Battery including all active material electrode and methods of making all active material electrodes

Abstract

The present disclosure provides for batteries including an all-active material cathode, methods of making material cathodes, and the like. The battery can be a single-use battery, in other words, the battery does not need to be rechargeable. The cathode architecture of the present disclosure is referred to as an all-active material (AAM) electrode. AAM architecture can produce improved volume loading efficiency in the cell, removal of inactive components that can reduce efficiency of the battery, improved mechanical characteristics, and a homogeneous material distribution.

Description

TH Docket No.: 222117-2490BATTERY INCLUDING ALL ACTIVE MATERIAL ELECTRODE AND METHODS OF MAKING ALL ACTIVE MATERIAL ELECTRODESCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application entitled “ALL ACTIVE MATERIAL ELECTRODE PRIMARY BATTERY CELLS” and having Serial No. 63 / 691 ,719, filed September 6, 2024, which is herein incorporated by reference in its entirety.FEDERAL SPONSORSHIP

[0002] This invention was made with government support under 1652488 awarded by the National Science Foundation. The government has certain rights in the invention.BACKGROUND

[0003] Miniaturization of energy storage (<100 mm3) at relatively low power widely serves broad applications including, but not limited thereto, watches, continuous glucose monitors (CGMs), wearable insulin pumps, and capsule endoscopy (CE). Therefore, it is desirable to reduce cost, decrease size, and improve discharge duration (increase battery capacity), among other things, of the batteries that power wearable devices. Low voltage primary batteries broadly power small electronics used in health, biomedical, and wearable applications. These devices are generally more sensitive to volumetric capacity than gravimetric capacity. The current state- of-the-art for smaller button cells is Zn-Ag2O, where contributors that limit volumetric capacity include the incorporation of inactive materials in the electrode microstructure such as gelling agents, binders, and conductive additives.

[0004] Zn-Ag2O cells have about 40% higher volumetric capacity, but a much higher cost due to electroactive materials used, than lower cost alternatives such as alkaline batteries (i.e. , Zn-MnO2). Compared to Zn-Ag2O, the theoretical gravimetric capacity is 320% and 400% more for CuO and FeS2, while the volumetric capacity is only 10% higher. The limited volumetric capacity advantage at the material level is likely a contributor of why Zn-Ag2O has not been replaced by these alternatives. Even though the gravimetric capacity advantage is large, the relevant applications are less sensitive to weight relative to volume in powering wearable and biomedical devices.TH Docket No.: 222117-2490SUMMARY

[0005] The present disclosure provides for batteries including an all-active material cathode, methods of making material cathodes, and the like.

[0006] The present disclosure provides for a battery, having: an all-active material cathode made of an electroactive material, wherein the electroactive material is comprised of about 95% or more of the electroactive material, an anode, a separator positioned between the all-active material cathode and the anode, and an electrolyte, wherein the battery has a volume loading efficiency of about 55 to 80%, and wherein the battery has a volumetric capacity of about 500 to 2,500 mAh cm'2.

[0007] The present disclosure provides for a single-use Li-CuO battery, including: a lithium cathode, and a CuO all-active material anode, wherein the CuO all-active material anode consists essentially of CuO, wherein the battery has a volume loading efficiency of about 55 to 80%, and wherein the battery has a volumetric capacity of about 200 to 850 mAh cm-3.

[0008] The present disclosure provides for a single-use Li-FeS2 battery, comprising: a lithium cathode, and a FeS2 all-active material anode, wherein the FeS2 anode consists essentially of FeS2, wherein the battery has a volume loading efficiency of about 55 to 80%, and wherein the battery has a volumetric capacity of about 200 to 850 mAh cm'3.

[0009] The present disclosure provides for a method of making an all-active material cathode, comprising: compressing pellets under a pressure of about 50-250 MPa for about 3 to 10 seconds, wherein the pellets are made of a precursor electroactive material; and heating the pellets in a furnace to about 500-1200 °C for about 30 minutes to 90 minutes to form the allactive material cathodeBRIEF DESCRIPTION OF THE DRAWINGS

[0010] Further aspects of the present disclosure will be more readily appreciated upon review of the detailed description of its various embodiments, described below, when taken in conjunction with the accompanying drawings.

[0011] Figure 1 illustrates a schematic of commercially available coin cell architecture.

[0012] Figure 2 illustrates a schematic of all active material (AAM) electrode fabrication process.

[0013] Figures 3A and 3B illustrate a schematic of a general battery cell (FIG. 3A, left) and a zoomed in cartoon of (FIG. 3A, right) a conventional composite electrode architecture with tortuous lithium diffusion pathway through the interstitial microstructure due to inactive binderTH Docket No.: 222117-2490 and conductive additives; and (FIG. 3B) AAM electrode with reduced lithium transport restrictions due to only electrolyte filling the electrode pore regions.

[0014] Figures 4A and 4B illustrate (FIG. 4A) a discharge voltage profile of a primary AAM Li-CuO battery, and (FIG. 4B) cell.

[0015] Figure 5 illustrates a schematic of AAM electrode fabrication.

[0016] Figure 6 illustrates the FeS2 porosity change across the compression pressure.

[0017] Figures 7A-7C illustrate CuO porosity as a function of compression pressure and sintering conditions for (FIG. 7A) 800 mesh size, (FIG. 7B) 325 mesh size, and (FIG. 3C) 200 mesh size.

[0018] Figure 8 illustrates a highest achieved volumetric capacity summary for CuO and FeS2.

[0019] Figures 9A and 9B illustrate voltage profiles for (FIG. 9A) CuO and (FIG. 9B) FeS2discharged over - 100 hours with 1.2 M LiPFe in 3:7 EC:EMC electrolyte (purple (P) and orange (O) for after 6 months storage) and 0.8 M UCIO4 in PC (blue (B) and green (G) for after 6 months storage).

[0020] Figure 10 illustrates a table showing porosity of CuO and FeS2at different sintering temperatures.

[0021] Figure 11 illustrates a schematic of AAM electrode fabrication.

[0022] Figures 12A and 12B illustrate discharge voltage profiles for AAM (FIG. 12A) CuO and (FIG. 12B) FeS2. The gravimetric capacity (low axis) is based on the cathode material mass, and the volumetric capacity is based on the total volume of the cathode including void / pores.

[0023] Figures 13A-13D illustrate the theoretical (FIG. 13A) gravimetric and (FIG. 13B) volumetric capacity of the individual electrode active materials noted. Theoretical (FIG. 13C) gravimetric and (FIG. 13D) volumetric capacity after balancing electrodes on an active material basis for Zn-Ag2O, Li-FeS2, and Li-CuO are also shown.

[0024] Figures 14A-14D illustrate cartoon schematics of electrode regions and relative volume fractions in the electrodes in (FIG. 14A, FIG. 14C) conventional Zn-Ag2O button batteries and (FIG. 14B, FIG. 14D) the cells in the present disclosure.

[0025] Figure 15 illustrates discharge voltage profiles for 200 mesh CuO heated at 950 °C discharged at 0.92 mA cnrr2(blue; B) and 4.6 mA cm'2(green; G). The slower rate had a discharge time of about 130 hours.TH Docket No.: 222117-2490

[0026] Figure 16 illustrates discharge voltage profiles for 200 mesh CuO heated at 950 °C discharged at 0.75 mA-cnr2(blue; B) and 3.8 mA-crrr2(green; G). The lower rate had a discharge time of about 120 hours.

[0027] Figure 17 illustrates discharge voltage profiles for 395 / 927 button cells from Energizer (B), Duracell (O), Renata (G), and the present disclosure (P). The discharge current was constant at 1 mA.

[0028] Figure 18 shows XRD patterns for AAM CuO electrode processed at 950 °C (G) and the as received pristine CuO material (P).

[0029] Figure 19 shows a discharge voltage profile for 200 mesh CuO active material processed into a conventional composite electrode at a rate of ~ C / 20. The current density was 0.08 mA crrr2and the anode was Li metal.

