Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M6/00—Primary cells; Manufacture thereof
  • H01M6/04—Cells with aqueous electrolyte
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/05—Accumulators with non-aqueous electrolyte
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/05—Accumulators with non-aqueous electrolyte
  • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
  • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/36—Accumulators not provided for in groups H01M10/05-H01M10/34
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M6/00—Primary cells; Manufacture thereof
  • H01M6/04—Cells with aqueous electrolyte
  • H01M6/045—Cells with aqueous electrolyte characterised by aqueous electrolyte
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M2300/00—Electrolytes
  • H01M2300/0002—Aqueous electrolytes
  • H01M2300/0005—Acid electrolytes
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
  • Y02E60/10—Energy storage using batteries

Definitions

• the field of the invention is batteries and battery electrolytes.
• Zn/C batteries zinc is frequently employed in primary batteries. Such batteries are typically found in many simple flashlight batteries to provide a relatively inexpensive and reliable power source. Although manufacture of Zn/C batteries is typically simple and poses only relatively little environmental impact, various disadvantages of Zn/C batteries exist. Among other things, the ratio of power to weight in commonly used Zn C batteries is relatively poor.
• zinc air battery systems may be employed in applications where a favorable ratio of weight to capacity is particularly important.
• atmospheric oxygen is used as a gaseous coupling partner for zinc, which is typically provided in form of gelled zinc powder anodes.
• air i.e., oxygen
• coupling partner for zinc significantly reduces weight.
• reasonable shelf life of such batteries can often only be achieved by using an airtight seal.
• air must have an unobstructed path through the battery to the cathode so that the oxygen in the air is available to discharge the cathode.
• commercial applications of zinc-air batteries have previously been limited to primary or non-rechargeable types.
• zinc may form a redox pair with nickel to provide a rechargeable redox system.
• rechargeable zinc/nickel batteries frequently exhibit a relatively good power to weight ratio, several problems of the zinc/nickel redox pair persist. Among other difficulties, such batteries tend to have a comparably poor cycle life of the zinc electrode.
• nickel is known to be a carcinogen in water-soluble form, and is thus problematic in production and disposal.
• zinc may be combined with silver oxide to form a secondary battery.
• Rechargeable zinc/silver batteries often have a relatively high energy and power density. Moreover, such batteries typically operate efficiently at extremely high discharge rates and generally have a relatively long dry shelf life.
• the comparably high cost of the silver electrode generally limits the use of zinc/silver batteries to applications where high energy density is a prime requisite.
• nickel/cadmium batteries are typically inexpensive to manufacture, exhibit a relatively good power to weight ratio, and require no further maintenance other than recharging.
• cadmium is a known toxic element, and thereby further increases the problems associated with health and environmental hazards.
• the present invention is directed to a battery comprising an electrolyte that contacts the anode and includes a redox pair formed by a first element and a second element, wherein the battery is charged at a voltage sufficient to plate the first element at the anode, and wherein the voltage is insufficient to plate the second element on the anode when the second element is present at the anode.
• Especially contemplated batteries are secondary batteries that comprise a mixed electrolyte.
• Especially preferred redox pairs provide an open circuit voltage of at least 2.3 Volt per cell.
• contemplated electrolytes are acid electrolytes, and it is particularly preferred that such electrolytes comprise an organic acid (e.g., methane sulfonic acid, trifluoromethane sulfonic acid) or inorganic acid (e.g., perchloric acid, nitric acid, hydrochloric acid, or sulfuric acid), wherein the anion of the acid forms a complex (e.g., salt) with at least one of the first and second element.
• suitable electrolytes may also be gelled.
• contemplated first elements particularly include zinc and/or titanium
• preferred second elements include lanthanides (e.g., cerium, praseodymium, neodymium, terbium, or dysprosium).
• contemplated batteries may include a separator that separates a battery cell into an anode compartment and a cathode compartment, wherein the anode compartment comprises an anolyte that includes the first element, wherein the cathode compartment that comprises a catholyte that includes the second element, and wherein the anode compartment comprises at least 5vol% catholyte, more preferably at least 10vol% catholyte, and most preferably least 25vol% catholyte.
• Figure 1 A is a schematic view of an exemplary battery during discharge.
• Figure IB is a schematic view of an exemplary battery during charge.
