Indium metal batteries for energy storage

Abstract

The present technology relates generally to secondary electrochemical cells, and methods of making and using secondary electrochemical cells. The electrochemical cells include an anode, a cathode, and an electrolyte. The anode includes indium metal or an indium alloy. The electrolyte includes an indium (III) salt and water or tetrahydrofuran (THF) solvent.

Description

Atty. Dkt. No. 118347-0123INDIUM METAL BATTERIES FOR ENERGY STORAGE CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of and priority to U.S. Provisional Appl. No. 63 / 595672, filed November 2, 2024, which is incorporated herein by reference in its entirety for any and all purposes.GOVERNMENT RIGHTS

[0002] This invention was made with government support under 1849243 awarded by the National Science Foundation. The government has certain rights in the invention.TECHNICAL FIELD

[0003] The present technology relates generally to electrochemical cells that include indium metal or indium metal alloy anodes and electrolytes where a charge carrier is In3+.SUMMARY

[0004] In an aspect, an electrochemical cell is disclosed. The electrochemical cell includes an anode comprising indium metal or an indium alloy, a cathode, and an electrolyte. The electrolyte includes water or tetrahydrofuran (THF) and an indium (III) salt.

[0005] The electrolyte may include water and the indium (III) salt may be present in the electrolyte at a concentration of about 0.05 M to about 1.5 M. The electrolyte may include THF and the indium (III) salt may be present in the electrolyte at a concentration of about 0.05 M to about 0.1 M. In some embodiments, the indium (III) salt is InXs and X is F , Cl", Br , I", or "OS(O)2CF3. The InXs salt may be an InCh salt. The electrolyte may include water and the InCh salt may be present in the electrolyte at a concentration of about 0.8 M to about 1.2 M.

[0006] The cathode may include MnCh, V2O5, FeFe(CN)e, a S-C composite, or a mixture of two or more thereof. The cathode may include MnCh. The indium metal or the indium alloy may be present as a metal foil. The indium metal may be further present as indium-1-4880-1498-6974.1Atty. Dkt. No. 118347-0123 metal particles on a surface of the metal foil. The indium metal particles may have a diameter of about 10 pm to about 200 pm. In3+may be a charge carrier in the electrolyte.

[0007] In another aspect, a method of fabricating an electrochemical cell is disclosed. The method includes disposing an anode and a cathode in an electrolyte to form the electrochemical cell. The anode includes indium metal or an indium alloy. The electrolyte includes water or tetrahydrofuran (THF), and an indium (III) salt.

[0008] The step of disposing may be conducted in atmospheric air. The method may further include disposing the anode on a current collector, wherein the anode is present as a metal foil. The method may further include electrochemically plating indium metal particles onto a surface the metal foil, the indium metal particles having a diameter of about 10 pm to about 200 pm. Electrochemically plating indium metal particles may include plating indium metal from In3+present in the electrolyte.

[0009] In another aspect, a rechargeable battery includes an indium metal anode, a cathode comprising MnCh, and an aqueous electrolyte comprising InCh present in a concentration of about 0.8 M to about 1.2 M.

[0010] Further aspects and embodiments of the present technology are described herein.BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.

[0012] FIG. 1 is an illustration of an electrochemical cell with an indium metal anode and an aqueous electrolyte including In3+.

[0013] FIG. 2A is a graph of symmetrical In / In batteries at 0.5 mA cm2current and 0.25 mAh cm2capacity.

[0014] FIG. 2B is a graph of the rate performance of symmetrical In / In batteries.

[0015] FIG. 2C is a graph of the polarization comparison of different metal electrodes under similar electrochemical conditions.-2-4880-1498-6974.1Atty. Dkt. No. 118347-0123

[0016] FIG. 2D is a graph of the charge / discharge curves of In / Ti batteries at 1.0 mA cm2.

[0017] FIG. 2E is a graph of Coulombic efficiency of In / Ti batteries at 1.0 mA cm2.

[0018] FIG. 2F is a graph comparing the Coulombic efficiency of Fe, Zn, and In metals.

[0019] FIG. 2G is a scanning electron microscope (SEM) image of electrochemically plated indium at 0.5 mA cm2current and 1.0 mAh cm2capacity.

[0020] FIG. 2H is a closer view of one of the plated indium particles in FIG. 2G.

[0021] FIG. 21 shows energy-dispersive X-ray spectroscopy (EDS) elemental mapping of a plated indium particle.

[0022] FIG. 3 A is a graph of X-ray diffraction (XRD) and SEM image (inset) of P-MnCh cathode material.

[0023] FIG. 3B is a graph of galvanostatic charge / discharge (GCD) curves of an In / MnCh battery at 100 mA g ' .

[0024] FIG. 3C is a graph of cyclic voltammetry (CV) curves of the In / MnCh battery at 0.1 mV s ' .

[0025] FIG. 3D is a graph of the rate performance of the In / MnCh battery.

[0026] FIG. 3E is a graph of the long-term cycling performance of the In / MnCh battery at 500 mA g where the battery was conditioned at 100 mA g1for the first several cycles.

[0027] FIG. 4A is a graph of selected charge / discharge states in the GCD curve from FIG. 3B.

[0028] FIG. 4B is a graph of ex-situ XRD patterns of the MnCh electrodes at different charge / discharge states in the GCD curve in FIG. 4 A.

[0029] FIG. 4C is an SEM image of the discharged MnCh electrode at point B in FIG. 4A.

[0030] FIG. 4D shows EDS analysis and elemental mapping results of the discharged MnCh electrode at point B in FIG. 4A.-3-4880-1498-6974.1Atty. Dkt. No. 118347-0123

[0031] FIG. 4E is an SEM image of the charged MnCh electrode at point C in FIG. 4A.

[0032] FIG. 4F is a proposed schematic of the charge / discharge reaction mechanism, where MnCh reacts with H+to form MnOOH, and In3+ions react with OH ions to form In metal.

[0033] FIG. 5A is a graph of a GCD curve of an In / V2Os battery.

[0034] FIG. 5B is a graph of GCD curves of an In / FeFe(CN)e battery.

[0035] FIG. 5C is a graph of GCD curves of an In / Si-C battery.

[0036] FIG. 6 A is a graph of indium metal plating performance in non-aqueous electrolyte.

[0037] FIG. 6B is a graph of GCD curves of an In / MnCh non-aqueous battery, where the electrolyte was 0.1 M InCh dissolved in tetrahydrofuran (THF).

[0038] FIG. 7A is a schematic illustration of indium metal plating on titanium depicting stacked indium particles on the titanium substrate.

[0039] FIG. 7B is a schematic illustration of indium metal plating on copper depicting planar indium metal on the copper substrate.

[0040] FIG. 8 A is a graph of galvanostatic charge / discharge (GCD) curves of In||Ti batteries at 1 mA cm2with different capacities.

[0041] FIG. 8B is a graph of comparison of capacity-efficiency for different metals.

[0042] FIG. 8C is a scanning electron microscopy (SEM) image of In metal plated on titanium at 1 mAh cm2.

[0043] FIG. 8D is another SEM image of In metal plated on titanium at 1 mAh cm2.

[0044] FIG. 8E is an SEM image of In metal plated on titanium at 5 mAh cm2.

