Abstract: Disclosed herein are processes comprising electrolyzing an aqueous solution comprising lithium, wherein the aqueous solution has a pH less than 0.5. Also disclosed are processes comprising electrolyzing a first aqueous solution comprising lithium to obtain a second aqueous solution comprising lithium, and an acidic aqueous solution having a pH less than 0.5, adjusting the pH of the second aqueous solution with the acidic aqueous solution to obtain a third aqueous solution comprising lithium having a pH less than 0.5, and electrolyzing the third aqueous solution comprising lithium. Additionally disclosed are, processes comprising stripping a liquid medium comprising lithium with an acidic aqueous solution to obtain an aqueous solution comprising lithium, and electrolyzing the aqueous solution comprising lithium. Further disclosed are processes for preparing a liquid medium comprising lithium.

Abstract: Disclosed herein is a membrane-electrode assembly containing: a gastight, selectively proton-conducting membrane which has a retentate side having an anode and a permeate side having a cathode; a voltage source for generating a potential difference between the anode and the cathode; an anode catalyst having a catalytically active material on the retentate side; and a cathode catalyst having a catalytically active material on the permeate side, in which the cathode catalyst has a smaller amount of catalytically active material than the anode catalyst. The present disclosure also includes a reactor containing the membrane-electrode assembly, and a process for separating off hydrogen using the membrane-electrode assembly.

Abstract: The invention relates to a catalyst for fuel cells which comprises a support, at least one catalytically active metal from the platinum group or an alloy comprising at least one metal of the platinum group and also at least one oxide of at least one metal selected from among Ti, Sn, Si, W, Mo, Zn, Ta, Nb, V, Cr and Zr. The invention further relates to a process for producing such a catalyst and its use.

Abstract: The present invention relates to rechargeable electrochemical zinc-oxygen cells comprising A) at least one anode comprising metallic zinc, B) at least one gas diffusion electrode comprising (B1) at least one cathode active material, and (B2) optionally at least one solid medium through which gas can diffuse, and C) an aqueous electrolyte comprising boric acid. The present invention further relates to uses of the inventive rechargeable electrochemical zinc-oxygen cells, to zinc-air batteries comprising the inventive rechargeable electrochemical zinc-oxygen cells, and to the use of an aqueous electrolyte comprising boric acid for production or for operation of rechargeable electrochemical zinc-oxygen cells.

Abstract: The invention relates to a process for producing a rechargeable electrochemical metal-oxygen cell, comprising at least one positive electrode, at least one negative metal-comprising electrode and at least one separator having two sides for separating the positive and negative electrodes, wherein, in one of the process steps, at least one side of the separator is coated with at least one material for forming one of the two electrodes (hereinafter referred to as electrode material) or at least one side of at least one of the two electrodes is coated with at least one material for forming the separator (hereinafter referred to as separator material) to form a separator-electrode assembly.

Abstract: The invention relates to gas diffusion electrodes for rechargeable electrochemical metal-oxygen cells, which comprise at least one porous support and one or more layers which are applied to one side of the porous support and comprise at least one catalyst for a metal-oxygen cell, wherein at least one function-relevant parameter changes continuously or discontinuously with increasing distance from the porous support in the catalyst-comprising layer or layers. The present invention further relates to processes for producing such gas diffusion electrodes and rechargeable electrochemical metal-oxygen cells comprising such gas diffusion electrodes.

Abstract: The invention relates to gas diffusion electrodes for rechargeable electrochemical cells, which comprise at least one support material bearing at least one catalyst, wherein the support material comprises at least one compound selected from the group consisting of electrically conductive metal oxides, carbides, nitrides, borides, silicides and organic semiconductors. The present invention further relates to a process for producing such gas diffusion electrodes and also rechargeable electrochemical cells comprising such gas diffusion electrodes.

Abstract: The invention relates to a process for the continuous production of a catalyst comprising an alloy of a metal of the platinum group and at least a second metal as alloying metal selected from among the metals of the platinum group and the transition metals, in which a catalyst comprising the metal of the platinum group is mixed with at least one complex each comprising the alloying metal to give an alloy precursor and the alloy precursor is heated in a continuously operated furnace to produce the alloy.

Abstract: The invention relates to a catalyst for fuel cells which comprises a support, at least one catalytically active metal from the platinum group or an alloy comprising at least one metal of the platinum group and also at least one oxide of at least one metal selected from among Ti, Sn, Si, W, Mo, Zn, Ta, Nb, V, Cr and Zr. The invention further relates to a process for producing such a catalyst and its use.

