Novel compositions of vertically oriented graphene nanosheets on aluminum electrodes are provided. These compositions are particularly useful for advanced electrolytic capacitors and fast response electric double layer capacitors. These compositions include a polycrystalline carbon layer, and an adjacent aluminum oxide layer that does not preclude ohmic contact between the carbon layer and an aluminum substrate.

Novel compositions of vertically oriented graphene nanosheets on aluminum electrodes are provided. These compositions are particularly useful for advanced electrolytic capacitors and fast response electric double layer capacitors. These compositions include a polycrystalline carbon layer, and an adjacent aluminum oxide layer that does not preclude ohmic contact between the carbon layer and an aluminum substrate.

The disclosed technology generally relates to thin film-based energy storage devices, and more particularly to printed thin film-based energy storage devices. The thin film-based energy storage device includes a first current collector layer and a second current collector layer over an electrically insulating substrate and adjacently disposed in a lateral direction. The thin film-based energy storage device additionally includes a first electrode layer of a first type over the first current collector layer and a second electrode layer of a second type over the second current collector layer. A separator separates the first electrode layer and the second electrode layer. One or more of the first current collector layer, the first electrode layer, the separator, the second electrode layer and the second current collector layer are printed layers.

An energy storage device is provided that has improved power performance at low temperature. In the present embodiment, an energy storage device is provided that includes an electrode having an active material layer, the active material layer contains at least active material particles, the particles contained in the active material layer gives a volume-based particle size frequency distribution that has a first peak and a second peak appearing in a particle size larger than a particle size of the first peak, and particles having particle sizes equal to or smaller than a particle size Dx have a volume proportion of 49% or more and 62% or less in a volume of whole particles contained in the active material layer, with the particle size Dx defined as a particle size at a local minimum frequency between the first peak and the second peak in the particle size frequency distribution.

An ink of the formula: 60-80% by weight BaTiO.sub.3 particles coated with SiO.sub.2; 5-50% by weight high dielectric constant glass; 0.1-5% by weight surfactant; 5-25% by weight solvent; and 5-25% weight organic vehicle. Also a method of manufacturing a capacitor comprising the steps of: heating particles of BaTiO.sub.3 for a special heating cycle, under a mixture of 70-96% by volume N.sub.2 and 4-30% by volume H.sub.2 gas; depositing a film of SiO.sub.2 over the particles; mechanically separating the particles; incorporating them into the above described ink formulation; depositing the ink on a substrate; and heating at 850-900° C. for less than 5 minutes and allowing the ink and substrate to cool to ambient in N.sub.2 atmosphere. Also a dielectric made by: heating particles of BaTiO.sub.3 for a special heating cycle, under a mixture of 70-96% by volume N.sub.2 and 4-30% by volume H.sub.2 gas; depositing a film of SiO.sub.2 over the particles; mechanically separating the particles; forming them into a layer; and heating at 850-900° C. for less than 5 minutes and allowing the layer to cool to ambient in N.sub.2 atmosphere.

Provided herein are devices comprising one or more cells, and methods for fabrication thereof. The devices may be electrochemical devices. The devices may include three-dimensional supercapacitors. The devices may be microdevices such as, for example, microsupercapacitors. In some embodiments, the devices are three-dimensional hybrid microsupercapacitors. The devices may be configured for high voltage applications. In some embodiments, the devices are high voltage microsupercapacitors. In certain embodiments, the devices are high voltage asymmetric microsupercapacitors. In some embodiments, the devices are integrated microsupercapacitors for high voltage applications.

Provided is a lithium titanate powder for an electrode of an energy storage device, the lithium titanate powder comprising Li.sub.4Ti.sub.5O.sub.12 as a main component, wherein, when the volume surface diameter calculated from the specific surface area determined by the BET method is represented as D.sub.BET and the crystallite diameter calculated from the half-peak width of the peak of the (111) plane of Li.sub.4Ti.sub.5O.sub.12 by the Scherrer equation is represented as D.sub.X, D.sub.BET is 0.1 to 0.6 μm, D.sub.X is greater than 80 nm, and (D.sub.BET/D.sub.X (μm/μm)) the ratio of D.sub.BET to D.sub.X is 3 or less. Also provided are an active material including the lithium titanate powder and an energy storage device using the active material.

Provided is a lithium titanate powder for an electrode of an energy storage device, the lithium titanate powder comprising Li.sub.4Ti.sub.5O.sub.12 as a main component, wherein, when the volume surface diameter calculated from the specific surface area determined by the BET method is represented as D.sub.BET and the crystallite diameter calculated from the half-peak width of the peak of the (111) plane of Li.sub.4Ti.sub.5O.sub.12 by the Scherrer equation is represented as D.sub.X, D.sub.BET is 0.1 to 0.6 μm, D.sub.X is greater than 80 nm, and (D.sub.BET/D.sub.X (μm/μm)) the ratio of D.sub.BET to D.sub.X is 3 or less. Also provided are an active material including the lithium titanate powder and an energy storage device using the active material.

The electrode (10) includes an electrically conductive surface (14) with a galvanic pellicle, or carbon nanotube mat (18), secured to the conductive surface (14). The pellicle (18) has a first surface (20) and an opposed outer surface (22) and defines an uncompressed thickness dimension (24) as a longest length of a straight axis (26) extending from the first surface (20) to the outer surface (22) of an uncompressed section (28) of the galvanic pellicle (18). Uncompressed sections (28) of the pellicle are defined between connected areas (30) and continuous connected areas (32) of the pellicle (18). Any point (35) within any uncompressed section (28) is no more distant from one of a nearest connected area (30) and/or a nearest segment (34) of a continuous connected area (32) than about ten times the uncompressed thickness dimension (24) of the pellicle (18), thereby achieving significantly reduced contact resistance.

The electrode (10) includes an electrically conductive surface (14) with a galvanic pellicle, or carbon nanotube mat (18), secured to the conductive surface (14). The pellicle (18) has a first surface (20) and an opposed outer surface (22) and defines an uncompressed thickness dimension (24) as a longest length of a straight axis (26) extending from the first surface (20) to the outer surface (22) of an uncompressed section (28) of the galvanic pellicle (18). Uncompressed sections (28) of the pellicle are defined between connected areas (30) and continuous connected areas (32) of the pellicle (18). Any point (35) within any uncompressed section (28) is no more distant from one of a nearest connected area (30) and/or a nearest segment (34) of a continuous connected area (32) than about ten times the uncompressed thickness dimension (24) of the pellicle (18), thereby achieving significantly reduced contact resistance.