Optimized electrode interfacial area for alkaline batteries

Abstract

Electrochemical cells are provided. Exemplary electrochemical cells can include a container, an electrolyte, an anode, a cathode, a current collector, and a separator disposed between the anode and the cathode. In some embodiments, the anode and cathode can define an interfacial area y, the separator defines a thickness x, and the relationship between the interfacial area y and the separator thickness x is 26.532x -0.15 ≦y≦284.5x -0.675 It is defined between.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Non-Provisional Patent Application No. 18 / 156,178, entitled "Optimized Electrode Interfacial Areas for Alkaline Batteries," filed January 18, 2023, the contents of which are incorporated herein by reference in their entirety.

[0002] The present disclosure relates generally to alkaline batteries, and more particularly to optimizing the interfacial area between electrodes in alkaline batteries. [Background technology]

[0003] The performance (e.g., runtime) of alkaline batteries varies depending on whether the battery is used in low-rate (e.g., low current draw) or high-rate (e.g., high current draw) applications. For low-rate applications, the active material in the anode and cathode of alkaline cells has been observed to have a relatively large depth of discharge (i.e., a large amount of active material discharges even at a relatively large distance from the interface between the anode and cathode). However, alkaline battery runtime for high-rate discharge applications depends on the interface between the anode and cathode within the electrochemical cell. Furthermore, to avoid short circuits, the anode and cathode in alkaline electrochemical cells must be electrically separated by a separator with a significant thickness. Therefore, increasing the interface between the anode and cathode requires a proportional increase in separator volume within the electrochemical cell. Because alkaline electrochemical cells are typically limited to industry-standard cell sizes (e.g., LR6, LR03, etc.), the amount of active material added to the cell must be reduced to accommodate any increase in separator volume. Therefore, tuning an alkaline electrochemical cell design to maximize high-rate performance (e.g., run time) can result in a decrease in low-rate performance (e.g., run time) due, at least in part, to the reduction in active material resulting from the increased interfacial area and therefore the increased volume of separator material within the cell. While this effect on low-rate performance can be mitigated by using thinner separator materials (which occupy a smaller volume), thinner separators can be more prone to structural integrity issues, including the potential for perforation during electrochemical cell manufacturing and internal short circuits upon discharge.

[0004] In practice, consumers use the same electrochemical cell for both high and low rate applications, and therefore, there is a need to optimize the interfacial area to achieve optimal performance for both high and low rate discharge of alkaline batteries. Summary of the Invention

[0005] Generally, embodiments of the present disclosure provide electrochemical cells and / or the like.

[0006] According to various embodiments, an electrochemical cell is provided that includes a container, an electrolyte, an anode, a cathode, a current collector, and a separator disposed between the anode and the cathode, wherein the anode and the cathode define an interfacial area y, the separator defines a thickness x, and the relationship between the interfacial area y and the separator thickness x is 26.532x -0.15 ≦y≦284.5x -0.675 It is defined as between.

[0007] In some embodiments, the relationship between the interfacial area y and the separator thickness x is 32.432 x-0.193 ≦y≦224.73x -0.63 It is defined as between.

[0008] In some embodiments, the relationship between the interfacial area y and the separator thickness x is 39.195x -0.232 ≦y≦183.08x -0.592 It is defined as between.

[0009] According to various embodiments, an electrochemical cell is provided that includes a container, an electrolyte, an anode, a cathode, a current collector, and a separator disposed between the anode and the cathode, wherein the anode and cathode define an interfacial area, and the separator defines a thickness, the separator thickness being selected from any of a first group ranging between 0.1 mil and 1 mil, a second group ranging between 1 mil and 5 mil, a third group ranging between 5 mil and 10 mil, and a fourth group ranging between 10 mil and 18 mil.

[0010] In some embodiments, the separator thickness is selected from a first group ranging between 0.1 mil and 1 mil, and the interfacial area is 27 cm 2 and 1346cm 2 The range is selected from the group consisting of:

[0011] In some embodiments, the separator thickness is selected from a first group ranging between 0.1 mil and 1 mil, and the interfacial area is 32 cm2 and 959cm 2 The range is selected from the group consisting of:

[0012] In some embodiments, the separator thickness is selected from a first group ranging between 0.1 mil and 1 mil, and the interfacial area is 39 cm 2 and 716cm 2 The range is selected from the group consisting of:

[0013] In some embodiments, the separator thickness is selected from a second group ranging between 1 mil and 5 mil, and the interfacial area is 21 cm 2 and 285cm 2 The range is selected from the group consisting of:

[0014] In some embodiments, the separator thickness is selected from a second group ranging between 1 mil and 5 mil, and the interfacial area is 24 cm 2 and 225cm 2 The range is selected from the group consisting of:

[0015] In some embodiments, the separator thickness is selected from a second group ranging between 1 mil and 5 mil, and the interfacial area is 27 cm 2 and 183cm 2 The range is selected from the group consisting of:

[0016] In some embodiments, the separator thickness is selected from a third group ranging between 5 mils and 10 mils, and the interfacial area is 19 cm 2 and 96cm 2 The range is selected from the group consisting of:

[0017] In some embodiments, the separator thickness is selected from a third group ranging between 5 mils and 10 mils, and the interfacial area is 21 cm 2 and 82cm 2 The range is selected from the group consisting of:

[0018] In some embodiments, the separator thickness is selected from a third group ranging between 5 mils and 10 mils, and the interfacial area is 23 cm2 and 71cm 2 The range is selected from the group consisting of:

[0019] In some embodiments, the separator thickness is selected from a fourth group ranging between 10 mils and 18 mils, and the interfacial area is 17 cm 2 and 60cm 2 The range is selected from the group consisting of:

[0020] In some embodiments, the separator thickness is selected from a fourth group ranging between 10 mils and 18 mils, and the interfacial area is 19 cm 2 and 53cm 2 The range is selected from the group consisting of:

[0021] In some embodiments, the separator thickness is selected from a fourth group ranging between 10 mils and 18 mils, and the interfacial area is 20 cm 2 and 47cm 2 The range is selected from the group consisting of:

[0022] According to various embodiments, a chemical-electrical cell is provided that includes a container, an electrolyte, an anode, a cathode, a current collector, and a separator disposed between the anode and the cathode, wherein the anode and the cathode define an interfacial area, the interfacial area being selected such that the electrochemical cell has an average ANSI performance within 8% of the maximum theoretical performance of the electrochemical cell, and wherein z=0.1191x 2 The maximum theoretical performance is given by -4.9119x + 178.16, and the equation y = 86.697x -0.423 This is achieved by a theoretical electrochemical cell having an interfacial area defined according to:

[0023] In some embodiments, the electrochemical cell has an average ANSI performance within 5% of the maximum theoretical performance of the electrochemical cell.

[0024] In some embodiments, the electrochemical cell has an average ANSI performance that is within 3% of the maximum theoretical performance of the electrochemical cell.

[0025] The above summary is intended to merely summarize some example aspects to provide a basic understanding of some aspects of the present disclosure. Accordingly, it should be understood that the above-described aspects are merely examples. It should be understood that the scope of the present disclosure encompasses many potential aspects in addition to those summarized herein, some of which are described in more detail below.

