cross-sectional view of an alkaline electrochemical cell according to one embodiment;

[0014] Figures 3A-3D A schematic diagram of an extrusion die according to certain embodiments is shown;

[0015] Figure 4 The function of an extrusion die according to certain embodiments is schematically illustrated; and

[0016] Figure 5 The functionality of an alternative extrusion die according to certain embodiments is illustrated schematically. Detailed Implementation

[0017] The invention will now be described more fully with reference to the accompanying drawings, which show some, but not all, embodiments of the invention. In fact, the invention can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to enable this disclosure to meet applicable legal requirements. Throughout the text, the same reference numerals refer to the same elements.

[0018] Alkaline electrochemical batteries are commercially available in sizes commonly referred to as LR6 (AA), LR03 (AAA), LR14 (C), and LR20 (D). These batteries have a cylindrical shape conforming to size standards set by organizations such as the International Electrotechnical Commission (IEC). Consumers use electrochemical batteries to power a variety of electrical devices, such as clocks, radios, toys, video games, film cameras (which typically include a flash unit), and digital cameras. These devices have a wide range of discharge conditions, from low to relatively high consumption. Due to the increasing use of high-consumption devices (such as digital cameras), manufacturers seek to produce batteries with desired high-consumption discharge characteristics.

[0019] Figure 1 A frontal cross-section of a cylindrical battery 1 is shown, which has a nail-shaped or spool-shaped structure and is comparable in size to a conventional LR6(AA) type alkaline battery. However, it should be understood that batteries according to various embodiments may have other sizes and shapes, such as prismatic or button-shaped; and electrode configurations, as known in the art. Figure 1 The materials and designs of the components of the electrochemical cell shown are for illustrative purposes and may be replaced by other materials and designs.

[0020] The electrochemical battery 1 includes a container or canister 10 having a closed end 24, an open end 22, and a sidewall 26 between the closed end and the open end. The closed end 24 includes a terminal cap 20, which includes a protrusion. The canister 10 has an inner wall 16. In this embodiment, the positive terminal cap 20 is welded or otherwise attached to the closed end 24. In one embodiment, the terminal cap 20 may be formed of plated steel, for example, having a protruding hub in its central region. The container 10 may be made of a metal (e.g., steel, the interior of which may be plated with nickel, cobalt, and / or other metals or alloys) or other materials, thereby having sufficient structural characteristics to be compatible with various inputs in the electrochemical battery. A label 28 may be formed around the outer surface of the container 10 and may be formed on the peripheral edges of the positive terminal cap 20 and the negative terminal cap 46, provided that the negative terminal cap 46 is electrically insulated from the container 10 and the positive terminal cap 20.

[0021] A first electrode 18 and a second electrode 12 are disposed within the container 10, with a separator 14 between the first electrode and the second electrode. The first electrode 18 is disposed within the space defined by the separator 14 and a closure assembly 40 fixed to the open end 22 of the container 10. The closed end 24, the sidewall 26, and the closure assembly 40 define a cavity for accommodating the battery electrode.

[0022] The sealing assembly 40 includes a sealing member 42 such as a gasket, a current collector 44, and a negative terminal cap 46 electrically in contact with the current collector 44. The sealing member 42 may include a pressure relief port that would allow the sealing member to rupture if the internal pressure of the battery becomes excessive. If the current collector 44 and the negative terminal cap 46 are electrically insulated from the container 10 of the current collector, which serves as the second electrode 12, the sealing member 42 may be formed of a polymer or elastomeric material such as nylon-6,6, an injection-moldable polymer blend such as a polypropylene matrix bonded to polyphenylene ether or polystyrene, or another material such as a metal. In the illustrated embodiment, the current collector 44 is an elongated nail or spool-shaped component. The current collector 44 is made of metal or metal alloy, such as copper or brass, electroplated metal, or plastic current collectors, etc. Other suitable materials may also be used. The current collector 44 is inserted through a hole (e.g., a centrally located hole) in the sealing member 42.

[0023] The first electrode 18 may be a negative electrode or an anode. The negative electrode comprises one or more active materials (e.g., zinc), conductive materials, solid zinc oxide, and / or a mixture of surfactants in some embodiments. The negative electrode may optionally include other additives, such as binders or gelling agents.

[0024] although Figure 1 The embodiments illustrate that the first electrode 18 has generally uniform characteristics, but it should be understood that various embodiments include non-uniform anode configurations. For example, the first electrode 18 may define a first anode portion (composed of a first anode formulation) near the current collector 44 and a second anode portion (composed of a second anode formulation) near the separator 14. The first and second anode portions may define discrete regions defined by different characteristics, which may be separated by boundary regions. The boundary regions may be defined by discrete boundaries between adjacent anode compositions or by mixed regions, for example, as a result of processing steps that add multiple anode compositions to discrete regions of the battery, where a portion of each adjacent anode composition is mixed in the mixed regions.

[0025] In some embodiments, the boundary between adjacent anode compositions may be centered about the radius of the first electrode 18 (or, in embodiments containing more than two anode compositions, the boundary may be equidistant from the radius of the first electrode 18). However, in some embodiments, the boundary between adjacent anode compositions may be inclined toward the separator 14 or the current collector 44. Differences in quantity between the various anode compositions may be defined based on different properties, such as weight (e.g., weight percentage of the total weight of the first electrode 18), volume (e.g., volume percentage of the total volume of the first electrode 18), thickness (e.g., radial thickness percentage of the total thickness of the first electrode 18; in other words, percentage of the radial length of the first electrode 18), etc. As an example, the weight of each anode composition (e.g., the first anode composition and the second anode composition) may be at least substantially equal. As another example, the volume of each anode composition (e.g., the first anode composition and the second anode composition) may be at least substantially equal. As yet another example, the thickness of each anode composition (e.g., the first anode composition and the second anode composition) may be at least substantially equal. It should be understood that, in some embodiments, the first electrode 18 may include more or less of a particular anode composition (e.g., such that the weight, volume, or thickness of each anode composition is not equal). As a specific example, the amount of the first anode composition may exceed the amount of the second anode composition, by weight.

