Highly reversible trivalent antimony batteries stabilized by a chlorine-based water-in- salt electrolyte

Abstract

The present technology relates generally to trivalent metal battery systems. In particular, the present technology relates to trivalent antimony batteries, electrodes comprising antimony metal, and methods of making the same. The electrochemical cells of the current technology may incorporate antimony metal in the cathode or the anode. One or more electrolytes may be used in the electrochemical cells of the present technology, for example: about 0.5 m to about 1.5 m SbCl3, about 7 m to about 15 m LiCl, and water; about 0.5 m to about 1.5 m SbCl3, about 7 m to about 15 m NH4CI, and water; and about 0.5 m to about 1.5 m SbCl3 and ethanol.

Description

Atty. Dkt. No. 118347-0141 (25-002-UPR)Highly Reversible Trivalent Antimony Batteries Stabilized by a Chlorine- Based Water-in- Salt ElectrolyteCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and the benefit of U.S. Provisional Patent App. No. 63 / 760,222, filed February 19, 2025, the contents of which is incorporated herein by reference in its entirety.U.S. GOVERNMENT RIGHTS

[0002] This invention was made with government support under OIA- 1849243 awarded by The National Science Foundation and 80NSSC23M0189 awarded by The National Aeronautics and Space Administration. The government has certain rights in the invention.TECHNICAL FIELD

[0003] The present technology relates generally to trivalent metal battery systems, and more specifically to trivalent antimony batteries, electrodes comprising antimony metal, and methods of making the same.SUMMARY

[0004] In an aspect, an electrochemical cell includes a first electrode comprising antimony metal; a second electrode; and a first electrolyte comprising (a) about 0.5 molal (m) to about 1.5 m SbCh, about 7 m to about 15 m LiCl, and water; (b) about 0.5 m to about 1.5 m SbCh, about 7 m to about 15 m NH4Q, and water; or (c) about 0.5 m to about 1.5 m SbCh and ethanol.

[0005] In another aspect, a method of forming the electrochemical cell is disclosed. The method includes disposing the first electrode, the second electrode, and the separator in the first electrolyte to form the electrochemical cell.

[0006] In another aspect, a method of operating the electrochemical cell is disclosed. The method includes cycling the electrochemical cell at about 6.7 A g'1for at least 10,000 cycles with a specific capacity of about 150 mAh g'1to about 200 mAh g'1.Atty. Dkt. No. 118347-0141 (25-002-UPR)

[0007] In another aspect, a method of forming the electrochemical cell is disclosed. The method includes disposing the first electrode and the first electrolyte in the first electrode chamber; disposing the second electrode and the second electrolyte in the second electrode chamber; and ionically coupling the first electrode chamber and the second electrode chamber with the anion-exchange component.

[0008] In another aspect, a method of operating the electrochemical cell is disclosed. The method includes cycling the electrochemical cell at about 125 pA cm'2for at least 3500 hours with a Coulombic efficiency of at least 90%.

[0009] In any embodiment, Sb3+may be a charge carrier in the electrochemical cell. The first electrolyte may include about 1 m SbCh, about 10 m LiCl, and water. The first electrode may include an antimony metal powder, conductive carbon, and a binder. The antimony metal powder may include particles having a diameter of about 1 pm to about 150 pm. A weight ratio of the antimony metal powder, the conductive carbon, and the binder may be about 8:1:1. The binder may include polytetrafluoroethylene (PTFE).[0010 J In any embodiment, the second electrode may include an inorganic active cathode material. The electrochemical cell may further include a separator disposed between the first electrode and the second electrode. The inorganic active cathode material may include MnCh. The electrochemical cell may include a housing in which the first electrode, second electrode, separator, and first electrolyte are disposed.

[0011] In any embodiment, the second electrode may include zinc metal. The electrochemical cell may further include a first electrode chamber to hold the first electrode and the first electrolyte; a second electrode chamber to hold the second electrode and a second electrolyte; the second electrolyte comprising about 0.5 m to about 1.5 m ZnCh, about 2 m to about 15 m LiCl, and water; and an anion-exchange component to exchange Cl' between the first electrode chamber and the second electrode chamber. The second electrolyte may include about 1 m ZnCh, about 15 m LiCl, and water. The anion-exchange component may include a salt bridge.

[0012] Further aspects and embodiments of the present technology are described herein.Atty. Dkt. No. 118347-0141 (25-002-UPR)BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIGS. 1A-1B depict a schematic demonstrating the working mechanism of an antimony metal battery. FIG. 1A demonstrates that the anode operates on the Sb3+ / Sb plating / stripping mechanism while the cathode works on an insertion / desertion of electrolyte-bom Sb3+or other associated cations (protons or additive ions). FIG. IB is a schematic illustration of a Sb | |Zn battery where the Sb cathode and Zn anode operate on their corresponding Sb3+ / Sb and Zn2+ / Zn plating reactions, with Cl’ anions serving as shuttling ions for the charge balance.[0014 J FIG. 2 is a digital photograph showing electrolyte solutions of 1 m SbCh with varying molality of LiCl (0 m, 1 m, 5 m, 6 m, 7 m, 8 m, 9 m, 10 m, and 15 m), where 1-5 m LiCl electrolyte solutions are cloudy due to hydrolysis reactions, 6 m LiCl electrolyte has less hydrolysis, and 7-15 m LiCl electrolytes appear transparent.

[0015] FIG. 3 shows the X-ray diffraction (XRD) pattern of precipitation compounds formed from 1 m SbCh with 0 m, 1 m, and 5 m LiCl electrolytes.

[0016] FIGS. 4A-4C provide the Raman spectra of electrolyte solutions. FIG. 4A provides Raman spectra of 1 m SbCh with 10 m LiCl and 1 m SbCh with 15 m LiCl electrolytes. FIGS. 4B and 4C provide the Raman fitting results for the 1 m SbCh with 10 m LiCl electrolyte and 1 m SbCh with 15 m LiCl electrolyte, respectively.

[0017] FIGS. 5A-5C provide the galvanostatic charge / discharge (GCD) curves of Sb||Ti batteries with a 1.0 mA cm’2current density and a plating capacity of 1.0 mAh cm’2. FIG.5A provides the GCD curve when the electrolyte is 1 m SbCh with 7 m LiCl. FIG. 5B provides the GCD curve when the electrolyte is 1 m SbCh with 8 m LiCl. FIG. 5C provides the GCD curve when the electrolyte is 1 m SbCh with 9 m LiCl. GCD experiments were conducted using a Landt battery tester (CT3002AU).

[0018] FIGS. 6A-6B provide the GCD curves of Sb||Ti batteries with a 1.0 mA cm’2current density and a plating capacity of 1.0 mAh cm’2. FIG. 6A provides the GCD curve when the electrolyte is 1 m SbCh with 10 m LiCl. FIG. 6B provides the GCD curve when the electrolyte is 1 m SbCh with 15 m LiCl. GCD experiments were conducted using a Landt battery tester (CT3002AU).Atty. Dkt. No. 118347-0141 (25-002-UPR)

[0019] FIGS. 7A-7B compare the long-term Coulombic efficiency (i.e., the Coulombic efficiency over several hundred cycles) of Sb||Ti batteries with a 1.0 mA cm'2current density and a plating capacity of 1.0 mAh cm'2. FIG. 7A provides the Coulombic efficiency when the electrolyte is 1 m SbCh with 10 m LiCl. FIG. 7B provides the Coulombic efficiency when the electrolyte is 1 m SbCh with 15 m LiCl.

[0020] FIGS. 8A-8C provide scanning electron microscopy (SEM) images obtained using plated Sb when using 1 m SbCh with 7 m LiCl electrolyte (FIG. 8A), 1 m SbCh with 8 m LiCl electrolyte (FIG. 8B), and 1 m SbCh with 9 m LiCl electrolyte (FIG. 8C).