[0026] Having generally described the present disclosure, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale. [Brief explanation of the drawings]

[0027] [Figure 1] 1 is a cross-sectional side elevation view of an exemplary electrochemical cell design according to some embodiments. FIG. [Figure 2A] 2A and 2B are radial cross-sectional views of an exemplary jellyroll electrode assembly, according to some embodiments, with FIG. 2A showing a cathode outer wrap design. [Figure 2B] FIG. 2B is a radial cross-sectional view of an exemplary jellyroll electrode assembly, according to some embodiments; FIG. 2B shows an anode outer wrap design. [Figure 3] FIG. 1 illustrates a discharge profile of an exemplary electrochemical cell according to some embodiments. [Figure 4] FIG. 10 graphically illustrates run time, active material input, and discharge efficiency versus interfacial area between electrodes in alkaline cells according to some embodiments. [Figure 5] FIG. 10 graphically illustrates run time, active material input, and discharge efficiency versus interfacial area between electrodes in alkaline cells according to some embodiments. [Figure 6] FIG. 10 graphically illustrates run time, active material input, and discharge efficiency versus interfacial area between electrodes in alkaline cells according to some embodiments. [Figure 7] FIG. 10 graphically illustrates run time, active material input, and discharge efficiency versus interfacial area between electrodes in alkaline cells according to some embodiments. [Figure 8]FIG. 1 illustrates electrochemical cell performance measured against interfacial area, according to some embodiments. [Figure 9] FIG. 1 illustrates electrochemical cell performance versus optimized interfacial area, according to some embodiments. [Figure 10] FIG. 1 illustrates the maximum performance and optimized interfacial area of ​​various electrochemical cells as measured by interfacial area and separator thickness, according to some embodiments. [Figure 11] FIG. 1 illustrates the maximum performance and optimized interfacial area of ​​various electrochemical cells as measured by interfacial area and separator thickness, according to some embodiments. [Figure 12] FIG. 1 illustrates the maximum performance and optimized interfacial area of ​​various electrochemical cells as measured by interfacial area and separator thickness, according to some embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0028] Various embodiments will now be described in more detail with reference to the accompanying drawings, in which some, but not all, embodiments are shown. Indeed, various embodiments may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are presented so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout. In the following description, various components may be referred to as having specific values ​​or parameters, which are provided as exemplary embodiments. In practice, many equivalent parameters, sizes, ranges, and / or values ​​are possible, and the exemplary embodiments do not limit various aspects and concepts of the embodiments. Terms such as "first," "second," "primary," "exemplary," and "secondary" do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. Additionally, the terms "a," "an," and "the" do not denote a limitation of quantity, but rather indicate the presence of "at least one" of a reference. For example, "an organic additive" may refer to two or more organic additives.

[0029] To the extent not expressly mutually inconsistent, each embodiment disclosed herein is contemplated as being applicable to each of the other disclosed embodiments, and all combinations and subcombinations of the various embodiments described herein are included within the scope of the embodiments.

[0030] When a parameter range is indicated, all integers and ranges within that range, as well as their first, second, third, fourth, and fifth decimal places, are understood to be included by those embodiments. For example, "5 to 10%" includes 5%, 6%, 7%, 8%, 9%, and 10%, 5.0%, 5.1%, 5.2%, 9.8%, 9.9%, and 10.0%, as well as 5.00%, 5.01%, 5.02%, 9.98%, 9.99%, and 10.00%, as well as, for example, 6 to 9%, 7 to 10%, 5.1% to 9.9%, and 5.01% to 9.99%. As another example, "0.00001 to 1M" includes 0.00005 to 0.0001M and 0.001 to 0.01M.

[0031] As used herein, "about" in the context of a numerical value or range means within ±10% of the stated or claimed numerical value or range.

[0032] As used herein, "runtime" refers to the length of time that an electrochemical cell is capable of providing a particular level of charge.

[0033] As used herein, unless otherwise specified, the following terms are defined and used as follows throughout this disclosure.

[0034] Ambient or room temperature - about 20°C to about 25°C. Unless otherwise specified, all examples, data and other performance and manufacturing information are conducted under normal atmospheric conditions at ambient temperature.

[0035] Anode – A negative electrode that functions as the primary electrochemically active material; an example of the primary active material is zinc.

[0036] Capacity - The capacity output by a single electrode or an entire cell upon discharge under a particular set of conditions (e.g., consumption rate, temperature, etc.), typically expressed in milliampere-hours (mAh) or milliwatt-hours (mWh), or by the number of minutes or images taken in a digital still camera (DSC) test. The capacities described herein may be expressed and / or measured for low-rate or high-rate discharge.

[0037] Cathode - The positive electrode; in some embodiments, the active material of the cathode can be manganese dioxide (MnO2), such as electrolytic manganese dioxide (EMD).

[0038] Cell Housing - A structure that physically encloses the electrode assembly (e.g., anode, cathode, separator, and current collector). The cell housing contains all built-in safety devices, inert components, and connecting materials that comprise a fully functional battery. Typically, this will include a container (shaped like a cup, also called a "can" or "receptacle") and a closure (which fits over the container opening and usually includes a venting and sealing mechanism to prevent electrolyte evacuation and moisture / atmospheric ingress), and may be used interchangeably with the terms can or container depending on the context.

[0039] Cylindrical Cell Size - Any cell housing that has a circular shaped cylinder with a height greater than its diameter.

[0040] Electrochemically active material - One or more compounds that participate in the cell's discharge reaction and contribute to the cell's discharge capacity, but which may contain impurities and small amounts of other moieties inherent to the material.

[0041] LR6 or AA size cell - Referring to International Standard IEC-60086-1 published by the International Electrotechnical Commission after November 2000, a cylindrical cell size zinc-manganese dioxide (Zn-MnO2) battery having a maximum external height of approximately 50.5 mm and a maximum external diameter of approximately 14.5 mm.

[0042] LR03 or AAA Size Cell - Referring to International Standard IEC-60086-1 published by the International Electrotechnical Commission after November 2000, a cylindrical cell size zinc-manganese dioxide (Zn-MnO2) battery having a maximum outer diameter of approximately 10.5 mm by a maximum outer height of approximately 44.5 mm.

[0043] Interfacial Area - The surface area between the anode and cathode.

[0044] "Jellyroll" (or "spiral wound") electrode assembly - anode and cathode strips, along with a suitable separator, are combined into an assembly by being wound along their length or width, for example, around a mandrel or core.

[0045] 1 shows cell 10 as one embodiment of an LR6 (AAA) type cylindrical Zn-MnO battery cell, although the present disclosure applies equally to LR03 (AAA) or other cylindrical cells. Cell 10 has a housing that, in one embodiment, includes a container in the form of a can 12 having a closed bottom and an open top closed by a cell cover 14 and a gasket 16. Can 12 has a bead or small step near the top to support gasket 16 and cover 14. Gasket 16 is squeezed between can 12 and cover 14 to seal anode or negative electrode 18, cathode or positive electrode 20, and electrolyte within cell 10.

[0046] The anode 18, cathode 20, and separator 26 are spirally wound together into an electrode assembly. The cathode 20 has a metal current collector 22 extending from the top of the electrode assembly and connected to the inner surface of the cover 14 by a contact spring 24. The anode 18 is electrically connected to the inner surface of the can 12 by a metal lead (or tab) 36. The lead 36 is secured to the anode 18 and extends from the bottom of the electrode assembly, crossing the bottom and bending upward along the side of the electrode assembly. The lead 36 is in pressure contact with the inner surface of the sidewall of the can 12. It should be understood that this configuration is exemplary only, and that in other embodiments, the cathode may be in electrical contact with the can and the anode may be in electrical contact with the cover. In such embodiments, the physical structures of the can and cover may be different (e.g., the positive terminal tab shown integral with the cover may be integral with the can, or the cover may have a generally flat configuration). After the electrode assembly is wound, it may be held together before being inserted by tooling in the manufacturing process, or the outer edges of the material (e.g., separator or polymer film jacket 38) may be secured down, for example, by heat sealing, gluing, or taping.

