413results about How to "Improve power performance" patented technology

The present application is directed to hard carbon materials. The hard carbon materials find utility in any number of electrical devices, for example, in lithium ion batteries. Methods for making the disclosed carbon materials are also disclosed.

Provided herein are electrolytes for lithium-ion electrochemical cells, electrochemical cells employing the electrolytes, methods of making the electrochemical cells and methods of using the electrochemical cells over a wide temperature range. Included are electrolyte compositions comprising a lithium salt, a cyclic carbonate, a non-cyclic carbonate, and a linear ester and optionally comprising one or more additives.

The invention discloses a super capacitor-based electric automobile hybrid power control system. The system comprises a super capacitor, a power storage battery, a motor, a motor driving control device, a vehicle-mounted measuring unit, a first bidirectional direct current (DC)/DC converter and a second bidirectional DC/DC converter, wherein the motor driving control device is connected with the motor; the vehicle-mounted measuring unit is connected with the motor driving control device through a controller area network (CAN) bus; the first bidirectional DC/DC converter is connected between the super capacitor and the motor driving control device; and the second bidirectional DC/DC converter is connected between the power storage battery and the motor driving control device. Through the system, the super capacitor provides high-power current when an electric automobile is started and accelerated and climbs, so that the power performance of the entire automobile is enhanced; instant heavy current generated by a generator is quickly stored during braking; the braking feedback energy is absorbed; the energy is saved; and the cyclic service life of the storage battery is prolonged. By using the system, the power performance and the economy of the electric vehicle are improved, the storage battery is protected, and the stability of the system is enhanced.

The invention relates to a method for preparing nitrogen-doped porous carbon nanofiber cloth. The nitrogen-doped porous carbon nanofiber cloth is prepared by adding a nitrogen-rich compound into an organic solution, electrospinning and subsequent carbonizing-activating, has a self-support structure, omits preparation steps of size mixing, coating and the like, needs no conductive agent or binder, and can be directly used as the negative electrode of a lithium ion battery. The electrochemical performance of the negative electrode material of the lithium ion battery is improved by doping nitrogen and activating and forming pores; compared with a commercial graphite lithium ion battery negative electrode material, the nitrogen doping porous carbon nanofiber cloth used as the negative electrode material of the lithium ion battery has simple steps for preparing the electrode, has higher specific capacity, good power performance and circulatory stability. The method also can be used as the electrode material of super capacitors and other novel batteries.

The present invention is a positive electrode active material that can be used in secondary lithium and lithium-ion batteries to provide the power capability, i.e., the ability to deliver or retake energy in short periods of time, desired for large power applications such as power tools, electric bikes and hybrid electric vehicles. The positive electrode active material of the invention includes at least one electron conducting compound of the formula LiM¹_x−y{A}_yO_z and at least one electron insulating and lithium ion conducting lithium metal oxide, wherein M¹ is a transition metal, {A} is represented by the formula Σw_iB_i wherein B_i is an element other than M¹ used to replace the transition metal M¹ and w_i is the fractional amount of element B_i in the total dopant combination such that Σw_i=1; B_i is a cation in LiM¹_x−y{A}_yO_z; 0.95≦x≦2.10; 0≦y≦x/2; and 1.90≦z≦4.20. Preferably, the lithium metal oxide is LiAlO₂ or Li₂M²O₃ wherein M² is at least one tetravalent metal selected from the group consisting of Ti, Zr, Sn, Mn, Mo, Si, Ge, Hf, Ru and Te. The present invention also includes methods of making this positive electrode active material.

The invention relates to a preparation method of a silicon/graphene laminar composite material for lithium ion battery cathode. The composite material adopts a laminar sandwich structure, silicon nano-particles are dispersed on each lamina of the grapheme, the laminas of the grapheme are separated from one another by the silicon nano-particles and the edges of the laminas are in lapped joint so as to constitute a laminar conductive network structure. The preparation method thereof comprises the steps of: formulating anhydrous silicon tetrachloride, surface active agent, sodium naphthalene and graphite oxide to tetrahydrofuran solution, adding the tetrahydrofuran solution into a reactor for reaction in vacuum at the temperature ranging from 380 to 400 DEG C, filtering the reactant to result in the product, and then washing, drying and heating the product to obtain the silicon/grapheme composite material. The preparation method of the invention has the advantages of simple preparation process and great easiness for industrial production; and the silicon/graphene laminar composite material prepared according to the method includes excellent conductivity, power performance, electrochemical activity and cycle stability, and is particularly suitable for manufacturing lithium ion battery cathode.