[0045] FIG. 8F is another SEM image of In metal plated on titanium at 5 mAh cm2.

[0046] FIG. 8G is an SEM image of In metal plated on titanium at 10 mAh cm2.-4-4880-1498-6974.1Atty. Dkt. No. 118347-0123

[0047] FIG. 8H is another SEM image of In metal plated on titanium at 10 mAh cm2.

[0048] FIG. 9A is an SEM image of In metal plated on copper at 1 mAh cm2.

[0049] FIG. 9B is another SEM image of In metal plated on copper at 1 mAh cm2.

[0050] FIG. 9C is an SEM image of In metal plated on copper at 5 mAh cm2.

[0051] FIG. 9D is another SEM image of In metal plated on copper at 5 mAh cm2.

[0052] FIG. 9E is an SEM image of In metal plated on copper at 10 mAh cm2.

[0053] FIG. 9F is another SEM image of In metal plated on copper at 10 mAh cm2.

[0054] FIG. 9G is a graph of the cycling performance of In||Cu batteries at 1 mAh cm2.

[0055] FIG. 9H is a graph of selected GCD curves during cycling at 1 mAh cm2.

[0056] FIG. 91 is a graph of the cycling performance of In||Cu batteries at 10 mAh cm2.

[0057] FIG. 10A is a graph of X-ray diffraction (XRD) patterns of plated In at different plating time (current: 1 mA cm2).

[0058] FIG. 10B is a cross-sectional SEM and mapping analysis of the plated In at 10 mAh cm2.DETAILED DESCRIPTION

[0059] It is to be appreciated that certain aspects, modes, embodiments, variations and features of the present methods are described below in various levels of detail in order to provide a substantial understanding of the present technology.Definitions

[0060] Unless defined otherwise, all technical and scientific terms used herein generally have the same meaning as commonly understood by one of ordinary skill in the art to which this technology belongs.

[0061] As used herein and in the appended claims, singular articles such as “a” and “an” and “the” and similar referents in the context of describing the elements (especially in the-5-4880-1498-6974.1Atty. Dkt. No. 118347-0123 context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the embodiments and does not pose a limitation on the scope of the claims unless otherwise stated. No language in the specification should be construed as indicating any non-claimed element as essential. For example, reference to “a cell” includes a combination of two or more cells, and the like. Generally, the nomenclature used herein and the laboratory procedures in cell culture, molecular genetics, organic chemistry, analytical chemistry and nucleic acid chemistry and hybridization described below are those well-known and commonly employed in the art.

[0062] As used herein, “about” will be understood by persons of ordinary skill in the art and will vary to some extent depending upon the context in which it is used. If there are uses of the term which are not clear to persons of ordinary skill in the art, given the context in which it is used, “about” will mean up to plus or minus 10% of the particular term - for example, “about 10 wt.%” would be understood to mean “9 wt.% to 11 wt.%.” It is to be understood that when “about” precedes a term, the term is to be construed as disclosing “about” the term as well as the term without modification by “about” — for example, “about 10 wt.%” discloses “9 wt.% to 11 wt.%” as well as disclosing “10 wt.%.”

[0063] The phrase “and / or” as used in the present disclosure will be understood to mean any one of the recited members individually or a combination of any two or more thereof - for example, “A, B, and / or C” would mean “A, B, C, A and B, A and C, B and C, or the combination of A, B, and C.”

[0064] As will be understood by one skilled in the art, for any and all purposes, particularly in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range-6-4880-1498-6974.1Atty. Dkt. No. 118347-0123 being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a nonlimiting example, each range discussed herein can be readily broken down into a lower third, middle third and upper third, etc. As will also be understood by one skilled in the art all language such as “up to,” “at least,” “greater than,” “less than,” and the like include the number recited and refer to ranges which can be subsequently broken down into subranges as discussed above. Finally, as will be understood by one skilled in the art, a range includes each individual member. Thus, for example, a group having 1-3 atoms refers to groups having 1, 2, or 3 atoms. Similarly, a group having 1-5 atoms refers to groups having 1, 2, 3, 4, or 5 atoms, and so forth.

[0065] Throughout this disclosure, various publications, patents, and published patent specifications are referenced by an identifying citation. Also within this disclosure are Arabic numerals referring to referenced citations, the full bibliographic details of which are provided immediately preceding the claims. The disclosures of these publications, patents, and published patent specifications are hereby incorporated by reference into the present disclosure to more fully describe the state of the art to which this invention pertains.The Present Technology

[0066] Disclosed herein are indium secondary electrochemical cells, and methods of making and using indium secondary electrochemical cells. The indium secondary electrochemical cells may be rechargeable indium metal batteries. The indium secondary electrochemical cells include an anode, a cathode, and an electrolyte. The anode includes indium metal and / or an indium metal alloy. The electrolyte includes an indium (III) salt dissolved in a solvent such that the electrolyte includes In3+ions in solution. The In3+ions may act as charge carriers in the secondary electrochemical cells. The indium secondary electrochemical cells exploit the redox reaction between soluble In3+ions and solid indium metal, which involves the transfer of three electrons.

[0067] These electrochemical cells are compatible with water and may be fabricated in atmospheric air without degradation of electrochemical performance. In some embodiments, the electrolyte may be an aqueous electrolyte, where the solvent is water. In some embodiments, the electrolyte may be an organic electrolyte, where the solvent includes THF. The indium (III) salt may be, for example, indium (III) sulfate, indium (III) nitrate, an indium halide salt, or a combination of two or more thereof. For example, the-7-4880-1498-6974.1Atty. Dkt. No. 118347-0123 indium halide salt may be InXs, where X is F , Cl", Br , I", or OS(O)2CF3, or a combination of two or more thereof. For example, the indium halide salt may include InFs, InCh, InBrs, Inb, or a mixture of two or more thereof.

[0068] In one aspect, an electrochemical cell is provided that includes an anode, a cathode, and an electrolyte. The anode active material in the anode includes indium metal and / or an indium metal alloy. The electrolyte, which may be aqueous or non-aqueous, includes In3+ions. The electrochemical cell may be a rechargeable indium metal battery. The secondary electrochemical cell may further include a separator between the cathode and the anode. The secondary electrochemical cell may further include current collectors for one or all electrodes.

[0069] The electrolyte includes In3+ions as charge carriers. In3+ions may be present in the electrolyte in a concentration of about 0.05 M to about 1.5 M (e.g., about 0.05 M to about 0.1 M, about 0.08 M to about 0.12 M, about 0.1 M, 0.5 M to about 1.5 M, about, 0.8 M to about 1.2 M, or about 1.0 M). The electrolyte may be an aqueous electrolyte and the In3+ions may be present in the electrolyte in a concentration of about 0.05 M to about 1.5 M (e.g., 0.5 M to about 1.5 M, about, 0.8 M to about 1.2 M, or about 1.0 M), or the electrolyte may be a non-aqueous electrolyte and the In3+ions may be present in the electrolyte in a concentration of about 0.05 M to about 0.12 M (e.g., about 0.05 M to about 0.1 M, about 0.08 M to about 0.12 M, or about 0.1 M). The non-aqueous electrolyte solvent may be THF.