[0047] In the illustrated embodiment, an insulating cone 46 is positioned around the periphery of the top of the electrode assembly to prevent the cathode current collector 22 from contacting the can 12, and contact between the bottom edge of the cathode 20 and the bottom of the can 12 is prevented by an inwardly folded extension of the separator 26 and an electrically insulating bottom disk 44 positioned at the bottom of the can 12.

[0048] In one embodiment, cell 10 has a separate positive terminal cover 40 with one or more vent holes (not shown) that is held in place by a rolled top edge and gasket 16 inside can 12. Can 12 serves as the negative contact terminal. An insulating jacket, such as an adhesive label 48, can be applied to the sidewall of can 12.

[0049] In one embodiment, a positive temperature coefficient (PTC) device 42 is disposed between the peripheral flange of the terminal cover 40 and the cell cover 14 to substantially limit current flow under abusive electrical conditions. In another embodiment, the cell 10 may also include a pressure relief vent. The cell cover 14 has an opening including an inwardly protruding central vent well 28 with a vent hole 30 at the bottom of the vent well 28. The opening is sealed by a vent ball 32 and a thin-walled thermoplastic bushing 34, which is squeezed between the vertical wall of the vent well 28 and the outer periphery of the vent ball 32. When the internal cell pressure exceeds a predetermined level, the vent ball 32 or both the vent ball 32 and bushing 34 are forced out of the opening to allow pressurized gas to escape from the cell 10. In other embodiments, the pressure relief hole may be an opening closed by a relatively thin section such as a rupture membrane, such as those disclosed in U.S. Patent Application Publication Nos. 20050244706 and 20080213651, which are incorporated by reference in their entireties, or a coined groove that cracks or otherwise breaks to form a vent opening in a portion of the cell, such as a sealing plate or container wall.

[0050] In one embodiment, the terminal end of the electrode lead 36, located between the side of the electrode assembly and the sidewall of the can, may preferably be non-planar and have a shape that enhances electrical contact with the sidewall of the can and provides a spring-like force to bias the lead against the can sidewall prior to insertion of the electrode assembly into the can. During cell manufacture, the shaped terminal end of the lead can be deformed, for example, toward the side of the electrode assembly to facilitate insertion into the can, after which the terminal end of the lead can partially spring back toward its initially non-planar shape but remain at least partially compressed to apply force to the inner surface of the sidewall of the can, thereby providing good physical and electrical contact with the can. Alternatively, this connection and / or other connections within the cell may be maintained using welding.

[0051] In some embodiments, the cell container may be a metal can with a closed bottom, such as the can in FIG. 1. The can material and container wall thickness will depend in part on the active material and electrolyte used in the cell. A common material type is steel. For example, the can may be made of cold-rolled steel (CRS) and may be nickel-plated on at least the outside to protect the outside of the can from corrosion. The type of plating can be varied to provide varying degrees of corrosion resistance, improve contact resistance, or provide a desired appearance. The type of steel will depend in part on the manner in which the container is formed. For drawn cans, the steel may be diffusion-annealed low-carbon aluminum-killed SAE 1006 or equivalent steel with an ASTM 9-11 grain size and equiaxed to a slightly elongated grain shape. Other steels, such as stainless steel, can be used to meet special needs. For example, if the can is in electrical contact with the cathode, stainless steel may be used to improve resistance to corrosion by the cathode and electrolyte.

[0052] The cell cover can be metallic. Nickel-plated steel may be used, but stainless steel is often desirable, especially when the closure and cover make electrical contact with the cathode. The complexity of the cover shape also factors into the material selection. The cell cover may have a simple shape, such as a thick, flat disk, or a more complex shape, such as the cover shown in FIG. 1. If the cover has a complex shape, such as that shown in FIG. 4, soft-annealed stainless steel type 304 with an ASTM 8-9 grain size may be used to provide the desired corrosion resistance and ease of metal forming. The formed cover may be plated, for example, with nickel, or may be fabricated from stainless steel or other known metals and their alloys.

[0053] Terminal covers must have good resistance to corrosion from water in the ambient environment or other corrosives commonly encountered during battery manufacture and use, good electrical conductivity, and an attractive appearance if visible on a consumer battery. Terminal covers are often made of nickel-plated cold-rolled steel or steel that is nickel-plated after the cover is formed. If the terminal is located over a pressure relief hole, the terminal cover typically has one or more holes to facilitate venting of the cell.

[0054] The gasket used to complete the seal between the can and the closure / terminal cover may be made of any suitable thermoplastic material exhibiting the desired sealing properties. Material selection is based in part on the electrolyte composition. Examples of suitable materials include polypropylene, polyphenylene sulfide, tetrafluoride-perfluoroalkyl vinyl ether copolymer, polybutylene terephthalate, and combinations thereof. Preferred gasket materials include polypropylene (e.g., PRO-FAX® 6524, manufactured by Basell Polyolefins, Wilmington, Delaware, USA) and polyphenylene sulfide (e.g., XTEL™ XE3035 or XE5030, manufactured by Chevron Phillips, The Woodlands, Texas, USA). Small amounts of other polymers, reinforcing inorganic fillers, and / or organic compounds may also be added to the gasket's base resin. Examples of suitable materials are described in U.S. Patent Publication Nos. 20080226982 and 20050079404, which are incorporated by reference.

[0055] The gasket may be coated with a sealant to provide the best seal. Ethylene propylene diene terpolymer (EPDM) is a suitable sealant material, although other suitable materials may be used.

[0056] The anode comprises a mixture of one or more active materials, a conductive material, optionally solid zinc oxide, and a surfactant. The negative electrode may optionally contain other additives, such as binders or gelling agents. Zinc is an example of a primary active material in the negative electrode of embodiments. Preferably, the amount of active material used in the negative electrode is sufficient to maintain desired particle-to-particle contact and a desired anode-to-cathode (A:C) ratio. In some embodiments, the anode may comprise micrometer-scale zinc particles suspended in a gelled electrolyte of concentrated potassium hydroxide (KOH) in water.

[0057] Interparticle contact must be maintained throughout the battery's service life. If the amount of active material in the negative electrode is too low, the cell's voltage may suddenly drop unacceptably low while the cell is powering the device. This voltage drop is believed to be caused by a loss of continuity in the negative electrode's conductive matrix. The conductive matrix can consist of undischarged active material particles, conductive electrochemically formed oxides, or a combination of these. After oxides begin to form, a voltage drop can occur before a sufficient network is established to bridge all of the active material particles present.

[0058] Zinc suitable for use in embodiments can be purchased from several different commercial sources under various designations, such as BIA100 and BIA115. Umicore SA, Brussels, Belgium, is one example of a zinc supplier. In preferred embodiments, the zinc powder generally has 25-40 percent fine particles less than 75 μm, preferably 28-38 percent fine particles less than 75 μm. Generally, a lower percentage of fine particles will not allow for the desired DSC service, and using a higher percentage of fine particles can result in improved gassing. The proper zinc alloy is required to reduce negative electrode gassing in the cell and to maintain test service results.