[0021] FIGS. 9A-9D provide SEM images of plated Sb when using 1 m SbCh with 10 m LiCl electrolyte (FIGS. 9A-B) and 1 m SbCh with 15 m LiCl electrolyte (FIGS. 9C-D).

[0022] FIG. 10 is a digital photograph of solutions of 1 m SbCh with 6 m NaCl, 1 m SbCh with 4.5 m KC1, 1 m SbCh withl 1 m CsCl, 1 m SbCh with 7 m NELCl, and 1 m SbCh with 5 mL ethanol.

[0023] FIGS. 11A-11B provide the GCD curves of two Sb||Ti batteries with a 1.0 mA cm'2current density and a plating capacity of 1.0 mAh cm'2. FIG. 11A shows the GCD curve for 1 m SbCh with 7 m NFhCl electrolyte. FIG. 11B shows the GCD curve for 1 m SbCh with 5 mL ethanol electrolyte. GCD experiments were conducted using a Landt battery tester (CT3002AU).

[0024] FIGS. 12A-12B provide SEM images of plated Sb when using 1 m SbCh with 7 m NH4Q electrolyte (FIG. 12A) and 1 m SbCh with 5 mL ethanol electrolyte (FIGS. 12B-C).

[0025] FIG. 13 provides the cyclic voltammetry curves of the Sb||Ti battery using 1 m SbCh with 10 m LiCl at a scan rate of 0.1 mV / s.

[0026] FIG. 14 provides GCD curves of Sb 11 Sb batteries using 1 m SbCh with 10 m LiCl obtained using a constant current density of 1 mA cm'2and capacity of 1 mAh cm'2over 5000 hours of cycling. GCD experiments were conducted using a Landt battery tester (CT3002AU).

[0027] FIG. 15 provides XRD spectra of Sb electrodes before and after 5000 hours of cycling.Atty. Dkt. No. 118347-0141 (25-002-UPR)

[0028] FIG. 16 provides GCD curves of Sb 11 Sb batteries using 1 m SbCh with 10 m LiCl obtained using a constant capacity of 1 mAh cm'2and current densities of 0.5, 1, 2, 4, 8, 10, 20, and 30 mA cm'2. GCD experiments were conducted using a Landt battery tester (CT3002AU).

[0029] FIG. 17 provides GSD curves of the Sb||Ti battery using 1 m SbCh with 10 m LiCl at a current density of 2.0 mA cm'2and capacity of 1.0 mAh cm'2.

[0030] FIG. 18 provides the Coulombic efficiency of the Sb||Ti battery using 1 m SbCh with 10 m LiCl at a current density of 2.0 mA cm'2and capacity of 1.0 mAh cm'2.

[0031] FIG. 19 provides Coulombic efficiency of Sb||Ti battery at the current density of 4.0 mA cm'2withan area capacity of 1.0 mAh cm'2.

[0032] FIG. 20 provides the X-ray diffraction spectrum of synthesized MnCh material.

[0033] FIGS. 21A-21B provide SEM images of P-phase MnCh, where FIG. 21A depicts the uniformity of the P-phase MnCh and FIG. 21B is at higher magnification to depict the nanowire-like morphology of the P-phase MnCh.

[0034] FIG. 22 provides GCD curves of the Sb||MnCh battery with 1 m SbCh with 10 m LiCl electrolyte at a current density of 2.7 A g'1. GCD experiments were conducted using a Landt battery tester (CT3002AU).

[0035] FIG. 23 provides the discharge capacity of the Sb||MnCh battery at various current densities.

[0036] FIG. 24 provides the cycling performance of the Sb||MnCh battery at 6.7 A g'1over the course of 20,000 cycles.

[0037] FIG. 25 provides GCD curves of the Sb||LiMnCh battery with 1 m SbCh with 10 m LiCl electrolyte at a current density of 50 mA g'1. GCD experiments were conducted using a Landt battery tester (CT3002AU).

[0038] FIG. 26 provides GCD curves of Zn||Sb battery in 15m LiCl with 1 m ZnCh and 10 m LiCl with 1 m SbCh electrolyte. GCD experiments were conducted using a Landt battery tester (CT3002AU).Atty. Dkt. No. 118347-0141 (25-002-UPR)

[0039] FIG. 27 provides the charging curve of the Sb electrode in a Zn| | Sb battery at 50 mA g’1-

[0040] FIG. 28 provides the rate capability of the Zn| | Sb battery at various current densities.

[0041] FIG. 29 provides the potential over time for a Zn| | Sb battery at a current density of 125 pA cm'2, demonstrating the ability of the battery to cycle for 3500 hours.DETAILED DESCRIPTION

[0042] 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

[0043] 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.[0044J 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 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 any two or more cells, and the like. Generally, the nomenclature used herein and the laboratory procedures in cell culture, molecular genetics,Atty. Dkt. No. 118347-0141 (25-002-UPR)organic chemistry, analytical chemistry and nucleic acid chemistry and hybridization described below are those well-known and commonly employed in the art.[0045 J 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.%.”

[0046] 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.”(0047 J 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 non-limiting 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.The Present Technology[0048} Disclosed herein are electrodes for trivalent metal battery systems that include antimony metal. Also disclosed herein are electrochemical cells using these electrodes,Atty. Dkt. No. 118347-0141 (25-002-UPR)methods of forming these electrodes and electrochemical cells, and methods of operating the electrochemical cells.[0049 J The electrochemical cell includes a first electrode comprising antimony metal, a second electrode, and a first electrolyte. Sb3+may be a charge carrier in the electrochemical cell. The first electrolyte may include (a) about 0.5 m to about 1.5 m SbCh, about 7 m to about 15 m LiCl, and water; (b) about 0.5 m to about 1.5 m SbCh, about 7 m to about 15 m NH4Q, and water; or (c) about 0.5 m to about 1.5 m SbCh and ethanol. For example, the first electrolyte may include about 1 m SbCh, about 10 m LiCl, and water.

[0050] The electrochemical cell of the present technology may include one or more electrolytes. For example, a charge carrier may be trivalent antimony (Sb3+) ions. The source of Sb3+ions may be SbCh. The concentration of SbCh may be about 0.1 m, about 0.2 m, about 0.3 m, about 0.4 m, about 0.5 m, about 0.6 m, about 0.7 m, about 0.8 m, about 0.9 m, about 1.0 m, about 1.1 m, about 1.2 m, about 1.3 m, about 1.4 m, about 1.5 m, about 1.6 m, about 1.7 m, about 1.8 m, about 1.9 m, about 2.0 m, or any range including and / or inbetween any two of these values. For example, in any embodiment, the concentration of SbCh may be about 0.1 m to about 2.0 m, about 0.2 m to about 1.9 m, about 0.3 m to about 1.8 m, about 0.4 m to about 1.7 m about 0.5 m to about 1.6 m, about 0.5 m to about 1.5 m, about 0.5 m to about 1.0 m, about 1.0 m to about 1.5 m, about 1.5 m to about 2.0 m, about l.0 m to about 2.0 m, or any range including and / or in-between any two of these values. For example, the first electrolyte may include about 0.5 m to about 1.5 m SbCh.