• a battery may comprise an electrolyte that contacts the anode and includes a redox pair formed by a first element and a second element, wherein the battery is charged at a voltage sufficient to plate the first element at the anode, and wherein the voltage is insufficient to plate the second element on the anode when the second element is present at the anode.
• a secondary battery may comprising a mixed electrolyte that includes a redox pair formed by a first element and a second element.
• first element refers to a chemical element that may be in ionic form as well as in non-ionic form.
• a preferred first element is zinc, which may be present as metallic (e.g., plated) zinc as well as ionic zinc (e.g., as Zn in a salt with an anion of an acid).
• second element refers to a chemical element that may be in ionic form as well as in non-ionic form.
• a preferred second element is cerium, which may be present in a first ionic form (e.g.
• the first and second elements are chemically distinct, i.e., are not the same chemical element in a different oxidation state.
• the term "redox pair” is interchangeably used with the term “redox couple” and refers to a combination of the first element (or ion of the first element) and the second element (or ion of the second element) in a battery, in which reduction of one element and oxidation of the other element produce the current provided by the battery.
• the term "the battery is charged” refers to a process in which one element is reduced and the other element is oxidized by providing an electric current such that after charging reduction of one element and oxidation of the other element produces a current in the battery.
• the electrochemical redox reactions in the battery during discharge are reversed during charging by providing electric current to the battery.
• anode refers to the negative electrode of a battery (i.e., the electrode where oxidation occurs) during discharge of the battery.
• anode compartment refers to the battery compartment that includes the anode
• anolyte refers to the electrolyte in the anode compartment.
• cathode refers to the positive electrode of a battery (i.e., the electrode where reduction occurs) during discharge of the battery.
• cathode compartment refers to the battery compartment that includes the cathode
• catholyte refers to the electrolyte in the cathode compartment.
• the term “plate the first element at the anode” means that the first element is reduced at the anode by a current (during charging) at a particular voltage from an ionic species to a non-ionic species.
• plat will refer to electrochemical deposition of the element as well as to electrochemical gas formation if the element is in gas form under standard conditions (20°C, atmospheric pressure) when in an non-ionic state.
• mixed electrolyte refers to an electrolyte in which the first and second element are present in the same compartment (i.e., anode and/or cathode compartment) under normal operating conditions.
• normal operating condition refers to repeated (i.e., at least 10) charge/discharge cycles and specifically excludes operation during which a separator has been accidentally perforated (e.g., during charging).
• a battery will comprise methane sulfonic acid as acid electrolyte in which cerium and zinc form a redox couple, and in which the anion of the methane sulfonic acid will form a complex with the cerium and zinc ions.
• cerium-zinc redox couples have an open circuit voltage of at least 2.3 Volt, and more typically 2.40 to 2.46 Volt, which is superior to numerous known zinc-based redox couples.
• plated non-ionic zinc metal will be dissolved from the anode into the electrolyte during discharge of the battery and re-plated onto the electrode during charging following the equation (I) below.
• cerium ions will donate/receive electrons following the equation (H) below.
• cerium-zinc redox pair will have numerous advantages over other known redox pair configuration.
• the inventors discovered that such cerium-zinc redox pairs (and other redox couples) may be operated in a battery, and especially in a secondary battery, without a separator or with a separator that allows at least partial mixing of the anode and cathode electrolyte.
• battery 100A includes a cell 110A that is at least partially divided by separator 140A into an anode compartment 120A and a cathode compartment 130A.
• Both anode and cathode compartment include methane sulfonic acid as acid electrolyte, wherein the anion of the acid (MSA ' ) complexes the ionic forms of zinc (2 + ) and cerium (3V4*).
• the anode compartment 120 A further comprises anode 122 A that is at least partially covered by non- ionic plated metallic zinc (Zn°).
• the cathode compartment 130A comprises cathode 132A.
• Anode 122A and cathode 132A are electrically coupled to the load 150A, and the arrow above the load indicates the flow of the electrons from the anode to the cathode during discharge.
• Figure IB depicts an exemplary battery during charge.
• the battery 100B includes a cell HOB that is at least partially divided by separator 140B into an anode compartment 120B and a cathode compartment 13 OB.
• Both anode and cathode compartments include methane sulfonic acid as acid electrolyte, wherein the anion of the acid (MSA " ) complexes the ionic forms of zinc (2 ) and cerium (3 + /4 + ).