[0026] In some embodiments, the anode composition associated with each anode characteristic may be defined by the difference in the type of surfactant contained in the respective anode composition. For example, a first anode composition may contain a first surfactant type, and a second anode composition may contain a second surfactant type. As a specific example, a first anode composition incorporating a first surfactant (the first surfactant is incorporated into a portion of the first electrode 18 adjacent to the separator 14) may have a higher charge transfer resistance than a second anode composition incorporating a second surfactant located in a portion of the first electrode 18 adjacent to the current collector 44. A first anode composition containing a first surfactant may also have a lower anode conductivity than a second anode composition containing a second surfactant. In such an example, the first anode composition may contain a phosphate surfactant, and the second anode composition may contain a sulfonate surfactant (e.g., anionic sulfonate surfactant). The inventors understand that the inclusion of a phosphate surfactant (e.g., a nonionic phosphate surfactant) in the first anode composition results in the first anode composition having a higher charge transfer resistance and a lower conductivity than a second anode composition containing a sulfonate surfactant. By including a low charge transfer resistance portion near the current collector 44 and a high charge transfer resistance portion near the separator 14, the discharge of the first electrode 18 causes the portion closer to the current collector 44 to discharge first, and this causes ZnO particles to form in the portion of the first electrode closest to the current collector 44 before ZnO particles form closer to the separator 14. The formation of ZnO particles near the separator 14 before the anode portion closer to the anode interior is fully discharged could prevent or at least hinder the complete discharge of the anodic active material inside the anode by obstructing electrolyte diffusion through the separator 14. As described above, configuring the first electrode (anode) such that the anode portion near the current collector 44 discharges before the anode portion near the separator 14 ensures that undischarged active material within the first electrode is not prevented from discharging by the formation of ZnO near the separator 14. After the portion of the first electrode 18 closer to the current collector 44 and having lower charge transfer resistance has at least substantially discharged, the portion of the first electrode 18 closer to the separator 14 and having higher charge transfer resistance begins to discharge.

[0027] In some embodiments, a first outer region of the anode (adjacent to separator 14) contains a first anode composition doped with a first surfactant, and a second inner region (adjacent to current collector 44) contains a second anode composition doped with a second surfactant. There may be a discontinuous boundary between the first and second anode compositions, or a small mixing region may exist at the boundary between the first and second anode compositions, wherein the mixing region contains both the first and second surfactants.

[0028] As described in co-pending U.S. Patent Application No. 15 / 896,917, filed February 14, 2018, the entire contents of which are incorporated herein by reference. For example, varying characteristics may include the average particle size of the active material (e.g., zinc), the average alloy composition of the active material, the average concentration of the active material, the average concentration of additives, the average concentration of surfactants, etc. As a non-limiting example, the percentage of the relative composition of the active material to the total composition of the first electrode 18 may vary along the radius of the first electrode 18 (e.g., between the outer surface and interior of the first electrode 18); one or more active material particle characteristics (e.g., particle size, surface roughness, porosity, etc.) may vary along the radius of the first electrode 18; the active material alloy type may vary along the radius of the first electrode; the surfactant type may vary along the radius of the first electrode; the percentage of the relative composition of the surfactant to the total composition of the first electrode 18 may vary along the radius of the first electrode 18; one or more inactive material particle characteristics may vary along the radius of the first electrode 18; and / or the like.

[0029] In various embodiments, multiple properties can vary along the anode radius to form a multi-property gradient anode composition. For example, the average particle size of the active material within the anode can vary along the anode radius, and the surfactant type can also vary along the anode radius. Any of a variety of combinations of anode property variations is conceivable to provide an anode with desired properties. As a specific example, the anode can contain a first surfactant type and a first average active material particle size in the anode region near the separator; and a second surfactant type and a second average active material particle size in the anode region near the current collector. This configuration ideally provides lower charge transfer resistance in the region closer to the current collector 44, which increases high-speed discharge service while minimizing gas evolution in the region near the current collector 44.

[0030] In some embodiments, the anode may be defined by two or more discrete regions, each having consistent material properties. The discrete regions may be formed simultaneously and / or sequentially. For example, as... Figure 2 As shown ( Figure 2 (This is a side cross-sectional view of an electrochemical cell according to various embodiments), the first electrode 18 may include a first portion 18a and a second portion 18b. For example... Figure 2As shown, a first portion 18a may be located between the outer surface of the first electrode 18 and the second portion 18b. Therefore, a second portion may be located between the first portion 18a and the interior of the first electrode 18 (e.g., adjacent to the current collector 44). Thus, the first portion 18a may define a hollow tubular shape defining an outer surface coexisting with the outer surface of the first electrode 18 and an inner surface surrounding the open interior of the first portion 18a. The second portion 18b may be located within the internal opening of the first portion 18a, such that the second portion 18b defines an outer surface near the inner surface of the first portion 18a and an interior coexisting with the interior of the first electrode 18. In various embodiments, the interface between the first portion 18a and the second portion 18b (defined between the outer surface of the second portion 18b and the inner surface of the first portion 18a) may define a discrete boundary between the first portion and the second portion. However, in some embodiments, the interface between the first portion 18a and the second portion 18b may be defined by a mixing region defined by the mixture between the first portion 18a and the second portion 18b.

[0031] In some embodiments, the first portion 18a may account for about 20% to 80% of the total weight of the first electrode 18, and the second portion 18b may account for about 20% to 80% of the total weight of the first electrode 18. In the exemplary embodiments discussed herein, the weight of the first anode portion 18a may exceed the weight of the second anode portion 18b.

[0032] although Figure 2 Not shown, but in various embodiments, the first electrode 18 may include more than two discrete portions. Additional portions may be located between the first portion 18a and the second portion 18b, thereby forming a series of rings (e.g., concentric rings) surrounding the second portion 18b and within the first electrode 18. As will be discussed in more detail herein, the various discrete portions of the first electrode 18 may be co-extruded into the electrochemical cell, the various discrete portions may be extruded in series / sequentially into the electrochemical cell, and so on.