[0051] The first electrolyte may be a chlorine-based water-in-salt electrolyte. Without being bound by any theory, the water-in-salt electrolyte may mitigate hydrolysis and stabilize the charge carriers such as Sb3+ions by acting as a coordinating ligand to attach Sb3+ions. A source of CF ions in such electrolytes may be LiCl, NaCl, KC1, CsCl, NH4Q, any other suitable salt containing chlorine, or a combination of any two or more thereof. The concentration of chloride ions in the electrolyte may be about 1 m, about 5 m, about 6 m, about 7 m, about 8 m, about 9 m, about 10 m, about 15 m, about 16 m, about 17 m, about 20 m, or any range including and / or in-between any two of these values. For example, the concentration of chloride ions may be about 1 m to about 20 m, about 1 m to about 17 m, about 1 m to about 16 m, about 5 m to about 20 m, about 5 m to about 17 m, about 5 m to about 16 m, about 7 m to about 20 m, about 7 m to about 16 m, or any range include and / or in-between any two of these values.Atty. Dkt. No. 118347-0141 (25-002-UPR)

[0052] For example, in any embodiment, the first electrolyte may include LiCl at a concentration of about 1 m, about 5 m, about 6 m, about 7 m, about 8 m, about 9 m, about 10 m, about 15 m, or any range including and / or in-between any two of these values. For example, the concentration of LiCl may be about 1 m to about 15 m, about 1 m to about 10 m, about 1 m to about 9 m, about 1 m to about 8 m, about 1 m to about 7 m, about 1 m to about 6 m, about 1 m to about 5 m, about 5 m to about 15 m, about 5 m to about 10 m, about 5 m to about 9 m, about 5 m to about 8 m, about 5 m to about 7 m, about 6 m to about 16 m, about 6 m to about 10 m, about 6 m to about 9 m, about 7 m to about 15 m, about 7 m to about 10 m, or any range include and / or in-between any two of these values. Therefore, the first electrolyte may comprise about 0.5 m to about 1.5 m SbCh, about 7 m to about 15 m LiCl, and water. For example, the first electrolyte may comprise about 1 m SbCh, about 10 m LiCl, and water.

[0053] As another example, in any embodiment, the first electrolyte may comprise NFLC1 at a concentration of about 1 m, about 5 m, about 6 m, about 7 m, about 8 m, about 9 m, about 10 m, about 15 m, or any range including and / or in-between any two of these values. For example, the concentration of NFLC1 may be about 1 m to about 15 m, about 1 m to about 10 m, about 1 m to about 9 m, about 1 m to about 8 m, about 1 m to about 7 m, about 1 m to about 6 m, about 1 m to about 5 m, about 5 m to about 15 m, about 5 m to about 10 m, about 5 m to about 9 m, about 5 m to about 8 m, about 5 m to about 7 m, about 6 m to about 16 m, about 6 m to about 10 m, about 6 m to about 9 m, about 7 m to about 15 m, about 7 m to about 10 m, or any range include and / or in-between any two of these values. Therefore, the electrolyte may comprise about 0.5 m to about 1.5 m SbCh, about 7 m to about 15 m NFLCl, and water. For example, the electrolyte may comprise about 1 m SbCh, about 10 m NFLCl, and water.

[0054] In any embodiments, non-aqueous solvents may be used to minimize hydrolysis and stabilize charge carriers. Therefore, in any embodiment, the electrolyte may comprise ethanol. For example, the electrolyte may comprise between about 0.5 m and about 1.5 m SbCh and ethanol.[0055) The first electrode may include antimony metal. The antimony metal may include monolithic antimony metal, antimony metal power, or a combination thereof. For example, the first electrode may include antimony metal powder, conductive carbon, and a binder.Atty. Dkt. No. 118347-0141 (25-002-UPR)

[0056] The antimony metal powder may include particles having a diameter of about 1 pm, about 2 pm, about 3 pm, about 4 pm, about 5 pm, about 6 pm, about 7 pm, about 8 pm, about 9 pm, about 10 pm, about 12 pm, about 14 pm, about 16 pm, about 18 pm, about 20 pm, about 25 pm, about 30 pm, about 35 pm, about 40 pm, about 45 pm, about 50 pm, about 60 pm, about 70 pm, about 80 pm, about 90 pm, about 100 pm, about 110 pm, about 120 pm, about 130 pm, about 140 pm, about 150 pm, about 175 pm, about 200 pm, about 225 pm, about 250 pm, or any range including and / or in-between any two of these values. For example, in any embodiment, the antimony metal power may comprise particles having diameters of about 1 pm to about 250 pm, about 1 pm to about 200 pm, about 1 pm to about 150 pm, about 1 pm to about 130 pm, about 1 pm to about 100 pm, about 2 pm to about 100 pm, about 5 pm to about 100 pm, about 10 pm to about 100 pm, about 10 pm to about 100 pm, about 10 pm to about 90 pm, about 10 pm to about 80 pm, about 10 pm to about 70 pm, about 10 pm to about 60 pm, about 10 pm to about 50 pm, about 10 pm to about 40 pm, about 20 pm to about 50 pm, about 20 pm to about 60 pm, about 20 pm to about 70 pm, about 30 pm to about 80 pm, about 40 pm to about 90 pm, about 50 pm to about 100 pm, about 60 pm to about 110 pm, about 70 pm to about 120 pm, about 80 pm to about 130 pm, about 90 pm to about 140 pm, about 100 pm to about 150 pm, about 100 pm to about 250 pm, or any range including and / or in-between any two of these values. The diameter may be measured by any suitable means. For example, the diameter may be measured using scanning electron microscopy.

[0057] The binder in the first electrode may include 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. The binder may be present in the first electrode in an amount of about 0 wt.% to about 20 wt.% (e.g., about 5 wt.% to about 20 wt.%, about 5 wt.% to about 15 wt.%, or about 10 wt.%).

[0058] The conductive carbon in the first electrode may include carbon black (e.g., Ketjen black, acetylene carbon black, or Super P), graphite, hard carbon, amorphous carbon, soft carbon, mesocarbon microbeads (MCMB), mesoporous carbon, carbon nanotubes, carbon nanofibers, graphene, or a mixture of any two or more thereof. The conductive carbon may be present in the first electrode an amount of about 0 wt.% to about 50 wt.% (e.g., about 5 wt.% to about 20 wt.%, about 5 wt.% to about 15 wt.%, or about 10 wt.%).Atty. Dkt. No. 118347-0141 (25-002-UPR)

[0059] In any embodiment, the weight of antimony metal powder in an electrode may be about 1 times the weight of the binder, about 2 times the weight of the binder, about 3 times the weight of the binder, about 4 times the weight of the binder, about 5 times the weight of the binder, about 6 times the weight of the binder, about 7 times the weight of the binder, about 8 times the weight of the binder, about 9 times the weight of the binder, about 10 times the weight of the binder, or any range including and / or in-between any two of these values. In any embodiment, the weight of conductive carbon in an electrode may be about 1 times the weight of the binder, about 2 times the weight of the binder, about 3 times the weight of the binder, or any range including and / or in-between any two of these values. Therefore, the weight ratio of the antimony metal powder, the conductive carbon, and the binder may be about 1:1:1, about 2:1:1, about 3:1:1, about 4:1:1, about 5:1:1, about 6:1:1, about 7:1:1, about 8:1:1, about 9:1:1, about 10:1:1, about 5:2:1, about 6:2:1, about 7:2:1, about 8:2:1, about 9:2:1, about 10:2:1, about 5:3:1, about 6:3:1, about 7:3:1, about 8:3:1, about 9:3:1, about 10:3 : 1, or any ratio including and / or in-between any two ratios. For example, the weight ratio of the antimony metal powder, the conductive carbon, and the binder may be about 8:1:1.

[0060] The electrochemical cell may further include current collectors for the first electrode and / or the second electrode. The current collectors may include copper, stainless steel, titanium, platinum, gold, aluminum, nickel, or a mixture or alloy of two or more thereof. The current collectors may be in the form of a foil, mesh, or screen.

[0061] In an embodiment, the electrochemical cell may include the second electrode including an inorganic active cathode material. The electrochemical cell may include a separator disposed between the two electrodes. The separator may be disposed between the anode and the cathode to prevent or reduce the risk of an electrical short in the electrochemical cell. As an example, the electrochemical cell may include a housing to contain the first electrode, the second electrode, the separator, and the electrolyte.

[0062] The separator may be a microporous polymer film, glass fiber, paper fiber, ceramic material, or a combination of any two or more thereof. Illustrative microporous polymer films include, but are not limited, nylon, cellulose, nitrocellulose, polysulfone, polyacrylonitrile, polyvinylidene fluoride, polypropylene, polyethylene, polybutene, or a blend or copolymer thereof. The separator may be a commercially available separator. Commercially available separators include those such as, but not limited to, Celgard® 2400,Atty. Dkt. No. 118347-0141 (25-002-UPR)2025, 3501, and 2325. Separators of a wide range of thickness may be used. For example, the separator may be from about 5 pm to about 50 pm thick.