[0070] The electrolyte may have a pH that is acidic, neutral, or weakly basic. For example, the acidic pH may fall in a range of about 1.5 to about 6.8 (e.g., about 2 to about 3); the neutral pH may fall in a range of about 6.8 to about 7.2; and the weakly basic pH may fall in a range of about 7.2 to about 9.0. In some embodiments, the electrolyte does not have a basic pH (e.g., about 1.5 to about 7.2).

[0071] The indium and / or indium metal alloy in the anode may be in the form of bulk metal or powder. The bulk metal may be in the form of a metal foil. The anode may also include a conductive carbonaceous material. The carbonaceous material may include natural graphite, synthetic graphite, hard carbon, amorphous carbon, soft carbon, mesocarbon microbeads (MCMB), acetylene black, Ketjen black, carbon black, mesoporous carbon, porous carbon matrix, carbon nanotubes, carbon nanofibers, graphene, or a mixture-8-4880-1498-6974.1Atty. Dkt. No. 118347-0123 of two or more thereof. When the indium and / or indium metal alloy is in the form of a powder, the powder may be mixed with a powder of the carbonaceous material. In some embodiments, the indium and / or indium metal alloy is in the form of a thin film (e.g., as deposited via sputtering).

[0072] The cathode may include a cathode active material. The cathode active material may be MnCh (e.g., P-MnCh), V2O5, FeFe(CN)e, a sulfur / carbon (S / C) composite, or a mixture of two or more thereof. The S-C composite may include a weight ratio of about 1 :5 to about 5: 1 sulfur to carbon (e.g., 1 : 1, 1 :2, 2: 1, 2:3, or 3:2 sulfur to carbon). The cathode may also include a conductive carbonaceous material. The carbonaceous material may include natural graphite, synthetic graphite, hard carbon, amorphous carbon, soft carbon, mesocarbon microbeads (MCMB), acetylene black, Ketjen black, carbon black, mesoporous carbon, porous carbon matrix, carbon nanotubes, carbon nanofibers, graphene, or a mixture of two or more thereof.

[0073] Illustrative binder materials for the cathode and / or anode include, but are not limited to poly(vinylidene fluoride) (PVDF), carboxymethyl cellulose (CMC), polyacrylic acid (PAA), poly(tetrafluoroethylene) (PTFE), styrene-butadiene rubber (SBR), or a mixture of two or more thereof.

[0074] The electrochemical cell may include a separator between the cathode and anode. Illustrative separator materials include, but are not limited to, cellulose filter paper, glass fiber, and Celgard polymer separators.

[0075] The electrochemical cell may include current collectors disposed on the cathode and / or anode. The current collectors may be titanium, stainless steel, copper, carbon, lead, nickel, or aluminum. The current collectors may be in the form of metal foils and / or metal meshes.

[0076] In another aspect, a method of fabricating any of the electrochemical cells described herein is provided. The method may include disposing the anode and the cathode in the electrolyte to form the electrochemical cell. The anode, cathode, and electrolyte may be any of those described herein.

[0077] The anode may be prepared according to its form. When the anode includes an indium metal or indium alloy foil, the anode may be formed by forming the foil into the -9-4880-1498-6974.1Atty. Dkt. No. 118347-0123 shape appropriate for the shape of the electrochemical cell. When the anode includes indium metal or indium alloy powder, the anode may be prepared by mixing the indium metal or indium alloy powder with the binder in the presence of a solvent to form a slurry. A conductive carbonaceous material as described herein may also be mixed into the slurry. The solvent may be N-methylpyrrolidone (NMP), acetone, water, or the like. The anode may be prepared by coating and drying the slurry mixture of the indium and / or indium metal alloy powder, conductive carbon material, and binder directly on a current collector, or by casting the mixture on a separate support to form a film and then laminating the film on a current collector.

[0078] The anode may include indium metal particles deposited on the surface of the anode via electroplating (e.g., via galvanostatic charge / discharge cycling). The indium metal particles may have a diameter of about 10 pm to about 200 pm (e.g., about 20 pm to about 150 pm, about 30 pm to about 100 pm, about 40 pm to about 80 pm, or about 60 pm). The indium metal particles may be smooth, rounded particles. The indium metal particles may lack any sharp dendritic structures.

[0079] The cathode may be prepared by mixing the cathode active material with the conductive carbon material and the binder in the presence of a solvent to form a slurry. The solvent may be N-methylpyrrolidone (NMP), acetone, water, or the like. The cathode may be prepared by coating and drying the mixture of the cathode active material, conductive carbon material, and binder directly on a current collector, or by casting the mixture on a separate support to form a film and then laminating the film on a current collector.

[0080] When the cathode include includes a S-C composite, the S-C composite may be prepared by a melt-infusion method. For example, a mixture of sulfur and carbon black may be milled to create a homogenous mixture. The mixture may be pressed into a pellet, and then melt-infused in an autoclave at a temperature of about 100 °C to about 200 °C. After melt-infusion, the pellet may be ground into a fine S-C powder before being used to form the cathode.EXAMPLES

[0081] The present technology is further illustrated by the following Examples, which should not be construed as limiting in any way. The examples herein are provided to-10-4880-1498-6974.1Atty. Dkt. No. 118347-0123 illustrate advantages of the present technology and to further assist a person of ordinary skill in the art with preparing or using the compositions and systems of the present technology. The examples should in no way be construed as limiting the scope of the present technology, as defined by the appended claims. The examples can include or incorporate any of the variations, aspects, or embodiments of the present technology described above. The variations, aspects, or embodiments described above may also further each include or incorporate the variations of any or all other variations, aspects or embodiments of the present technology. The following Examples demonstrate the preparation, characterization, and use of illustrative indium metal batteries.

[0082] Example 1: In / In and I11 / M11O2 Aqueous Electrochemical Cells

[0083] Herein, trivalent indium metal was demonstrated as a high-capacity, high- efficiency, low-polarization, and long-cycling metal anode for aqueous batteries. The anode delivered a high capacity of about 700 mAh g and showed an exceedingly low polarization value of about 1 mV. Furthermore, the redox potential of In / In3+imparts high compatibility with water because it is within the window of water stability, so that In / In3+redox reactions do not cause water splitting. This water compatibility aided high plating / stripping efficiency (e.g., about 99.2% to about 99.8%) in conventional electrolytes. Indium-indium symmetrical cells operated stably for 600 hours without short-circuit, and the plated indium did not suffer from dendrite growth and appeared as micron-sized bulk particles. A battery with an indium metal foil anode and a manganese dioxide cathode delivered a voltage of 1.2 V, a capacity of about 330 mAh g and stable cycling for 680 cycles.