[0030] Figures 20A-20C illustrate the porosity of (FIG. 20A) 200 mesh CuO, (FIG. 20B) 325 mesh CuO, and (FIG. 20C) 800 mesh CuO compressed at 75 (B), 150 (O), and 225 (G) MPa as a function of heating temperature. 200 mesh, 325 mesh, and 800 mesh size corresponds to maximum particle size of 74 pm, 44 pm, and 18 pm, respectively. Fewer temperatures were investigated for 200 mesh CuO due to relatively low change at 900 °C relative to initial compression.

[0031] Figure 21 illustrates XRD patterns for AAM FeS2 electrode processed at 500 °C (G) and the as received pristine FeS2 material (P).

[0032] Figure 22 illustrates the discharge voltage profile at ~ C / 50 for 99% purity FeS2 active material processed into a conventional composite electrode. The current density was 0.1 mA cnr2and anode was Li metal.

[0033] Figure 23 illustrates the porosity 325 mesh 99% purity FeS2 as a function of compression pressure. Porosity was the same both before and after heat treatment at 500 °C.DETAILED DESCRIPTION

[0034] The present disclosure is directed to methods of using all-active material (AAM) electrodes for primary (single use) as opposed to rechargeable applications. Moreover, an aspect of an embodiment includes using copper oxide and iron sulfide, for example, for this allactive material electrodes application; where the capacity compared to commercial primary cells is greater and the raw material inputs cost less than existing commercial cells.

[0035] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Although any methods and materials similar or equivalent to thoseTH Docket No.: 222117-2490 described herein can also be used in the practice or testing of the present disclosure, the preferred methods and materials are now described.

[0036] As will be apparent to those of skill in the art upon reading this disclosure, each of the individual embodiments described and illustrated herein has discrete components and features which may be readily separated from or combined with the features of any of the other several embodiments without departing from the scope or spirit of the present disclosure. Any recited method can be carried out in the order of events recited or in any other order that is logically possible.

[0037] Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range, is encompassed within the disclosure. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges and are also encompassed within the disclosure, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the disclosure.

[0038] It must be noted that, as used in the specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a support” includes a plurality of supports. In this specification and in the claims that follow, reference will be made to a number of terms that shall be defined to have the following meanings unless a contrary intention is apparent.

[0039] As used herein, the following terms have the meanings ascribed to them unless specified otherwise. In this disclosure, "comprises," "comprising," "containing" and "having" and the like can have the meaning ascribed to them in U.S. patent law and can mean " includes," "including," and the like; "consisting essentially of' or "consists essentially" or the like, when applied to methods and compositions encompassed by the present disclosure refers to compositions like those disclosed herein, but which may contain additional structural groups, composition components or method steps (or analogs or derivatives thereof as discussed above). Such additional structural groups, composition components or method steps, etc., however, do not materially affect the basic and novel characteristic(s) of the compositions or methods, compared to those of the corresponding compositions or methods disclosed herein. "Consisting essentially of" or "consists essentially" or the like, when applied to methods and compositions encompassed by the present disclosure have the meaning ascribed in U.S. patent law, allowing for the presence of more than that which is recited so long as basic or novelTH Docket No.: 222117-2490 characteristics of that which is recited is not changed by the presence of more than that which is recited, but excludes prior art embodiments.Discussion:

[0040] The present disclosure provides for batteries including an all-active material cathode, methods of making material cathodes, and the like. The battery can be a single-use battery, in other words, the battery does not need to be rechargeable and in some embodiments may not be rechargeable. The cathode architecture of the present disclosure is referred to as an all-active material (AAM) electrode. AAM architecture can produce improved volume loading efficiency in the cell, removal of inactive components that can reduce efficiency of the battery, improved mechanical characteristics, and a homogeneous material distribution. The mechanical strength and electronic conductivity of AAM cathode are provided solely from the electroactive material itself and interparticle connections therein. In an example where the anode is a Li- based anode is used in conjunction with the AAM cathode, the Li metal does not need to be processed using pores / voids. The fabrication can be achieved using mature processing for producing Li metal foils which in turn can produce a more efficient battery.

[0041] For miniature applications with confined volume, electrodes must be made much thicker (> 500 pm) than conventional composite electrodes (<100 pm), because more conventional wiring and multilayering would take up too much volume and impair volume loading efficiency. At increased electrode thickness, some of the significant advantages of AAM cathodes relative to composite electrodes are, but not limited thereto, improved volume loading efficiency in the cell, removal of inactive components that can reduce efficiency of the battery, and a homogeneous material distribution. For conventional composite electrodes, if current collectors are included, the active material volume loading is difficult to exceed 60% due to the packing limitations of the particles and volume occupied by inactive materials. However, the AAM cathode has no inactive additive volume and can further reduce porosity during the sintering step, which can exceed conventional electroactive material particle packing limitations and achieve high volume loading of electroactive material up to 65-75% (also including current collector). The removal of inactive components reduces relative ion transport restrictions through the electrode microstructure. During discharge, ions must traverse from anode to cathode. Due to the microstructure, and especially the presence of electrochemical inactive materials (conductive additives and polymer binder) in the electrodes, the total path length for ions to traverse within the electrodes is always greater than the electrode thickness. The removal of electrochemically inactive material can significantly mitigate the ion transport pathTH Docket No.: 222117-2490 lengths, which alleviation enables relatively higher rates of charge / discharge and improved voltage efficiency. Conventional composite electrode fabrication includes blending a homogenous slurry, casting the slurry onto a current collector, solvent drying, and calendaring by rollers to decrease porosity. With increased slurry thickness, drying times increase. Although the slurry is viscous, electroactive material with greater physical density sediments, resulting in electrode inhomogeneity. Inhomogeneity can be detrimental to mechanical integrity.

[0042] In general, lithium-ion batteries include an anode, a cathode, an electrolyte material, and a separator(s). Conventional rechargeable lithium-ion batteries operate by reversibly passing lithium-ions back and forth between the negative electrode and the positive electrode. A separator and an electrolyte may be disposed between the anode and the cathode. The electrolyte is suitable for conducting lithium-ions and may be in solid (e.g., solid state diffusion) or liquid form. Lithium-ions move from a cathode to an anode during charging of the battery, and in the opposite direction when discharging the battery.

[0043] The AAM cathode described herein can be incorporated into various commercial battery designs, such as prismatic shaped batteries, wound cylindrical batteries, coin batteries or other reasonable battery shapes. Another battery that the electrodes described herein can be disposed in is a 2032-type coin cell and other coin / button cell form factors, for example 2025, 2016, 312, and others. Small form factor cells such as 2032-type coin cells can be used for portable or wearable applications depending on power demands. For many small form factor cells, multi-layering or stacking of electrodes can be challenging and thus designs such as AAM cathodes are well suited for these applications.