[0063] The second electrode may include particles of the inorganic active cathode material. The second electrode may further include a binder, conductive carbon, or a combination thereof. As an example the inorganic active cathode material may include MnCh (e.g., P-MnCh).100641 The binder in the second electrode may include 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. The binder may be present in the electrode in an amount of about 0 wt.% to about 20 wt.% (e.g., about 5 wt.% to about 20 wt.%, about 5 wt.% to about 15 wt.%, or about 10 wt.%).

[0065] The conductive carbon in the second electrode may include carbon black (e.g., Ketjen black, acetylene carbon black, or Super P), graphite, hard carbon, amorphous carbon, soft carbon, mesocarbon microbeads (MCMB), mesoporous carbon, carbon nanotubes, carbon nanofibers, graphene, or a mixture of any two or more thereof. The conductive carbon may be present in an amount of about 0 wt.% to about 50 wt.% (e.g., about 5 wt.% to about 20 wt.%, about 5 wt.% to about 15 wt.%, or about 10 wt.%).

[0066] The weight of inorganic active cathode material in an electrode may be about 1 times the weight of the binder, about 2 times the weight of the binder, about 3 times the weight of the binder, about 4 times the weight of the binder, about 5 times the weight of the binder, about 6 times the weight of the binder, about 7 times the weight of the binder, about 8 times the weight of the binder, about 9 times the weight of the binder, about 10 times the weight of the binder, or any range including and / or in-between any two of these values. In any embodiment, the weight of conductive carbon in an electrode may be about 1 times the weight of the binder, about 2 times the weight of the binder, about 3 times the weight of the binder, or any range including and / or in-between any two of these values. Therefore, the weight ratio of the inorganic active cathode material, the conductive carbon, and the binder may be about 1:1:1, about 2:1:1, about 3:1:1, about 4:1:1, about 5:1:1, about 6:1:1, about 7:1:1, about 8:1:1, about 9:1:1, about 10:1:1, about 5:2:1, about 6:2:1, about 7:2:1, about 8:2:1, about 9:2:1, about 10:2:1, about 5:3:1, about 6:3:1, about 7:3:1, about 8:3:1, about 9:3:1, about 10:3 : 1, or any ratio including and / or in-between any two ratios. For example,Atty. Dkt. No. 118347-0141 (25-002-UPR)the weight ratio of the inorganic active cathode material, the conductive carbon, and the binder may be about 8:1:1.[0067 | In an aspect, a method of forming the electrochemical cell including the first electrode comprising antimony metal and the second electrode comprising an inorganic active cathode material is disclosed. The method may include disposing the first electrode, the second electrode, and the separator in the first electrolyte to form the electrochemical cell. The method may further include disposing the first electrode, the second electrode, the separator, and the first electrolyte in a housing. The housing may be any suitable housing for an electrochemical cell (e.g., coin cell, pouch cell, or other battery casing).[0068J In an aspect, a method of operating the electrochemical including the first electrode comprising antimony metal and the second electrode comprising an inorganic active cathode material is disclosed. The electrochemical cell may be cycled at about 5.0 A g’1, about 5.5 A g’1, about 6.0 A g’1, about 6.5 A g’1, about 6.6 A g’1, about 6.7 A g’1, any range including and / or in-between any two of these values. In any embodiment, the electrochemical cell may be cycled for at least 1,000 cycles, at least 5,000 cycles; at least 6,000 cycles; at least 7,000 cycles; at least 8,000 cycles; at least 9,000 cycles; at least 10,000 cycles; or any range including and / or in-between any two of these values. In any embodiments, the electrochemical cell may be cycled with a specific capacity of about 140 mAh g’1, about 150 mAh g’1, about 160 mAh g’1, about 170 mAh g’1, about 180 mAh g’1, about 190 mAh g’1, about 200 mAh g’1, or any range including and / or in-between any two of these values. The electrochemical cell may be cycled with a specific capacity of about 50 mAh g’1to about 200 mAh g’1, about 100 mAh g’1to about 200 mAh g’1, about 150 mAh g’1to about 200 mAh g’1, about 175 mAh g’1to about 200 mAh g’1, or any range including and / or in-between any two of these values. For example, a method of operating an electrochemical cell of the present technology may include cycling the electrochemical cell at about 6.7 A g’1for at least 10,000 cycles with a specific capacity of about 150 mAh g’1to about 200 mAh g’1.[0069) In an embodiment, the electrochemical cell may include the second electrode including zinc metal, where the electrochemical cell includes a first electrode chamber to hold the first electrode and the first electrolyte; a second electrode chamber to hold the second electrode and a second electrolyte; the second electrolyte; and an anion-exchange component to exchange anions (e.g., Cl’) between the first electrode chamber and theAtty. Dkt. No. 118347-0141 (25-002-UPR)second electrode chamber. The electrochemical cell may be a dual -metal Zn| | Sb battery with Sb3+ / Sb and Zn2+ / Zn plating reactions at respective electrodes.[0070 J The second electrode may include zinc metal. The zinc metal may include monolithic zinc metal, zinc metal power, or a combination thereof. For example, the first electrode may include zinc metal powder, conductive carbon, and a binder. The conductive carbon and binder may be any of those disclosed herein. The ratio of zinc metal to conductive carbon and binder may be consistent with any of the ranges disclosed herein with respect to the antimony metal powder electrodes.[0071 J In any embodiments, the second electrolyte may comprise Zn2+ions. The source of the Zn2+ions may be any acceptable Zn salt, including for example ZnCh. The concentration of ZnCh may be about 0.1 m, about 0.2 m, about 0.3 m, about 0.4 m, about 0.5 m, about 0.6 m, about 0.7 m, about 0.8 m, about 0.9 m, about 1.0 m, about 1.1 m, about 1.2 m, about 1.3 m, about 1.4 m, about 1.5 m, about 1.6 m, about 1.7 m, about 1.8 m, about l.9 m, about 2.0 m, or any range including and / or in-between any two of these values. For example, in any embodiment, the concentration of ZnCh may be about 0.1 m to about 2.0 m, about 0.2 m to about 1.9 m, about 0.3 m to about 1.8 m, about 0.4 m to about 1.7 m about 0.5 m to about 1.6 m, about 0.5 m to about 1.5 m, about 0.5 m to about 1.0 m, about 1.0 m to about 1.5 m, about 1.5 m to about 2.0 m, about 1.0 m to about 2.0 m, or any range including and / or in-between any two of these values. Additionally, in some embodiments, the second electrolyte may include LiCl. For example, in any embodiment, the second electrolyte may comprise LiCl at a concentration of about 1 m, about 2 m, about 3 m, about 4 m, about 5 m, about 6 m, about 7 m, about 8 m, about 9 m, about 10 m, about 15 m, or any range including and / or in-between any two of these values. For example, the concentration of LiCl may be about 1 m to about 15 m, about 1 m to about 10 m, about 1 m to about 9 m, about 1 m to about 8 m, about 1 m to about 7 m, about 1 m to about 6 m, about 1 m to about 5 m, about 2 m to about 15 m, about 2 m to about 10 m, about 2 m to about 9 m, about 2 m to about 8 m, about 2 m to about 7 m, about 2 m to about 6 m, about 5 m to about 15 m, about 5 m to about 10 m, about 5 m to about 9 m, about 5 m to about 8 m, about 5 m to about 7 m, about 6 m to about 16 m, about 6 m to about 10 m, about 6 m to about 9 m, about 7 m to about 15 m, about 7 m to about 10 m, or any range include and / or in-between any two of these values. For example, the electrolyte may comprise about 0.5 mAtty. Dkt. No. 118347-0141 (25-002-UPR)to about 1.5 ZnCh, about 2 m to about 15 m LiCl, and water. For example, the electrolyte may comprise about 1 m ZnCh, about 15 m LiCl, and water.