[0084] FIG. 1 is an illustration of an electrochemical cell with an indium metal anode and an aqueous electrolyte including In3+. To explore the indium metal anode performance, symmetrical In / In, asymmetrical In / Ti, and asymmetrical In / MnCh electrochemical cells were assembled using an aqueous electrolyte of 1 M InCh. The indium metal (99.99% purity, 0.1 mm thickness) was purchased commercially. The indium foil was punched into circular shapes for use in electrochemical cells. The indium metal foil area was about 0.5 cm2in In / In and In / Ti electrochemical cells, and it was 1.27 cm2in In / MnCh electrochemical cells. To prepare the aqueous electrolyte, anhydrous InCh was dissolved in distilled water to make 1.0 M InCh aqueous electrolyte. Symmetrical In / In cells were fabricated by sandwiching two indium metal circular shapes with a glass fiber separator in -11-4880-1498-6974.1Atty. Dkt. No. 118347-0123 between. The In / In sandwich was assembled into 2032 coin cells, which were tested at different current density. The asymmetrical In / Ti cells were assembled in the 2032 coin cells with a glass fiber separator, and with Ti foil as the working electrode and In metal as the counter / reference electrode. The In / MnCh electrochemical cells were assembled in Swagelok cells, which use titanium rods as the current collectors. The electrolyte volume was 100 pL. Galvanostatic charge-discharge tests were performed at room temperature.

[0085] FIG. 2A is a graph of symmetrical In / In batteries at 0.5 mA cm2current and 0.25 mAh cm2capacity. The current density was 0.5 mA cm2, and the plating / stripping time was fixed at 30 minutes. FIG. 2A shows the galvanostatic charge / discharge (GCD) curves of the symmetrical cell, which exhibited highly stable cycling for 600 hours, without a cell short-circuit or voltage fluctuations. The symmetrical In / In electrochemical cells were also tested at a higher current of 2.0 mA cm2and a larger plating / stripping capacity of 1.0 mAh cm2), and demonstrated stable cycling for 400 hours.

[0086] FIG. 2B is a graph of the rate performance of symmetrical In / In batteries. The In / In symmetrical electrochemical cell exhibited a low polarization of 1 mV at 0.5 mA cm2, which may indicate fast reaction kinetics. The rate performance of In / In cells was tested, where the polarization was 1.5 mV, 3 mV, 6 mV, and 10 mV at 1 mA cm2, 2 mA cm2, 4 mA cm2, and 8 mA cm2, respectively, as shown in FIG. 2B. Even at a high current density of 10 mA cm2, the polarization was as low as 11 mV, which was smaller than many metal electrodes.

[0087] FIG. 2C is a graph of the polarization comparison of different metal electrodes under similar electrochemical conditions. To have a better idea of the polarization, the indium metal was compared with other metals under similar conditions (FIG. 2C), including Mn (700 mV), Fe (230 mV), Ni (400 mV), Cu (18 mV), Zn (50 mV), and Sn (11 mV). Remarkably, such a polarization value of 1 mV was 1 to 2 orders of magnitude lower than other metal electrodes compared. The low polarization of In metal may indicate high energy efficiency of indium metal batteries.

[0088] FIG. 2D is a graph of the charge / discharge curves of In / Ti batteries at1.0 mA cm2. FIG. 2E is a graph of Coulombic efficiency of In / Ti batteries at 1.0 mA cm2. Besides stable cycling and small polarization, the indium metal exhibited excellent Coulombic efficiency (CE) for plating / stripping reactions. Titanium foil was used as the-12-4880-1498-6974.1Atty. Dkt. No. 118347-0123 substrate due to its high chemical stability. The high-purity titanium foil (0.03 mm thickness) was purchased commercially. The asymmetrical In / Ti cells were tested at different current densities, and the plating capacity was controlled at 1.0 mAh cm2.

[0089] FIG. 2D shows GCD curves of the In / Ti cell at 1.0 mA cm2. The CE in the first cycle was 98.6%, and it increased to 99.0% in the tenth cycle and remained consistent at about 99.2% in the following cycles. FIG. 2E depicts the CE values with cycling numbers, where the average Coulombic efficiency over 180 cycles was greater than 99.2%. The plating / stripping performance was also tested at higher current rates. At 2.0 mA cm2, the average CE was 99.6% over 350 cycles. At 4.0 mA cm2, the average CE was further boosted to about 99.8%, and it was stable for 700 cycles.

[0090] FIG. 2F is a graph comparing the Coulombic efficiency of Fe, Zn, and In metals. In efficiency was compared to Fe and Zn anodes under similar conditions. As shown in FIG. 2F, Zn plating efficiency was only about 96.2% in 1 M ZnSCh, and the Fe plating efficiency was about 91% in 0.5 M FeSCU By contrast, In metal exhibited a higher CE of 99.2 to 99.8%.

[0091] FIG. 2G is a scanning electron microscope (SEM) image of electrochemically plated indium at 0.5 mA cm2current and 1.0 mAh cm2capacity. Metal plating morphology may play a role in the Coulombic efficiency and cycling stability of metal electrodes. Hence, scanning electron microscopy (SEM) analysis was conducted on the plated indium metal (FIG. 2G) on the Ti foil, where the current density and plating capacity was 0.5 mA cm2and 1.0 mAh cm2, respectively.

[0092] FIG. 2H is a closer view of one of the plated indium particles in FIG. 2G. The plated indium metal appeared as large, dense, and smooth particles, and the average particle size was about 60 pm.

[0093] FIG. 21 shows energy-dispersive X-ray spectroscopy (EDS) elemental mapping of a plated indium particle. Energy dispersive spectroscopy (EDS) analysis revealed the presence of indium and titanium elements only, with minimal oxygen or chloride elements (FIG. 21). EDS mapping showed that the indium element evenly distributed in the entire particle. Note that the lower indium signal at the bottom of the image was related to the beam light direction, which cannot fully detect the indium metal that was obscured. The-13-4880-1498-6974.1Atty. Dkt. No. 118347-0123 morphology of the indium metal after 100 hours cycling still showed a smooth and flat surface without any dendrite growth. EDS analysis indicated that the indium element dominated the entire electrode, suggesting high indium purity.

[0094] The above results collectively indicated that indium metal exhibited high compatibility with aqueous electrolytes, where reversible In3+ / In plating occurred with few side reactions. This compatibility is an advantage over conventional zinc metal, which is known to trigger water splitting and generate side reaction compounds in aqueous electrolytes. The In3+ / In redox couple has a higher redox potential of -0.34 V than that of the Zn2+ / Zn redox couple. This higher redox potential may mitigate side reactions. The dense and dendrite-free plating morphology of indium particles decreased the electrodeelectrolyte contact area, which may benefit the plating efficiency and cycling stability.

[0095] Manganese dioxide (MnCh) is a low-cost, high abundance, high capacity (250 mAh g1to 500 mAh g ') active cathode material that may be used in aqueous multivalent-ion batteries. A commercial MnCh active material was selected for the cathode. The MnCh electrodes included MnCh powders, Ketjen black carbon, and poly vinylidene fluoride (PVDF) binder in a mass ratio of 8: 1 : 1. The composites were well dispersed in N- Methyl-2-pyrrolidone (NMP) solvent, and the slurry was cast on carbon fiber papers (0.37 mm thickness, and 1 cm diameter). The MnCh electrodes were thoroughly dried in an oven at 45°C overnight. The MnCh electrodes has an active mass loading of about 1.5 to about 2.0 mg cm2.

[0096] FIG. 3 A is a graph of X-ray diffraction (XRD) and SEM image (inset) of P-MnCh cathode material. FIG. 3A shows the X-ray diffraction (XRD) pattern of the MnCh, which was indexed to a P-phase MnCh (JCPDS # 24-0735, space group P42 / mnm). The MnCh exhibited irregular morphology, with particle size ranging from 100 nm to 1 pm (Fig. 3 A, inset). EDS detected the presence of Mn and O elements only, which indicated the high chemical purity of the MnCh material.