[0033] As an example only, the surfactant in the first portion 18a may differ from the surfactant in the second portion 18b. Specifically, the surfactant in the first portion 18a may result in the first portion having a higher charge transfer resistance and a lower anodic conductivity than the second portion 18b. In some embodiments, the surfactant in the first portion 18a is a phosphate surfactant, and the surfactant in the second portion 18b is a sulfonate surfactant. As another example, a nonionic surfactant may be used in one of the first portion 18a or the second portion 18b, and an anionic surfactant may be used in the other portion of the anode. Specifically, a first surfactant having a first affinity for attachment to zinc particles may be provided in the first portion 18a, and a second surfactant having a second affinity for attachment to zinc particles (e.g., a lower affinity for attachment to zinc particles) may be provided in the second portion 18b. This gradient of surfactant types allows for zinc plating on the current collector 44, thereby reducing venting, while providing a highly active surfactant in the anode region with the highest zinc oxidation concentration during high-speed discharge.

[0034] As another example, the average particle size of the active anode material (e.g., zinc) in the first portion 18a may be larger than the average particle size of the active anode material in the second portion 18b. As another example, the average amount of active material in the first portion 18a may be greater than the average amount of active material in the second portion 18b (e.g., measured as a weight percentage of the active material relative to the total weight of the respective first electrode portion; measured as a volume percentage of the active material relative to the total volume of the respective first electrode portion; and / or the like). As yet another example, the average amount of surfactant in the first portion 18a may be greater than the average amount of surfactant in the second portion 18b (e.g., measured as a weight percentage of the surfactant relative to the total weight of the respective first electrode portion; measured as a volume percentage of the surfactant relative to the total volume of the respective first electrode portion; and / or the like).

[0035] As another example, the type of active material used in the first part 18a may differ from the type of active material used in the second part 18b (e.g., different grades of zinc may be used; zinc purchased from different suppliers may be used; zinc recovered from different zinc mines may be used; zinc with different average porosity may be used; zinc with different surface roughness characteristics may be used; active materials with different alloy compositions may be used (e.g., different alloys may be used for different anode sections, and these alloys may be selected from non-limiting examples of zinc-bismuth alloys, zinc-indium alloys, zinc-aluminum alloys, etc.). As a specific example, zinc alloys known to be highly reactive may be included in the first part 18a, while zinc known to be less reactive may be included in the second part 18b to increase high-rate service (where the reactivity of zinc is typically concentrated near the separator) while reducing venting in the area near the current collector 44.

[0036] Zinc suitable for various embodiments can be purchased from many different commercial sources under various names (such as BIA 100, BIA 115). Umicore, based in Brussels, Belgium, is one such zinc supplier. In a preferred embodiment, the zinc powder typically has 25-40% fine particles smaller than 75 micrometers, particularly 28-38% fine particles smaller than 75 micrometers. Generally, a lower percentage of fine particles will not achieve the desired high-rate service, while using a higher percentage of fine particles will result in more gas evolution. The correct zinc alloy is required to reduce gas evolution at the negative electrode in the battery and maintain test service results.

[0037] In some embodiments, the amount of zinc present in the negative electrode is typically from about 62% to about 78% by weight, ideally from about 64% to about 74% by weight, and specifically from about 68% to about 72% by weight, based on the total weight of the negative electrode (i.e., zinc, solid zinc oxide, surfactant, and gel electrolyte).

[0038] The solid zinc oxide used in various embodiments can be highly active to increase high-rate service, such as digital camera (DSC) service, as well as to increase anodic rheology and reduce DSC service variability.

[0039] The solid zinc oxide added to the anode is particularly high in purity and contains low levels of impurities that can lead to higher zinc gas evolution and shorter service life. Specifically, the solid zinc oxide contains less than 30 ppm of iron, less than 3 ppm of silver and arsenic, less than 1 ppm each of copper, nickel, chromium, and cadmium, less than 0.50 ppm each of molybdenum, vanadium, and antimony, less than 0.1 ppm of tin, and less than 0.05 ppm of germanium.

[0040] In various embodiments, the surfactant added to one or more portions of the first electrode 18 may be a nonionic surfactant, an anionic surfactant, or a combination thereof. For example, as described above, a nonionic surfactant may be added to one portion of the first electrode 18, and an anionic surfactant may be added to another portion of the first electrode 18. It has been found that adding solid zinc oxide alone during discharge increases the anode viscosity, but adding a surfactant reduces the anode viscosity. As described above, the addition of a surfactant increases the surface charge density of solid zinc oxide and reduces the anode viscosity. Therefore, adding a surfactant to a portion of the anode (e.g., discrete portions of the anode and / or changing the concentration of the surfactant within the anode) or adding different surfactants to different portions of the anode can create a charge distribution gradient within the anode.

[0041] When surfactants are adsorbed onto solid zinc oxide, the use of surfactants is believed to contribute to the formation of more porous discharge products. When the surfactant is anionic, it carries a negative charge, and in alkaline solutions, the surfactant adsorbed on the surface of solid zinc oxide is believed to alter the surface charge density of the solid zinc oxide particles. It is believed that the adsorbed surfactant induces repulsive electrostatic interactions between the solid zinc oxide particles. It is believed that the addition of surfactants leads to an increase in the surface charge density of the solid zinc oxide particles. The larger the Brunauer-Emmett-Teller (BET) surface area of ​​solid zinc oxide, the more surfactant can be adsorbed onto the solid zinc oxide surface.

[0042] Furthermore, the inventors discovered that differences in the chemical properties of surfactants can cause differences in anode charge transfer resistance and anode conductivity. As a specific example, the inventors found that anode compositions containing phosphate ester surfactants (e.g., nonionic phosphate ester surfactants) have higher charge transfer resistance and lower anode conductivity than anode compositions containing sulfonate surfactants (e.g., anionic sulfonate surfactants). When multiple anode compositions with different charge transfer resistances are included in a single cell, the anode portion with lower charge transfer resistance discharges first before the other portions of the anode discharge. Therefore, including a first anode composition containing a phosphate ester surfactant (e.g., nonionic phosphate ester surfactant) and a second anode composition containing a sulfonate surfactant (e.g., anionic sulfonate surfactant) in a single cell (e.g., within the corresponding portions of the anode) causes the second anode composition to discharge before the first anode composition discharges.