[0044] The present disclosure provides for a battery that includes an all-active material cathode made of an electroactive material, an anode, a separator and an electrolyte. In an aspect, the battery is a one-use battery. In an aspect, the battery is a non-rechargeable battery. In an aspect, the battery can have a volume loading efficiency of about 55 to 80% or 60 to 80%, or about 65 to 75%. The volume loading efficiency is the volume fraction of the electrode regions within the battery cell which are comprised of electroactive material which participates in electrochemical reactions. In an aspect, the battery can have a volumetric capacity of about 500 to 2,500 mAh cm-3or about 1 ,000 to 1 ,500 mAh cm-3. The volumetric capacity is the number of electrons that the battery cell can deliver normalized by the volume, where the volume is typically either the electrode volume or the cell volume. The discharge process typically occurs in a voltage range between 0.5 and 2.0 volts, where at low discharge current most of the capacity is between 1.2 and 1.5 volts.TH Docket No.: 222117-2490

[0045] In an aspect, the all-active material cathode is made of electroactive material. In particular, the electroactive material is comprised of about 95% or more, about 96% or more, about 97% or more, about 98% or more, or about 99% or more of the electroactive material, where the other remaining percentage is primarily impurities present in the “as-received” (also referred to as “precursor”) electroactive material. The impurities can include other oxides (e.g., CuO, CuC>2, CU4O3, CU2O3) or sulfides (e.g., FeS, Fe3S4, Fei+xS, Fei.yS) of the material or typical impurities present in the as-received electroactive material (as opposed to primary oxide or sulfide electroactive material (e.g., CuO, FeS2). The impurities referred to do not include binders, additives, or other materials that are typically added during processing of the as- received electroactive material to form non-AAM electrodes. In an aspect, the AAM cathode after the thermal treatment fabrication step can be free of or at least substantially free of: binder material, conductive additive material, or binder material and conductive additive material. The term “at least substantially free” is defined as one of: about 100% free, about 98% free or more, about 95% to about 100% free, about 95% to about 98% free, about 95% to about 96% free, or about 98% percent to about 100% free. In an embodiment, the AAM cathode does not include (e.g., include about 1% (by weight) or less, about 2% or less, about 4% or less, about 5%) additives such as conductive additives and polymer binders. In an aspect, conductive additives can include carbon-based materials such as a conductive carbon or acetylene black. In an aspect, binders can include polyvinylidiene fluoride, carboxymethyl cellulose, polytetrafluoroethylene, styrene butadiene rubber, and / or polyvinyl pyrrolidone. In an embodiment the AAM cathode consists essentially of the electroactive material, where “consist essentially of” means that the AAM cathode includes the electroactive material no other inactive additives (other than trace amounts such as less than about 1% (by weight) or less or 2% or less, about 4% or less, about 5% or less), but may include trace amounts of other materials such impurities found in the as-received electroactive material powder.

[0046] In an aspect, the electroactive material can be CuO, Fe2O3, Fe3O4, CoO, CO3O4, NiO, Ni2O3, MOO3, MOO2, W2O3, WO2, WO3, W2O5, NbO, Nb2O5, NbO2, FeS2, FeS, NiS, NiS2, N i2S3, CoS, C0S2, CogSs, CuS, M0S2, MoS, WS2, TiS2, or NbS2. The electroactive material, as described in more detail herein, is made by compressing and heating as-received electroactive material. The as-received electroactive material can be the powder form of the electroactive material (e.g., CuO, Fe2O3, Fe3O4, CoO, CO3O4, NiO, Ni2O3, MoOs, MOO2, W2O3, WO2, WO3, W2O5, NbO, Nb20s, NbO2, FeS2, FeS, NiS, NiS2, Ni2Ss, CoS, C0S2, CogSs, CuS, M0S2, MoS, WS2, TiS2, or NbS2).TH Docket No.: 222117-2490

[0047] In an aspect, the an all-active material cathode can have a thickness of about 50 pm to about 2000 pm, about 50 pm to about 1500 pm, about 50 pm to about 1000 pm, about 50 pm to about 500 pm, about 50 pm to about 350 pm, about 100 pm to about 2000 pm, about 300 pm to about 2000 pm, about 400 pm to about 2000 pm, about 500 pm to about 2000 pm, about 200 pm to about 800 pm, or about 300 pm to about 500 pm. The length, width, or diameter can be on the micrometer scale to millimeter scale. The dimensions can be made according to the desired use of the all-active material cathode and battery.

[0048] In an aspect, the AAM cathode can be made of electroactive materials lithium-based anode, a sodium-based anode, a potassium-based anode, a zinc-based anode, a magnesium- base anode, or an aluminum-based anode. In an aspect, the AAM cathode can be made of electroactive materials such as metal oxides: lithium cobalt oxide (LiCoO2) (LCO), lithium manganese oxide (LiMn2O4) (LMO), lithium nickel manganese spinel (LiNio.5Mn1.5O4) (LMNO), lithium nickel cobalt aluminum oxide (LiNiCoAIO2) (NCA), lithium nickel cobalt manganese oxide (LiNiCoMnO2) (NMC), lithium iron phosphate (LiFePO4) (LFP), and combinations thereof.

[0049] The separator is located between the cathode and anode. The separator is electrically insulating while providing for at least selected ion conduction between the two electrodes. A variety of materials can be used as separators. Commercial separator materials are generally formed from polymers, such as polyethylene and / or polypropylene that are porous sheets that provide for ionic conduction. Commercial polymer separators include, for example, the Celgard® line of separator material from Hoechst Celanese, Charlotte, N.C. Also, ceramic- polymer composite materials have been developed for separator applications. The separator can also be a glass fiber separator. These composite separators can be stable at higher temperatures, and the composite materials can significantly reduce the fire risk. In some further examples the separator can include glass fibers. Glass fiber separators can be especially useful when a sintered electrode is used.

[0050] The polymer membrane of a battery can be made of a polyolefin (e.g., polyethylene (PE), polypropylene (PP), a blend of PE and PP), polyethylene terephthalate (PET), polyvinylidene fluoride (PVdF), polyamides (Nylons), polyurethanes, polycarbonates, polyesters, polyetheretherketones (PEEK), polyethersulfones (PES), polyimides (PI), polyamide-imides, polyethers, polyoxymethylene (e.g., acetal), polybutylene terephthalate, polyethylenenaphthenate, polybutene, polyolefin copolymers, acrylonitrile-butadiene styrene copolymers (ABS), polystyrene copolymers, polymethylmethacrylate (PMMA), polyvinyl chloride (PVC), polysiloxane polymers (such as polydimethylsiloxane (PDMS)), polybenzimidazole (PBI), polybenzoxazole (PBO), polyphenylenes, polyarylene ether ketones, polyperfluorocyclobutanes,TH Docket No.: 222117-2490 polytetrafluoroethylene (PTFE), polyvinylidene fluoride copolymers and terpolymers, polyvinylidene chloride, polyvinylfluoride, and liquid crystalline polymers.

[0051] The use of glass fiber as a separator in AAM electrode cells is a strategic choice that addresses the mechanical stability challenges posed by the rough surface of AAM electrodes. The thickness and compressibility of glass fiber separators not only prevent shortcircuiting but also accommodate the volume changes of the electrodes during cycling. This feature is particularly important for maintaining the structural integrity of the cell over multiple charge-discharge cycles.

[0052] In an aspect, the electrolyte of the battery can be lithium-based, for example. In an aspect, the electrolyte of the battery can include a solution that can conduct lithium ions between the cathode and anode. A non-aqueous electrolyte solution can be an ether- based electrolyte (that is stabilized with lithium nitrite), a lithium salt dissolved in an organic solvent or a mixture of organic solvents. In an aspect, the lithium salts can include: LiCICU, LiAICU, Lil, LiBr, LiB(C2O4)2(LiBOB), LiBF2(C2O4) (LiODFB), LiSCN, LiBF4, LiB(C6H5)4, LiAsF6, UCF3SO3, LiN(FSO2)2(LIFSI), LiN(CF3SO2)2(LITFSI), LiPF6, LiPF4(C2O4) (LiFOP), LiNO3, and mixtures thereof.

[0053] In a particular aspect, the battery is a single-use Li-CuO battery that includes a lithium cathode and a CuO all-active material anode. The CuO all-active material anode consists essentially of CuO.

[0054] In a particular aspect, the battery is a single use single-use Li-FeS2battery that includes a lithium cathode and a FeS2all-active material anode. The FeS2anode consists essentially of FeS2.

[0055] In a particular aspect, the battery is a button cell format battery, where the battery has the characteristics of being able to deliver about 40 to 150 mAh. The battery can be of any of the types described herein and in particular can be single-use Li-CuO battery or Li-FeS2battery. The CuO or FeS2anode can have a thickness of about 300 to 500 micrometers.