[0097] FIG. 3B is a graph of galvanostatic charge / discharge (GCD) curves of an In / MnCh battery at 100 mA g1. FIG. 3B shows GCD curves of the In / MnCh battery at 100 mA g '. In the first cycle, there was a discharge plateau at about 1.10 V, and the initial discharge capacity was as high as about 500 mAh g which gave rise to a high specific energy of 512 Wh kg1based on the MnCh active mass. After the first discharge, the following GCD-14-4880-1498-6974.1Atty. Dkt. No. 118347-0123 curves appeared as S-shaped reaction slopes, and the average charge / discharge voltage was about 1.50 V and 1.22 V, respectively. There was slight capacity fading in the first five cycles, but the capacity gradually stabilized at about 280 mAh g1in the 10th cycle. Based on the 1.22 V discharge voltage and the electrode capacity (MnCh: 330 mAh g1in the 3rd cycle; In: 700 mAh g '), the theoretical energy density of In-MnCh batteries may reach about 270 Wh kg1.

[0098] FIG. 3C showed the cyclic voltammetry (CV) curves of the In / MnCh battery at 0.1 mV s ' . There was a sharp CV peak at about 1.0 V in the first cathodic scan, which corresponded to the initial discharge plateau in GCD curves. After the first cycle, the remaining CV curves appeared as a pair of broad oxidization / reduction peaks at 1.55 V and 1.22 V, which suggested a one-electron redox reaction.

[0099] FIG. 3D is a graph of the rate performance of the In / MnCh battery. The In / MnCh battery also exhibited excellent rate and cycling performance. The discharge capacity was about 300 mAh233 mAh g 197 mAh g 157 mAh127 mAh g and 106 mAh g1at the current density of 100 mA g 200 mA g 300 mA g 500 mA g 800 mA g and 1000 mA g respectively (FIG. 3D). Based on the discharge curves, the energy and power density were calculated, a high-power density of 1200 Wh kg1and a specific energy of 120 Wh kg1.

[0100] FIG. 3E is a graph of the long-term cycling performance of the In / MnCh battery at 500 mA g where the battery was conditioned at 100 mA g1for the first several cycles. FIG. 3E showed the long-term cycling performance at 500 mA g where there was capacity fading in the initial three cycles, but the capacity stabilized at about 113 mAh g1at the 10th cycle. After 680 cycles, the discharge capacity faded from 113 to 78corresponding to a capacity retention of about 70%. The cycling performance was also tested at a low current of 100 mAwhere the capacity retention was about 70% over 100 cycles.

[0101] The battery reaction chemistry of the In / MnCh battery system was investigated. Specifically, The In / MnCh battery was investigated to determine whether In3+or H+ions served as charge carriers. H+insertion is a common phenomenon that prevails in aqueous Zn / MnCh batteries. The 1.0 M InCh electrolyte used in the In / MnCh battery system was moderately acidic at pH of 2 to 3, as compared with 1.0 M ZnSCh at a pH of 4 to 5 used in-15-4880-1498-6974.1Atty. Dkt. No. 118347-0123Zn / MnCh batteries. Ex-situ XRD and SEM tests were carried out to study the structure and morphology evolution of MnCh during charge / discharge reactions. FIG. 4A showed the four representative GCD states, where the points A, B, C, and D denoted the pristine, first discharge, full charge, and second discharge states, respectively. FIG. 4B is a graph of ex- situ XRD patterns of the MnCh electrodes at different charge / discharge states in the GCD curve in FIG. 4A.

[0102] During the initial discharge (point A to B), the XRD pattern changed significantly, with multiple new peaks appearing at different positions. No standard diffraction pattern matched all of the observed XRD peaks. Thus, it is possible that the MnCh material may include complex composite materials with mixed phases in the discharged state. The peaks at about 22.3°, 41.5°, and 49.8° may be attributed to the I Ch material, whereas the peaks at about 25.3°, 33.3°, and 47.3° may index to the InOOH material. The four peaks at about 24.3°, 45°, and 45.8° may result from the InOCl material. These results suggested proton insertion into MnCh, which may change the local pH value and thus precipitate In3+and Cl" ions. Two peaks were also observed at 19.0° and 33.9°, which may be ascribed to the MnOOH phase (PDF#99-000-l 111), further suggesting proton insertion.

[0103] During the charge process (point B to C), the MnOOH material weakened in its XRD intensity, and new peaks emerged at 28.7°, 37.5, 42.8, 56.9, and 59.5°. These peaks are in good accordance with pristine P-phase Mn02. Therefore, the MnOOH material may have released H+and restored to Mn02. In the second-cycle discharge state (point D), the overall XRD peaks resembled those at the point B stage, which suggested a reversible structural evolution. Mn02 peaks nearly vanished, and the MnOOH peaks were intensified, further indicating the Mn02 — MnOOH transition.

[0104] FIG. 4C is an SEM image of the discharged Mn02 electrode at point B in FIG. 4A. Ex-situ SEM analysis further indicated proton insertion and precipitation compound formation. The SEM image showed rounded particles present surrounding the Mn02 material. These rounded particles had a relatively smooth particle surface, and the particle size was about 500 nm. FIG. 4D shows EDS elemental mapping of the SEM image in FIG. 4C indicated the presence of Mn, In, O, and Cl elements in the sample. The elemental mapping indicated that indium and manganese elements were separated from each other (FIG. 4D), and the chloride element overlapped with the indium signal. The oxygen signal was present across much of the sample, but was more concentrated in the area of MnCh.-16-4880-1498-6974.1Atty. Dkt. No. 118347-0123These results indicated that the discharged electrode may be a mixture of MnOOH and indium precipitation compounds, the latter of which contains oxygen and chloride. In conjunction with the XRD results, the precipitation material may include a composite material with I Ch, InOOH, and InOCl.

[0105] FIG. 4E is an SEM image of the charged cathode. When the electrode was charged to 1.6 V (point C), the rounded particles present in the discharged electrode in FIG. 4C were still present in the sample. The SEM image agreed with the XRD results. When the electrode was discharged to 0 V again (point D), these rounded particles were present surrounding the MnCh material, resembling the SEM image at the first discharge state (point B). These SEM results suggested a reversible proton insertion process in MnCh, which is in good accordance with the XRD analysis.

[0106] FIG. 4F is a schematic of a proposed reaction mechanism based on the results disclosed above. Proton insertion in MnCh may lead to the formation of MnOOH, making the electrolyte more basic locally, which results in the precipitation of indium-based compounds. The precipitation compounds may deposit in the vicinity of Mn02 materials. The chemical reactions can be written according to the following:Water ionization: H2O «-> H++ OHRedox reaction: Mn02 + H+ + e" <-> MnOOHPrecipitation: In3++ OH + Cl ImCh, InOOH, and / or InOCl

[0107] In conclusion, this example demonstrated trivalent indium as a metal anode for aqueous batteries. These batteries exhibited superior electrochemical performance, including a high capacity (about 700 mAh g '), extremely low polarization (about 1 mV), a long lifespan (600 hours), and high plating efficiency (99.2% to 99.8%). Such a promising performance may bey related to the In / In3+redox potential and the large, dense, and dendrite-free plating morphology. When assembled with a MnCh cathode, the In / MnCh battery delivered attractive voltage of about 1.2 V, high-rate capability of about 1000 mA g and long cycling of 680 cycles.