[0043] Based on this understanding, the anode according to various embodiments includes multiple anode compositions, with the anode composition closest to the current collector 44 having a lower charge transfer resistance than the anode composition closest to the separator 14. In such embodiments, the anode composition closest to the current collector 44 discharges before the anode composition located at the separator 14, thereby preventing premature formation of a zinc oxide barrier near the separator 14, which could potentially hinder further discharge of the anode active material closer to the current collector 44.

[0044] Aqueous alkaline electrolytes contain alkali metal hydroxides, such as potassium hydroxide (KOH), sodium hydroxide, etc., or mixtures thereof. Based on the total weight of the alkaline electrolyte, the alkaline electrolyte used to form the gel electrolyte for the negative electrode contains approximately 26% to approximately 36% by weight, ideally approximately 26% to approximately 32% by weight, and particularly approximately 26% to approximately 30% by weight of alkali metal hydroxide. An interaction occurs between the alkali metal hydroxide at the negative electrode and the added solid zinc oxide, and it has been found that less alkali metal hydroxide improves DSC service. A less alkaline electrolyte is preferred, but this can lead to rapid electrolyte separation at the anode. Increasing the concentration of alkali metal hydroxide produces a more stable anode, but reduces DSC service.

[0045] As is well known in the art, gelling agents, such as cross-linked polyacrylic acid, can be used in the negative electrode. 940, which is available from Noveon Corporation in Cleveland, Ohio, USA. Carboxymethyl cellulose, polyacrylamide, and sodium polyacrylate are other examples of gelling agents suitable for alkaline electrolyte solutions. A gelling agent is ideal for maintaining a substantially uniform dispersion of zinc and solid zinc oxide particles in the negative electrode. The amount of gelling agent present is chosen to achieve a low electrolyte separation rate and to ensure that the anode viscosity at yield stress is not so high as to cause anode dispersion problems.

[0046] Other components optionally present in one or more portions of the negative electrode include, but are not limited to, gas evolution inhibitors, organic or inorganic corrosion inhibitors, electroplating agents, binders, or other surfactants. Examples of gas evolution inhibitors or corrosion inhibitors may include indium salts, such as indium hydroxide, perfluoroalkylammonium salts, alkali metal sulfides, etc. In one embodiment, dissolved zinc oxide may be present by dissolving in the electrolyte to improve electroplating on spools or nail-type current collectors and reduce gas evolution on the negative electrode housing. The added dissolved zinc oxide is separate from and distinct from the solid zinc oxide present in the anode composition. In one embodiment, the amount of dissolved zinc oxide is preferably about 1% by weight based on the total weight of the negative electrode electrolyte. Soluble or dissolved zinc oxide typically has about 4m 2 / g or less of BET surface area, measured from a Micrometrics analyzer with multi-point calibration using a Tristar 3000 BET surface area analyzer after zinc oxide degassing at 150°C for 1 hour; and a particle size D50 (average diameter) of approximately 1 micrometer, measured using a CILAS particle size analyzer as described above. In another embodiment, an amount of sodium silicate of approximately 0.3% by weight in the negative electrode, based on the total weight of the negative electrode electrolyte, is preferred to substantially prevent short circuits of the battery through the separator during battery discharge.

[0047] Example nozzle

[0048] Figure 3A-5 Various schematic diagrams of an example nozzle 300 for providing electrode material (e.g., anode material) within an internal opening formed by a second electrode 12 (e.g., cathode) and a separator 14 in an electrochemical cell 1 are shown. Specifically, regarding Figure 3A-5 The nozzle 300 shown is configured to form a hollow tubular electrode portion 18a (referred to herein as the first portion 18a of the first electrode) adjacent to the inner wall of the separator 14, wherein the first portion 18a defines an internal opening extending along the length of the first portion 18a, the internal opening being configured to receive a second portion 18b therein (it should be understood that, for example, in embodiments including more than two discrete anode portions, additional portions may be provided within the internal opening of the first portion 18a). See reference Figure 2 As shown, the first part 18a may have an outer diameter AD1 that substantially matches the inner diameter of the separator 14, and the first part may additionally have an inner diameter AD2 that defines the diameter of the internal opening and at least substantially matches the outer diameter of the second part 18b.

[0049] like Figures 3A-3C As shown, the nozzle 300 includes a hollow tubular body 301, the length of which corresponds to the intended length of the electrochemical cell 1 in which electrode material (e.g., anode material) is filled using the nozzle 300. For example, the hollow tubular body 301 may have a length at least as long as the intended electrochemical cell 1 in which the nozzle 300 is to be used to fill the electrode material, such that the nozzle 300 can extend along the entire internal height of the electrochemical cell 1 during use. The hollow tubular body 301 also defines an outer diameter (measured between relative points on the outer surface of the hollow tubular body 301) and an inner diameter (measured between relative points on the inner surface of the hollow tubular body 301). Furthermore, the wall thickness of the hollow tubular body 301 is half the difference between the outer diameter and the inner diameter of the hollow tubular body 301.

[0050] Furthermore, the cross-sectional shape and size of the hollow tubular body 301 in the illustrated embodiment correspond to the cross-sectional shape and size of the internal opening of the first portion 18a of the first electrode (such as the anode). Specifically, in the illustrated embodiment, the hollow tubular body 301 has a circular outer cross-sectional shape and an outer diameter corresponding to the inner diameter of the internal opening of the first portion 18a. In some embodiments, the outer diameter of the hollow tubular body 301 may be at least approximately 0.242 inches (0.242”) for forming an LR6(AA) electrochemical cell. It should be understood that other outer diameter dimensions may be provided in other embodiments, and / or for other electrochemical cell sizes. However, it should be understood that in some embodiments, the hollow tubular body 301 may have any of a variety of shapes and sizes, depending on the dimensions and positioning of the lower steering member 310 discussed herein, and does not need to correspond to the size and shape of the internal opening of the first portion 18a. By extension and as discussed in more detail herein, the outer diameter of the hollow tubular body 301 does not need to be equal to the diameter of the lower steering member 310, and the lower steering member 310 may be used to establish the inner diameter AD2 of the first portion 18a when material of the first portion 18a is supplied to the cell interior. For example, the outer diameter of the hollow tubular body 301 may be smaller than the diameter of the lower steering member 310.

