2568results about "Double layer capacitors" patented technology

Graphitic nanofibers, which include tubular fullerenes (commonly called "buckytubes"), nanotubes and fibrils, which are functionalized by chemical substitution, are used as electrodes in electrochemical capacitors. The graphitic nanofiber based electrode increases the performance of the electrochemical capacitors. Preferred nanofibers have a surface area greater than about 200 m2 / gm and are substantially free of micropores.

A high kinetics rate electrochemical cell in which at least one of the electrodes is composed of a mesostructural electroactive material comprising nanoparticles forming a three-dimensional framework structure of mesoporous texture having a bicontinuous junction of large specific surface area with the electrolyte. A low temperature method of preparation of the electrodes employs a high-speed deposition of the electrically active material in the form of a thin film. The application of said electrodes in high power lithium ion insertion batteries, photovoltaic cells, supercapacitors and fast electrochromic devices is disclosed.

A powder material which can electrochemically store and release lithium ions rapidly in a large amount is provided. In addition, an electrode structure for an energy storage device which can provide a high energy density and a high power density and has a long life, and an energy storage device using the electrode structure are provided. In a powder material which can electrochemically store and release lithium ions, the surface of particles of one of silicon metal and tin metal and an alloy of any thereof is coated by an oxide including a transition metal element selected from the group consisting of W, Ti, Mo, Nb, and V as a main component. The electrode structure includes the powder material. The battery device includes a negative electrode having the electrode structure, a lithium ion conductor, and a positive electrode, and utilizes an oxidation reaction of lithium and a reduction reaction of lithium ion.

A low temperature chemical route to efficiently produce nanomaterials is described. The nanomaterials are synthesized by intercalating ions into layered compounds, exfoliating to create individual layers and then sonicating to produce nanotubes, nanorods, nanoscrolls and / or nanosheets. It is applicable to various different layered inorganic compounds (for example, bismuth selenides / tellurides, graphite, and other metal complexes, particularly transition metal dichalcogenides compounds including oxygen, sulfur, tellurium or selenium).

Thin-film micro-electrochemical energy storage cells (MEESC) such as microbatteries and double-layer capacitors (DLC) are provided. The MEESC comprises two thin layer electrodes, an intermediate thin layer of a solid electrolyte and optionally, a fourth thin current collector layer; said layers being deposited in sequence on a surface of a substrate. The MEESC is characterized in that the substrate is provided with a plurality of through cavities of arbitrary shape, with high aspect ratio. By using the substrate volume, an increase in the total electrode area per volume is accomplished.

The present invention relates to a supercapacitor, also known as an electrical double-layer capacitor or ultracapacitor, having electrode material comprising single-wall carbon nanotubes. The carbon nanotubes can be derivatized with functional groups. The electrode material is made by preparing a polymer-nanotube suspension comprising polymer and nanotubes, forming the polymer-nanotube suspension into a polymer-nanotube composite of the desired form, carbonizing the polymer-nanotube composite to form a carbonaceous polymer-nanotube material, and activating the material. The supercapacitor includes electrode material comprising activated carbonaceous polymer-nanotube material in contact with current collectors and permeated with an electrolyte, which may be either fluid or solid. In the case of a fluid or compressible electrolyte, an electrolyte-permeable separator or spacer is interposed between the electrodes to keep the electrodes from shorting. The supercapacitor made with electrodes comprising underivatized single-wall carbon nanotubes and polymer that has been carbonized and activated appears to operate as a non-Faradaic supercapacitor.

It is an object of the present invention to provide a material for electrolytic solutions suited for use as material in electrolytic solutions serving as ionic conductors in electrochemical devices, such as large-capacity cells or batteries. The present invention is related to a material for electrolytic solutions which comprises, as an essential constituent, an anion represented by the general formula (1): wherein X represents at least one element selected from among B, N, O, Al, Si, P, S, As and Se; M<1 >and M<2 >are the same or different and each represents an organic linking group; a is an integer of not less than 1, and b, c and d each independently is an integer of not less than 0.

An electrode material of the present invention includes a plurality of particles capable of absorbing and desorbing lithium, and a plurality of nanowires capable of absorbing and desorbing lithium. The particles and the nanowires include silicon atoms. The plurality of nanowires are entangled with each other to form a network, and the network is in contact with at least two of the plurality of particles.

The invention features an electrode array (7) in which pairs of electrodes (1) are geometrically arranged so that the broadest faces of the exposed electrodes are not directly opposing to each other. Rather, the broadest facing surfaces of the electrodes in the array are parallel, adjacent, or offset at an angle. The electrode geometry of an electrode array of the invention permits electrodes to be in close proximity, thereby lowering series resistance, while minimizing the possibility for short circuits that can cause electrical leakage. An electrode array of the invention can be used in an electrochemical cell, such as a battery, e.g., a lithium battery, a capacitor, a flow-through capacitor, or a fuel cell.

An electrolyte comprising at least one organic aprotic solvent, at least one salt and at least one chelatoborate additive. A method of forming an SEI layer in a cell comprising a positive electrode, a negative electrode and an electrolyte, said method comprising the step of overcharging the electrolyte prior to fabricating the cell, or said cell during the formation cycle.