[0108] Example 2: In / In and In / MnCh Aqueous Electrochemical Cells-17-4880-1498-6974.1Atty. Dkt. No. 118347-0123

[0109] Herein, trivalent indium metal was demonstrated as a high-capacity, high- efficiency, low-polarization, and long-cycling metal anode with different cathode active materials. In / V2Os, In / FeFe(CN)e, In / S-C composite electrochemical cells were fabricated and tested. Besides the MnCh cathode described in Example 1, cathode active materials V2O5, FeFe(CN)e, and S-C composite were used in cathodes in effective indium metal batteries.

[0110] The V2O5 material was purchased commercially. The Prussian blue material of FeFe(CN)e was prepared by a precipitation method. Specifically, KsFe(CN)6 aqueous solution (50 mL, 0.1 M) was added to a FeCh aqueous solution (100 mL, 0.1 M) under magnetic stirring, and then the final solution was heated to 60 °C and subjected to reaction for 6 hours, resulting in a dark green precipitate. The dark green precipitates were centrifuged and washed with water multiple times, and then were dried in an oven at 60 °C overnight. The sulfur / carbon (S-C) composite was prepared by a melt-infusion method. Specifically, 0.3 g sulfur and 0.2 g Ketjen black carbon was milled in a mortar for 30 minutes, and then the mixture was transferred to a planetary ball-mill and subjected to ball milling at 400 rpm for 5 hours. The ball-milled S-C mixture was pressed into a pellet with a hydraulic press at 3 tons, and the pellet was transferred to an autoclave for melt-infusion reaction. The reaction temperature for melt-infusion was 155 °C, and the reaction time was 6 hours. After the reaction was finished, the pellet was milled into a fine S-C powder for use. The V2O5, FeFe(CN)e, and S / C electrodes were prepared in the same manner as MnCh electrodes described in Example 1. The In / V2Os, In / FeFe(CN)e, In / S-C composite electrochemical cells were assembled in the same way as the In / MnCh electrochemical cell described in Example 1.

[0111] FIG. 5A is a graph of a GCD curve of an In-V2Os battery. As shown in FIG. 5A, the indium metal battery with a vanadium pentoxide (V2O5) cathode delivered a moderate capacity of about 40 mAhand the average potential was about 0.7 V vs. In3+ / In.

[0112] FIG. 5B is a graph of GCD curves of an In-FeFe(CN)e battery. FeFe(CN)e is a Prussian blue analogue of Berlin green. This material has a three-dimensional large open structure, and two Fe3+ions which may serve as redox centers. As shown in FIG. 5B, the In-FeFe(CN)e cathode exhibited an initial discharge capacity of about 70 mAh g1and a capacity fade in the following cycles. The average reaction potential was about 0.7 V vs. In3+ / In.-18-4880-1498-6974.1Atty. Dkt. No. 118347-0123

[0113] FIG. 5C is a graph of GCD curves of an In-Si / C battery. Sulfur is highly abundant on Earth and has a lower price than many active materials. Furthermore, sulfur can receive two electrons per atom, which leads to a higher theoretical capacity of 1675 mAh g '. In this Example, the sulfur was encapsulated in nano-sized carbon to enhance its electrical conductivity, and the sulfur loading was about 60%. As shown in FIG. 5C, the first-cycle discharge capacity reached about 1900 mAh g '. The charge capacity in the first cycle was even higher, at about 2200 mAh g '. In the following cycles, the discharge capacity remained stable at about 1250 mAh g '. The potential gap between the charge (about 1.0 V) and discharge (about 0.2 V) was large (about 0.8 V), which may lead to a low round-trip energy efficiency.

[0114] Example 3: I11 / M11O2 Electrochemical Cells with Non-Aqueous Electrolytes

[0115] In addition to aqueous electrolytes, the indium metal electrochemical cell may include a non-aqueous electrolyte. InCh was soluble in the solvent THF, and the molar solubility was approximately 0.1 M. Asymmetrical In / Ti batteries were assembled with an electrolyte of 0.1 M InCh in THF. Electrochemical In3+ / In plating / stripping was conducted at a current density of about 0.1 mA cm2with a plating capacity of about 0.1 mAh cm2.

[0116] FIG. 6 A is a graph of indium metal plating performance in non-aqueous electrolyte. As shown in FIG. 6 A, the In / Ti batteries had a plating efficiency of about 55%. FIG. 6B is a graph of GCD curves of an In / MnCh non-aqueous battery, where the electrolyte was 0.1 M InCh dissolved in tetrahydrofuran (THF). The non-aqueous In / MnCh battery also showed charge / discharge capacity. Although the cathode capacity was lower than the aqueous system, the results indicated the feasibility of developing non-aqueous indium metal batteries.

[0117] Example 4: Indium Plating on Copper and Titanium

[0118] A planar, smooth, and dense indium metal layer was uniformly deposited on the copper substrate, leading to outstanding plating efficiency (99.8-99.9%) and an exceedingly long lifespan (6.4-7.4 months). The plated indium anode was further paired with a high- mass-loading Prussian blue cathode (2 mAh cm2), and the full cell (negative / positive electrode capacity, N / P = 2.5) delivered an excellent cycling life of 1000 cycles with 72% retention (data not shown).-19-4880-1498-6974.1Aty. Dkt. No. 118347-0123

[0119] The effect of substrates on In plating was examined in a 1.0 M InCh electrolyte. Titanium foil provided a particle-stacking morphology (FIG. 7A) with a high efficiency of 99.3-99.5%, whereas copper foil produced a planar foil-like morphology (FIG. 7B) with a high efficiency of 99.8-99.9%.

[0120] To gain more insights into the In plating behavior, its plating efficiency was examined at various capacities (1, 5, and 10 mAh cm-2) with a current of 1.0 mA cm-2. FIG. 8 A displays galvanostatic charge / discharge (GCD) curves of In||Ti batteries with 1.0 M indium chloride (InCh) electrolyte . The increment of capacity resulted in a higher plating efficiency, where the average efficiency was 99.3%, 99.4%, and 99.5% at 1, 5, and 10 mAh cm2, respectively. This capacity-efficiency correlation is quite counterintuitive (FIG. 2B), as a higher plating capacity usually leads to inferior efficiency for most metal electrodes. For instance, the asymmetrical Zn||Ti battery exhibited efficiencies of 98.8%, 96.4%, 92.6% at 1, 5, and 10 mAh cm2, respectively (data not shown). The Fe metal also encountered a similar efficiency decrease issue (data not shown). This unusual property motivated the investigation of the In plating morphology, which impacted the plating efficiency.Scanning electron microscopy (SEM) images under these conditions are shown in FIGS. 8C-8H. As shown, at 1 mAh cm2, the deposited In metal particles had a sphere-like morphology and were partially interconnected. The average size for each particle was 10- 20 pm. The spherical morphology and particle size was further corroborated by cross- sectional SEM(FIG. 8D). At this stage, In particles did not fully cover the Ti foil substrate surface, and the substrate surface was relatively exposed. At 5 mAh cm2capacity, In metals further grow into densely packed and well-connected chunks (FIGS. 8E and 8F), and their particle size increased to about 50 pm. Meanwhile, the Ti foil surface was almost fully covered. At 10 mAh cm2capacity (FIGS. 8G and 8H), indium chunks had “melted” or “welded” to provide a continuous film. At this capacity, the surface was quite smooth, and the stacking manner was dense (FIGS. 8G and 8H). Without being bound by any theory, the morphological transition in plating may be related to the softness, elasticity, and ductility of indium metal as compared to more stiff and rigid transition metals like iron, copper, and zinc.