[0051] A hollow tubular body 301 extends between an open upper end 302 (configured therein to receive the anode material of the first anode portion 18a) and an open lower end 303 (configured therein to discharge the anode material of the first anode portion 18a). At the open upper end 302, a nozzle 300 can be connected to a conduit supplying the anode material of the first anode portion 18a, for example, via a connector 304 as shown. As shown, the connector 304 can be configured to adapt the size of the conduit to the size of the nozzle 300. However, it should be understood that other connection configurations may be utilized in some embodiments.

[0052] like Figures 3A-3C As shown in the illustrated embodiment, the nozzle 300 also includes a lower deflector 310 spaced apart from the open lower end 303 of the hollow tubular body 301. The lower deflector 310 may define a deflection surface (e.g., an upper surface of the lower deflector 310) configured to redirect a flow of electrode material exiting from the lower end 303 of the hollow tubular body 301, for example, from a direction at least substantially parallel to the length of the hollow tubular body 301 to a direction at least substantially perpendicular to the length of the hollow tubular body 301, such that the electrode material (e.g., anode material) is extruded at least substantially radially from the nozzle 300, such that the electrode material is extruded against the sidewall of the separator 14 of the electrochemical cell 1. Figure 3AAs shown, the turning surface can be manifested as a surface that is at least substantially flat and whose orientation is at least substantially perpendicular to the length of the hollow tubular body 301. Figure 3C Another exemplary embodiment is shown, wherein the steering surface is embodied as a curved (e.g., having a concave curvature) surface to redirect electrode material (e.g., anode material) toward the outside of nozzle 300. Other embodiments may utilize beveled steering surfaces or other steering surface shapes.

[0053] Furthermore, the cross-sectional shape of the lower deflector 310 corresponds to the internal opening shape of the first portion 18a of the first electrode (e.g., the anode). Therefore, when electrode material is extruded from the nozzle 300 against the sidewall of the separator 14, the lower deflector 310 operates as a die portion against which the electrode material flows and is shaped. Thus, the annular first portion 18a of the first electrode (or other shape, at least partially defined by the cross-sectional shape of the internal opening of the second electrode 12 and the cross-sectional shape of the lower deflector 310) is formed between the separator 14 and the outer surface of the lower deflector 310. The height of the lower deflector 310 can be optimized to allow for the extrusion of electrode material of sufficient height to form a structurally stable annular shape of the first portion 18a of the first electrode before the nozzle 300 moves, as described herein. In some embodiments, the diameter of the lower deflector 310 may be larger than the resulting inner diameter AD2 of the first portion 18a, because the electrode material of the first portion 18a may settle according to the viscosity of the electrode material of the first portion 18a. Therefore, the diameter of the lower steering member 310 can be selected at least in part based on the desired inner diameter AD2 of the first portion 18a and the known viscosity of the electrode material of the first portion 18a. As an example only, the lower steering member 310 can have a diameter of about 0.240 inches to about 0.275 inches. When the first portion 18a is formed with a high-viscosity anode material, the lower steering member 310 can have a diameter at least substantially equal to the inner diameter AD2 of the first portion 18a. In such an embodiment, the lower steering member 310 can have a diameter of at least about 0.242 inches to form the inner diameter AD2 of the first portion 18a of the LR6 electrochemical cell of at least about 0.242 inches. However, when using a lower-viscosity anode material, the diameter of the lower steering member 310 can be larger than the final inner diameter AD2 of the first portion 18a. In such an embodiment, the lower steering member 310 may have a diameter of about 0.245 inches to about 0.275 inches to form an inner diameter AD2 of at least about 0.242 inches for the first portion 18a of an LR6-sized electrochemical cell. As described herein, the diameter of the lower steering member 310 may be larger than the outer diameter of the hollow tubular body 301. For an electrochemical cell with an outer diameter AD1 of 0.301 inches for the first portion 18a, the thickness of the first portion 18a is at least about 0.0295 inches.

[0054] In the illustrated embodiment, the lower steering member 310 is supported by a support rod 311, which is suspended inside the hollow tubular body 301 by multiple support trusses 312. Each support truss 312 extends from the inner wall of the hollow tubular body 301 to the outer surface of the support rod 311. Each support truss 312 may be sufficiently thin and / or have a sufficiently small cross-sectional shape to minimize or eliminate the impact on the flow of electrode material through the hollow tubular body 301. Figure 3A As shown in the embodiments, a plurality of support trusses 312 may be vertically aligned along the length of the hollow tubular body 301 at different radial locations surrounding the interior of the hollow tubular body 301. For example, the support trusses 312 may be positioned at three radial locations on the hollow tubular body 301 (e.g., at least substantially equidistant from the interior). Figure 3D An alternative embodiment is shown comprising a plurality of elongated support trusses 312 spaced apart at multiple radial locations, the plurality of elongated support trusses being positioned at least substantially equidistantly around the interior of a hollow tubular body 301. For example, a single elongated support truss 312 may be positioned at each radial location within the hollow tubular body 301. In some embodiments, each elongated support truss 312 may extend between an open upper end and an open lower end of the hollow tubular body 301. However, as... Figure 3D As shown, the slender support truss 312 at each radial position can extend only along a portion of the length of the hollow tubular body 301.

[0055] Furthermore, in some embodiments, the lower steering member 310 is detachably fixed to the support rod 311 (e.g., via a threaded interface), thereby allowing lower steering members 310 of different diameters to be fixed to one end of the nozzle 300 to accommodate different electrochemical cell sizes, to accommodate different desired inner diameter AD2 dimensions of the first anode portion 18a, to accommodate different anode material viscosities, etc.