Abstract: Catalyst ink comprising one or more catalyst materials, a solvent component and at least one acid, an electrode comprising at least one catalyst ink according to the present invention, a membrane-electrode assembly comprising at least one electrode according to the invention or comprising at least one catalyst ink according to the present invention, a fuel cell comprising at least one membrane-electrode assembly according to the invention and also a process for producing a membrane-electrode assembly according to the present invention.

Abstract: Catalyst comprising a support and a catalytically active material for use as heterogeneous catalyst for electrochemical reactions, wherein the support is a carbon support having a BET surface area of less than 50 m2/g. The invention further relates to the use of the catalyst as electrode catalyst in a fuel cell.

Abstract: The invention relates to a catalyst for electro-chemical applications comprising an alloy of platinum and a transition metal, wherein the transition metal has an absorption edge similar to the absorption edge of the transition metal in oxidic state, measured with x-ray absorption near-edge spectroscopy (XANES) wherein the measurements are performed in concentrated H3PO4 electrolyte. The invention further relates to a process for an oxygen reduction reaction using the catalyst as electrocatalyst.

Abstract: Catalyst ink comprising one or more catalyst materials, a liquid medium and polymer particles comprising one or more proton-conducting polymers, an electrode comprising at least one catalyst ink according to the present invention, a membrane-electrode assembly comprising at least one electrode according to the invention or comprising at least one catalyst ink according to the present invention, a fuel cell comprising at least one membrane-electrode assembly according to the invention and also a process for producing a membrane-electrode assembly according to the present invention.

Abstract: The invention relates to a process for the continuous production of a catalyst comprising an alloy of a metal of the platinum group and at least a second metal as alloying metal selected from among the metals of the platinum group and the transition metals, in which a catalyst comprising the metal of the platinum group is mixed with at least one complex each comprising the alloying metal to give an alloy precursor and the alloy precursor is heated in a continuously operated furnace to produce the alloy.

Abstract: The present invention relates to a catalyst ink comprising at least one catalytically active material and at least one ionic liquid, a process for producing this catalyst ink, a process for producing a membrane-electrode assembly (MEA) comprising at least one membrane and at least one electrode by applying this catalyst ink to a membrane or by applying this catalyst ink to any gas diffusion layer present, the use of this catalyst ink in the production of a membrane-electrode assembly (MEA), a catalyst coated membrane (CCM) or a gas diffusion electrode (GDE) and the use of an ionic liquid for producing a catalyst ink.

Abstract: The invention relates to a process for producing a membrane-electrode assembly comprising an anode catalyst layer (13), a polymer electrolyte membrane (1) and a cathode catalyst layer (14) and to a fuel cell comprising such a membrane-electrode assembly.

Abstract: The present invention relates to a membrane-electrode assembly comprising at least one membrane, at least two electrode layers and at least one barrier layer, wherein the at least one barrier layer comprises at least one catalytically active species and/or at least one adsorbent material and the barrier layer is electronically nonconductive when a catalytically active species is present, the use of such a barrier layer in a membrane-electrode assembly and in a fuel cell, and also a gas-diffusion electrode and a fuel cell comprising such a membrane-electrode assembly.

Abstract: The invention relates to devices and/or methods for determining the availability of electrical energy in two-energy accumulator vehicle electric systems, in which both energy accumulators, particularly batteries, can be connected to one another via a D.C. converter. The required electric energy is generated by means of a generator that is driven by a vehicle engine. The customary consumers are connected to a first consumer battery circuit (10, 24). Additional consumer, for example, high-current consumers, particularly the starter, are connected to the second battery circuit (11, 29). A control device, for example, a controller that is equipped with a microprocessor determines the availability of the electric energy and occurring faults while evaluating.

Abstract: Devices and/or methods for determining the availability of electrical energy in dual energy-storing means and on-board electrical systems, in which the two energy-storing means, in particular batteries, can communicate with one another via a direct-voltage converter. The requisite electrical energy is generated by means of a generator driven by the vehicle engine. The usual consumers are connected to a first consumer battery circuit 10, 24. Further consumers, such as high-current consumers and in particular the starter, communicate with the second battery circuit 11, 29. A control unit, for instance a control unit with a microprocessor, ascertains the availability of the electrical energy and any defects that occur by evaluating various algorithms and performs the requisite triggering and signalling operations. The algorithms include threshold value statements on the availability of the electrical energy (SOCS) and threshold value statements for detecting system defects (SOHS).