[0056] The present disclosure also includes a method of making the AAM cathode as described herein. In general, an as-received AAM powder is first coated with a low-cost sacrificial binder material via blending with a dissolved binder solution and air drying. Binder- coated powder then undergoes hydraulic compression by loading into a die and then using the die in a press. After compression, the resulting pellet undergoes a mild heat treatment which both removes the binder and improves the mechanical strength of the pellet through early-stage mild sintering. Combining compression and sintering into a single step can be performed as well.TH Docket No.: 222117-2490

[0057] In particular, the present disclosure provides for a method of making an all-active material cathode. The method includes compressing pellets (e.g., optionally with a binder layer) under a pressure of about 50-250 MPa for about 3 to 10 seconds. The pellets are made of an as-received electroactive material that can be pretreated with binder. The pellets are then heated (sintered) in a furnace to about 500-1200 °C for about 30 minutes to 90 minutes to form the all-active material anode. The heating process burns off all or substantially all of the binder material (e.g., polyvinyl butyral). The step of compressing and heating are performed simultaneously or separately. The as-received electroactive material can be a powder of CuO or FeS2.

[0058] In an aspect, for cell fabrication buffer layers can be used to improve electronic contact. The buffer layer is between the AAM electrode and a current collector, where the current collector could be a separate thin film (e.g., aluminum or copper) or the external cell case (e.g., stainless steel) if the case is conductive such as with common battery button and coin cell designs. The buffer layers can be made of a conductive composite paste or a conductive composite film (e.g., conductive additive carbon black mixed binders polyvinylpyrrolidone or polyvinylidene difluoride) coated on a metal thin film (e.g., aluminum or copper)Example 1 - Single-Use High Energy Density Microbattery via All Active Material CathodeIntroduction

[0059] Miniaturization of energy storage (<100 mm3) at relatively low power widely serves broad applications including, but not limited thereto, watches, continuous glucose monitors (CGMs), wearable insulin pumps, and capsule endoscopy (CE). Through research it was determined that there is a strong need to reduce cost, decrease size, and improve discharge duration (increase battery capacity), among other things, of the batteries that power wearable devices. With Internet of Things (loTs) and wearable electronics increasing their use, small form factor microbatteries need improvement. Three case examples are described below.

[0060] Capsule endoscopy (CE) is a non-invasive method to probe the digestive tract. The total US market size was over $200 million in the year 2019 [1], Numerous studies have suggested the technology was limited by the finite battery life, ranging from 8-12 hours [2], One study found the incompletion rate was high as 75.1 %, which could easily occur on patients with delayed gastric emptying [3], In addition, essential functions such as picture quality, picture frequency, data transmission, and illumination intensity are usually restricted [4], There is thus aTH Docket No.: 222117-2490 desire to extend the battery life and even decrease the battery size for completion rate and patient comfort.

[0061] Wearable continuous glucose monitor (CGM) and wearable insulin pump are two major products for treating diabetes. These diabetes devices totaled $1.8 billion in sales in year 2020 [5], The smallest wearable sensor, Freestyle Libre 3 by Abbott, is button shaped, and the single-use device is attached to the skin. It only lasts for 14 days. There is a strong motivation to prolong the device life by enhancing the battery without increasing size. For the smallest wearable insulin pump patch by EOFIow (soon to be acquired by Medtronic), most integrated pump patches last up to 3.5 days. In the diabetes care space, for example, it was determined that there is interest in improving battery discharge duration.

[0062] The luxury / traditional watch market achieved over $3 billion in the US in year 2021 [6], They are often powered by button cells needing battery replacement every 2-3 years. Replacement often involves users finding a watch repair shop instead of swapping the batteries themselves due to the sophistication and delicacy of the watch. It was determined that there is high dissatisfaction by end users about the high expense and effort of sending their watch for repair to replace the battery.

[0063] A leading energy storage solution for micro primary (single-use) batteries at present are alkaline cells in dozens of standard form factors (e.g., SR 7 I 6Sw, 319, 317) with Zn anodes and cathodes of MnC>2, Ag2O, or HgO and operated between 0.7-1 .5 V [7-9], Among these, Zn- HgO has the highest theoretical volumetric capacity (1870 mAh cm-3), however, these cells have faced bans due to toxicity and environmental concerns. Zn-MnC>2 and Zn-Ag2O are commercially available, where Zn-Ag2O has higher theoretical volumetric capacity (1280 mAh cm-3) than Zn-MnO2(800 mAh cm-3). Due to the nature of the chemistry, the anode (Zn metal side) must be in gel form, where the electrode contains gelling agent and conductive additives. The cathode (Ag2O or MnO2) is a conventional composite, containing polymer binder and conductive additives (shown schematically in Figure 1). Both cathode and anode have relatively low volume efficiency of electroactive material volume loading, with capacity well below that theoretically available based on the cell volume. Taking a form factor of button cell 315 / SR 7 I 6SW with total volume of 81 mm3(interior available volume of 41 mm3) as an example, the capacity theoretically could achieve 52 mAh, but commercially available cells can only deliver capacity of 21 mAh based on discharge measurements of commercial cells in the lab. Such observation suggested the combined total volume efficiency and active material utilization inside the battery was only -40%.TH Docket No.: 222117-2490

[0064] Herein, but not limited thereto, a new cell chemistry is proposed coupled with a unique electrode architecture in the cathode, which is referred to as an all-active material (AAM) electrode. AAM results in, among other things, significantly improved volume loading efficiency in the cell. In an aspect of an embodiment, the proposed cells will use Li-Copper oxide (CuO) chemistry, which has a theoretical volumetric capacity of 1390 mAh cm-3, greater than any of the commercially available options described earlier.

[0065] On the anode side, Li metal does not need to be processed using pores / voids. The fabrication can be achieved using mature processing for producing Li metal foils. On the cathode side (CuO), the AAM electrode architecture fabrication is shown in Figure 2. CuO powder is first coated with a low-cost sacrificial binder material via blending with a dissolved binder solution and air drying. Binder-coated powder then undergoes hydraulic compression by loading into a die and then using the die in a press. After compression, the resulting pellet undergoes a mild heat treatment which both removes the binder and improves the mechanical strength of the pellet through early-stage mild sintering. Combining compression and sintering into a single step could be explored in the future to achieve higher throughput. It is noted that the cathode processing and design is novel, but the cathode powder can be readily sourced in bulk quantities. Some other cell components and manufacturing steps are mature materials and technologies, which de-risks accelerating this technology to market.

[0066] Conventional composite electrodes (Figure 3A) have been the majority electrode architecture for high energy battery technology, and are comprised of electroactive material that stores energy, conductive carbon that improves electronic conductivity, and polymer binder that provides mechanical integrity. In contrast, an aspect of an embodiment of the present disclosure, AAM electrodes, contain only electroactive material (Figure 3B). Mechanical strength and electronic conductivity of AAM electrodes are provided solely from the electroactive material itself and interparticle connections.

[0067] For miniature applications with confined volume, electrodes must be made much thicker (> 500 pm) than conventional composite electrodes (<100 pm), because more conventional wiring and multilayering would take up too much volume and impair volume loading efficiency. At increased electrode thickness, some of the significant advantages of AAM electrodes relative to composite electrodes are, but not limited thereto, the three provided below.

[0068] First, the volume loading efficiency is significantly improved. For conventional composite electrodes, if current collectors are included, the active material volume loading is difficult to exceed 60% due to the packing limitations of the particles. However, the AAMTH Docket No.: 222117-2490 electrode can have inactive volume reduced during the sintering step, which can exceed conventional electroactive material particle packing limitations and achieve high volume loading of electroactive material up to 65-75% (also including current collector). It is noted that at very high volume loading, tradeoffs with regards to power density need to be considered.

