Abstract: A zinc air battery, and preferably a secondary zinc air battery has an acid electrolyte in which the anionic form of an acid forms a complex with a zinc ion, and wherein the acid in the electrolyte reduces dendrite formation.

Abstract: A battery (100B) comprises an electrolyte in which a first element forms a redox pair with a second element, wherein the battery (100B) is charged at a voltage sufficient to plate the first element at the anode (122B) and wherein the voltage is insufficient to plate the second element on the anode (122B). Preferred batteries include secondary batteries comprising a mixed electrolyte that includes a redox pair formed by a first element and a second element.

Abstract: Contemplated devices and methods for arsenic recovery employ a two-step process in which an arsenite and arsenate-containing solution is first subjected to a non-electrochemical reduction that reduces arsenate and arsenite. The arsenate-depleted arsenite-containing solution is the subjected to electrochemical reduction at alkaline pH using a cathode with a high-surface carbon portion. Most preferably, the treated solution is then used as eluent for an adsorbent that removed arsenate and arsenite from a water supply.

Abstract: Contemplated devices and methods include an electrolytic cell having a cathode and a carbon felt anode, wherein the carbon felt anode is configured as a flow-through anode for an aqueous solution in which a contaminant is dissolved or dispersed. The cell is operated at a current density that promotes formation of oxidizing species in neutral pH to thus destroy the contaminant and at a flow rate sufficient to prevent oxidative damage of the carbon felt.

Abstract: Devices and methods are presented for removal and destruction of nitrate from water using an ion exchange medium from which the nitrate is eluted using brine, and in which the so generated eluent is sequentially reduced and oxidized in distinct compartments to form nitrogen from nitrate and ammonia, respectively. In especially preferred devices and methods, the reduced and oxidized eluent is re-reduced to electrochemically destroy hypohalites formed during oxidation. Among other advantages, contemplated devices and methods allow nitrate destruction with minimal concomitant production of nitrite and hypohalites.

Abstract: Perchlorate is removed and effectively destroyed in devices and methods that employ a eluting solvent in which the anion of an acid solubilizes Ti (III), which may be electrochemically generated or added in situ. Using such solvents, destruction of perchlorate is unexpectedly and several orders of magnitude faster than using solvents without solubilizing acids. In most preferred aspects, the solubilizing acid is methane sulfonic acid and/or sulfamic acid, and Ti (III) is electrochemically generated. Perchlorate destruction will then result in formation of Ti (IV), which may be present in the eluent in a subsequent elution.

Abstract: An electric device comprises a gelled acid electrolyte in complex with a lanthanide that forms a redox pair with a second element. Preferred electric devices include batteries, and especially primary batteries, while preferred acid electrolytes have a sulfonic acid group. Contemplated lanthanides especially include cerium, and preferred second elements particularly include zinc. Alternatively, contemplated electric devices may comprise a gelled electrolyte in which with a lanthanide forms a redox pair with zinc.

Abstract: Perchlorate is removed and effectively destroyed in devices and methods that employ a eluting solvent in which the anion of an acid solubilizes Ti (III), which may be electrochemically generated or added in situ. Using such solvents, destruction of perchlorate is unexpectedly and several orders of magnitude faster than using solvents without solubilizing acids. In most preferred aspects, the solubilizing acid is methane sulfonic acid and/or sulfamic acid, and Ti (III) is electrochemically generated. Perchlorate destruction will then result in formation of Ti (IV), which may be present in the eluent in a subsequent elution.

Abstract: A metal hydroxide complex has a formula Me(OH)4*A?*nH2O or MeO2*A?*nH2O. Preferred complexes are formed in an alkaline medium, and particularly especially preferred anions include cyanide and cyanide gold complexes. Contemplated complexes are formed on a metal hydroxide (e.g., hydrated zirconium, hafnium, and titanium hydroxide), which may be disposed in a porous container. Consequently, contemplated compounds may be used in methods of reducing the concentration of an anion in an alkaline medium.

Abstract: A load leveling battery (122) comprising an electrolyte that includes a cerium zinc redox pair wherein preferred electrolytes are acid electrolytes, and most preferably comprise methane sulfonic acid. Contemplated load leveling batteries (122) have an open circuit voltage of at least 2.4 Volt per cell. Such batteries are useful at power grid substations (120) and commercial and industrial applications were large amounts of power are used. Preferred capacity is at least 100,000 kWh, more preferably 250,000 kWh.