An electrical storage device of the present invention is characterized in that a positive electrode, a negative electrode, a lithium electrode, and an electrolyte capable of transferring lithium ion is included, the lithium electrode is arranged to be out of direct contact with the negative electrode, and lithium ion can be supplied to the negative electrode by flowing a current between the lithium electrode and the negative electrode through an external circuit. With the above characteristic, problems such as non-uniform carrying of lithium ion to the negative electrode, shape-change of a cell, and temperature increase of an electrolytic solution under incomplete sealing of a cell and the like can be easily solved. A using method of the electrical storage device is characterized in that, by using the lithium electrode as a reference electrode, the positive electrode potential and negative electrode potential can be measured, and the potential of the positive or negative electrode can be controlled when the electrical storage device is charged or discharged. Therefore, the potentials of the positive electrode and negative electrode can be monitored, thereby it can be easily determined whether deterioration of the electrical storage device is caused by the positive electrode or the negative electrode. Also, it is possible to control the device with the potential difference between the negative electrode and reference electrode, that is, the negative potential. In addition, when characteristics deteriorate such as the internal resistance increase, an appropriate amount of lithium ion can be supplied to the negative electrode and / or positive electrode by the lithium electrode.

The energy content of supercapacitor is determined by its capacitance value and working voltage. To attain a high capacitance and a high voltage, several pieces of electrodes and separators are spirally wound with edge sealing to form a bipolar supercapacitor in cylindrical, oval or square configuration. While the winding operation effectively provides a large surface area for high capacitance, the bipolar packaging instantly imparts a unitary roll a minimum working voltage of 5V on using an organic electrolyte. The bipolar roll is a powerful building block for facilitating the assembly of supercapacitor modules. Using containers with multiple compartments, as many bipolar rolls can be connected in series, in parallel or in a combination of the two connections to fabricate integrated supercapacitors with high energy density as required by applications.

There is provided an organic electrolyte capacitor having electrodes on current collectors that have holes penetrating the front and rear surfaces, in which electrode materials formed an the through-holes of the current collectors seldom fall off and high energy density and high power density can be obtained. The organic electrolyte capacitor includes positive electrodes, negative electrodes and an electrolyte capable of transferring lithium ions, in which the positive electrodes contain a substance capable of carrying lithium ions and / or anions reversibly as a positive electrode active material, the negative electrodes contain a substance capable of carrying lithium ions as a negative electrode active material, the positive and negative electrodes possess the positive or negative electrode active material layers on an electrode substrate that has conductive layers made of conductive materials on current collectors, which have through-holes, and the negative electrodes carry lithium electrochemically.

A polarizable electrode for an electric double layer capacitor includes an activated carbon powder, and a binder material mixed with the activated carbon. The amount of water contained in the polarizable electrode is 1500 ppm or less with respect to the weight of the polarizable electrode.

A composite particle for an electrode including an active material particle, carbon nanofibers bonded to the surface of the active material particle, and a catalyst element for promoting the growth of the carbon nanofibers, wherein the active material particle includes an electrochemically active phase. As the catalyst element, for example, Au, Ag, Pt, Ru, Ir, Cu, Fe, Co, Ni, Mo, Mn and the like are used. The composite particle for an electrode may be produced, for example, by means of a method which includes: a step of preparing an active material particle including a catalyst element for promoting the growth of carbon nanofibers at least in the surface layer of the active material particle; and a step of growing carbon nanofibers on the surface of the active material particle in an atmosphere including a raw material gas.

A carbon fine powder is obtained by uniformly coating the surface of a carbon fine powder having a large specific surface area with a uniform thin film layer of a metal oxide, metal nitride or metal carbide as an electrode active substance material through induction of a sonochemical reaction. It is found that the obtained carbon fine powder has a low electrical resistance and shows a rapid faradaic process (pseudo-capacitance) of the surface coating layer. The coated carbon fine powder, a process for producing the same, and a supercapacitor and a secondary battery using the carbon fine powder are disclosed.

There is disclosed a carbon material from which an electric double layer capacitor (EDLC) having a large capacitance can be fabricated. First, a carbon material is activated to produce crystallites of graphite-like carbon having interlayer distances of 0.365 to 0.385 nm. Positive and negative plates are fabricated using the crystallites.

A negative electrode material comprises a conductive powder of particles of a lithium ion-occluding and releasing material coated on their surface with a graphite coating. The graphite coating, on Raman spectroscopy analysis, develops broad peaks having an intensity I1330 and I1580 at 1330 cm−1 and 1580 cm−1 Raman shift, an intensity ratio I1330 / I1580 being 1.5<I1330 / I1580<3.0. Using the negative electrode material, a lithium ion secondary battery having a high capacity and improved cycle performance can be manufactured.