[0056] The support rod 311 extends at least partially along the length of the hollow tubular body 301 and supports the lower steering member 310 at a distance from the open lower end 303 of the hollow tubular body 301 to form an annular gap 315 between the steering surface of the lower steering member 310 and the open lower end 303 of the hollow tubular body 301. Electrode material (e.g., anode material) passing through the nozzle 300 moves along the length of the hollow tubular body 301 from the open upper end 302 to the open lower end 303 and is deflected away from the nozzle 300 through the annular gap 315. In some embodiments, the annular gap 315 has a height between the lowest point of the open lower end 303 of the hollow tubular body 301 and the steering surface of the lower steering member 310, which is optimized to provide electrode material into the electrochemical cell as the nozzle 300 moves to form a structurally stable first portion 18a of the first electrode, while still allowing the electrode material to flow smoothly through the nozzle 300. In other embodiments, the height of the annular gap 315 may be adjustable to allow for optimization of the height of the annular gap 315 during use. In some embodiments, the height of the annular gap 315 is about 0.080 inches to about 0.125 inches, for example, about 0.090 inches to about 0.124 inches. The height of the annular gap 135 can be adjusted to regulate the pressure and / or flow rate of the electrode material provided to form the first portion 18a, which can affect the amount of electrode material of the first portion 18a deposited after it is provided to the electrochemical cell.

[0057] Although not shown, nozzle 300 may have an associated linear actuator configured to move nozzle 300 at least substantially linearly (e.g., vertically within electrochemical cell 1 as electrode material passes through nozzle 300). As discussed herein, nozzle 300 may be initially positioned such that the bottom surface of lower deflector 310 contacts or at least approaches the bottom surface of the internal opening of electrochemical cell 1. As electrode material (e.g., anode material) passes through nozzle 300, nozzle 300 retracts upward while the electrode material continuously passes through nozzle 300 and is extruded against the sidewall of separator 14. As nozzle 300 moves upward, the sidewall of lower deflector 310 forms the inner surface of a first portion 18a of the first electrode, which surrounds the internal opening of the first portion 18a of the first electrode (e.g., anode), which can be filled with a second portion 18b (and / or additional portions) of the first electrode (e.g., anode), accomplished using at least substantially simultaneous or sequential processing steps as described herein. The speed at which the nozzle 300 retracts from the interior of the electrochemical cell can be optimized to ensure that the electrode material of the first portion 18a is fully solidified, thereby avoiding excessive settling during the movement of the nozzle 300, which could lead to unpredictable or excessive settling of the first anode portion 18a.

[0058] Simple reference Figure 5 In some embodiments, the support rod 311 and the lower steering member 310 define an internal channel 313 through which additional electrode material corresponding to the second portion 18b (also referred to herein as second electrode material, which may be embodied as, for example, second anode material) can be extruded. With this configuration, the first portion 18a and the second portion 18b of the first electrode can be formed at least substantially simultaneously using a single forming tool. Specifically, the electrode material (e.g., anode material) of the first portion 18a can be provided between the support rod 311 and the hollow tubular body 301, while the second electrode material (e.g., second anode material) of the second portion 18b flows through the hollow interior of the support rod 311. Such embodiments can increase the production speed associated with producing multi-part internal electrodes (e.g., multi-part anodes). Furthermore, providing the second portion 18b of the electrode simultaneously with the first portion 18a can suppress the settling of the first portion 18a, as the presence of the second portion 18b counteracts the settling of the first portion 18a.

[0059] Example manufacturing method

[0060] As briefly mentioned herein, one or more portions of the anode (e.g., a first portion 18a of the first electrode 18; a second portion 18b of the first electrode 18; and / or the entire first electrode 18) may be extruded to form the first electrode within an electrochemical cell. In some embodiments, the various portions of the first electrode 18 may be co-extruded (e.g., by means of...) Figure 5 The nozzles 300 in the illustrated configuration simultaneously or sequentially extrude individual portions of the first electrode 18, and sequentially extrude (using the method according to...) Figure 3A-4 The configured nozzle 300 extrudes a first portion 18a of the first electrode 18, retracts the nozzle 300 from the internal opening formed in the first portion 18a, and then, for example, extrudes a second portion 18b of the first electrode 18 into the internal opening created by removing the nozzle 300 through a separate nozzle.

[0061] Specifically, to form the first portion 18a of the first electrode according to the methods of various embodiments, the nozzle 300 is first inserted into the opening formed by the second electrode 12 and the separator 14, to a first position, in which the bottom surface of the lower steering member 310 abuts against the bottom surface of the opening (e.g., the bottom wall of the separator 14). After the nozzle 300 is in the first position, the electrode material of the first portion 18a of the first electrode 18 (e.g., the anode material for forming the first portion of the anode) passes through the hollow tubular body 301 of the nozzle 300 and flows out from the annular opening 15. As the electrode material continues to flow through the hollow tubular body 301 and out from the annular opening 15, the nozzle 300 retracts from the electrochemical cell 1 at a rate determined at least in part based on the extrusion rate of the electrode material through the nozzle 300 (e.g., fluid pressure and / or flow rate) (e.g., slowly retracting). Figure 4 As shown, as electrode material is extruded into the electrochemical cell 1 to form the first portion 18a, the height of the electrode material within the electrochemical cell 1 increases (and the upper surface of the first portion 18a of the first electrode (e.g., the anode) continues to rise). The retraction rate of the nozzle 300 is maintained such that the rising upper surface of the first portion 18a of the first electrode remains above the bottom surface of the lower steering member 310. For example, the rising upper surface of the first portion 18a remains aligned with the sidewall of the lower steering member 310, or the rising upper surface of the first portion 18a remains above the steering surface of the lower steering member 310. At least partly due to the viscosity of the material of the first electrode 18a, the first portion 18a retains its tubular shape with an open interior as the nozzle 300 (and the lower steering member 310) retracts.

[0062] Once the desired amount of electrode material is supplied to the electrochemical cell 1 through the nozzle 300, the flow of electrode material stops, and the nozzle 300 is completely withdrawn from the interior of the electrochemical cell 1. In those embodiments where the nozzle 300 is configured to supply only the electrode material of the first portion 18a, a separate nozzle (not shown) may be used to fill the internal opening of the first portion 18a with the second electrode material of the second portion 18b.

[0063] In other embodiments, for example, having Figure 5 In the embodiment of the configuration shown, as the nozzle 300 retracts, the second electrode material of the second portion 18b can be provided through the channel 313 to fill the internal opening of the first portion 18a, so as to form the second portion 18b of the electrode at least substantially simultaneously with the formation of the first portion 18a.