• the anode compartment 120B further comprises anode 122B that is at least partially covered by non- ionic plated metallic zinc (Zn°).
• the cathode compartment 130B comprises cathode 132B.
• Anode 122B and cathode 132B are electrically coupled to the power source 150A, and the arrow above the power source indicates the flow of the electrons during charging of the battery.
• secondary batteries having an electrolyte with contemplated redox pairs may be charged in a configuration where anolyte (i.e. , electrolyte in the anode compartment) and catholyte (i.e., electrolyte in the cathode compartment) may be at least partially mixed in at least one compartment. Consequently, it is contemplated that batteries according to the inventive subject matter may or may not have a separator.
• the separator separates a cell into an anode compartment and a cathode compartment, wherein the anode compartment comprises an anolyte that includes the first element, and wherein the cathode compartment that comprises a catholyte that includes the second element.
• the separator may be configured (by design or by incidental perforation of the separator) such that the anode compartment comprises at least 5vol% catholyte, more typically at least 10vol% catholyte, and most typically at least 25vol% catholyte.
• separators include membranes that allow flow of hydrogen/H + ions across the membrane.
• membranes There are numerous such membranes known in the art, and all of those are deemed suitable for use in conjunction with the teachings presented herein.
• a particularly preferred membrane includes a Nafion® membrane (Perfluorosulfonic acid - PTFE copolymer in the acid form; commercially available from DuPont, Fayetteville, NC).
• suitable elements may include various elements other than zinc, and a particularly preferred alternative element is titanium.
• suitable elements include lead, mercury, cadmium, and/or tin.
• the second element need not be limited to cerium, and numerous alternative elements are also considered suitable for use herein.
• Especially suitable alternative elements include lanthanides. Many lanthanides are known to exhibit similar physico-chemical and electrochemical properties among each other.
• first and second elements may form a redox pair with zinc (or any other first element) in contemplated batteries: Lanthanum, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium and/or ytterbium. Further contemplated aspects of alternative first and second elements are disclosed in the PCT patent application entitled “Lanthanide Batteries", filed on or about Robert Lewis Clarke, Brian J. Dougherty, Stephen Harrison, J. Peter Millington and Samaresh Mohanta, which was filed on or about February 12, 2002, which is incorporated herein by reference.
• first and second elements are deemed suitable, in which during charging the first element has a reduction potential between a first and a second reduction state (e.g., between 4 + and 2 + , or between 1 + and 0) that is more positive than the reduction potential between a first and a second reduction state of the second element.
• a reduction potential between a first and a second reduction state (e.g., between 4 + and 2 + , or between 1 + and 0) that is more positive than the reduction potential between a first and a second reduction state of the second element.
• preferred first elements will reduced on the battery anode during charging at a charging voltage, while the second element is not reduced, and more preferably not plated (i.e., reduced to non-ionic state) at the anode at the same charging voltage.
• the electrolyte may also be gelled, and that preferred gelled electrolytes include one or more anions of an organic or inorganic acid.
• preferred gelled electrolytes include one or more anions of an organic or inorganic acid.
• the cerium ion concentration may vary considerably and may generally be in the range of between one micromolar (and even less) and the maximum saturation concentration of the particular cerium ion. However, it is preferred that the cerium ion concentration in the electrolyte is at least 0.2M, more preferably at least 0.5M, and most preferably at least 0.7M. Viewed from another perspective, it is contemplated that preferred cerium ion concentrations lie within 5-95% of the solubility maximum of cerium ions in the electrolyte at a pH ⁇ 7 and 20°C.
• cerium ions may be introduced into the electro- lyte in various forms. However, it is preferred that cerium ions are added to the electrolyte solution in form of cerium carbonate, numerous alternative forms, including cerium hydrate, cerium acetate, or cerium sulfate are also contemplated. Similarly, the concentration of zinc ions in the electrolyte is at least 0.3M, more preferably at least 0.8M, and most preferably at least 1.2M. With respect to the particular form of zinc addition to - l i the electrolyte, the same considerations as described above apply. Thus, contemplated zinc forms include ZnCO 3 , ZnAcetate, Zn(NO ) 2 , etc.
• the electrolyte is an acid electrolyte and comprises an organic acid.
• organic acids include those that are able to dissolve eerie ions, cerous ions and zinc ions at a relatively high concentration (e.g., greater than 0.2M, more preferably greater than 0.5M, and most preferably greater than 0.7M), and an especially suitable organic acid is methane sulfonic acid (MSA).