[0121] As compared to Ti, using the Cu foil significantly altered the plating morphology, resulting in a planar foil morphology at all testing capacities. At 1 mAh cm2, the Cu foil was almost completely covered with In metal, with only a few small bare copper surfaces,-20-4880-1498-6974.1Aty. Dkt. No. 118347-0123 and the In surface was notably flat (FIG. 9A). Cross-sectional SEM further indicated the formation of a flat, uniform, and dense In deposition layer (FIG. 9B), with an approximate thickness of 11 pm. The original Cu foil was 9 pm thick, indicating that the plated In metal was approximately 2 pm thick. Extrapolating from the specific capacity (about 700 mAh g ') and density (7.29 g cm3) of In, a 2 pm thickness may correspond to 1.03 mAh cm2. This suggests that the plated In metal is densely packed on the Cu foil.

[0122] At 5 mAh cm2(FIG. 9C), the previous metal gaps were no longer present, and the In metal appeared as an integral, smooth, and crack-free foil. Cross-sectional SEM indicated that the plated In was densely packed without appreciable voids or gaps (FIG.9D), and the entire thickness of the combination of the indium layer and the copper layer was approximately 19 pm. Thus, the plated In had a thickness of about 10 pm, corresponding to a capacity of about 5.1 mAh cm2. Even at a high capacity of 10 mAh cm2(FIGS. 9E and 9F), the In metal maintained a uniform planar, and dendrite-free foil morphology. The thickness of the combination of the indium layer and the copper layer measured about 29 pm, suggesting that the In metal was approximately 20 pm thick.Digital photos are provided in the figure insets in FIGS. 9A-9F, displaying shiny metallic surfaces. As shown in FIG. 9G, the average efficiency reached a value of 99.81% over 2680 cycles (calendar life: 5360 hours, 7.4 months) at 1 mAh cm2capacity, surpassing the 99.3% efficiency observed on Ti foil. The data indicated the circumvention of soft short circuits. FIG. 9H presents selected GCD curves from FIG. 9G at the 50th, 100th, 1000th, 2000th, and 2500thcycle, which substantially overlapped without noticeable polarization increment, further indicating plating stability. The average efficiency was 99.82% at 5 mAh cm2over 527 cycles (calendar life: 5270 hours, 7.3 months), which further increased to 99.85% at 10 mAh cm2(calendar life: 4600 hours, 6.4 months), as demonstrated in FIG. 91. Even at an ultrahigh plating capacity of 20 mAh cm2, the In||Cu battery maintained a high efficiency of 99.72% over 79 cycles (calendar life: 3160 hours, 4.4 months, data not shown), which indicated the efficacy of planar plating in stabilizing the metal plating process. In contrast, the In| |Ti battery short-circuited at 20 mAh cm-2 (data not shown). Besides the high capacity, the Cu foil supported higher efficiency at higher current densities. The efficiency further increased to 99.9% at 2 mA cm2, likely due to the kinetic suppression of HER side reactions. At 4 mA cm2, the efficiency remained high at 99.9%, suggesting its potential for high-power applications.-21-4880-1498-6974.1Atty. Dkt. No. 118347-0123

[0123] Besides the Cu foil, other metal substrates may achieve similar planar plating behavior. For instance, when a tin (Sn) foil was used, the In metal also indicated a flat, dense, and planar plating morphology.

[0124] As shown in FIG. 10A, at a shallow plating depth (i.e., 0.2-1 mAh cm2), two characteristic peaks emerged at 34.5° and 60.1°, which may be attributed to the InCu alloy phase. As plating progressed (5-10 mAh cm2), the intensity of In metal increased, while the InCu alloy was present during all measurements. Without being bound by any theory, this suggests the in situ formation of InCu alloy preceding the In plating. The index of this InCu alloy indicates that the alloy adopts a monoclinic structure (JCPDS#00-035-l 150).

[0125] Cross-sectional SEM further corroborated the alloy formation. For better visualization, we selected the 10 mAh cm2electrode for observation. As depicted in FIG. 10B, the Cu element resided in the base of the indium layer on copper composite, while the In element was distributed throughout the entire composite. This suggests that after film plating, the Cu substrate may contain appreciable amounts of InCu alloy, while the upper material may be pure or substantially pure In metal. In contrast, no alloy formation was observed in the In layer on Ti substrate (data not shown).REFERENCES

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[0163] Sun, W.; Wang, F.; Hou, S.; Yang, C.; Fan, X.; Ma, Z.; Gao, T.; Han, F.; Hu, R.; Zhu, M. Zn / MnCh battery chemistry with H+and Zn2+coinsertion. J. Am. Chem. Soc. 2017, 139, 9775-9778.

[0164] Liu, W.; Zhang, X.; Huang, Y.; Jiang, B.; Chang, Z.; Xu, C.; Kang, F. P-MnCh with proton conversion mechanism in rechargeable zinc ion battery. J. Energy Chem. 2021, 56, 365-373.

[0165] Li, L.; Hoang, T.K.A.; Zhi, J.; Han, M.; Li, S.; Chen, P. Functioning mechanism of the secondary aqueous Zn-P-MnCh battery. ACS Appl. Mater. Interfaces 2020, 12, 12834-12846.EQUIVALENTS

[0166] While certain embodiments have been illustrated and described, a person with ordinary skill in the art, after reading the foregoing specification, can effect changes, substitutions of equivalents and other types of alterations to the compounds of the present technology or salts, pharmaceutical compositions, derivatives, prodrugs, metabolites, tautomers or racemic mixtures thereof as set forth herein. Each aspect and embodiment described above can also have included or incorporated therewith such variations or aspects as disclosed in regard to any or all of the other aspects and embodiments.-26-4880-1498-6974.1Atty. Dkt. No. 118347-0123

[0167] The present technology is also not to be limited in terms of the particular aspects described herein, which are intended as single illustrations of individual aspects of the present technology. Many modifications and variations of this present technology can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. Functionally equivalent methods within the scope of the present technology, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the appended claims. It is to be understood that this present technology is not limited to particular methods, reagents, compounds, compositions, labeled compounds or biological systems, which can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only, and is not intended to be limiting. Thus, it is intended that the specification be considered as exemplary only with the breadth, scope and spirit of the present technology indicated only by the appended claims, definitions therein and any equivalents thereof.

[0168] The embodiments, illustratively described herein may suitably be practiced in the absence of any element or elements, limitation or limitations, not specifically disclosed herein. Thus, for example, the terms “comprising,” “including,” “containing,” etc. shall be read expansively and without limitation. Additionally, the terms and expressions employed herein have been used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the claimed technology. Additionally, the phrase “consisting essentially of’ will be understood to include those elements specifically recited and those additional elements that do not materially affect the basic and novel characteristics of the claimed technology. The phrase “consisting of’ excludes any element not specified.

