Abstract: A cathode active composite containing a nanoparticle composite of an amorphous matrix containing vanadium, oxygen and sulfur and crystalline regions of vanadium and oxygen embedded in the matrix is provided. Electrochemical cells and a reversible battery having a cathode containing the cathode active composite is also provided. In specific embodiments the battery is a magnesium battery.

Abstract: A metal-air battery comprising an emulsified or dispersed aqueous/ionic liquid two phase electrolyte system is provided. The two phase electrolyte system contains an aqueous phase and an ionic liquid phase wherein an amount of water exceeds the aqueous solubility of the ionic liquid. In one embodiment the metal-air battery is a lithium-air battery.

Abstract: A magnesium-air battery is described. The battery comprises: an anode compartment; a cathode compartment; and a membrane separating the anode compartment from the cathode compartment. The anode compartment comprises an anode having magnesium, a magnesium alloy or a material capable of insertion and extraction of magnesium, while the cathode compartment comprises an air electrode, a glyme ether or an ionic liquid capable of supporting the reduction of oxygen and a soluble magnesium salt.

Abstract: A magnesium electrochemical cell having a positive electrode containing as an active ingredient, a material of formula [V2O5]c [MaOb]d and/or a material of formula [V2O5]c[MaOb]d[MgXe]g in a metastable structural and morphological phase is provided. In the formulas M is an element selected from the group consisting of P, B, Si, Ge and Mo; and X is O or a halide.

Abstract: A Li-air battery is provided. The battery contains: an anode compartment containing lithium or a lithium alloy as active metal; a cathode compartment supplied with an O2 source; and a lithium ion conductive membrane separating the anode compartment from the cathode compartment. The cathode compartment contains an air electrode with a skin alloy platinum or palladium catalyst.

Abstract: A method for production of a magnesium battery with low impedance is provided. A cell is constructed comprising an uncoated current collector anode, an electrolyte system comprising a non-aqueous solvent and a magnesium salt soluble in the non-aqueous solvent, and a cathode. The cell is charged to electrodeposit magnesium metal unto the uncoated current collector to obtain an anode having magnesium metal as the active material. Also provided are rechargeable magnesium batteries obtained by the method.

Abstract: An all-solid-state metal-metal battery with both high energy density and high power density is provided. The battery has an anolyte including at least one active anode metal ion conducting ceramic solid and a catholyte including at least one active cathode metal ion conducting ceramic solid sandwiched between an anode including an alkali metal or an alkaline earth metal as the active anode metal and an cathode including a transition metal as the active cathode metal. Prior to the initial charge, the battery may have an anode current collector devoid of the active anode metal or a cathode current collector devoid of the active cathode metal.

Abstract: A positive electrode comprising ?-VOPO4 and/or Nax(?-VOPO4) wherein x is a value from 0.1 to 1.0 as an active ingredient, wherein the electrode is capable of insertion and release of sodium ions and a reversible sodium battery containing the positive electrode are provided.

Abstract: A solid-phase electrolyte is provided having a magnesium salt. The salt contains a magnesium cation and a boron cluster anion and can include an ether or other weakly-coordinating molecule in dative interaction with the magnesium cation. A magnesium electrochemical cell is also provided. The magnesium electrochemical cell includes the solid-phase electrolyte, and also includes an anode in ionic communication with the solid-phase electrolyte. The anode, when charged, contains reduced magnesium.

Abstract: A cathode active composite containing an amorphous composite of vanadium oxide and an inorganic sulfide is provided. In one embodiment the composite contains vanadium pentoxide and phosphorous pentasulfide. An elctrochemical cell and a reversible battery having a cathode containing the cathode active composite are also provided. In one embodiment the battery is a magnesium battery.

Abstract: A solid-phase electrolyte is provided having a magnesium salt. The salt contains a magnesium cation and a boron cluster anion and can include an ether or other weakly-coordinating molecule in dative interaction with the magnesium cation. A magnesium electrochemical cell is also provided. The magnesium electrochemical cell includes the solid-phase electrolyte, and also includes an anode in ionic communication with the solid-phase electrolyte. The anode, when charged, contains reduced magnesium.

Abstract: A metal-air battery comprising a two phase electrolyte system is provided. The two phase electrolyte system contains an aqueous phase and an ionic liquid phase wherein an amount of water exceeds the aqueous solubility of the ionic liquid. In one embodiment the metal-air battery is a lithium-air battery.

Abstract: A lithium-air electrochemical cell is provided. The battery comprises: an anode compartment; a cathode compartment; and a lithium ion conductive membrane separating the anode compartment from the cathode compartment. The anode compartment comprises an anode having lithium or a lithium alloy as active metal and a lithium ion electrolyte, while the cathode compartment comprises an air electrode and an ionic liquid capable of supporting the reduction of oxygen. A lithium ion concentration in the cathode compartment is such that the lithium ion concentration is greatest at the lithium ion selective membrane and lowest at the cathode.

Abstract: A positive electrode comprising ?-VOPO4 and/or Nax(?-VOPO4) wherein x is a value from 0.1 to 1.0 as an active ingredient, wherein the electrode is capable of insertion and release of sodium ions and a reversible sodium battery containing the positive electrode are provided.

Abstract: A Li-air battery is provided. The battery comprises: an anode compartment containing lithium or a lithium alloy as active metal; a cathode compartment supplied with an O2 source; and a lithium ion conductive membrane separating the anode compartment from the cathode compartment. The cathode compartment comprises an air electrode with a skin alloy platinum or palladium catalyst.

Abstract: A metal-nitric oxide electrochemical cell which is fed a gas comprising nitric oxide (NO) and at least one gas selected from the group consisting of a nitrogen oxide of formula NxOy, oxygen, water vapor, a gaseous hydrocarbon, carbon monoxide and carbon dioxide is provided. Also provided is a rechargeable battery containing the metal-nitrogen oxides electrochemical cell. A vehicle system wherein exhaust gas from a combustion engine serves as a feed of active cathode material to a metal-nitrogen oxides battery is additionally provided.

Abstract: A magnesium electrochemical cell having a positive electrode containing as an active ingredient, an amorphous material of formula [V2O5]c[MgXy]d[MaOb]e is provided. In the formula M is an element selected from the group consisting of P, B, Si, Ge and Mo, and X is O, F, Cl, Br or I.

Abstract: An electrolyte composition for a magnesium electrochemical cell includes a magnesium salt dissolved in an ionic liquid. The ionic liquid includes an organic cation and a first boron cluster anion. The magnesium salt has a magnesium cation and a second boron cluster anion. The magnesium electrochemical cell includes an anode that contains elemental magnesium when charged, a cathode suitable for magnesium insertion or deposition, and the aforementioned electrolyte composition that is in ionic communication with the anode, the cathode, or both.

Abstract: An anode active material for a magnesium battery includes a Metal M which electrochemically alloys with magnesium, magnesium, and carbon that are ball milled forming an active material mixture. The mixture may be of the formula: MgaM1-a (0?a<1)+Carbon wherein the mixture is ball milled and has a stoichiometric amount of M and Mg and carbon of from 0.1-50 weight percent of the total mixture.

Abstract: A MnO2 electrode active material of high capacity is provided. The high capacity MnO2 has a surface area which is greater than 60 m2/g and the MnO2 is obtained by a process comprising a redox reaction of a Mn (II) salt and permanganate at a reaction temperature less than 30° C. and a pH of 2 to 4. Also provided are a magnesium electrochemical cell having a cathode containing the MnO2 and a rechargeable magnesium battery having a cathode containing the MnO2.