[0059] A surfactant, typically a nonionic or anionic surfactant or a combination thereof, is present in the anode. It has been found that the addition of solid zinc oxide alone increases the anode resistance during discharge, but this is mitigated by the addition of a surfactant. The addition of a surfactant increases the surface charge density of the solid zinc oxide, lowering the anode resistance as shown above.

[0060] As in the cell of Figure 1, a separate current collector (i.e., a conductive member such as a metal foil onto which the anode is coated, or a conductive strip extending along a substantial portion of the length of the anode such that the collector is spirally wound in a jelly roll) may be used. If used, the anode current collector comprises copper, aluminum, zinc, and / or other suitable highly conductive metals that are stable when exposed to other internal components of the cell (e.g., the electrolyte).

[0061] Electrical connection is maintained between each of the electrodes and an opposing external battery terminal adjacent to or integral with the housing. An electrical lead 36 can consist of a thin metal strip connecting the anode or negative electrode to one of the cell terminals (the can in the LR6 cell embodiment shown in FIG. 1). The negative electrode may be provided with a lead prior to being wound into a jellyroll configuration. The leads may be connected by a suitable weld.

[0062] The metal strip comprising lead 36 is often made of nickel or nickel-plated steel with a sufficiently low resistivity (e.g., typically less than 15 mΩ / cm, preferably less than 4.5 mΩ / cm) to allow sufficient transmission of electrical current through the lead. Examples of suitable negative electrode lead materials include, but are not limited to, copper, copper alloys such as copper alloy 7025 (a copper-nickel alloy containing about 3% nickel, about 0.65% silicon, and about 0.15% magnesium, the remainder being copper and minor impurities) and copper alloy 110, and stainless steel. The lead material should be selected so that its composition is stable in an electrochemical cell containing a nonaqueous electrolyte.

[0063] The cathode is in the form of a strip that may include a current collector and a mixture containing one or more electrochemically active materials, usually in particulate form. The active material in an alkaline battery cathode may be an electrochemically modified material (EMD). The EMD is generally present in an amount of about 80 to about 92 weight percent, preferably about 81 to 85 weight percent, based on the total weight of the positive electrode, i.e., manganese dioxide, conductive material, positive electrode electrolyte, and additives, including organic additives, if any. The cathode may also include small amounts of one or more additional active materials, depending on the desired cell electrical and discharge characteristics. This additional cathode active material may be any suitable cathode active material. Examples include metal oxides, Bi2O3, CF2, CF4, and CF4. x , (CF) n , CoS2, CuO, CuS, FeS, FeCuS2, MnO2, Pb2Bi2O5 and S.

[0064] The cathode can include other components, such as a conductive material, e.g., graphite, that, when mixed with the EMD, provides a conductive matrix for substantially the entire positive electrode. The conductive material can be natural, i.e., mined, or synthetic, i.e., man-made. In one embodiment, the cell includes a positive electrode having an active material or oxide-to-carbon ratio (O:C ratio) ranging from about 12 to about 24. In one embodiment, the O:C ratio is in the range of about 12 to 14. If the oxide-to-carbon ratio is too high, the can-to-cathode resistance increases, which can affect the overall cell resistance and adversely affect high-rate discharge performance, which may be evident from DSC testing, and / or cell use that relies on higher cutoff voltages (e.g., cutoff voltages greater than 1.05 V). The graphite can also be expanded or non-expanded. Suppliers of graphite for use in alkaline batteries include Superior Graphite Company of Chicago, Illinois, USA, and Lonza Ltd. of Basel, Switzerland. The conductive material is generally present in an amount of about 5 to about 10 weight percent, based on the total weight of the positive electrode. Too much graphite can reduce EMD loading and therefore cell capacity, while too little graphite can increase collector-to-cathode contact resistance and / or bulk cathode resistance. Depending on the specific electrochemical cell chemistry used, binders such as barium sulfate (BaSO), barium acetate, titanium dioxide, coastylene, and other additives such as calcium stearate, nickelate materials (as described in U.S. Patent Application No. 17 / 032,496, the subject matter of which is incorporated herein by reference in its entirety), and / or other additives may be used. Certain additives may also be added to facilitate the fabrication of a cathode suitable for inclusion in a jellyroll electrode. For example, in certain embodiments, an additive may be mixed with the cathode material to allow it to be extruded, spread, coated, or otherwise applied onto a cathode current collector and then rolled into a jellyroll shape without breakage.

[0065] In one embodiment, the positive electrode components (EMD), conductive material, and optional additives are mixed together to form a homogeneous mixture. During the mixing process, an alkaline electrolyte solution, such as a KOH solution, optionally containing organic additives, is evenly dispersed in the mixture, thereby ensuring uniform distribution of the solution throughout the positive electrode material.

[0066] The cathode mixture may be coated on one or both sides of a thin metal strip or mesh, or expanded or perforated material (typically nickel, about 16 to about 20 μm thick), which serves as the cathode current collector. Nickel is a commonly used material, but steel and other metal foils and their alloys are also possible. The current collector may extend beyond the portion of the cathode containing the cathode mixture. This extension of the current collector can provide a convenient compartment for contacting the electrical lead connected to the positive terminal, preferably via spring or pressure contacts, eliminating the need for leads and / or welded contacts. It is desirable to minimize the volume of the current collector extension to maximize the cell's internal volume available for active materials and electrolyte.

[0067] The cathode is electrically connected to the cell's positive terminal. This can be accomplished with an electrical lead, often in the form of a thin metal strip or spring, as shown in FIG. 1, although a welded connection is also possible. If used, this lead can be made of nickel-plated stainless steel or other suitable material. An optional current-limiting device, such as a standard PTC, is used as a safety mechanism. Suitable PTCs are sold by Tyco Electronics of Menlo Park, California, USA. A typical standard PTC device generally includes a resistance of approximately 36 mΩ / cm. Other alternatives, including lower resistance devices, are available and may be preferred. Alternative current-limiting devices are described in U.S. Publication Nos. 20070275298 and 20080254343, which are incorporated herein by reference in their entireties.

[0068] A separator is provided to separate the cathode and anode. The separator maintains physical dielectric separation of the electrochemically active material of the positive electrode from the electrochemically active material of the negative electrode, allowing ion transport between the electrode materials. Additionally, the separator functions as a core for the electrolyte and as a collar to prevent fragmented portions of the negative electrode from contacting the top of the positive electrode. The separator can be a layered, ion-permeable nonwoven fabric. A typical separator usually includes two or more layers of paper.

[0069] The battery cells of the present invention use electrolytes such as potassium hydroxide (KOH) containing only very small amounts of water as a contaminant (e.g., about 500 ppm by weight or less, depending on the electrolyte salt used). The electrolyte may further include an alkali metal hydroxide, such as potassium hydroxide (KOH), sodium hydroxide (NaOH), or a mixture thereof. Potassium hydroxide is preferred. The alkaline electrolyte used to form the gelled electrolyte of the negative electrode contains the alkali metal hydroxide in an amount of about 26 to about 36 weight percent, e.g., about 26 to about 32 weight percent, and particularly about 26 to about 30 weight percent, based on the total weight of the alkaline electrolyte. Electrolytes with lower alkalinity are preferred but may cause rapid electrolyte separation in the anode. Increasing the alkali metal hydroxide concentration results in a more stable anode but reduces high-rate operation. In some embodiments with a solid ZnO design, the dissolved ZnO concentration can be significantly higher. The metal ions in the electrolyte can have a concentration of 0.1 to 6,000 ppm. In alternative embodiments, the electrolyte may be neutral or salt-based, as in zinc-carbon cells.