[0072] The anion-exchange component may include a salt bridge. Without being bound by any theory, the salt bridge may prevent the first electrolyte and the second electrolyte from mixing while maintaining charge balance by ionically coupling the first electrode chamber and the second electrode chamber. The salt bridge may include a polymer with an anion disposed within the polymer, where the polymer facilitates the movement of anions through the polymer matrix. For example, the polymer may include agar with the anion disposed in the agar polymer matrix. For example, the polymer may include agar and the salt may include KC1. The KC1 and agar of the salt bridge may be present in a 1 :3 weight ratio.

[0073] The electrochemical cell may include a housing in which one or more of the first electrode chamber, the second electrode chamber, and the anion-exchange component are disposed.

[0074] In an aspect, a method of forming the electrochemical cell including the first electrode comprising antimony and the second electrode comprising zinc is disclosed. The method includes disposing the first electrode and the first electrolyte in the first electrode chamber; disposing the second electrode and the second electrolyte in the second electrode chamber; and ionically coupling the first electrode chamber and the second electrode chamber with the anion-exchange component.

[0075] In another aspect, a method of operating the electrochemical cell including the first electrode comprising antimony metal and the second electrode comprising zinc metal is disclosed. The method may include cycling the electrochemical cell. The electrochemical cell may be cycled for at least 500 hours; at least 1,000 hours; at least 1,500 hours; at least 2,000 hours; at least 2,500 hours; at least 3,000 hours; at least 3,500 hours; or any range including and / or in-between any two of these values. The electrochemical cell may be cycled at a current density of about 70 pA cm'2, about 80 pA cm'2, about 90 pA cm'2, about 100 pA cm'2, about 110 pA cm'2, about 120 pA cm'2, about 125 pA cm'2, or any range including and / or in-between any two of these values. For example, the electrochemical cell may be cycled at about 125 pA cm'2. The electrochemical cell may be operated with a Coulombic efficiency of at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, at least 99.9%, orAtty. Dkt. No. 118347-0141 (25-002-UPR)any range including and / or in-between any two of these values. For example, the electrochemical cell may be operated by cycling the electrochemical cell at about 125 pA cm'2for at least 3500 hours with a Coulombic efficiency of at least 90%.EXAMPLES[0076) 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 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 electrodes comprising antimony metal. In these examples, electrodes comprising antimony metal were fabricated and investigated as cathodes and anodes for trivalent metal batteries.Example 1: Materials

[0077] Antimony (III) chloride (>99.0%), antimony powder- 100 mesh (99.5%) lithium chloride (> 99.0%), ammonium chloride (> 99.99%), and ethanol were purchased from Sigma Aldrich. Titanium foil with a high purity and thickness of 0.03 mm was purchased from Amazon.

[0078] P-phase manganese oxide (P- MnCh) was synthesized using a hydrothermal method. Initially, 0.25 g of polyvinyl pyrrolidone (PVP, K-30, MW 40,000) was dissolved in 20 mL of water. Subsequently, 0.15 g of KMnCU dissolved in 15 mL of water was added dropwise with continuous stirring. In a separate beaker, 0.05 g of (NHThSCU was dissolved in 10 mL of water and then added dropwise to the above mixture. After vigorous stirring for 20 minutes, the resulting solution was transferred to a 100 mL Teflon-lined stainless-steel autoclave and heated at 130 °C for 10 hours. Once cooled to room temperature, the precipitate was collected by centrifugation, washed four times with water and ethanol, andAtty. Dkt. No. 118347-0141 (25-002-UPR)dried at 80 °C for 5 hours. Finally, the dried product was calcined at 450 °C in a muffle furnace for 4 hours at a ramping rate of 5 °C / min, resulting in black P-MnCh powder.Example 2: Preparation of Electrodes and Battery Assembly

[0079] Antimony Electrodes. A self-standing film of antimony powder was made and punched into circular-shaped discs for direct use. Antimony powder, Ketjen black, and polytetrafluoroethylene (PTFE) were mixed in an 8: 1 : 1 ratio by weight, resulting in a paste. The paste was rolled with a glass rod on a glass slab to be pressed into a 0.4 mm thin film, which was subsequently cut into circular pieces of 0.71 mm in diameter.

[0080] Manganese Electrodes. The positive electrodes were prepared by grinding MnCh, Ketjen black, and poly vinylidene fluoride (PVDF) together in an 8: 1 : 1 ratio by weight. The resulting mixture was dispersed in N-methyl-2-pyrollidone (NMP) solvent, resulting in a uniform slurry. The slurry was cast onto carbon fiber paper with a 0.37 mm thickness and 1 cm diameter. The electrodes were dried in an oven at 60 °C for 12 hours.

[0081] Battery Cell Assembly. Symmetrical antimony-antimony cells were assembled, each with two Sb electrodes separated by a glass fiber separator in a Swagelok cell.Asymmetrical antimony-titanium (Sb||Ti) cells were also assembled in Swagelok cells, with Ti foil as the working electrode and the Sb circular disk as the counter / reference electrode. The asymmetrical cells were tested at various current densities of 1 mA cm’2, 2 mA cm’2, and 4 mA cm’2with a plating capacity of 1 mAh cm’2. Additionally, Sb||MnC>2 batteries were assembled in Swagelok cells, having titanium rods as the current collectors. The Sb electrode size was about 0.71 cm2both in symmetrical Sb| | Sb and asymmetrical Sb||Ti batteries.Example 3: Effect of Electrolyte Concentrations on Hydrolysis

[0082] The effect of LiCl additives on 1 m SbCh was studied. Solutions of 1 m SbCh with X m LiCl (X = 0, 1, 5, 6, 7, 8, 9, 10, and 15) were prepared. The electrolyte solutions were allowed to sit at room temperature for 24 h.

[0083] As shown by FIG.2, 0-5 m LiCl electrolyte solutions underwent hydrolysis reactions, leading to cloudy precipitation solutions. The 6 m electrolyte solution was slightly milky, indicating some hydrolysis. By contrast, the 7 m, 8 m, 9 m, 10 m, and 15 mAtty. Dkt. No. 118347-0141 (25-002-UPR)LiCl electrolyte solutions appeared to be transparent liquid solutions, indicating that hydrolysis was mitigated when LiCl additives were present at concentrations of at least 7 m.

[0084] The precipitates from electrolyte solutions of 1 m SbCh with 0 m, 1 m, and 5 m LiCl were analyzed using XRD. As shown by FIG. 3, the hydrolysis reaction resulted in the Sb4ChO5 phase (PDF # 97-000-2233) through the reaction 4 SbCh + 5 H2O — Sb4ChO5 + 10 HC1.|0085| The ionic compounds from electrolyte solutions of 1 m SbCh with 10 m LiCl and 1 m SbCh with 15 m LiCl were analyzed using Raman spectroscopy. As shown in FIG. 4, these two electrolytes exhibited comparable Raman results. Two Raman peaks appeared at 254 cm’1and 316 cm’1, attributable to the vibration modes of SbCh" and SbCh3'. Peaks at 389 cm’1and 215 cm’1may be attributed to the Li-Cl and hydrated lithium chloride (Li-OFh-Cl), respectively. As the LiCl concentration increased from 10 m to 15 m, the intensity of both peaks associated with SbCh" and SbCh3' increased, which, without being bound by any theory, may indicate that chloride ions act as competing ligands to H2O, the former of which coordinates with Sb3+cations and forms antimony halide anions that are stable in water. This data suggested that the Sb3+hydrolysis reaction may be suppressed using chloride ions.Example 4: Effect of Electrolyte Concentrations on Coulombic Efficiency

[0086] The Coulombic efficiency of the Sb plating / stripping reaction was determined for various electrolyte solutions. For Coulombic efficiency studies, the SbCh concentration was fixed at 1 m and the LiCl concentrations were 7 m, 8 m, or 9 m. Asymmetrical Sb||Ti batteries were assembled, with Sb metal as the anode and inert Ti foil as the substrate. The current density was set at 1.0 mA cm’2, and the plating capacity was fixed at 1.0 mAh cm’2.

