摘要:
Electrochemical capacitors and methods for producing such electrochemical capacitors. The electrochemical capacitor can have an initial charged state and a cycled charged state and can include an anode, a cathode, and an electrolyte. The anode can include a first mixture having a first plurality of electrically conductive carbon-comprising particles having a first average porosity. The cathode can include a second mixture having a second plurality of electrically conductive carbon-comprising particles having a second average porosity greater than said first average porosity. The electrolyte can be physically and electrically contacting said anode and said cathode, and the first mixture in the cycled charged state can be substantially free of lithium metal particles and can further include a plurality of lithium ions intercalating the first plurality of carbon comprising particles. The mass ratio of the cathode and the electrolyte can be less than 1.
摘要:
A membrane electrode assembly (MEA) for a fuel cell comprising a catalyst layer and a method of making the same. The catalyst layer can include a plurality of catalyst nanoparticles, e.g., platinum, disposed on buckypaper. The catalyst layer can have 1% or less binder prior to attachment to the membrane electrode assembly. The catalyst layer can include (a) single-wall nanotubes, small diameter multi-wall nanotubes, or both, and (b) large diameter multi-wall nanotubes, carbon nanofibers, or both. The ratio of (a) to (b) can range from 1:2 to 1:20. The catalyst layer can produce a surface area utilization efficiency of at least 60% and the platinum utilization efficiency can be 0.50 gPt/kW or less.
摘要:
An electrode material comprised of hydrous metal oxide, such as ruthenium oxide, is annealed up to temperature just below the temperature at which the hydrous metal oxide would crystallize. Therefore, the hydrous metal oxide remains amorphous or non-crystalline. A hydrous metal oxide material treated in this manner provides a charge storage capacity and energy density greater than 747 F/g and 92 joules/gram, respectively, over 1 V range in a sulfuric acid electrolyte. This invention also provides a method of material preparation, wherein a sol-gel process is used to fabricate the hydrous metal oxides and wherein commercially available hydrous ruthenium oxide powders are treated and annealed.
摘要:
Electrochemical capacitors and methods for producing such electrochemical capacitors. The electrochemical capacitor can have an initial charged state and a cycled charged state and can include an anode, a cathode, and an electrolyte. The anode can include a first mixture having a first plurality of electrically conductive carbon-comprising particles having a first average porosity. The cathode can include a second mixture having a second plurality of electrically conductive carbon-comprising particles having a second average porosity greater than said first average porosity. The electrolyte can be physically and electrically contacting said anode and said cathode, and the first mixture in the cycled charged state can be substantially free of lithium metal particles and can further include a plurality of lithium ions intercalating the first plurality of carbon comprising particles. The mass ratio of the cathode and the electrolyte can be less than 1.
摘要:
This invention relates to a composite electrode material for use in high rgy and high power density electrochemical capacitors, and to the electrochemical capacitor containing the electrodes. The electrodes are comprised of materials with high specific capacitance and electronic conductivity/high porosity. Specifically, the electrode is comprised of RuO.sub.2.xH.sub.2 O powder and carbon black or carbon fiber.
摘要:
This invention relates to a novel electrode material for electrochemical ) capacitors. This invention also relates to a novel method for making such electrode. The electrode material is an amorphous phase of ruthenium oxide formed directly on titanium (Ti) substrate. The method is the application of heat on the Ti substrate which is wetted by metal alkoxide precursor. The method produces film which adheres to the substrate before and after charge/discharge cycling. As a result, the EC capacitors made of the electrode exhibit high power and also high energy which is higher than that of the traditional crystalline phase of ruthenium oxide thin film on Ti. This type of capacitor is especially suited for burst communication which requires energy with high power density, high energy density, and high cycle life at medium to low voltages (10-20 volts).
摘要:
Electrochemical capacitors and methods for producing such electrochemical capacitors. The electrochemical capacitor can have an initial charged state and a cycled charged state and can include an anode, a cathode, and an electrolyte. The anode can include a first mixture having a first plurality of electrically conductive carbon-comprising particles having a first average porosity. The cathode can include a second mixture having a second plurality of electrically conductive carbon-comprising particles having a second average porosity greater than said first average porosity. The electrolyte can be physically and electrically contacting said anode and said cathode, and the first mixture in the cycled charged state can be substantially free of lithium metal particles and can further include a plurality of lithium ions intercalating the first plurality of carbon comprising particles. The mass ratio of the cathode and the electrolyte can be less than 1.
摘要:
A high energy density electrochemical capacitors with electrodes is formed from proton inserted ruthenium oxides (e.g. HRuO.sub.2.xH.sub.2 O or HRuO.sub.2). The electrode material is formed by reducing ruthenium oxides (e.g. RuO.sub.2.xH.sub.2 O or RuO.sub.2) using electrochemical method or chemical reaction between ruthenium oxides with acetone or methanol. Electrochemical capacitors with electrodes formed of proton inserted ruthenium oxides possess higher energy density, lower resistance, broader operating temperature range, and longer lifetime than that with electrodes comprised ruthenium oxides.
摘要:
A capacitor having an enhanced dielectric breakdown strength is obtained m a base dielectric film by coating the base dielectric film on both sides with an adherent coated dielectric film having a dielectric constant that is at least 50 percent higher than that of the base dielectric film and that adheres to the base dielectric film; and wherein metal foil is adherently joined to each of the coated dielectrics films to form electrodes for the capacitor.
摘要:
A membrane electrode assembly (MEA) for a fuel cell comprising a gradient catalyst structure and a method of making the same. The gradient catalyst structure can include a plurality of catalyst nanoparticles, e.g., platinum, disposed on layered buckypaper. The layered buckypaper can include at least a first layer and a second layer and the first layer can have a lower porosity compared to the second layer. The gradient catalyst structure can include single-wall nanotubes, carbon nanofibers, or both in the first layer of the layered buckypaper and can include carbon nanofibers in the second layer of the layered buckypaper. The MEA can have a catalyst utilization efficiency of at least 0.35 gcat/kW or less.