[0070] The anode, cathode, and separator strips are combined together to form an electrode assembly. The electrode assembly can be a spirally wound design, such as that shown in FIG. 1, in which alternating strips of cathode, separator, anode, and separator are wound around a mandrel, and the mandrel is removed from the electrode assembly upon completion of the winding. Typically, at least one layer of separator and / or at least one layer of electrically insulating film is wound around the outside of the electrode assembly. This serves several purposes: it helps hold the assembly together and can be used to adjust the width or diameter of the assembly to a desired dimension. The outermost edges of the separator or other outer membrane layer may be held down by adhesive tape or heat-sealed. The anode can be the outermost electrode, as shown in FIGS. 1 and 2B, or the cathode can be the outermost electrode, as shown in FIG. 2A. Both electrodes are in electrical contact with the cell container, but by matching the polarity of the outermost winding of the electrode assembly with the polarity of the can, internal short circuits between the outermost electrode and the sidewall of the container can be avoided.

[0071] The cell can be closed and sealed using any suitable process. Such processes may include, but are not limited to, crimping, redrawing, collecting, and combinations thereof. For example, in the cell shown in FIG. 1, after the electrodes and insulator cones are inserted, a bead is formed on the can, and the gasket and cover assembly (including the cell cover, contact spring, and vent bushing) is placed on the open end of the can. The cell is supported on the bead, with the gasket and cover assembly pressed down against the bead. The diameter of the top of the can above the bead is reduced by a segmented collet to hold the gasket and cover assembly in place within the cell. After electrolyte is injected into the cell through the openings in the vent bushing and cover, a vent ball is inserted into the bushing to seal the opening in the cell cover. The PTC device and terminal cover are placed on the cell above the cell cover, and the top edge of the can is bent inward by a crimping die to hold and secure the gasket, cover assembly, PTC device, and terminal cover, completing the seal of the open end of the can with the gasket.

[0072] It is also desirable to use cathode materials with small particle sizes to minimize the risk of separator perforation and / or to improve rate performance under certain conditions.

[0073] The cathode mix is ​​applied to the foil collector using any number of suitable processes, such as three-roll reverse, comma coating, or slot die coating. The coating process can incorporate massless sections on one or, more preferably, both sides of the cathode current collector to facilitate electrical connection (welding or pressure contact) along the upper edge of each cathode, substantially corresponding to the longitudinal, uncoated portion along the upper edge. After or concurrently with drying to remove undesired solvent, the resulting cathode strip is densified, such as by calendering, to further compress the entire positive electrode. This densification maximizes the electrochemical material loading in the jellyroll electrode assembly, considering that the strip is then wound with a separator and a similarly (but not necessarily identically) sized anode strip to form the jellyroll electrode assembly.

[0074] Within a fixed space, such as an LR6 can, the thickness of the electrodes at least partially determines the amount of interfacial area between the electrodes. Thicker electrodes occupy more space within the fixed interior space of the cell, and therefore fewer jelly roll wraps can fit within the cell canister. However, separator thickness also affects the number of jelly roll electrode wraps that can fit within the fixed interior space of the cell canister; a thicker separator occupies more space, and as the interfacial area of ​​the electrodes increases (e.g., by reducing the electrode thickness), a proportionately larger amount of separator material is required to completely cover the interfacial area, thereby limiting the number of jelly roll wraps that can be inserted into a fixed-size cell canister.

[0075] An example of a cathode-outside-wound cell design is shown in cross section in FIG. 2A, i.e., a cross section taken along the radius of the jelly roll 19, and an anode-outside-wound design is shown in FIG. 2B. In both of these figures, the cathode 20 is shown in black, the anode 18 is shown in white, and the separator 26 is shown in dashed lines. To better illustrate the design differences, the remaining elements of the cell (discussed below) have been omitted. As used herein, cathode-outside-wound design and cell include any jelly roll electrode assembly in which a portion of the surface area on the outermost perimeter of the active material in the jelly roll is attributed to the cathode (or less than 50% of the outermost perimeter is attributed to the anode). An anode-outside-wound cell refers to an electrode assembly in which more than 50% of the outermost perimeter of the active material is attributed to the anode, although in preferred embodiments, substantially all of the outermost active material becomes the anode. When identifying whether a cell is anode-outerwound or cathode-outerwound, any separators, leads, insulating tape, and other inactive components are not taken into account, and the interfacial orientation of the electrodes is not taken into consideration. Instead, the outermost circumference of the jelly roll is determined solely based on the outermost portions of the anode and cathode that are exposed or will be exposed. Also, as used herein, leads are considered separate components compared to current collectors insofar as they establish electrical contact between the electrode assembly and the battery terminals, while current collectors are used only within the electrode assembly itself (e.g., the current collectors conduct electrons to the leads).

[0076] In either case (i.e., anode or cathode outer-wound design), the electrode, particularly the anode, has a substantially uniform thickness for ease of manufacture and because this configuration maintains the lowest possible internal resistance throughout discharge of the cell. Cathode coatings applied to one side of the current collector also have a uniform thickness, although intermittent coating techniques may be employed to optimize the amount of active material and improve cathode utilization.

[0077] The above description of a jellyroll electrochemical cell design is by way of example only: the interfacial area between the anode and cathode can be easily adjusted in the jellyroll configuration by varying the thickness of the anode and cathode electrodes. However, the interfacial area between the anode and cathode can also be adjusted by other electrochemical cell structures, such as by adjusting the electrode geometry of a bobbin-type electrochemical cell structure (e.g., as described in U.S. Pat. No. 6,074,781 or U.S. Patent Publication No. 2020 / 0203713, the contents of both of which are incorporated herein by reference in their entirety), a dual-anode electrochemical cell structure (e.g., as described in U.S. Patent Publication No. 2022 / 0077473, U.S. Pat. No. 5,962,163, or U.S. Pat. No. 5,869,205, the entire contents of which are incorporated herein by reference in their entirety), a central cathode electrochemical cell structure (e.g., as described in U.S. Patent Publication No. 2020 / 0411878, the contents of which are incorporated herein by reference), alternating discs of anode and cathode material (with intervening separator discs) stacked within a cylindrical battery cell, and / or the like.

[0078] Experimental results and optimized interfacial area design Figure 3 shows the discharge profile of an electrochemical cell according to some embodiments. Figure 3 shows the results of a discharge performance test conducted on an LR6(AA)Zn-MnO2 bobbin-type alkaline cell using the standard ANSI digital still camera (DSC) test method. Discharge time is shown on the x-axis in minutes, and voltage is shown on the y-axis in volts. During testing, voltage was measured as a function of discharge time for cells with high interfacial area and cells with low interfacial area. The low interfacial area cells had a separator thickness of 13 mils and a thickness of approximately 12 cm. 2 The high interfacial area cell has three cylindrical anodes with a 13 mil separator and a total area of ​​19 cm. 2Both cells were discharged using the same current / voltage draw. As shown in Figure 3, the high interfacial area cell had a discharge time of approximately 148 minutes (measured until the cell voltage exceeded the lower threshold voltage of 1.05 V), while the cell with the low interfacial area had a discharge time of approximately 65 minutes. The increase in interfacial area from the low interfacial area to the high interfacial area cell, as reflected in Figure 3, increases the cathode (MnO2) discharge efficiency, based on one-electron discharge of the cathode during DSC discharge conditions, from 24% to 44%. Therefore, increasing the interfacial area between the anode and cathode is generally considered desirable for extending the cell's runtime in high-rate discharge applications (such as DSC testing). However, as discussed above, a high interfacial area design requires a larger separator volume, thereby reducing the amount of volume within a fixed-size battery cell that can be occupied by the active material in the electrochemical cell. This reduction in the amount of active material (cathode and anode) that can be loaded into the cell can reduce the battery run-time performance in low-rate discharge applications, which are typically characterized by higher discharge efficiency of the active material.