[0087] Referring now to FIG. 5A, the GSD curve indicated that the first cycle Coulombic efficiency was 77% for 1 m SbCh with 7 m LiCl, and Coulombic efficiency increased to 99.5% at 60 cycles. FIG. 5B indicated that increasing the LiCl concentration to 8 m LiCl increased the efficiency of the first cycle to 85%, and stabilized at 99.6% in successive cycles. FIG. 5C indicated that increasing the LiCl concentration to 9 m LiCl increased the first cycle efficiency to 91.3%, which reached 99.6% in the following cycles. Together, this data indicated that LiCl may play a role in the stabilization of Sb and controlling the plating efficiency. Without being bound by any theory, at low LiCl concentration, the chloride ionsAtty. Dkt. No. 118347-0141 (25-002-UPR)may not completely stabilize the Sb, which may lead to the oxidation of Sb to Sb20s during the charging cycle, resulting in low Coulombic efficiency.[0088J Referring now to FIG. 6, the first cycle efficiency improved as the concentration of LiCl further increased to 10 m and 15 m. For the 1 m SbCh with 10 m LiCl electrolyte, the initial Coulombic efficiency was 96.4%. In subsequent cycles, the GCD curves indicated a highly reversible process with increasing Coulombic efficiency values. FIG. 6A indicated that the Coulombic efficiency for the 10th, 20th, 40th and 60th cycle was 98.1%, 99.2%, 99.3%, and 99.9%, respectively. FIG. 6B shows that for the 1 m SbCh with 15 m LiCl electrolyte, the efficiency was 97.6%, 98.3%, 98.9%, 98.5%, and 99.3% at the 1st, 10th, 20th, 40th, and 60th cycle.

[0089] Based on the first cycle efficiency, 1 m SbCh with 10 m LiCl and 1 m SbCh with 15 m LiCl electrolytes were selected for further studies.Lons-Term Coulombic Efficiency Studies

[0090] The 1 m SbCh with 10 m LiCl and 1 m SbCh with 15 m LiCl electrolytes were studied for long-term Coulombic efficiency. As demonstrated by FIG. 7A, the average Coulombic efficiency was 99.66% for 1 m SbCh with 10 m LiCl electrolyte. FIG. 7B shows that the average Coulombic efficiency of 1 m SbCh with 15 m LiCl was 99.61%, and that the battery was short-circuited after 900 cycles, which may have been due to side reactions.Example 5: Effect of Electrolyte Concentrations for Sb Plating Efficiency

[0091] SEM was used to observe the morphology differences in various electrolytes.

[0092] Referring now to FIG. 8 A, the SEM image of the plated Sb metals from the 1 m SbCh with 7 m LiCl electrolyte showed non-uniform morphology, having some spherical particles among spindle-shaped structures. As shown in FIG. 8B, the SEM image of the 1 m SbCh with 8 m LiCl electrolyte resulted in a more uniform structure than that resulting from the use of 1 m SbCh with 7 m LiCl, but still contained some irregular structures. Similarly, referring now to FIG. 8C, the SEM image of the 1 m SbCh with 9 m LiCl electrolyte showed even more uniform spherical morphology of Sb particles compared to the Sb particles resulting from the use of 7 m and 8 m LiCl, but still contained someAtty. Dkt. No. 118347-0141 (25-002-UPR)irregular structures. Together, without being bound by any theory, this data indicated that LiCl plays a role in regulating the nucleation of Sb particles leading to uniform growth and attaining spherical structures.(0093) Referring now to FIG. 9, as the concentration of LiCl further increased to 1 m SbCh with 10 m LiCl electrolyte, a complete spherical morphology with more uniform structures was observed, as shown in FIGS. 9A and 9B. However, as shown in FIGS. 9C and 9D, beyond this point, a further increase in concentration to 1 m SbCh with 15 m LiCl electrolyte led to a less homogeneous size distribution, with some large metal deposits (500-800 nm) and some smaller metal particles (about 100 nm).

[0094] Based on this data, the 1 m SbCh with 10 m LiCl electrolyte was selected for further studies.Example 6: Effect of Solvent on Sb Plating

[0095] The results in Examples 3-5 suggest that reducing water content or activity is critical to stabilize the Sb3+ions and make a transparent solution. Therefore, non-aqueous solvents and different chloride salts were explored.

[0096] Chloride solutions were made using NaCl, KC1, and CsCl, and NH4Q. Each chloride salt has different solubility in water: NaCl (36 g / 100 mL, about 6.15 m), KC1 (34 g / 100 mL, about 4.5 m), CsCl (191 g / 100 mL, about 11.3 m), andNH4Cl (39.5 g / 100 mL, about 7.4 m). Therefore, 1 m SbCh was mixed with the respective near-saturation chloride salt solutions. The results are shown in FIG. 10, which showed that using 6 m NaCl and 4.5 m KC1 resulted in precipitation. Interestingly, the concentration of CsCl was as high as 11 m before precipitation occurred; however, some antimony salts precipitated out, which, without being bound by any theory, may be related to the relatively large size of Cs+ions as compared to Sb3+ions that compete for CT ions. The 7 m NH4CI solution was clear, which, without being bound by any theory, may be due to the weak acid properties of NH4+ions that inhibit Sb3+hydrolysis. Additionally, 1 m SbCh in ethanol, which was substantially free of water, was also a clear solution.Plating Performance in 1 m SbCh with 7 m NH4CI and 1 m SbCh in EthanolAtty. Dkt. No. 118347-0141 (25-002-UPR)

[0097] The Sb plating performance was studied in two additional electrolytes: 1 m SbCh with 7 m NH4CI and 1 m SbCh in ethanol. FIG. 11A shows the GCD curves for 1 m SbCh with 7 m NH4CI electrolyte. The Coulombic efficiency was 89% in the first cycle, which increased in successive cycles reaching 99.7% in a few cycles. FIG. 11B shows the GCD curves in the 1 m SbCh in ethanol electrolyte. The Coulombic efficiency was 99% in the first cycle, and it reached 99.8 % at the 60th cycle. This data indicated that each of these electrolytes offered highly reversible and stable plating performance for the Sb electrode, indicating the feasibility of this approach to reduce or limit the amount / activity of water molecules.

[0098] The morphology of plated Sb using 1 m SbCh with 7 m NH4CI and 1 m SbCh in ethanol was also studied. FIG. 12A shows the plated Sb using 1 m SbCh with 7 m NH4Q electrolyte had uniform spherical morphology resembling the LiCl case. FIGS. 12B and 12C show that the plated Sb using 1 m SbCh with 5mL ethanol resulted in a layer-like morphology that covered the surface of the substrate. The higher magnification in FIG. 12C shows polyhedral particles closely contacted to form a continuous layer.Example 7: Analysis of 1 m SbCh with 10 m LiCl ElectrolyteRedox Potential

[0099] Cyclic voltammetry was used to determine the redox potential of Sb electrodes. As shown in Fig. 13, there is a cathodic peak at -0.25 V (vs. Ag / AgCl) and an anodic peak at 0 V, attributable to Sb plating and stripping, respectively. The average redox potential was thus calculated as -0.12 V vs. Ag / AgCl, which corresponded to +0.08 V vs. SHE. The cyclic voltammetry curves suggested high reaction reversibility.Electrochemical Performance with Symmetrical Sb\\Sb Batteries

[0100] Cyclic voltammetry was used to determine the redox potential. As shown in Fig.13, there was a cathodic peak at -0.25 V (vs. Ag / AgCl) and an anodic peak at 0 V, which may be attributed to the Sb plating and stripping, respectively. The average redox potential was thus calculated as -0.12 V vs. Ag / AgCl, which corresponded to +0.08 V vs. standard hydrogen electrode (SHE). The cyclic voltammetry curves suggested high reaction reversibility.Atty. Dkt. No. 118347-0141 (25-002-UPR)

[0101] The electrochemical performance of Sb electrodes was further investigated by assembling symmetrical Sb| | Sb batteries, where GCD tests were conducted at a constant current density of 1 mA cm’2and plating capacity of 1 mAh cm’2. As shown in FIG. 14, the symmetrical Sb| | Sb cell exhibited stable GCD curves with a small voltage gap (polarization) of 0.08 V. There were no voltage fluctuations or short-circuits after 5000 hours, indicating stable antimony plating / stripping.

