The present invention relates to an electrode for use in electrochemical cells and systems, such as rechargeable batteries, having a metal substrate and a catalytic coating applied onto the substrate. The catalytic coating has a mixture of noble metals or noble metal oxides and can be used to improve the energy efficiency of the cell.

An electrode comprises an acid treated, cathodically cycled carbon-comprising film or body. The carbon consists of single walled nanotubes (SWNTs), pyrolytic graphite, microcrystalline graphitic, any carbon that consists of more than 99% sp.sup.2 hybridized carbons, or any combination thereof. The electrode can be used in an electrochemical device functioning as an electrolyser for evolution of hydrogen or as a fuel cell for oxidation of hydrogen. The electrochemical device can be coupled as a secondary energy generator into a system with a primary energy generator that naturally undergoes generation fluctuations. During periods of high energy output, the primary source can power the electrochemical device to store energy as hydrogen, which can be consumed to generate electricity as the secondary source during low energy output by the primary source. Solar cells, wind turbines and water turbines can act as the primary energy source.

Described are aqueous rechargeable hydrogen batteries operating in the full pH range (e.g., pH: 1 to 15) with potential for electrical grid storage. The pH-universal hydrogen batteries operate with different redox chemistry on the cathodes and reversible hydrogen evolution/oxidation reactions (HER/HOR) on the anode. The reactions can be catalyzed by a highly active ruthenium-based electrocatalyst. The ruthenium-based catalysts exhibit comparable specific activity and superior long-term stability of HER/HOR to that of state-of-the-art Pt/C electrocatalyst in the full pH range. New chemistries for aqueous rechargeable hydrogen batteries are also provided.

An electrode comprises an acid treated, cathodically cycled carbon-comprising film or body. The carbon consists of single walled nanotubes (SWNTs), pyrolytic graphite, microcrystalline graphitic, any carbon that consists of more than 99% sp.sup.2 hybridized carbons, or any combination thereof. The electrode can be used in an electrochemical device functioning as an electrolyzer for evolution of hydrogen or as a fuel cell for oxidation of hydrogen. The electrochemical device can be coupled as a secondary energy generator into a system with a primary energy generator that naturally undergoes generation fluctuations. During periods of high energy output, the primary source can power the electrochemical device to store energy as hydrogen, which can be consumed to generate electricity as the secondary source during low energy output by the primary source. Solar cells, wind turbines and water turbines can act as the primary energy source.

An electrode comprises an acid treated, cathodically cycled carbon-comprising film or body. The carbon consists of single walled nanotubes (SWNTs), pyrolytic graphite, microcrystalline graphitic, any carbon that consists of more than 99% sp.sup.2 hybridized carbons, or any combination thereof. The electrode can be used in an electrochemical device functioning as an electrolyser for evolution of hydrogen or as a fuel cell for oxidation of hydrogen. The electrochemical device can be coupled as a secondary energy generator into a system with a primary energy generator that naturally undergoes generation fluctuations. During periods of high energy output, the primary source can power the electrochemical device to store energy as hydrogen, which can be consumed to generate electricity as the secondary source during low energy output by the primary source. Solar cells, wind turbines and water turbines can act as the primary energy source.

Various embodiments provide a method of manufacturing an oxygen electrode. The method comprises: providing an electrically conductive substrate; depositing an electrocatalyst layer on the substrate; and intercalating alkali-metal ions into the catalyst layer. Some other embodiments provide an oxygen electrode manufactured in accordance with the method and a metal-air battery, a regenerative H.sub.2O.sub.2 fuel cell, a direct fuel cell, and an electrochemical cell comprising the oxygen electrode.

Disclosed are a reversible fuel cell oxygen electrode in which IrO.sub.2 is electrodeposited and formed on a porous carbon material and platinum is applied thereon to form a porous platinum layer, a reversible fuel cell including the same, and a method for preparing the same. According to the corresponding reversible fuel cell oxygen electrode, as the loading amounts of IrO.sub.2 and platinum used in the reversible fuel cell oxygen electrode can be lowered, it is possible to exhibit excellent reversible fuel cell performances (excellent fuel cell performance and water electrolysis performance) by improving the mass transport of water and oxygen while being capable of reducing the loading amounts of IrO.sub.2 and platinum. Further, it is possible to exhibit a good activity of a catalyst when the present disclosure is applied to a reversible fuel cell oxygen electrode and to reduce corrosion of carbon.

The invention provides for a fully electrically rechargeable metal anode battery systems and methods of achieving such systems. An electrically rechargeable metal anode cell may comprise a metal electrode, an air contacting electrode, and an aqueous electrolyte separating the metal electrode and the air contacting electrode. In some embodiments, the metal electrode may directly contact the liquid electrolyte and no separator or porous membrane is needed between the air contacting electrode and the electrolyte. Rechargeable metal anode cells may be electrically connected to one another through a centrode connection where a metal electrode of one cell and an air contacting electrode of a second cell are electrically connected. Air tunnels or pathways may be provided between individual metal anode cells arranged in a stack. In some embodiments, an electrolyte flow management system may also be provided to maintain liquid electrolyte at constant levels during charge and discharge cycles.

The present application is directed to mesoporous carbon materials comprising bi-functional catalysts. The mesoporous carbon materials find utility in any number of electrical devices, for example, in lithium-air batteries. Methods for making the disclosed carbon materials, and devices comprising the same, are also disclosed.

A novel multi cell stack architecture has specific features allowing deployment of simple electrical instrumentation of data collection/monitoring of crucial hydraulic, electrical and electrochemical quantities, on the basis of which the operator or electronic controller is able to gather/process critical information of such a depth and enhanced reliability, for immediately identifying any cell in state of sufferance and eventually to exclude it from the system and possibly substitute it with a spare cell. A method of monitoring/controlling the operation of an all-vanadium redox flow battery system is also disclosed.