[0079] Figures 4-12 show the effect of varying the interfacial area in alkaline cells for different separator thicknesses. These figures graphically illustrate theoretical experiments on how varying the interfacial area affects the amount of active material added to the cell, the discharge efficiency of the active material, and the runtime of the cell under different discharge conditions. For runtime and active material input, these graphs show the percentage change relative to a control cell, i.e., a standard bobbin-type electrochemical cell. For example, a runtime of 110% refers to a cell having a runtime that is 110% of the runtime of the control cell. Similarly, a cell with an active material input of 85% means that the cell contains 85% of the amount of active material in the control cell. Discharge efficiency is expressed as a percentage and refers to the percentage of cathode active material based on one-electron EMD capacity that discharges when the cell reaches a specified cutoff voltage (e.g., 1.05 V for DSCs or 1.0 V for a 50 mA discharge rate). For example, a discharge efficiency of 95% means that 95% of the active material in the cell has discharged when the cell reaches the discharge output voltage. It should be noted that the active material chemistry (i.e., the mix of anode materials within the anode gel and the mix of cathode materials within the cathode mixture) remains the same for all cell designs.

[0080] Figures 4 and 5 show the effect of varying the interfacial area in a cell under low rate discharge (50 mA discharge) conditions. Figure 4 shows the effect of varying the interfacial area in a cell with a separator having an 18 mil thickness, and Figure 5 shows the effect of varying the interfacial area in a cell with a 0.1 mil separator (nearly zero thickness separator). As shown in Figure 4, for an 18 mil thick separator, 11 cm 2 From 100cm 2 As the interfacial area increases, the low rate discharge ANSI 50mA discharge runtime decreases from 100% to approximately 31%, and the cathode discharge efficiency is 11cm 2 88% to 100cm 2As shown in Figure 4, the input reduction with the high interfacial area design is due to the increased separator volume when the separator is relatively thick (18 mils in Figure 4). Thinner separators are expected to have a smaller (possibly negligible) impact on active material input, resulting in higher electrochemical cell performance with increased interfacial area. This is illustrated in Figure 5, which shows the effect of interfacial area on active material input, runtime, and discharge efficiency (as in Figure 4) but using a theoretical separator with a 0.1 mil thickness. As shown in Figure 5, active material input remains at 100% when the interfacial area is increased (because the separator has negligible thickness / volume even with increased interfacial area), and the runtime and discharge efficiency each increase with increasing interfacial area, with the runtime approaching approximately 117% and the discharge efficiency approaching approximately 96%.

[0081] 6 and 7 illustrate the effect of varying interfacial area within a cell under conditions of high-rate discharge (e.g., discharge according to an ANSI standardized DSC test). FIG. 6 specifically illustrates the effect of varying interfacial area within a cell having a negligible separator thickness (0.1 mil thick). FIG. 7 illustrates the effect of varying interfacial area within a cell having an 18 mil thick separator. In general, electrochemical cells with high interfacial area are believed to perform better under high-rate discharge conditions (i.e., have longer run times and higher discharge efficiencies even with lower active material input) than under low-rate discharge conditions. Referring now to FIG. 6, which illustrates the performance of a cell with a 0.1 mil separator under DSC discharge parameters, the run time was 11 cm. 2 of interfacial area by 113% to 100cm 2 With interfacial area of ​​0.1 mil, there is an increase of 313% with a corresponding improvement in discharge efficiency from 25% to 69%. Active material loading remains at 100%. Therefore, it is believed that reducing the separator thickness (e.g., to 0.1 mil) and increasing the interfacial area can lead to significant improvements in run time and discharge efficiency for both high rate performance devices such as DSCs (Figure 7) and low rates such as 50 mA (Figure 5).

[0082] Next, referring to Figure 7, even with an 18 mil separator thickness, the DSC runtime was 11 cm despite the reduced active material loading. 2 100% to 30cm of the interfacial area 2 However, the DSC service in Figure 7 2 A maximum value of 194% is reached at an interfacial area of ​​18 mils, after which performance decreases with interfacial area. Similar to the comparison of Figures 6 and 5, a comparison of the parameters in Figures 7 and 4 shows that high-rate performance appears to have a greater relative advantage compared to low-rate performance. However, Figure 7 also shows that with increasing separator thickness (e.g., 18 mils), there is a corresponding decrease in performance (as indicated by, for example, runtime and active material input) after a certain value of interfacial area is reached.

[0083] As reflected in Figure 8, average ANSI performance is plotted against the interfacial area of ​​electrochemical cells with 18 mil separators. A simple average ANSI was calculated for LR6 size Zn / MnO2 alkaline cells over seven ANSI 2021 standard tests. That is, seven ANSI 2021 standard tests were run, summed, and divided by seven to arrive at this calculation. As shown in Figure 8, performance is plotted against the interfacial area of ​​electrochemical cells with 18 mil separators. 2 increases with interfacial area until an optimum point (or "peak performance") is reached at , after which performance decreases with increasing interfacial area.

[0084] FIG. 8 graphically illustrates how varying the interfacial area of ​​an alkaline electrochemical cell affects performance, with the maximum possible performance being achieved at the optimal interfacial area, as discussed above. The inventors have discovered that the optimized interfacial area depends on the separator thickness used in the cell. FIG. 9 graphically illustrates the maximum performance of an alkaline cell (shown as a percentage of performance relative to a control cell) as a function of separator thickness. Maximum performance is plotted on the z-axis on the right side of the graph. FIG. 9 also graphically illustrates the optimal interfacial area as a function of separator thickness. Interfacial area is plotted on the y-axis on the left side of the graph. As discussed above, the maximum possible performance of an alkaline cell is the performance of an alkaline cell with the optimized interfacial area at a given separator thickness. In other words, to obtain the maximum possible performance of a cell with a given separator thickness, the cell must be designed with the optimal interfacial area.

[0085] As reflected in FIG. 9, the maximum performance of the cell can be calculated by the following equation (1): z=0.1191x 2 -4.9119x+178.16

[0086] In equation (1), z is the maximum performance (percentage of the control cell performance) and x is the separator thickness in mils. Figure 9 also shows that the optimized interfacial area decreases as the separator thickness increases. The optimized interfacial area can be calculated by equation (2) as follows: y=86.697x -0.423

[0087] In formula (2), y is in cm 2 where σ is the interfacial area in mm and x is the separator thickness in mils.