• alternative organic acids also include trifluoromethane sulfonic acid (CF 3 S0 H), which is thought to make a better solvent anion than methane sulfonic acid for eerie ions.
• Still further contemplated acids include inorganic acids such as perchloric acid (HClO 4 ), nitric acid, hydrochloric acid (HC1), or sulfuric acid (H 2 S0 4 ).
• inorganic acids such as perchloric acid (HClO 4 ), nitric acid, hydrochloric acid (HC1), or sulfuric acid (H 2 S0 4 ).
• H 2 S0 4 sulfuric acid
• any Bronsted acid (a compound that donates a hydrogen ion (H + ) to another compound) may be employed as counter ion in the electrolyte.
• concentration of the MSA or other acid it should be appreciated that the concentration of MSA or other acid is not limiting to the inventive subject matter. However, a particularly preferred concentration of methane sulfonic acid is in the range of between IM and 4M, and more preferably between 2.5M and 3.5M. In further alternative aspects of the inventive subject matter, it is contemplated that EDTA or alternative chelating agents could replace at least a portion, if not all of the methane sulfonic acid in at least the zinc cathode part of the cell.
• a battery will include an electrolyte in which a first element Ei and a second element E 2 form a redox pair, and in which the redox reaction will follow equation (HI)
• E, x + E 2 y E, x+n + E 2 y - n (HI)
• E ⁇ x is the first element having electric charge of x
• E 2 y is the second element having an electric charge of y
• E ⁇ x+n is the first element having electric charge of x increased (i.e., made more positive) by n electrons donated to the anode during discharge
• E 2 y n is the second element having electric charge of x decreased (i.e., made more negative) by n electrons received at the cathode during discharge, and wherein during charging:
• first and second elements and particularly lanthanides as first elements and zinc or titanium as second elements are contemplated that will follow equation (III) and have the order of reduction potentials as indicated above.
• Indium is added to the electrolyte to significantly increase the hydrogen overpotential. Addition of Indium is thought to act as a barrier to hydrogen evolution, thereby forcing zinc deposition upon charging of the battery. While addition of indium to alkaline electrolytes has been previously shown to reduce hydrogen the hydrogen ove ⁇ otential, the inventors su ⁇ risingly discovered that zinc deposition in an acid electrolyte in the presence of indium ions was almost 95% efficient compared to 70- 80% without indium (at less than 1% substitution of indium ions for zinc ions in the electrolyte).
• suitable batteries may be configured in a battery stack in which a series of battery cells are electrically coupled to each other via a bipolar electrode.
• the particular nature of the bipolar electrode is not limiting to the inventive subject matter, and it is generally contemplated that any material that allows for oxidation of cerous ions to eerie ions during charging (and the reverse reaction during discharge) is suitable for use herein.
• a particularly preferred material for a bipolar electrode is glassy carbon.
• glassy carbon provides, despite operation in a highly acidic electrolyte, an excellent substrate for plating of zinc during charging.
• glassy carbon is a relatively inexpensive and comparably light-weight material, thereby further improving the ratio of cost/weight to capacity.
• a Nation® membrane may operate more satisfactorily than other membranes, it is generally contemplated that the exact physical and/or chemical nature of the membrane is not limiting to the inventive subject matter so long as such membranes allow H+ exchange between an anode and cathode compartment in contemplated acidic electrolytes. Consequently, it should be appreciated that numerous alternative membranes other than Nafion are also suitable, and exemplary membranes include all known solid polymer electrolyte membranes, or similar materials.
• membranes are suitable for use even if such membranes exhibit some leakage or permeability for catholyte and/or anolyte into the opposite compartment, since contemplated batteries are operable even under conditions in which the electrolytes are mixed.
• contemplated batteries are typically limited only by the supply of the anolyte and catholyte. Consequently, it is contemplated that a particular capacity of such batteries will predominantly be determined by a particular type of application.
• contemplated anolyte and catholyte volumes may be between about 0.5ml and 5ml.
• contemplated anolyte and catholyte volumes may be between about 50ml and 3000ml.
• contemplated anolyte and catholyte volumes may be between about 5m 3 and
• a cell was built by using two blocks of plastic Ultra High Molecular Weight Polyethylene (UHMWP), with gaskets in between each face, two electrodes, and a Nafion® membrane that separated the cell into two compartments. Electrolyte inlets were formed in the top and bottom portion of each compartment; the electrolyte was introduced into the compartment via the bottom inlet and exited the cell from the top.