[0069] Second, the removal of inactive components reduces relative ion transport restrictions through the electrode microstructure

[0010] , During discharge, ions must traverse from anode to cathode. Due to the microstructure, and especially the presence of electrochemical inactive materials (conductive additives and polymer binder) in the electrodes, the total path length for ions to traverse within the electrodes is always greater than the electrode thickness (Figure 3A). The removal of electrochemically inactive material can significantly mitigate the ion transport path lengths (Figure 3B). For cell designs especially with much thicker electrodes, this transport restriction alleviation enables relatively higher rates of charge / discharge and improved voltage efficiency

[0011] ,

[0070] Third, conventional composite electrode fabrication include blending a homogenous slurry, casting the slurry onto a current collector, solvent drying, and calendaring by rollers to decrease porosity. With increased slurry thickness, drying times increase. Although the slurry is viscous, electroactive material with greater physical density sediments, resulting in electrode inhomogeneity. Inhomogeneity can be detrimental to mechanical integrity of the electrode and result in electrode cracking and / or delamination

[0012] , An aspect of an embodiment of the present disclosure provides for AAM electrode fabrication that circumvents the slurry drying process, resulting in improved mechanical stability for very thick electrodes

[0013] ,

[0071] In addition, the raw material price advantage of Li / CuO over Zn / Ag2O cells is significant. The annual average price for silver and zinc were $670 kg-1and $0.42 kg-1in 2022; the annual average price for battery grade IJ2CO3 (relevant benchmark for Li) and Cu were 37 kg-1and $0.88 kg-1in 2022 [14-17], Assuming the electrode active materials will be a major cell price consideration, the price based upon capacity would be $2.7 Ah'1and $0,052 Ah'1. Taking coin cell 315 / SR716SW as an exemplar form factor, the electrode active material cost would be $57 and $2.4 per thousand units. The difference in raw material cost will further drive disruptions of the current market.

[0072] Preliminary experiments have shown that Li-CuO chemistry has achieved ~ 1160 mAh cm'3at electrode level (total volume of cathode and anode). The discharge voltage is also shown in Figure 4A, where the discharge occurred over ~100 hours.

[0073] Taking an example of the aforementioned 315 / SR716SW form factor, in an aspect of an embodiment, a cell design according to embodiments of the present disclosure withTH Docket No.: 222117-2490 specific dimensions is shown in Figure 4B. In the exemplar button cell 315 / SR 7 I 6SW assuming the same amount of available volume inside the package, over 48 mAh would be achieved, about 230% the capacity of commercially available options. It is expected to have shelf life over 3 years with 90% capacity retention. Embodiments of the present disclosure can be translatable to other format batteries with different geometries, dimensions and in some cases chemistry. Additionally, various embodiment of the present disclosure can be translatable to other applications (other than watches, continuous glucose monitors (CGMs), wearable insulin pumps, and capsule endoscopy (CE)) with different geometries, dimensions and in some cases chemistry.

[0074] With this technology, the projected outcome for wearable electronics would be: (i) in the CE field, the capsule could be made smaller which would improve patient experience and decrease time spent traversing the digestive system, both dictated by the battery size

[0018] ; in addition, the capacity improvement would increase image acquisition / transmission which is limited by power, (ii) In the diabetes field, patients would less frequently switch the CGM sensors / insulin patch, by a factor of 55% (elongate the device life from 14 days to 32 days), (iii) Watch users would spend less to find and pay a watchmaker, and at a lower frequency.Materials and Methods

[0075] In an aspect of an embodiment, CuO or FeS2 powder is first coated with Polyvinyl butyral (PVB) or Sucrose. For PVB binder coating process, the powder is blended with PVB (ethanol solution) with a mass ratio of 100:1.6 powder: PVB. The slurry is kept mixing until dried. For the sucrose binder coating process, the sucrose was first dissolved in small amount of water / ethanol solution, and the powder is blended in with a mass ratio of 100:2 powdensucrose.

[0076] The resulting coated power is loaded into a pellet die, and compressed between 25- 250 MPa for 10 seconds into a pellet. The CuO is sintered in air between 600-1000 °C; FeS2pellet is sintered in air or argon between 300-500 °C. The AAM electrode fabrication process is shown in Figure 5.

[0077] The pellet is then fabricated into batteries paired with Li metal anode. 3 electrolyte were tested: 1.2 M LiPFe in 3:7 ethylene carbonate (EC):ethyl methyl carbonate (EMC) (baseline electrolyte), 2.4 M LiPFe in ethyl acetate, and 0.8 M UCIO4 in propylene carbonate (PC).TH Docket No.: 222117-2490Densification Results

[0078] After sintering, the pellets all had loading ranged 110-150 mg cm-2with thickness ranged 300-500 pm. The thermal treatment below 500 °C did not have any noticeable impact on porosity for FeS2. Above 500 °C in Argon and above 400 °C in air, the material was decomposed or oxidized. The pellet porosity was directly manipulated by the compression pressure, shown in Figure 6. The porosity range was ~ 32-42 vol%.

[0079] For CuO densification, the particle mesh size, compression pressure, and sintering temperature all impacts the porosities. Figures 7A-7C shows the resulting porosity, ranging from below 10 vol% up to low 50 vol%.Battery Results

[0080] A summary of highest achieved volumetric capacity is shown in Figure 8, leveraging electrolyte of 1.2 M LiPFe in 3:7 EC: EMC. Electrolyte of 0.8 M LiCIC in PC achieved over 90% capacity retention, but the ester-based electrolyte showed substantial lowered capacity.

[0081] Exemplar discharge voltage profiles are shown in Figures 9A and 9B. After 6 months storage, there was no noticeable decrease in capacity due to degradation or self discharge.Example 2 - Single-Use High Volumetric Capacity Li-ion Battery via All Active Material CathodeMaterials and Methods

[0082] In an aspect of an embodiment of the present disclosure, CuO or FeS2powder is first coated with Polyvinyl butyral (PVB). The powder is blended with PVB (ethanol solution) with a mass ratio of 100:1.6 powder: PVB. The slurry is kept mixing until dried. The resulting coated power is loaded into a pellet die and compressed above 300 MPa for 10 seconds into a pellet. The CuO and FeS2pellet is mildly sintered in air and argon, respectively. The temperature profile has ramp up and down rates of 2 °C min-1with a holding temperature between 500-1000 °C, and resulting porosity at different temperature is shown in Figure 10. The pellet thickness, geometry, and diameter are all customizable. The AAM electrode fabrication process is shown in Figure 11.

[0083] The pellet is then attached onto current collectors using a custom carbon paste. The custom paste was prepared by blending CB, polyvinyl pyrrolidone (PVP, Sigma Aldrich, 360 kDa molecular weight), and ethanol with mass ratio of 1 :1 :19 for CB:PVP:ethanol. The attached pellets were dried at 80 °C for 30 mins in air and then transferred into a glove box before use asTH Docket No.: 222117-2490AAM cathodes. Celgard 2325 was used a separator, and carbonate-based and / or ester-based serves as electrolyte solvent containing LiPF6or LiCICU as solute. Li metal is used as anode without porosity.Battery Performances

[0084] An exemplar discharge voltage profile is shown in Figures 12A and 12B. For CuO, the discharge was about 100 hours, with CuO loading of 59 mg cm-2with porosity of 35% (sintered at 900 °C). For FeS2, the discharge was about 100 hours, with CuO loading of 57 mg cm'2with porosity of 40% (sintered at 500 °C). Both cells were using carbonated-based, LiPF6electrolyte. Optimization on these cells awaits.Example 3 - High Volumetric Capacity Primary Battery via All Active Material Cathode

[0085] Low voltage primary batteries broadly power small electronics used in health, biomedical, and wearable applications. These devices are generally more sensitive to volumetric capacity than gravimetric capacity. The current state-of-the-art for smaller button cells is Zn-Ag2O, where contributors that limit volumetric capacity include the incorporation of inactive materials in the electrode microstructure such as gelling agents, binders, and conductive additives. Herein, cathode materials of CuO and FeS2 will be described for small form factor coin / button cells, where when paired with Li metal anodes the operating voltage is similar to Zn-Ag2O. A more important aspect of these cathodes is that they will be processed into all active material (AAM) electrode architectures, where the electrodes will be comprised of only electroactive materials and pores that are filled with electrolyte during cell fabrication. The AAM architecture significantly enhanced electroactive material volume utilization, and thus volumetric capacity, at the cell level. FeS2 and CuO were processed into AAM electrodes under various processing conditions, and Li-FeS2and Li-CuO primary batteries were fabricated and evaluated. At the cell level, volumetric capacity of 1300 mAh cm'2was achieved, and in a button cell form factor 395 / 927, nearly 100 mAh was delivered, which compares favorably with commercially available options which typically range from 27-55 mAh.