[0102] The structural changes of the Sb electrodes after cycling were analyzed by X-ray diffraction. As shown in FIG. 15, there were no obvious changes in the peak diffraction positions or intensities, suggesting high structural integrity of the Sb electrode in 1 m SbCh with 10 m LiCl. This data provided further support for the long cycling performance in the symmetrical batteries.

[0103] The reaction kinetics of the Sb electrode were further investigated by performing a rate capability experiment, where various current densities were used with a constant plating capacity of 1.0 mA cm’2. As shown in FIG. 16, the polarization was 59 mV, 70 mV, 74 mV, 85 mV, 94 mV, 120 mV, 148 mV, and 178 mV at the current densities of 0.5 mA cm’2, 1 mA cm’2, 2 mA cm’2, 4 mA cm’2, 8 mA cm’2, 10 mA cm’2, 20 mA cm’2, and 30 mA cm’2, respectively. Even at an ultrahigh current density of 50 mA cm’2, the polarization remained low at 219 mV. Therefore, the antimony metal may be utilized for fast-charging and high-power battery applications.Electrochemical Performance with Sb\ Ti Battery

[0104] To further examine the performance of 1 m SbCh with 10 m LiCl and the efficiency of the Sb||Ti battery, GCD tests were performed at a higher current density of 2 mA cm’2while keeping the capacity constant at 1 mAh cm’2. As shown in FIG. 17, the first-cycle efficiency was 93.4%, and the subsequent efficiency was about 99.3%. As demonstrated in FIG. 18, the Coulombic efficiency of the Sb||Ti battery with a current density of 2.0 mA cm’2and area capacity of 1.0 mAh cm’2experienced a gradual increment in the first 50 cycles and stabilized afterward. The average Coulombic efficiency was 99.7% over 1500 cycles, which exceeded the Coulombic efficiency using 1 mA cm’2current density.

[0105] The effect of further increasing the current density to 4.0 mA cm’2was also studied, while keeping the capacity at 1 mAh cm’2. As shown in FIG. 19, the average CoulombicAtty. Dkt. No. 118347-0141 (25-002-UPR)efficiency was 99.8%. This data indicated that further increasing current density had no considerable impact on the efficiency.

[0106] Taken together, these results indicated that the Sb electrode may realize high efficiency at high current rates, which is promising for high-power battery applications.Example 8: Use of Sb Electrode as Anode

[0017] The Sb electrode showed a moderate redox potential of about 0.1 V vs. standard hydrogen electrode (SHE), which may be used as both an anode and cathode material depending on the choice of the counter electrodes. Sb was used as a metal anode and paired with manganese oxide (MnCh) for a fuel cell.Synthesis and Characterization ofMnCh Cathode

[0108] P-phase MnCh was synthesized by a hydrothermal method. The crystal structure was determined using XRD. As shown in FIG. 20, the diffraction peaks were well indexed to the P-phase MnCh phase (PDF# 24-0735) with a space group of P42 / mnm. There were no additional XRD peaks, suggesting a high phase purity.

[0109] The MnCh material was imaged using SEM. As shown in FIG. 21, the SEM image of the synthesized MnCh material showed well-defined and uniformly distributed nanowirelike morphology. The particles were about 10 pm in length and had a diameter of about 500 nm.Assembly and Characterization of Sb\ Mn(h Batteries

[0011] The Sb||MnC>2 batteries were assembled in a two-electrode cell configuration in the 1 m SbCh withlO m LiCl electrolyte. As depicted in FIG. 22, the Sb||MnC>2 battery almost stabilized in the 2nd cycle, delivering a high discharge capacity of 314 mAh g'1. The theoretical capacity ofMnCh is 308 mAh g'1based on the one-electron Mn4+ / Mn3+process, which closely aligned with the observed discharge capacity. There was a moderately flat plateau at 0.62 V during discharge. Considering the theoretical capacity of the cathode (308 mAh g'1), anode (660 mAh g'1), and the cell voltage (0.62 V), the theoretical energy density was calculated as about 130 Wh kg'1based on the active masses of two electrodes.Atty. Dkt. No. 118347-0141 (25-002-UPR)

[0111] The rate capability of Sb||MnC>2 batteries was also studied. As shown in FIG. 23, the discharge capacity was about 309 mAh g’1, 264 mAh g’1, 235 mAh g’1, and 215 mAh g'1at the current density of 2.7 A g’1, 4.0 A g’1, 5.3 A g’1, and 6.7 A g’1, respectively. Even at a high current density of 10 A g’1, the battery maintained a capacity of 185 mAh g’1, which corresponded to about 60% capacity utilization.[01121 The long-term cycling performance of Sb||MnC>2 batteries was also studied. The cycling performance of the Sb||MnC>2 battery was studied at 6.7 A g'1. FIG. 24 shows that the Sb||MnC>2 battery demonstrated 79% capacity retention over 20,000 cycles.

[0113] The Sb anode was also used with an LiMnCh cathode. The Sb||MnC>2 battery was assembled and used 1 m SbCh with 10 m LiCl electrolyte.

[0114] As shown in FIG.25, the Sb||LiMnC>2 battery demonstrated a first discharge capacity of 317 mAh g'1and subsequently demonstrated a discharge capacity of 127 mA g'1in the 2ndcycle.Example 9: Use of Sb Electrode as Cathode

[0115] The Sb electrode showed a moderate redox potential of about 0.1 V vs. standard hydrogen electrode (SHE), which could be used as both an anode and cathode material depending on the choice of the counter electrodes. Sb was used as a cathode in a dual-metal Zn| | Sb battery, where both the cathode and anode work on the multivalent-electron Sb3+ / Sb and Zn2+ / Zn plating reactions. The catholyte was 1 m SbCh with 10 m LiCl, whereas the anolyte was 1 M ZnCh with 15 m LiCl. These two electrolytes were further separated by a salt bridge (KC1 and agar in a 1:3 weight ratio) to prevent them from mixing. During the cell operation, the chloride anions in the salt bridge shuttled between the cathode and anode, thus maintaining the charge balance.

[0116] As shown in FIG. 26, the Zn| | Sb battery exhibited stable and overlapped GCD curves, with a discharge voltage of about 0.9 V and a charge voltage of about 1.0 V. This data indicated that a promising energy efficiency of about 90% may be achieved.

[0117] To determine the specific capacity of the Sb electrode, the charging performance of the Zn| | Sb battery was tested. As shown in FIG. 27, a high capacity of 638 mAh g'1Atty. Dkt. No. 118347-0141 (25-002-UPR)was obtained, which is close to the theoretical capacity of Sb (660 mAh g'1), thus indicating the three-electron transfer reaction of the Sb electrode.[0118) The rate capability of the Zn| | Sb battery was also studied. As shown in FIG. 28, the discharge voltage was 0.932 V, 0.930 V, 0.922 V, 0.914 V, 0.907 V, 0.901 V, 0.897 V, 0.884 V, 0.863 V, and 0.844 V at current density values of 10 pA cm’2, 25 pA cm’2, 50 pA cm’2, 75 pA cm’2, 100 pA cm’2, 125 pA cm’2, 150 pA cm’2, 200 pA cm’2, 300 pA cm’2, and 400 pA cm’2, respectively. The round-trip energy efficiency was thus calculated as 0.996, 0.973, 0.957, 0.944, 0.930, 0.918, 0.909, 0.901, 0.855, and 0.839, respectively.