[0064] In one embodiment, zinc and solid zinc oxide powder, along with other optional powders besides a gelling agent, are combined and mixed. In some embodiments, the zinc and solid zinc oxide powder may be mixed in separate batches corresponding to different portions of the first electrode 18 (e.g., the anode). For example, a first batch of zinc and zinc oxide powder may be mixed to form a first batch, and a second batch of zinc and zinc oxide powder may be mixed to form a second batch (e.g., the second batch contains zinc powder with an average zinc particle size different from that of the first batch).

[0065] Subsequently, a surfactant can be introduced into the mixture containing zinc and solid zinc oxide (e.g., the surfactant can be introduced into each batch). A pre-gel comprising an alkaline electrolyte, soluble zinc oxide, and a gelling agent, as well as optional other liquid components, can be introduced into the surfactant, zinc, and solid zinc oxide mixture, which is then further mixed to obtain a substantially homogeneous mixture (e.g., homogeneous within each batch) before being added to the battery. In various embodiments, one or more components may be varied for each batch to provide desired differences in anodic characteristics between batches (e.g., providing different amounts of surfactant; providing different grades of zinc; providing different amounts of zinc oxide; etc.).

[0066] In another embodiment, solid zinc oxide is pre-dispersed in a negative electrode pregel comprising an alkaline electrolyte, a gelling agent, soluble zinc oxide, and other desired liquids, and mixed, for example, for about 15 minutes. As described above, multiple batches can be provided, each batch comprising solid zinc oxide, an alkaline electrolyte, a gelling agent, soluble zinc oxide, and other desired liquids. In some embodiments, as described above, each batch may comprise a different composition consisting of multiple components combined together. Solid zinc and a surfactant are then added, and each batch of the first electrode composition is further mixed for a period of time, for example, about 20 minutes. The amount of gel electrolyte used in each batch of the first electrode composition (e.g., the anode composition) is typically from about 25% to about 35% by weight. For example, based on the total weight of each batch of the first electrode composition, the amount of gel electrolyte may be about 32% by weight. In some embodiments, the volume percentage of the gel electrolyte may be about 70% of the total volume of the first electrode. In addition to the aqueous alkaline electrolyte absorbed by the gelling agent during the manufacture of the first electrode, an additional amount of an aqueous solution of alkali metal hydroxide, i.e., the “free electrolyte,” may be added to the battery during the manufacture process. Free electrolytes can be incorporated into a battery by placing them in a cavity defined by a positive electrode, a negative electrode, or a combination thereof. In one embodiment, the free electrolyte is added both before and after the addition of the negative electrode mixture. In one embodiment, about 0.97 g of a 29 wt% KOH solution is added as the free electrolyte to an LR6 type battery, wherein about 0.87 g is added to the cavity lined with a separator before the addition of the negative electrode. As described herein, the free electrolyte added before the addition of the negative electrode may comprise a surfactant composition, which is subsequently absorbed by the negative electrode, thereby creating a surfactant concentration gradient within at least a portion of the negative electrode. After the negative electrode is inserted, the remaining 29 wt% KOH solution is injected into the cavity lined with a separator.

[0067] The second electrode 12 (also referred to herein as the positive electrode or cathode) may contain manganese dioxide as an electrochemically active material. Based on the total weight of the positive electrode (i.e., manganese dioxide, conductive material, positive electrode electrolyte, and additives such as barium sulfate), the amount of manganese dioxide present is typically from about 80% to about 86% by weight, for example, from about 81% to 85% by weight. Manganese dioxide is available as natural manganese dioxide (NMD), chemical manganese dioxide (CMD), or electrolytic manganese dioxide (EMD). Preferred manganese dioxide for use in batteries is EMD. Suppliers of EMD include Tronox Ltd. of Stanford, Connecticut; Tosoh Corporation of Tokyo, Japan; and Erachem Comilog, Inc. of Baltimore, Maryland. The positive electrode is formed by combining and mixing the desired components of the electrode, then dispensing a certain amount of the mixture to the open end of a container, and then molding the mixture into a solid tubular structure using a pressure head. This solid tubular structure defines a cavity within the container, in which the separator 14 and the first electrode 18 are subsequently disposed. Figure 1 As shown, the second electrode 12 has a platform 30 and an inner surface 32. Alternatively, the positive electrode can be formed by preforming a plurality of rings from a mixture containing manganese dioxide, and then inserting these rings into a container to form a tubular second electrode. Figure 1 The battery shown typically includes 3 or 4 rings.

[0068] The positive electrode may include other components, such as conductive materials like graphite, which, when mixed with manganese dioxide, provides a conductive matrix substantially distributed throughout the positive electrode. The conductive material can be natural, i.e., mined, or synthetic, i.e., manufactured. In one embodiment, the battery includes a positive electrode having an active material or oxide-to-carbon ratio (O:C ratio) ranging from about 12 to about 14. An excessively high oxide-to-carbon ratio reduces the resistance between the container and the cathode, affecting the overall battery resistance and potentially impacting high-rate testing (such as DSC testing) or higher cutoff voltages. Furthermore, the graphite can be expanded or non-expanded. Graphite suppliers for alkaline batteries include Imerys Graphite & Carbon of Bironico, Switzerland, and Superior Graphite of Chicago, Illinois. Based on the total weight of the positive electrode, the conductive material is typically present in an amount from about 5% to about 10% by weight. Too much graphite reduces the input of manganese dioxide, thus reducing battery capacity; too little graphite increases the contact resistance between the container and the cathode and / or the overall cathode resistance. One example of an additive is barium sulfate (BaSO4), which is available from Bario E. Derivati ​​SPA in Massa, Italy. The amount of barium sulfate present is typically from about 1% to about 2% by weight, based on the total weight of the positive electrode. Other additives may include, for example, barium acetate, titanium dioxide, binders such as coathylene, and calcium stearate.