[0086] Low voltage batteries with nominal voltage of 1.5 V have been widely used in many applications including wearable and health devices [1], The current state-of-the-art battery, especially in small form factor button cells, is Zn-Ag2O [1], Zn-Ag2O cells have about 40% higher volumetric capacity, but much higher cost due to electroactive materials used, than lower cost alternatives such as alkaline batteries (i.e., Zn-MnO2). For Zn-Ag2O cells, the Zn metal anodes have high theoretical volumetric and gravimetric capacity of 5850 mAh cm'3and 820 mAh g-1;TH Docket No.: 222117-2490 while the Ag2O cathode material has theoretical volumetric and gravimetric capacities of 1650 mAh cm-3and 230 mAh g-1, respectively. After cell balancing using the theoretical active material capacities, the theoretical volumetric and gravimetric capacities for the balanced Zn- Ag2O cell active materials are 1280 mAh cm-3and 180 mAh g-1. CuO and FeS2have been previously reported and commercialized as cathode materials for primary batteries paired with Li metal [2,3], although they are not typically found in smaller form factor button cells used in many wearable devices. The theoretical volumetric and gravimetric capacities of Li, CuO, and FeS2are 2060 mAh cm'3, 4310 mAh cm'3, and 4460 mAh cm'3; and 3860 mAh g’1, 670 mAh g and 890 mAh g-1, respectively. After balancing, the theoretical volumetric and gravimetric capacities of Li-CuO and Li-FeS2are 1390 mAh cm-3, 1410 mAh cm'3, 570 mAh g-1, and 720 mAh g-1, respectively. These theoretical gravimetric and volumetric capacities are benchmarked and illustrated in Figures 13A-13D. Compared to Zn-Ag2O , the theoretical gravimetric capacity is 320% and 400% more for CuO and FeS2, while the volumetric capacity is only 10% higher. The limited volumetric capacity advantage at the material level is likely a contributor of why Zn-Ag2O has not been replaced by these alternatives. Even though the gravimetric capacity advantage is large, the relevant applications are less sensitive to weight relative to volume in powering wearable and biomedical devices.

[0087] At the cell level, limitations in volume utilization of the electroactive material in the electrode leads to much lower capacity for Zn-Ag2O batteries relative to theoretical values. An illustration demonstrating this design element can be found in the schematic in Figure 14A, where inactive components such as gelling agents, polymer binders, and conductive additives, take up large amounts of the cell volume. As an example, according to a previous teardown report [4], the total electrode contained 37.1 wt% of a SR1120SW / 381 button cell from Maxell. According to the data sheet from Maxell, the cell total mass was 1 .0 g and capacity was 55 mAh. Assuming the electroactive material utilizing 95% of the theoretical capacity (180 mAh g-1) , the cell capacity would be 63.44 mAh, suggesting the inactives in the electrode would be 13.3 wt.%. Assuming an inactive material density of 2 g cm-3, and given the density of Zn and Ag2O are both 7.1 g cm-3, the inactive materials in the electrode would consume 35 vol.% of the total electrodes, with that volume not including pores that become laden with electrolyte during cell fabrication. Assuming a porosity of 30 vol.%, the electroactive material would only be 45 vol.%, less than half the electrode volume within the cell (summarized in Figure 14C).

[0088] Volumetric capacity of batteries is often more significant in applications powering miniature or wearable devices [5], A broadly effective way to improve cell level volumetric capacity is to improve the electroactive material volume utilization in the electrode. In principle,TH Docket No.: 222117-2490Li metal electrodes do not need pores and the stripping during discharge of a pore-free Li metal anode could effectively utilize all the anode capacity and volume if fully stripped. To improve cathode volume utilization, herein all active material (AAM) electrode architecture was applied that was free of inactive additives and only contained pores and the electroactive CuO or FeS2(schematic shown in Figure 14B). The pore-free anode and removal of inactives significantly increased the electroactive material volume fraction to over 80 vol.% (Figure 14D). The general processing procedures included coating the electroactive material with a sacrificial binder, hydraulic compression, and thermal treatment. The thermal treatment removes the binder, strengthens inter-particle connections to improve mechanical integrity, and in some cases also densifies the electrode. The CuO and FeS2materials have intrinsically high electronic conductivity, and as discharge proceeds the electronic conductivity of these materials increases with lithiation [6-8], The electron hopping between particles is facilitated by inter-particle connections, thus the matrix electronic conductivity was expected to be sufficient from the electroactive material within the electrode itself. The AAM architecture has previously been demonstrated for successful cycling of multiple Li-ion electrode materials, although these were for secondary batteries [9-18], In various embodiments, CuO and FeS2were processed into AAM electrodes and evaluated as high capacity primary cells.Materials and Methods

[0089] 200 mesh CuO (>99% purity) was obtained from Alfa Aesar, and 325 and 800 mesh sizes CuO (>99% purity) were obtained from Taixing Smelting Plant. FeS2(99% purity) at 325 mesh size was obtained from Sigma, FeS2(>95% purity) at 325 mesh size was obtained from Tongling Weight Mining. 200, 325, and 800 mesh size corresponds to maximum particle size of 74, 44, and 18 pm, respectively. For conventional composite electrodes, 200 mesh CuO or 99% purity FeS2was mixed with acetylene carbon black (CB, Alfa Aesar), and polyvinyl pyrrolidone (PVP, Sigma Aldrich, 360 kDa molecular weight) using ethanol (Fisher) solvent with a weight ratio of 8:1 :1 active material:CB:PVP. The slurry was blade coated with a gap width of 200 pm onto an aluminum current collector and dried at 80 °C overnight. The resulting electrode active material loadings for composite electrodes were 2.4 mg cm-2and 5.0 mg cm'2for CuO and FeS2, respectively.

[0090] For AAM electrodes, all powders were first coated with 1 .6 wt.% (wt.% indicates amount coating particles after processing and solvent removal) polyvinyl butyral (PVB, Pfaltz & Bauer) by blending in an ethanol suspension with a mortar and pestle by hand. The suspension was blended in a fume hood until it appeared dry to the naked eye. 0.2 g of PVB-coated CuOTH Docket No.: 222117-2490 was loaded into a circular pellet die with a diameter of 13 mm and pressed at pressures ranging from 75-225 MPa for 5 seconds. The compressed pellets were transferred to a box furnace and heated to maximum temperatures ranging from 600-1100 °C, where the pellets were held at the maximum temperature for 1 hour. The temperature ramp rates for both heating and colling were 2 °C min-1. The resulting CuO AAM electrodes had thicknesses ranging between 340-480 pm, diameters ranging between 10.8-13 mm, and porosity ranging between 12-52 vol% depending on the specific processing conditions. For higher purity FeS2 pellets, 0.15 g of PVB-coated 99% purity FeS2was loaded into a circular pellet die with diameter of 13 mm and compressed at pressures ranging between 25 - 225 MPa for 5 seconds. The compressed pellets were transferred to a tube furnace and heated at 500 °C for 1 hour with ramp up and down rates of 2 °C min-1under Argon atmosphere. The resulting 99% purity FeS2AAM electrodes had thicknesses ranging between 320-370 pm, diameters of ~13 mm, and porosities ranging between 32-42 vol%. For lower purity FeS2 pellets, 0.14 g of PVB-coated FeS2 of 95% purity was loaded to a circular pellet die with diameter of 7 mm and compressed at 30 MPa for 5 seconds. The thermal treatment condition was the same as for the 99% purity FeS2 pellets. The resulting 95% purity FeS2 AAM electrodes had thickness of 1100 pm, diameter of 7 mm, and porosity of 40 vol%.