An asymmetric electrochemical capacitor has at least a larger capacitance electrode and a smaller capacitance electrode, with an electrolyte therebetween. The larger capacitance electrode has a larger absolute capacitance than the smaller capacitance electrode. The capacitor thus has an overall capacitance which is approximately the absolute capacitance of the smaller capacitance electrode. The electrodes may be made of different materials, with the larger capacitance electrode made of the material having a larger specific capacitance. The larger capacitance electrode may thus be the same physical size as or smaller than the smaller capacitance electrode.

Synthesis process for new particles of Li4Ti5O12, Li(4-alpha)ZalphaTi5O12 or Li4ZbetaTi(5-beta)O12, preferably having a spinel structure, wherein beta is greater than 0 and less than or equal to 0.5 (preferably having a spinel structure), alpha representing a number greater than zero and less than or equal to 0.33, Z representing a source of at least one metal, preferably chosen from the group made up of Mg, Nb, Al, Zr, Ni, Co. These particles coated with a layer of carbon notably exhibit electrochemical properties that are particularly interesting as components of anodes and / or cathodes in electrochemical generators.

The present invention provides an electrode made of carbon nanotubes or carbon nanofibers and a process for preparing the same. The electrode comprising a current collector, sulfur or metal nanoparicles as a binder, and carbon nanotubes or carbon nanofibers is characterized in that the sulfur or metal nanoparticles are bonded, deposited, or fused on the surfaces of the carbon nanotubes or carbon nanofibers so that the carbon nanotubes or carbon nanofibers are bonded to each other and also bonded to the current collector. The electrode prepared according to the present invention exhibits low internal resistance, strong durability and low equivalent series resistance, and therefore the electrode can be effectively used for secondary batteries, supercapacitors or fuel cells.

The present invention is directed to a novel capacitor. The capacitor may be used in electric double layer capacitors. The capacitors include a polarizable electrode including activated carbon and a non-polarizable electrode including lead dioxide and lead sulfate. The capacitors of the present invention provide considerably higher electric capacity, higher durability, and low resistance, while maintaining high conductivity. Additionally, the electrodes may be produced more quickly and inexpensively.

The quick recharge energy storage device has a sufficient capacity due to the combination of a micro-battery and at least one micro-supercapacitor connected between two terminals of an integrated circuit. The integrated circuit, powered by the micro-battery, monitors high-speed (less than one second) charge of the micro-supercapacitors from an external energy source. The micro-supercapacitor can be connected in parallel with the micro-battery so as to subsequently recharge the micro-battery during the necessary time. The micro-battery provides a sufficient energy capacity, while the micro-supercapacitors allow high recharging speeds compatible with various applications (smart cards, smart labels, micro-system power supply, etc . . . ). The micro-battery and micro-supercapacitors are preferably formed on the same substrate, either side by side or stacked. Series connection of several micro-supercapacitors provides sufficient voltage for charging the micro-battery.

A halogen treatment is conducted comprising: a halogenation step wherein a halogenation heat treatment for preparing a halogenated carbonized charcoal is conducted in which the carbonized charcoal is brought into contact with halogen; and a dehalogenation step wherein a dehalogenation treatment is conducted in which a part of or all halogen atoms in the halogenated carbonized charcoal are eliminated. A porous carbonaceous material is obtained at a high yield, and the amounts of nitrogen, oxygen, carbon dioxide, and methane adsorbed by this porous carbonaceous material are large. When this porous carbonaceous material is used as an electrical double layer capacitor carbon, the electrostatic capacity is increased compared to conventional carbonaceous materials. Consequently, a carbonaceous material is obtained which has micopores and / or sub-micropores which are suitable for the adsorption of small molecules such as nitrogen, and for storage of electrochemical energy.

A dry process-based particle packaging method and system is disclosed where a matrix of dry fibrillized binder is formed so as to support one or more type of particle. Reliable and inexpensive products, including films, sheets, electrodes, batteries, capacitors, fuel cells, and / or medical devices can be thus manufactured.

An electric power storage unit includes plural storage element blocks, an external bus bar for electrically connecting the storage element blocks, a base made of metal for fixing the storage element blocks, and a cover fixed to the base for accommodating the storage element blocks. Each of the storage element blocks includes plural electric power storage elements connected electrically to each other, and a case made of heat-conductive insulating resin for holding the electric power storage elements. This electric power storage unit reduces variation of cooling of the electric power storage elements, hence having high reliability.

Particular aspects provide capacitors, and particularly ultracapacitors, comprising molecules suitable to substantially increasing the capacitance of the capacitor, and methods for making same Particular aspects provide ultracapacitors that include nanoparticles optionally coated with molecules, such as polymer electrolytes. Certain aspects provide an energy storage device or capacitor, comprising at least three layers sealed in a fluid-tight covering, wherein a first layer comprises at least one electrolytic polymer molecule of positive charge and at least one nanoparticle; a second dielectric layer comprising at least one insulative polymer; a third layer comprising at least one electrolytic polymer molecule of negative charge and at least one nanoparticle. In certain aspects, the electrolytic polymer of the first layer comprises at least one high charge density polymer electrolyte of positive charge, and wherein the electrolytic polymer of the third layer comprises at least one high charge density polymer electrolyte of negative charge.