[0069] In one embodiment, positive electrode components, such as manganese dioxide, conductive material, and barium sulfate, are mixed together to form a homogeneous mixture. During mixing, an alkaline electrolyte solution, such as about 37% to about 40% KOH solution, is uniformly dispersed into the mixture, ensuring a uniform distribution of the solution throughout the positive electrode material. The mixture is then added to a container and molded using a press head. Moisture and the positive electrode within the container are mixed before and after molding, and the composition of the mixture can be optimized to allow for the molding of a high-quality positive electrode. Optimization of mixing moisture allows the positive electrode to be molded with minimal splatter and flash due to wet mixing and minimal spalling and excessive tool wear due to dry mixing, where optimization contributes to achieving the desired high cathode weight. The moisture content in the positive electrode mixture affects the electrolyte balance of the entire battery and impacts high-rate testing.

[0070] The separator 14 is provided to separate the first electrode 18 from the second electrode 12. The separator 14 maintains physical dielectric separation between the electrochemically active materials of the positive electrode and the electrochemically active materials of the negative electrode, and allows ion transport between the electrode materials. Furthermore, the separator acts as a wicking medium for the electrolyte and as a collar to prevent fragments of the negative electrode from contacting the top of the positive electrode. The separator 14 can be a layered, ion-permeable nonwoven fabric. Typical separators typically consist of two or more layers of paper. Conventional separators are typically formed by pre-forming the separator material into a cup-shaped basket, which is then inserted below the cavity defined by the second electrode 12 and the closed end 24 and any positive electrode material thereon; or by forming a basket during battery assembly by inserting two rectangular separator sheets into the cavity, wherein the materials are rotated 90° relative to each other. Conventional pre-formed separators are typically made from a nonwoven fabric sheet rolled into a cylindrical shape, conforming to the inner wall of the second electrode and having a closed bottom end.

[0071] The aforementioned configuration addresses common discharge defects associated with existing alkaline batteries operating at high discharge rates. Experiments have shown that conventional alkaline batteries do not fully discharge when subjected to high discharge rates. Specifically, it has been found that during high-speed discharge of alkaline batteries containing typically homogeneous anodes, zinc oxidation within the anode, leading to ZnO formation, concentrates near the separator. As mentioned above, because ZnO has a larger particle size than unreacted zinc, ZnO formation near the separator effectively creates a barrier that hinders the discharge of zinc particles closer to the anode center.

[0072] Therefore, by providing multiple first electrode portions (e.g., multiple anode portions) each with different electrode characteristics, the characteristics of the first electrode can be modified to promote lower discharge resistance in the first electrode portion closer to the central current collector (and farther from the separator). This can increase the amount of available zinc near the separator after a certain depth of discharge during medium- and high-speed discharge of the battery. For example, different types of surfactants can be provided in the anode portions near the separator and near the current collector to disperse the current distribution, allowing a higher percentage of the anolyte active material within the anode to participate in the discharge reaction; anolyte active materials with larger average particle sizes can be disposed near the separator (e.g., to avoid complete consumption of zinc near the separator during medium- and high-speed discharge); and / or the like. Furthermore, the anode portion closer to the current collector can be modified to have reduced gas evolution characteristics, thereby reducing undesirable gas evolution at high anode discharge.

[0073] in conclusion

[0074] Many modifications and other embodiments of the invention will arise for those skilled in the art upon which these embodiments pertain, thanks to the teachings in the foregoing description and the accompanying drawings. Therefore, it should be understood that the embodiments are not limited to the specific embodiments disclosed, and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terminology is used herein, it is used only in a general and descriptive sense and not for limiting purposes.

Claims

1. A nozzle for supplying electrode material to an electrochemical cell, the nozzle comprising: A hollow tubular body extending between an open upper end and an open lower end; The lower steering component is spaced apart from the open lower end of the hollow tubular body, and an annular opening is formed between the steering surface of the lower steering component and the open lower end of the hollow tubular body. and A support rod connecting the lower steering component to the hollow tubular body, wherein the support rod is suspended inside the hollow tubular body by one or more support trusses.

2. The nozzle according to claim 1, wherein, The support rod and the lower steering element define a passage through it.

3. The nozzle according to claim 1, wherein, The diameter of the lower steering component is greater than the second outer diameter of the hollow tubular body.

4. The nozzle according to claim 1, wherein, The steering surface is concave.

5. The nozzle according to claim 1, wherein, The annular opening is adjustable.

6. The nozzle according to claim 1, wherein, The annular opening has a height of 0.09 inches to 0.125 inches.

7. The nozzle according to claim 1, wherein, The steering component has a diameter of 0.24 inches to 0.275 inches.

8. The nozzle according to claim 1, wherein, The one or more support trusses are spaced apart and arranged radially at equidistant locations around the interior of the hollow tubular body.

9. The nozzle according to claim 8, wherein, The one or more support trusses include multiple support trusses at each radial location.

10. A method for forming an electrode in an electrochemical cell, the method comprising: The nozzle is positioned within the central opening of the electrochemical cell, wherein the nozzle comprises: A hollow tubular body extending between an open upper end and an open lower end; The lower steering component is spaced apart from the open lower end of the hollow tubular body, and an annular opening is formed between the steering surface of the lower steering component and the open lower end of the hollow tubular body. and A support rod connecting the lower steering component to the hollow tubular body, wherein the support rod is suspended inside the hollow tubular body by one or more support trusses; While continuously extruding the first anode material through an annular opening located near the lower end of the nozzle, the nozzle is retracted from the central opening of the electrochemical cell to form a first anode portion with a central opening; and The second anode material is extruded into the central opening of the first anode portion.

11. The method according to claim 10, wherein, Extruding the second anode material into the central opening of the first anode portion includes: extruding the second anode material through a central channel within the nozzle while retracting the nozzle from the central opening of the electrochemical cell.

12. The method according to claim 10, The extrusion of the first anode material via the annular opening includes: The first anode material is extruded along the length of the hollow tubular body from the upper end of the opening to the lower end of the opening and against the turning surface of the turning member at the lower part, wherein the turning surface redirects the first anode material to pass through the annular opening.

13. The method of claim 12, further comprising adjusting the height of the annular opening.

14. The method of claim 10, wherein, Extruding the second anode material into the central opening of the first anode portion includes: after the nozzle has withdrawn from the central opening of the first anode portion, extruding the second anode material into the central opening of the first anode portion.

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