[0169] In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group. Each of the narrower species and subgeneric groupings falling within the generic disclosure also form part of the invention. This includes the generic description of the invention with a proviso or negative limitation removing any subject matter from the genus, regardless of whether or not the excised material is specifically recited herein.-27-4880-1498-6974.1Atty. Dkt. No. 118347-0123

[0170] As will be understood by one skilled in the art, for any and all purposes, particularly in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a nonlimiting example, each range discussed herein can be readily broken down into a lower third, middle third and upper third, etc. As will also be understood by one skilled in the art all language such as “up to,” “at least,” “greater than,” “less than,” and the like, include the number recited and refer to ranges which can be subsequently broken down into subranges as discussed above. Finally, as will be understood by one skilled in the art, a range includes each individual member.

[0171] All publications, patent applications, issued patents, and other documents (for examplejournals, articles and / or textbooks) referred to in this specification are herein incorporated by reference as if each individual publication, patent application, issued patent, or other document was specifically and individually indicated to be incorporated by reference in its entirety. Definitions that are contained in text incorporated by reference are excluded to the extent that they contradict definitions in this disclosure.

[0172] The present technology may include, but is not limited to, the features and combinations of features recited in the following lettered paragraphs, it being understood that the following paragraphs should not be interpreted as limiting the scope of the claims as appended hereto or mandating that all such features must necessarily be included in such claims:A. An electrochemical cell comprising an anode comprising indium metal or an indium alloy; a cathode; an electrolyte comprising water or tetrahydrofuran (THF); and an indium (III) salt.B. The electrochemical cell of paragraph A, wherein the electrolyte comprises water and the indium (III) salt is present in the electrolyte at a concentration of about 0.05 M to about 1.5 M.-28-4880-1498-6974.1Atty. Dkt. No. 118347-0123C. The electrochemical cell of paragraph A, wherein the electrolyte comprises THF and the indium (III) salt is present in the electrolyte at a concentration of about 0.05 M to about 0.1 M.C. The electrochemical cell of paragraph A, wherein the indium (III) salt is an InXs salt, and wherein X is F , Cl", Br , I", or OS(O)2CF3.D. The electrochemical cell of paragraph C, wherein the electrolyte comprises water and the InXs salt is a InCh salt present in the electrolyte at a concentration of about 0.8 M to about 1.2 M.E. The electrochemical cell of paragraph A, wherein the cathode comprises MnCh, V2O5, FeFe(CN)e, a S-C composite, or a mixture of two or more thereof.F. The electrochemical cell of paragraph A, wherein the cathode comprises MnCh.G. The electrochemical cell of paragraph A, wherein the indium metal or the indium alloy is present as a metal foil.H. The electrochemical cell of paragraph G, wherein the indium metal is further present as indium metal particles on a surface of the metal foil.I. The electrochemical cell of paragraph H, wherein the indium metal particles have a diameter of about 10 pm to about 200 pm.J. The electrochemical cell of claim 1, wherein In3+is a charge carrier in the electrolyte.K. The electrochemical cell of any one of paragraphs A- J, wherein the electrochemical cell is a rechargeable battery.L. The electrochemical cell of any one of paragraphs A-JK, wherein the anode is an indium metal anode.M. The electrochemical cell of any one of paragraphs A-L, wherein the cathode comprises MnCh.N. The electrochemical cell of any one of paragraphs A-M, wherein the electrolyte is an aqueous electrolyte comprising InCh at a concentration of about 0.8 M to about 1.2 M.-29-4880-1498-6974.1Atty. Dkt. No. 118347-0123O. A method of fabricating an electrochemical cell of any one of paragraphs A-N, the method comprising disposing an anode and a cathode in an electrolyte to form the electrochemical cell.P. The method of paragraph O, wherein the disposing is conducted in atmospheric air.Q. The method of paragraph P, further comprising disposing the anode on a current collector, wherein the anode is present as a metal foil.R. The method of paragraph Q, further comprising electrochemically plating indium metal particles onto a surface of the metal foil, the indium metal particles having a diameter of about 10 pm to about 200 pm.S. The method of paragraph O, wherein electrochemically plating indium metal particles comprises plating indium metal from In3+present in the electrolyte.

[0173] Other embodiments are set forth in the following claims, along with the full scope of equivalents to which such claims are entitled.-30-4880-1498-6974.1

Claims

1. Atty. Dkt. No. 118347-0123CLAIMS1. An electrochemical cell comprising: an anode comprising indium metal or an indium alloy; a cathode; an electrolyte comprising: water or tetrahydrofuran (THF); and an indium (III) salt.

2. The electrochemical cell of claim 1, wherein the electrolyte comprises water and the indium (III) salt is present in the electrolyte at a concentration of about 0.05 M to about 1.5 M.

3. The electrochemical cell of claim 1, wherein the electrolyte comprises THF and the indium (III) salt is present in the electrolyte at a concentration of about 0.05 M to about 0.1 M.

4. The electrochemical cell of claim 1, wherein the indium (III) salt is an InXs salt, and wherein X is F , Cl", Br , I , or OS(O)2CF3.

5. The electrochemical cell of claim 4, wherein the electrolyte comprises water and theInXs salt is a InCh salt present in the electrolyte at a concentration of about 0.8 M to about 1.2 M.

6. The electrochemical cell of claim 1, wherein the cathode comprises MnCh, V2O5,FeFe(CN)e, a S-C composite, or a mixture of two or more thereof.

7. The electrochemical cell of claim 1, wherein the cathode comprises MnCh.

8. The electrochemical cell of claim 1, wherein the indium metal or the indium alloy is present as a metal foil.

9. The electrochemical cell of claim 8, wherein the indium metal is further present as indium metal particles on a surface of the metal foil.

10. The electrochemical cell of claim 9, wherein the indium metal particles have a diameter of about 10 pm to about 200 pm.-31-4880-1498-6974.1Atty. Dkt. No. 118347-012311. The electrochemical cell of claim 1, wherein In3+is a charge carrier in the electrolyte.

12. The electrochemical cell claim 1, wherein the electrochemical cell is a rechargeable battery.

13. The electrochemical cell claim 1, wherein the anode is an indium metal anode.

14. The electrochemical cell of claim 1, wherein the cathode comprises MnCh.

15. The electrochemical cell of claim 1, wherein the electrolyte is an aqueous electrolyte comprising InCh at a concentration of about 0.8 M to about 1.2 M.

16. A method of fabricating an electrochemical cell of claim 1, the method comprising disposing an anode and a cathode in an electrolyte to form the electrochemical cell.

17. The method of claim 16, wherein the disposing is conducted in atmospheric air.

18. The method of claim 16, further comprising disposing the anode on a current collector, wherein the anode is present as a metal foil.

19. The method of claim 18, further comprising electrochemically plating indium metal particles onto a surface of the metal foil, the indium metal particles having a diameter of about 10 pm to about 200 pm.

20. The method of claim 16, wherein electrochemically plating indium metal particles comprises plating indium metal from In3+present in the electrolyte.-32-4880-1498-6974.1

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