• the anode compartment solution contained 193 grams/liter Ce 2 (C0 ) 3 *5H 2 0, 97 g/1 ZnO , 1000 g/1 methanesulfonic acid (MSA) and 193 g/1 of water.
• the cathode compartment solution contained 193 g/1 Ce 2 (C0 3 ) 3 *5H 2 0, 65 g/1 ZnO, 1000 g/1 methanesulfonic acid and 190 g/1 of water.
• the cathode compartment solution was fed to the cathode made of platinum-coated titanium mesh, and the anode compartment solution was fed to a anode made of carbon.
• the cell gap was 1.7 cm, flow rate about 1.7 liter per minute.
• the cell was charged at 4 A (current density is 40 mA/cm ) for three hours.
• the voltage across the cell during charging at 4 A was 3.1 to 3.2 V.
• the initially colorless cathode compartment solution turned yellow during charging, indicating the conversion of cerous ions (Ce 3+ ) to eerie ions (Ce 4+ ).
• the efficiency of this reaction was almost 100%; the zinc ions (Zn 2+ ) did not react with either the Ce 3+ or Ce 4+ , and were not oxidized at the electrode.
• Zinc was deposited as a smooth, light gray deposit from the anode compartment solution.
• the Ce 3+ ions were not reduced at the electrode. Furthermore, very little gassing at either the negative or positive electrode was observed during the charging process.
• the open circuit voltage maximum was 2.4 V.
• the cell was discharged at a constant voltage of 1.8 V.
• the intensity of the yellow color of the electrolyte decreased, indicating that Ce 4+ was being converted to Ce 3+ .
• No deposits were observed on the cathode, indicating that no zinc was being plated.
• zinc was dissolved into the electrolyte, but the solution remained colorless, indicating that Ce 3+ was not being converted to Ce 4+ .
• the cell was recharged/discharged for several more cycles without substantial loss of performance.
• contemplated batteries may operated under conditions where inadvertent mixing of the electrolytes in the anode compartment and the cathode compartment will not substantially reduce battery, and especially electrode performance.
• the redox element in the cathode compartment will substantially not plate on the anode when (inadvertently or by design) present at the anode (i.e., less than 10%, more typically less than 5%, and most typically less than 1% of the total redox element of the cathode compartment present at the anode will plate at the anode over at least 10 charge/discharge cycles).
• the redox element in the anode compartment will substantially not plate on the cathode when (inadvertently or by design) present at the cathode (i.e., less than 10%, more typically less than 5%, and most typically less than 1% of the total redox element of the anode compartment present at the cathode will plate at the cathode over at least 10 charge/discharge cycles).

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• 2001
  • 2001-08-10 WO PCT/US2001/041678 patent/WO2003017407A1/fr active Application Filing
• 2002
  • 2002-02-12 EP EP02717450A patent/EP1415354B1/fr not_active Expired - Lifetime
  • 2002-02-12 WO PCT/US2002/004740 patent/WO2003017397A1/fr not_active Application Discontinuation
  • 2002-02-12 PT PT02719005T patent/PT1415358E/pt unknown
  • 2002-02-12 WO PCT/US2002/004738 patent/WO2003017394A1/fr not_active Application Discontinuation
  • 2002-02-12 ES ES02719005T patent/ES2306761T3/es not_active Expired - Lifetime
  • 2002-02-12 DE DE60226147T patent/DE60226147T2/de not_active Expired - Lifetime
  • 2002-02-12 EP EP02719005A patent/EP1415358B1/fr not_active Expired - Lifetime
  • 2002-02-12 DK DK02719005T patent/DK1415358T3/da active
  • 2002-02-12 WO PCT/US2002/005145 patent/WO2003017408A1/fr not_active Application Discontinuation
  • 2002-02-12 AT AT02717450T patent/ATE496400T1/de not_active IP Right Cessation
  • 2002-02-12 WO PCT/US2002/004749 patent/WO2003017395A1/fr not_active Application Discontinuation
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  • 2002-02-12 DE DE60238988T patent/DE60238988D1/de not_active Expired - Lifetime
  • 2002-02-12 EP EP02709571A patent/EP1415357A4/fr not_active Withdrawn

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