[0091] The electrodes were transferred to an Argon-filled glove box for battery assembly. A conductive sheet was added between the AAM electrode and current collector to reduce surface contact resistance. The conductive sheet was fabricated in house and was similar to processing of a conventional composite electrode. An equal weight of CB and PVP in ethanol suspension was prepared and doctor blade coated onto an aluminum foil. The conductive film was dried at 80 °C overnight with film loading of the conductive composite being 1-2 mg cm-2, with a typical value being 1 .85 mg cm’2. Total thickness of the conductive sheet (Al and carbon composite) was ~25 mm. There were two electrolytes evaluated: 1.2 M LiPF6in 1 :3 ethylene carbonate (EC):ethyl methyl carbonate (EMC) from Gotion by volume, referred as “Gen2”, and 1.5 M Lithium bis(fluorosulfonyl)imide (LiFSI, Nippon Shokubai) in 1 :3 EC (Fisher):1 ,2- Dimethoxyethane (DME, Chem-lmpex Int’L) by volume, referred to as “DME” electrolyte.Celgard 3401 separator was used for DME electrolyte, and Celgard 2325 separator was used for Gen2 electrolyte. All electrodes were paired with Li metal and evaluated in 2032 format coin cells. Button cells of 395 / 927 format were also assembled and assessed for AAM cathodes of FeS2 with 95% purity.

[0092] Powder x-ray diffraction (XRD) patterns were collected using Empyrean (Panalytical) equipment. The XRD sample preparation for AAM electrodes included grinding theTH Docket No.: 222117-2490 pellet into powder after they had completed thermal treatment. Electrochemical evaluations were conducted using a multichannel battery cycler (MACCOR).Results and DiscussionCuO

[0093] The XRD pattern for the 200 mesh CuO can be found in Figure 18. The material was consistent with a monoclinic structure and had no observed impurity peaks, consistent with prior reports for CuO [19,20], The material was then evaluated electrochemically as a cathode active material in a conventional composite cathode paired with a lithium metal anode and Gen2 electrolyte. The cell was slowly discharged at a current density of 0.08 mA cm'2(-C / 20), and the discharge voltage profile can be found in Figure 19. The discharge capacity started to be delivered at ~1.3 V and the discharge process was allowed to proceed until the cutoff voltage of 0.5 V. The discharge profile for the CuO material was consistent with previous reports of the material paired with a Li metal negative electrodes [21 ,22], The capacity was 767 mAh g-1CuO, which exceeded the theoretical capacity of 670 mAh g'1CuO. It was expected that the capacity exceeding the theoretical capacity was likely due to irreversible carbonate-based electrolyte decomposition processes providing extra capacity

[0023] , The capacity above the theoretical capacity was all below 1 .5 V, with most of this capacity outside the stability window of the electrolyte

[0023] , again consistent with electrolyte decomposition likely being responsible for the excess capacity.

[0094] The porosity of AAM CuO electrodes can be modified through controlling the compression pressure and heating temperature after compression. The resulting porosity after compression and thermal treatments can be found in Figure 20. The porosity decreased as compression pressure and heating temperature increased. 200, 325, and 800 mesh size corresponds to maximum particle size of 74, 44, and 18 pm, respectively. As the particle size decreased (i.e. , mesh size increased), the porosity also decreased which was attributed to increased particle surface area facilitating increased densification during thermal treatment. These results highlighted the manufacturing / processing flexibility for the AAM electrodes with regards to targeting different cell geometries or higher energy vs. power density (where lower porosity will in general increase energy density at the expense of power density). XRD was conducted on the CuO pellet using 200 mesh powder compressed to 225 MPa and heated to 950 °C, and the resulting pattern can be found in Figure 18. The pellet was ground by hand with mortar and pestle to facilitate XRD sample preparation. The XRD pattern for the powder after heat treatment processing compared to the pristine powder had sharper peaks, suggesting theTH Docket No.: 222117-2490 thermal treatment increased the material crystallinity. No impurity peaks were noticed. The AAM CuO positive electrode paired with Li metal negative electrode and Gen2 electrolyte discharge voltage profiles are shown in Figure 15. At low rate of 0.92 mA cm-2(~C / 130), the capacity reached 700 mAh g-1CuO, and a high volumetric capacity of 3460 mAh cm-3AAM cathode (i.e. cathode electrode basis), or 1300 mAh cm3after balanced with Li metal (full cell electrodes only basis). The voltage plateau was similar to the conventional composite electrode at 1.3 V, although there was a dip in the beginning of discharge. This dip and then recovery of voltage was consistent with the electronic conductivity increasing as CuO was more lithiated. This would result in relatively high initial polarization for electronic matrix resistance, which then decreased as the active material was lithiated and the matrix electronic conductivity improved

[0024] , At higher discharge rate of 4.6 mA cm-2, the voltage plateau was lowered to 1.1 V, but still over 650 mAh g-1was delivered. The increased overpotential possibly originated from the low electroactive surface area of the 200 mesh CuO powder (74 pm, much greater than most battery material powders) which would result in relatively high interfacial resistance.

[0095] The XRD of the 99% purity FeS2 can be found in Figure 21. The material had a hexagonal structure consistent with literature reports for similar materials [2], and no impurity peaks were noticed. Like with the CuO material, the FeS2 material was initially evaluated in a conventional composite cathode paired with a Li metal anode with Gen2 electrolyte. The cell was discharged at a slow rate of 0.1 mA cm-2(-C / 50), and the resulting discharge voltage profile can be found in Figure 22. The discharge had a large voltage plateau region at approximately 1 .4 V, which started to more sharply decrease after ~ 800 mAh g-1FeS2. The final capacity at the 0.5 cutoff voltage was 945 mAh g-1FeS2, which was consistent with other literature reports for FeS2 [2,25], The capacity also exceeded the theoretical capacity of 890 mAh g-1FeS2, which similar to the CuO, was suspected to be due to capacity from electrolyte decomposition in the lower voltage regions.

[0096] Unlike CuO, thermal treatment of FeS2 did not reduce either thickness or diameter of a pellet at the processing temperature of 500 °C. 550 °C heating was attempted, but at this temperature significant mass loss was observed, suggesting the loss of sulfur. The onset of sulfur loss near this temperature range was consistent with previous thermal analysis of FeS2 materials

[0026] , Lower temperatures would not facilitate densification, thus only one processing temperature (500 °C) was evaluated. The porosity of AAM FeS2 electrodes as a function of compression pressure are shown in Figure 23. By increasing pressure from 25 MPa to 225 MPa, the porosity decreased from 42 vol% to 32 vol%. Decreased porosity via increased pressure has been observed for previous ceramic powder systems and can also beTH Docket No.: 222117-2490 implemented to improve mechanical strength [27,28], which could also potentially improve the electrochemical stability for AAM electrodes

[0014] , XRD was conducted on the 500 °C treated 99% FeS2 AAM electrode, and the resulting pattern can be found in Supporting Information, Figure S4. There were no noticeable changes to the XRD pattern before and after the thermal treatment, and no impurity peaks were observed. The AAM FeS2 cell with Li metal anode and Gen2 electrolyte discharge voltage profiles are shown in Figure 16. At low rate of 0.75 mA cm’2(-C / 120), the capacity reached 830 mAh g-1FeS2, which corresponded to a volumetric capacity of 2950 mAh cm’3for the AAM cathode and 1210 mAh cm’3on an electrode only basis for a cell balanced with a Li metal anode. The voltage plateau was similar to the conventional composite electrode with a plateau region at ~1.4 V. Unlike CuO, the initial voltage dip was much smaller, which was attributed to the higher electronic conductivity (10° - 101S cm’1