[0119] The Zn| | Sb battery also demonstrated long-term stability. FIG. 29 shows the long cycling of the Zn| | Sb battery at the current density of 125 pAcm'2, which demonstrated a stable and reversible redox of Zn2+ / Zn and Sb3+ / Sb for 3500 hours.EQUIVALENTS

[0120] 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, compositions, derivatives, and mixtures 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.[01211 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 withAtty. Dkt. No. 118347-0141 (25-002-UPR)the breadth, scope and spirit of the present technology indicated only by the appended claims, definitions therein and any equivalents thereof.

[0122] 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.[0123 J 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.

[0124] 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 non-limiting 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.Atty. Dkt. No. 118347-0141 (25-002-UPR)

[0125] All publications, patent applications, issued patents, and other documents (for example journals, 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.

[0126] 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:a first electrode comprising antimony metal;a second electrode; anda first electrolyte comprising(a) about 0.5 m to about 1.5 m SbCh, about 7 m to about 15 m LiCl, and water;(b) about 0.5 m to about 1.5 m SbCh, about 7 m to about 15 m NH4Q, and water; or(c) about 0.5 m to about 1.5 m SbCh and ethanol.B. The electrochemical cell of Paragraph A, wherein Sb3+is charge carrier in the electrochemical cell.C. The electrochemical cell of Paragraph A or Paragraph B, wherein the first electrolyte comprises about 1 m SbCh, about 10 m LiCl, and water.D. The electrochemical cell of any one of Paragraphs A-C, wherein the first electrode comprises an antimony metal powder, conductive carbon, and a binder.E. The electrochemical cell of Paragraph D, wherein the antimony metal powder comprises particles having a diameter of about 1 pm to about 150 pm.Atty. Dkt. No. 118347-0141 (25-002-UPR)F. The electrochemical cell of Paragraph D or Paragraph E, wherein a weight ratio of the antimony metal powder, the conductive carbon, and the binder is about 8:1:1.G. The electrochemical cell of any one of Paragraphs D-F, wherein the binder comprises polytetrafluoroethylene (PTFE).H. The electrochemical cell of any one of the preceding claims, whereinthe second electrode comprises an inorganic active cathode material; and the electrochemical cell further comprises a separator disposed between the first electrode and the second electrode.I. The electrochemical cell of Paragraph H, wherein the inorganic active cathode material comprises MnCh.J. The electrochemical cell of Paragraph H or Paragraph I, further comprising a housing in which the first electrode, second electrode, separator, and first electrolyte are disposed.K. A method of forming the electrochemical cell of any one of Paragraphs H-J, the method comprising disposing the first electrode, the second electrode, and the separator in the first electrolyte to form the electrochemical cell.L. A method of operating the electrochemical cell of any one of Paragraphs H-J, the method comprising cycling the electrochemical cell at about 6.7 A g'1for at least 10,000 cycles with a specific capacity of about 150 mAh g'1to about 200 mAh g'1.M. The electrochemical cell of any one of Paragraphs A-G, whereinthe second electrode comprises zinc metal; andthe electrochemical cell further comprisesa first electrode chamber to hold the first electrode and the first electrolyte;a second electrode chamber to hold the second electrode and a second electrolyte;the second electrolyte comprising about 0.5 m to about 1.5 m ZnCh, about 2 m to about 15 m Li Cl, and water; andAtty. Dkt. No. 118347-0141 (25-002-UPR)an anion-exchange component to exchange Cl’ between the first electrode chamber and the second electrode chamber.N. The electrochemical cell of Paragraph M, wherein the second electrolyte comprises about 1 m ZnCh, about 15 m LiCl, and water.O. The electrochemical cell of Paragraph M or Paragraph N, wherein the anion-exchange component comprises a salt bridge.P. A method of forming the electrochemical cell of any one of Paragraphs M-O, the method comprisingdisposing the first electrode and the first electrolyte in the first electrode chamber;disposing the second electrode and the second electrolyte in the second electrode chamber; andionically coupling the first electrode chamber and the second electrode chamber with the anion-exchange component.Q. A method of operating the electrochemical cell of any one of Paragraphs M-O, the method comprising cycling the electrochemical cell at about 125 pA cm’2for at least 3500 hours with a Coulombic efficiency of at least 90%.[0127 J Other embodiments are set forth in the following claims, along with the full scope of equivalents to which such claims are entitled.

Claims

Atty. Dkt. No. 118347-0141 (25-002-UPR)WHAT IS CLAIMED IS:

1. An electrochemical cell comprising:a first electrode comprising antimony metal;a second electrode; anda first electrolyte comprising(a) about 0.5 m to about 1.5 m SbCh, about 7 m to about 15 m LiCl, and water;(b) about 0.5 m to about 1.5 m SbCh, about 7 m to about 15 m NH4Q, and water; or(c) about 0.5 m to about 1.5 m SbCh and ethanol.

2. The electrochemical cell of Claim 1, wherein Sb3+is charge carrier in the electrochemical cell.

3. The electrochemical cell of Claim 1, wherein the first electrolyte comprises about 1 m SbCh, about 10 m LiCl, and water.

4. The electrochemical cell of Claim 1, wherein the first electrode comprises an antimony metal powder, conductive carbon, and a binder.

5. The electrochemical cell of Claim 4, wherein the antimony metal powder comprises particles having a diameter of about 1 pm to about 150 pm.

6. The electrochemical cell of Claim 4, wherein a weight ratio of the antimony metal powder, the conductive carbon, and the binder is about 8:1:1.

7. The electrochemical cell of Claim 4, wherein the binder comprises polytetrafluoroethylene (PTFE).

8. The electrochemical cell of any one of Claims 1-7, whereinthe second electrode comprises an inorganic active cathode material; and the electrochemical cell further comprises a separator disposed between the first electrode and the second electrode.

9. The electrochemical cell of Claim 8, wherein the inorganic active cathode material comprises MnCh.Atty. Dkt. No. 118347-0141 (25-002-UPR)10. The electrochemical cell of Claim 8, further comprising a housing in which the first electrode, second electrode, separator, and first electrolyte are disposed.

11. A method of forming the electrochemical cell of Claim 8, the method comprising disposing the first electrode, the second electrode, and the separator in the first electrolyte to form the electrochemical cell.

12. A method of operating the electrochemical cell of Claim 8, the method comprising cycling the electrochemical cell at about 6.7 A g’1for at least 10,000 cycles with a specific capacity of about 150 mAh g’1to about 200 mAh g’1.

13. The electrochemical cell of any one of Claims 1-7, wherein the second electrode comprises zinc metal;the electrochemical cell further comprisesa first electrode chamber to hold the first electrode and the first electrolyte; a second electrode chamber to hold the second electrode and a second electrolyte;the second electrolyte comprising about 0.5 m to about 1.5 m ZnCh, about 2 m to about 15 m LiCl, and water; andan anion-exchange component to exchange Cl’ between the first electrode chamber and the second electrode chamber.

14. The electrochemical cell of Claim 13, wherein the second electrolyte comprises about 1 m ZnCh, about 15 m LiCl, and water.

15. The electrochemical cell of Claim 13, wherein the anion-exchange component comprises a salt bridge.

16. A method of forming the electrochemical cell of Claim 13, the method comprising disposing the first electrode and the first electrolyte in the first electrode chamber;disposing the second electrode and the second electrolyte in the second electrode chamber; andionically coupling the first electrode chamber and the second electrode chamber with the anion-exchange component.Atty. Dkt. No. 118347-0141 (25-002-UPR)17. A method of operating the electrochemical cell of Claim 13, the method comprising cycling the electrochemical cell at about 125 pA cm'2for at least 3500 hours with a Coulombic efficiency of at least 90%.

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