[0088] The inventors have found that cells exhibiting performance within 8% of maximum performance provide acceptable performance while exhibiting sufficient manufacturing tolerance to provide a cell with an optimized interfacial area. More preferably, electrochemical cells exhibiting performance within 5% of maximum performance, and even more preferably, electrochemical cells exhibiting performance within 3% of maximum performance, exhibit acceptable performance with sufficient manufacturing tolerance. Figure 10 shows the range of interfacial areas selectable as a function of separator thickness to obtain alkaline electrochemical cells exhibiting performance within 8% of maximum performance. Figure 11 shows the range of interfacial areas selectable as a function of separator thickness to obtain alkaline electrochemical cells exhibiting performance within 5% of maximum performance. Figure 12 shows the range of interfacial areas selectable as a function of separator thickness to obtain alkaline electrochemical cells exhibiting performance within 3% of maximum performance. As reflected in each of Figures 10-12, the interfacial area of ​​an alkaline electrochemical cell can be above or below the optimal interfacial area while still achieving performance within the respective range. Note that the values ​​corresponding to these ranges are reflected in Table 1 below. FIG. 10 corresponds to interfacial area range 1 (8% below peak performance), FIG. 11 corresponds to interfacial area range 2 (5% below peak performance), and FIG. 12 corresponds to interfacial area range 3 (3% below peak performance).

[0089] Referring now to FIG. 10, alkaline cell performance for an LR6 size cell can be achieved to within 8% of maximum performance by using an interfacial area within the range of equation (3) below. 26.532x -0.15 ≦y≦284.5x -0.675

[0090] In formula (3), y is in cm 2 where x is the interfacial area in mils, and x is the separator thickness in mils. As reflected in Table 1 below, for cells using separators with thicknesses between 0.1 and 1 mil, the cell must have an interfacial area between 27 and 1346 cm to achieve performance within 8% of the cell's maximum performance. 2For cells using separators with thicknesses of 1 to 5 mils, the cell must have an interfacial area of ​​21 to 285 cm to achieve performance within 8% of the cell's maximum performance. 2 For cells using separators with thicknesses of 5 to 10 mils, the cell must have an interfacial area of ​​19 to 96 cm to achieve performance within 8% of the cell's maximum performance. 2 For cells using separators with thicknesses of 10 to 18 mils, the cell should have an interfacial area of ​​17 to 60 cm to achieve performance within 8% of the cell's maximum performance. 2 can be used.

[0091] Referring now to FIG. 11, alkaline cell performance for LR6 size cells can be achieved within 5% of maximum performance by using an interfacial area within the range of equation (4) below. 32.432x -0.193 ≦y≦224.73x -0.63

[0092] In equation (4), y is in cm 2 where x is the interfacial area in mils, and x is the separator thickness in mils. As reflected in Table 1 below, for cells using separators with thicknesses between 0.1 and 1 mil, the cell must be between 32 and 959 cm to achieve performance within 5% of the cell's maximum performance. 2 For cells using separators with thicknesses of 1 to 5 mils, the cell should have an interfacial area of ​​24 to 225 cm to achieve performance within 5% of the cell's maximum performance. 2 For cells using separators with thicknesses of 5 to 10 mils, the cell must be sized to achieve performance within 5% of the cell's maximum performance. 2 For cells using separators with thicknesses of 10 to 18 mils, the cell should have an interfacial area of ​​19 to 53 cm to achieve performance within 5% of the cell's maximum performance. 2 can be used.

[0093] Referring now to FIG. 12, alkaline cell performance for LR6 size cells can be achieved within 3% of maximum performance by using an interfacial area within the range of equation (5) below. 39.195x -0.232 <y<183.08x -0.592

[0094] In equation (5), y is in cm 2 where x is the interfacial area in mils, and x is the separator thickness in mils. As reflected in Table 1 below, for cells using separators with thicknesses between 0.1 and 1 mil, the cell must be between 39 and 716 cm to achieve performance within 3% of the cell's maximum performance. 2 For cells using separators with thicknesses of 1 to 5 mils, the cell must have an interfacial area of ​​27 to 183 cm to achieve performance within 3% of the cell's maximum performance. 2 For cells using separators with thicknesses of 5 to 10 mils, the cell must be sized to achieve performance within 3% of the cell's maximum performance. 2 For cells using separators with thicknesses of 10 to 18 mils, the cell must be sized to achieve performance within 3% of the cell's maximum performance. 2 can be used.

[0095] The peak or optimum performance of an alkaline cell can be determined using the optimum interfacial area equation disclosed in FIG. 9 and previously described as Equation (2). However, manufacturing cells that strictly adhere to this equation can be difficult and may not be economically feasible. As previously described with respect to FIGS. 10-12 and Equations (3), (4), and (5), it has been found that performances less than 8%, (preferably) 5%, and (more preferably) 3%, respectively, provide improved performance while remaining within reasonable manufacturing tolerances. As shown and discussed below, Table 1 details how to fabricate alkaline cells with separator thicknesses and interfacial areas that achieve performance within 8%, 5%, or 3% of the alkaline cell's peak / optimum performance.

[0096] The table below (Table 1) shows the simple average values ​​of the ANSI2021 test for the aforementioned LR6 / AA Zn-MnO2 alkaline battery over seven ANSI standard tests. [Table 1]

[0097] Table 1 lists separator thickness (in mils) in the leftmost column and lower and upper limits of interfacial area (in cm) in the remaining columns. 2 ) are displayed. Separator values ​​in a row correspond to the lower and upper limits of the interfacial area in that row. Table 1 is divided into three sections: the left section shows separator values ​​and interfacial areas for performance within 8% of peak performance, the middle section shows separator values ​​and interfacial areas for performance within 5% of peak performance, and the right section shows separator values ​​and interfacial areas for performance within 3% of peak performance. For example, for a 1 mil thick alkaline cell, to achieve performance within 8% of peak performance, the interfacial area ranges from 27 cm2 to 285 cm2. 2 As another example, for the same cell having a 1 mil thickness, to achieve performance within 5% of peak performance, the interfacial area can be in the range of 32 cm 2 ~225cm 2 The range can be:

[0098] According to various embodiments, one or more LR6 alkaline electrochemical cells can be designed based on the ratio of anode and cathode interfacial areas to separator thicknesses mentioned above. These various electrochemical cells can be based on the "jellyroll" cell described above and shown in Figures 1, 2A, and 2B. However, it should be understood that other cell configurations can be used while adhering to the interfacial area to separator thickness ratios described above.

[0099] In some embodiments, an LR6 alkaline electrochemical cell can include a container, an electrolyte, an anode, a cathode, a current collector, and a separator disposed between the anode and the cathode, where the separator can have a thickness x, an interfacial area of ​​the cathode and the anode can be y, and the relationship between the separator thickness and the interfacial area of ​​the anode and the cathode can be defined according to an interfacial area range as described with reference to FIG. 10, FIG. 11, or FIG. 12.