[0029] ) before lithiation compared to that of CuO (10‘2- 10’3S cm’1

[0030] ). At a higher discharge current density of 3.8 mA cm’2, the voltage plateau was lowered to -1.2 V, but still over 630 mAh g’1was delivered. It is noted here that the absolute discharge currents evaluated for both CuO and FeS2 cells in Figures 15 and 16 were 1 mA and 5 mA; however, the current densities were slightly different due to shrinkage of the CuO pellet after thermal treatment.395 / 927 Benchmark Button Cells

[0097] To further assess the effectiveness of implementing AAM cathodes in applicationrelevant small form factor cells, 395 / 927 button cells were fabricated with high loading of the electrodes within the cell geometry. 395 / 927 cells have a diameter of 9 mm and thickness of 2.7 mm and have wide applications in wearable and health applications. The AAM FeS2 had a diameter of 7 mm, thickness of 1.1 mm, mass of 127 mg, and porosity of 40 vol.%. The Li metal mass was 27 mg. The cell was discharged at 0.2 mA and delivered almost 100 mAh, with the voltage profile shown in Figure 17. The current state-of-the-art 1.5 V battery is zinc silver oxide batteries, with multiple commercial brands available. Commercial 395 / 927 cells were purchased from three different major commercial brands and discharged at the same fixed 1 mA current, and their discharge profiles can be found in Figure 17. The delivered discharge capacity of the commercial cells ranged from 27-55 mAh, which was greatly surpassed by the cells in this work.Conclusion

[0098] The current state-of-the-art Zn-Ag2O button cells have limited volumetric energy density due to the low volume utilization of electroactive material that originate from the incorporation of inactive materials in the electrode microstructure such as gelling agents,TH Docket No.: 222117-2490 binders, and conductive additives. In the present disclosure, alternative cell materials of Li-CuO and Li-FeS2 were investigated in AAM electrode architecture that is free of inactives to improve volume utilization. AAM electrode processing parameters of compression pressure and sintering temperature impact on electrode porosity were studied. At the electrode level, high volumetric capacity over 1300 mAh cm-2was achieved. In a 395 / 927 button cell format, nearly 100 mAh was delivered, which compares favorably with commercially available options which typically range from 27-55 mAh.REFERENCES:

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[0129] In summary, while the present disclosure has been described with respect to specific embodiments, many modifications, variations, alterations, substitutions, and equivalents will be apparent to those skilled in the art. The present disclosure is not to be limited in scope by the specific embodiment described herein. Indeed, various modifications of the present disclosure, in addition to those described herein, will be apparent to those of skill in the art from the foregoing description and accompanying drawings. Accordingly, the invention is to be considered as limited only by the spirit and scope of the disclosure (and claims) including all modifications and equivalents.

[0130] It should be noted that ratios, concentrations, amounts, and other numerical data may be expressed herein in a range format. It is to be understood that such a range format is used for convenience and brevity, and thus, should be interpreted in a flexible manner to includeTH Docket No.: 222117-2490 not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. To illustrate, a concentration range of “about 0.1 % to about 5%” should be interpreted to include not only the explicitly recited concentration of about 0.1 wt% to about 5 wt%, but also include individual concentrations (e.g., 1%, 2%, 3%, and 4%) and the sub-ranges (e.g., 0.5%, 1.1 %, 2.2%, 3.3%, and 4.4%) within the indicated range. The term “about” can include ±1%, ±2%, ±3%, ±4%, ±5%, ±6%, ±7%, ±8%, ±9%, or ±10%, or more of the numerical value(s) being modified. In addition, the phrase “about ‘x’ to ‘y’” includes “about ‘x’ to about ‘y’”.

[0131] It should be emphasized that the above-described embodiments of the present disclosure are merely possible examples of implementations and are set forth only for a clear understanding of the principles of the disclosure. Many variations and modifications may be made to the above-described embodiments of the disclosure without departing substantially from the spirit and principles of the disclosure. All such modifications and variations are intended to be included herein within the scope of this disclosure.

[0132] The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how to perform the methods and use the imaging agents disclosed and claimed herein. Efforts have been made to ensure accuracy with respect to numbers (e.g., amounts, temperature, etc.), but some errors and deviations should be accounted for. Unless indicated otherwise, parts are parts by weight, temperature is in °C, and pressure is at or near atmospheric. Standard temperature and pressure are defined as 20 °C and 1 atmosphere.

Claims

TH Docket No.: 222117-2490CLAIMSWhat is claimed:

1. A battery, comprising: an all-active material cathode made of an electroactive material, wherein the electroactive material is comprised of about 95% or more of the electroactive material, an anode, a separator positioned between the all-active material cathode and the anode, and an electrolyte, wherein the battery has a volume loading efficiency of about 55 to 80%, and wherein the battery has a volumetric capacity of about 500 to 2,500 mAh cm'2.

2. The battery of claim 1, wherein the electroactive material is CuO, Fe2Oa, FeaCU, CoO, CO3O4, NiO, Ni2O3, MoOs, MOO2, W2O3, WO2, WO3, W2O5, NbO, Nb2O5, NbO2, FeS2, FeS, NiS, NiS2, Ni2Ss, CoS, C0S2, CogSs, CuS, M0S2, MoS, WS2, TiS2, or NbS2.

3. The battery of claim 1 , wherein the electroactive material consists essentially of electroactive material.

4. The battery of claim 1 , wherein the electroactive material is substantially free of a conductive additive.

5. The battery of claim 5, wherein the conductive additive comprises a polymer binder, a conductive carbon, or a mixture thereof.

6. The battery of claim 1 , wherein the electroactive material is free of a binder, a conductive additive, an inactive additive, or a mixture thereof.

7. The battery of claim 1 , wherein the battery has a volume loading efficiency of about 65 to 80%.

8. The battery of claim 1 , wherein the battery has a volumetric capacity of about 1 ,000 to 1 ,500 mAh cm'2.TH Docket No.: 222117-24909. The battery of claim 1 , wherein the anode is a lithium-based anode, a sodium-based anode, a potassium-based anode, a zinc-based anode, a magnesium-base anode, or an aluminum-based anode.

10. The battery of claim 1, wherein the separator is made of a polymer material or glass material.

11. The battery of claim 1 , wherein the electrolyte is a lithium salt.

12. The battery of claim 1 , wherein a thickness of the all-active material cathode is about 50 pm to about 2000 pm.

13. The battery of claim 1 , wherein the battery is a button cell format battery, wherein the battery has the characteristics of being able to deliver about 40 to 150 mAh.

14. The battery of claim 1 , wherein the battery has a thickness of about 300 to 3,200 micrometers.

15. The battery of claim 1 , wherein the battery is a single-use battery, wherein the battery is not rechargeable.

16. A single-use Li-CuO battery, comprising: a lithium cathode, and a CuO all-active material anode, wherein the CuO all-active material anode consists essentially of CuO, wherein the battery has a volume loading efficiency of about 55 to 80%, and wherein the battery has a volumetric capacity of about 200 to 850 mAh cm'3.

17. A single-use Li-FeS2 battery, comprising: a lithium cathode, and a FeS2 all-active material anode, wherein the FeS2 anode consists essentially of FeS2, wherein the battery has a volume loading efficiency of about 55 to 80%, and wherein the battery has a volumetric capacity of about 200 to 850 mAh cm'3.TH Docket No.: 222117-249018. A method of making an all-active material cathode, comprising: compressing pellets under a pressure of about 50-250 MPa for about 3 to 10 seconds, wherein the pellets are made of a precursor electroactive material; and heating the pellets in a furnace to about 500-1200 °C for about 30 minutes to 90 minutes to form the all-active material cathode.

19. The method of claim 18, wherein the step of compressing and heating are performed simultaneously.

20. The method of claim 18, wherein the precursor electroactive material is a powder of CuO or FeS2.

21. The method of claim 18, wherein the precursor electroactive material includes a binder material that coats at least a portion of the precursor electroactive material, wherein the binder is substantially or completely burned away during the heating step.

22. The method of claim 21, wherein the binder is polyvinyl butyral.

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