Abstract: A battery (100) comprises a cell having a cathode compartment (120) that includes an element that is oxidized during charging of the battery (100), wherein the oxidized element forms a salt with an acid and thereby increases the H+ concentration in the cathode compartment (120) sufficient to promote an H+ flux into the anode compartment (110) across the separator (130), wherein the H+ flux across the separator (130) is sufficient to disintegrate a zinc dendrite proximal to the separator (130).

Abstract: An electric device has a plurality of cells in which in an acid electrolyte a lanthanide and zinc form a redox couple that provide a current, and in which at least two of the cells are separated by a bipolar electrode that comprises a glassy carbon or a Magneli phase titanium suboxide.

Abstract: A battery comprises an acid electrolyte in which a compound provides acidity to the electrolyte and further increases solubility of at least one metal in the redox pair. Especially preferred compounds include alkyl sulfonic acids and alkyl phosphonic acids, and particularly preferred redox coupled include Co3+/Zn0, Mn3+/Zn0, Ce4+/V2+, Ce4+/Ti3+, Ce4+/Zn0, and Pb4+/Pb0.

Abstract: A battery (100) comprises a cell having a cathode compartment (120) that includes an element that is oxidized during charging of the battery (100), wherein the oxidized element forms a salt with an acid and thereby increases the H+ concentration in the cathode compartment (120) sufficient to promote an H+ flux into the anode compartment (110) across the separator (130), wherein the H+ flux across the separator (130) is sufficient to disintegrate a zinc dendrite proximal to the separator (130).

Abstract: A power cell (100A) has an electrolyte that includes a reodox pair comprising cerium. The electrolyte in preferred cells is an acid electrolyte that comprises a element ion complexed by an organic acid or a chelating agent, and contemplated electrolytes may further include a compound that reduces the hydrogen overpotential. Where the power cell comprises a plurality of cells (100B), preferred configurations may include glassy carbon as bipolar electrolytes.

Abstract: An electric device comprises a gelled acid electrolyte (142A) in complex with a lanthanide that forms a redox pair with a second element. Preferred electric devices include batteries and especially primary batteries, while preferred acid electrolytes (124A) have a sulfonic acid group. Contemplated lanthanides especially include cerium, and preferred second elements particularly include zinc. Alternatively, contemplated electric devices may comprise a gelled electrolyte (142A) in which with a lanthanide forms a redox pair with zinc.

Abstract: A load leveling battery (122) comprising an electrolyte that includes a cerium zinc redox pair wherein preferred electrolytes are acid electrolytes, and most preferably comprise methane sulfonic acid. Contemplated load leveling batteries (122) have an open circuit voltage of at least 2.4 Volt per cell. Such batteries are useful at power grid substations (120) and commercial and industrial applications were large amounts of power are used. Preferred capacity is at least 100,000 kWh, more preferably 250,000 kWh.

Abstract: A battery (100) comprises an electrolyte in which a lanthanide and zinc form a redox pair. Preferred electorlytes are acid electrolytes, and most preferably comprise methane sulfonic acid, and it is further contemplated that suitable electrolytes may include at least two lanthanides. Contemplated lanthanides include cerium, praseodymium, neodymium, terbium, and dysprosium, and further contemplate lanthanides are samarium, europium, thulium and ytterbium.

Abstract: A metal hydroxide complex has a formula Me(OH)4*A−*nH2O or MeO2*A−*nH2O. Preferred complexes are formed in an alkaline medium, and particularly especially preferred anions include cyanide and cyanide gold complexes. Contemplated complexes are formed on a metal hydroxide (e.g., hydrated zirconium, hafnium, and titanium hydroxide), which may be disposed in a porous container. Consequently, contemplated compounds may be used in methods of reducing the concentration of an anion in an alkaline medium.

Abstract: A battery comprises an acid electrolyte in which a compound provides acidity to the electrolyte and further increases solubility of at least one metal in the redox pair. Especially preferred compounds include alkyl sulfonic acids and alkyl phosphonic acids, and particularly preferred redox coupled include Co3+/Zn0, Mn3+/Zn0, Ce4+/V2+, Ce4+/Ti3+, Ce4+/Zn0, and Pb4+/Pb0.