[0100] In some embodiments, an LR6 alkaline electrochemical cell can include a container, an electrolyte, an anode, a cathode, a current collector, and a separator between the anode and the cathode, where the separator can have a thickness in a first group of separator thickness ranges of 0.1 to 1 mil, and a thickness of 27 to 1346 cm such that the cell has a performance within 8% of the maximum achievable performance of the cell. 2 interfacial area, 32 to 959 cm, so that the cell performs within 5% of its maximum performance 2 interfacial area, or 39 to 716 cm so that the cell performs within 3% of its maximum performance 2 In other embodiments, the separator can have a thickness within a second group of separator thicknesses of 1 to 5 mils, and an interfacial area of ​​21 to 285 cm, such that the cell has performance within 8% of maximum performance. 2 interfacial area, 24 to 225 cm so that the cell performs within 5% of its maximum performance 2 or 27 to 183 cm2 so that the cell performs within 3% of its maximum performance. 2 In a further embodiment, the separator has a thickness in a third group of separator thicknesses ranging from 5 to 10 mils and an interfacial area of ​​19 to 96 cm such that the cell performs within 8% of maximum performance. 2 Interfacial area in the range of 21 to 82 cm, so that the cell performs within 5% of its maximum performance 2 or 23 to 71 cm2 so that the cell performs within 3% of its maximum performance. 2In a further embodiment, the separator can have a thickness in a fourth group of separator thicknesses ranging from 10 to 18 mils, and an interfacial area of ​​17 to 60 cm, such that the cell has performance within 8% of maximum performance. 2 interfacial area, 19 to 53 cm2 so that the cell performs within 5% of its maximum performance 2 and 20-47cm to ensure the cell performs within 3% of its maximum performance. 2 has an interfacial area of

[0101] In some embodiments, an LR6 alkaline electrochemical cell can include a container, an electrolyte, an anode, a cathode, a current collector, and a separator disposed between the anode and the cathode, wherein the anode and cathode define an interfacial area, the interfacial area selected such that the electrochemical cell has an average ANSI performance within 8% of the electrochemical cell's maximum theoretical performance, the maximum theoretical performance being achieved by a theoretical electrochemical cell having an interfacial area defined according to the equation described with reference to FIG. 9. In some embodiments, the electrochemical cell can have an average ANSI performance within 5% of the electrochemical cell's maximum theoretical performance. In some embodiments, the electrochemical cell can have an average ANSI performance within 3% of the electrochemical cell's maximum theoretical performance.

[0102] All of the references cited above, as well as all references cited herein, are incorporated herein by reference in their entirety.

[0103] While the embodiments have been illustrated and described in detail above, such illustration and description are to be considered as exemplary or exemplary and not restrictive. It is to be understood that changes and modifications may be made by those skilled in the art within the scope and spirit of the following claims. Embodiments include any combination of features of different embodiments described above and below.

[0104] In order that the embodiments and their many advantages may be better understood, the embodiments are further described by way of the following illustrative, non-limiting examples. The following examples are included to illustrate preferred embodiments. Those skilled in the art will understand that the techniques disclosed in the following examples represent techniques used in the embodiments to function properly in practicing the embodiments, and therefore can be considered to constitute preferred modes for their practice. However, those skilled in the art will understand, in light of the present disclosure, that many changes can be made to the specific embodiments disclosed and still obtain like or similar results without departing from the spirit and scope of the embodiments.

[0105] Numerous modifications and other embodiments of the disclosure set forth herein will come to mind to one skilled in the art to which this disclosure pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. It is to be understood, therefore, that the disclosure is not to be limited to the particular embodiments disclosed, but that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

1. 1. An electrochemical cell comprising: A container and Electrolytes, an anode; a cathode; a current collector; a separator disposed between the anode and the cathode; Equipped with the anode and the cathode define an interfacial area y, and the separator defines a thickness x; The relationship between the interfacial area y and the separator thickness x is 26.532x -0.15 ≦y≦284.5x -0.675 An electrochemical cell defined between.

2. The relationship between the interfacial area y and the separator thickness x is 32.432x -0.193 ≦y≦224.73x -0.63 10. The electrochemical cell of claim 1, wherein:

3. The relationship between the interfacial area y and the separator thickness x is 39.195x -0.232 ≦y≦183.08x -0.592 10. The electrochemical cell of claim 1, wherein:

4. 1. An electrochemical cell comprising: A container and Electrolytes, an anode; a cathode; a current collector; a separator disposed between the anode and the cathode; Equipped with the anode and the cathode define an interfacial area, and the separator defines a thickness; 1. An electrochemical cell, wherein the separator thickness is selected from a first group ranging between 0.1 mil and 1 mil, a second group ranging between 1 mil and 5 mil, a third group ranging between 5 mil and 10 mil, and a fourth group ranging between 10 mil and 18 mil.

5. The separator thickness is selected from the first group ranging between 0.1 mil and 1 mil, and the interfacial area is 27 cm 2 and 1346 cm 2 5. The electrochemical cell of claim 4, wherein the voltage is selected from the group ranging between

6. The separator thickness is selected from the first group ranging between 0.1 mil and 1 mil, and the interfacial area is 32 cm 2 and 959 cm 2 6. The electrochemical cell of claim 5, wherein the voltage is selected from the group ranging between

7. The separator thickness is selected from the first group ranging between 0.1 mil and 1 mil, and the interfacial area is 39 cm 2 and 716 cm 2 7. The electrochemical cell of claim 6, wherein the voltage is selected from the group ranging between

8. The separator thickness is selected from the second group ranging between 1 mil and 5 mil, and the interfacial area is 21 cm 2 and 285 cm 2 5. The electrochemical cell of claim 4, wherein the voltage is selected from the group ranging between

9. The separator thickness is selected from the second group between 1 mil and 5 mil, and the interfacial area is 24 cm 2 and 225 cm 2 9. The electrochemical cell of claim 8, wherein the voltage is selected from the group ranging between

10. The separator thickness is selected from the second group ranging between 1 mil and 5 mil, and the interfacial area is 27 cm 2 and 183 cm 2 10. The electrochemical cell of claim 9, wherein the voltage is selected from the group ranging between

11. The separator thickness is selected from the third group ranging between 5 mils and 10 mils, and the interfacial area is 19 cm 2 and 96 cm 2 5. The electrochemical cell of claim 4, wherein the voltage is selected from the group ranging between

12. The separator thickness is selected from the third group ranging between 5 mils and 10 mils, and the interfacial area is 21 cm 2 and 82 cm 2 12. The electrochemical cell of claim 11, wherein the voltage is selected from the group ranging between

13. The separator thickness is selected from the third group ranging between 5 mils and 10 mils, and the interfacial area is 23 cm 2 and 71 cm 2 13. The electrochemical cell of claim 12, wherein the voltage is selected from the group ranging between

14. The separator thickness is selected from the fourth group ranging between 10 mils and 18 mils, and the interfacial area is 17 cm 2 and 60 cm 2 5. The electrochemical cell of claim 4, wherein the voltage is selected from the group ranging between

15. The separator thickness is selected from the fourth group ranging between 10 mils and 18 mils, and the interfacial area is 19 cm 2 and 53 cm 2 15. The electrochemical cell of claim 14, wherein the voltage is selected from the group ranging between

16. The separator thickness is selected from the fourth group ranging between 10 mils and 18 mils, and the interfacial area is 20 cm 2 and 47 cm 2 16. The electrochemical cell of claim 15, wherein the voltage is selected from the group ranging between

17. 1. An electrochemical cell comprising: A container and Electrolytes, an anode; a cathode; a current collector; a separator disposed between the anode and the cathode; Equipped with the anode and the cathode define an interfacial area; The interfacial area is selected so that the electrochemical cell has an average ANSI performance within 8% of the maximum theoretical performance of the electrochemical cell, and z=0.1191x 2 The maximum theoretical performance defined by -4.9119x + 178.16 is expressed by the formula y = 86.697x -0.423 The electrochemical cell is achieved by a theoretical electrochemical cell having an interfacial area defined according to

18. 18. The electrochemical cell of claim 17, wherein the electrochemical cell has an average ANSI performance within 5% of the maximum theoretical performance of the electrochemical cell.

19. 20. The electrochemical cell of claim 18, wherein the electrochemical cell has an average ANSI performance within 3% of the maximum theoretical performance of the electrochemical cell.

Images