The present application is directed to hard carbon materials. The hard carbon materials find utility in any number of electrical devices, for example, in lithium ion batteries. Methods for making the disclosed carbon materials are also disclosed.

A brushless electrical machine, usable as a motor, generator, or alternator, has a rotor that is comprised of a rim portion and a substantially open center portion. The rim portion has a partially hollow core in which a stationary field coil is supported. Current to the field coil generates magnetic flux that circulates in a poloidal flux path in the rim, crossing a single magnetic air gap formed by the rim. Protrusions in the rim located around the circumference form poles all having the same polarity. As the rotor rotates, the flux exiting the poles passes through multiple stationary armature windings around the circumference that are located in the single air gap. An AC voltage is induced in the armature windings from rotation.

An organic transistor is capable of emitting light at high luminescence efficiency, operating at high speed, handling large electric power, and can be manufactured at low cost. The organic transistor includes an organic semiconductor layer between a source electrode and a drain electrode, and gate electrodes shaped like a comb or a mesh, which are provided at intervals approximately in the central part of the organic semiconductor layer approximately parallel to the source electrode and the drain electrode. The organic semiconductor layer consists of an electric field luminescent organic semiconductor material such as compounds of naphthalene, anthracene, tetracene, pentacene, hexacene, a phthalocyanine system compound, an azo system compound, a perylene system compound, a triphenylmethane compound, a stilbene compound, poly N-vinyl carbazole, and poly vinyl pyrene.

The invention relates to the technical field of lithium ion batteries, in particular to core-shell structured carbon for a cathode material of a lithium ion battery and a preparation method thereof, and the lithium ion battery taking the core-shell structured carbon as the cathode material and a preparation method thereof. The core-shell structured carbon comprises a hard carbon material serving as a 'core' and soft carbon 'shell' which is coated on the surface of the 'core'. On the one hand, the hard carbon material serving as the 'core' provides a large number of spaces for storing lithium and channels for lithium ions to move, and the energy density and power density of the material are improved, and on the other hand, the soft carbon 'shell' with a graphite structure ensures that the material has high coulombic efficiency and cycle performance, so that the lithium ion battery made of the core-shell structured carbon serving as the cathode material has high capacity, high power characteristic, high cycle performance and high first charge and discharge coulombic efficiency, the preparation method is simple, and the cost is low.

A high power high temperature superconductive circuit for use in various microwave devices including filters, dielectric resonator filters, multiplexers, transmission lines, delay lines, hybrids and beam-forming networks has thin gold films deposited either on a substrate or on top of the high temperature superconductive film. Alternatively, other metal films can be used or a plurality of dielectric films can be used or a dielectric constant gradient substrate can be used. The use of these materials in a part or parts of a microwave circuit reduces the current density in those parts compared to the level of current density if only high temperature superconductive film is used. This increases the power handling capability of the circuit.

An integrated circuit device package with a first part (101) having a cavity (104) to mount the chip (105), further I/O terminals (102) on the top surface and terminals (103) on the bottom surface. The chip has contact pads (107a and 107b). The second part (110) of the package has bottom surface terminals (111) aligned with the chip contact pads, and bottom terminals (112) aligned with the terminals (102) of the first package part. The connections are provided by stud bumps between the chip contact pads and terminals (111), and by reflow material between terminals (102) and (112). The connector lines (109a and 109b) in the second package part (110) comprise signal/power and ground layers. The layers are spaced by insulation between, 10 and 50 μm thick, and the connector lines have a width less than three times the insulator thickness.

A vertically polarized traveling wave antenna is omnidirectional, bottom-mounted, and bottom-fed. A robust center coax provides a self-supporting mechanical structure. Multiple dipoles are capacitively coupled to the coax in quads, with a first two dipoles placed on opposite sides of the center coax and spaced by a quarter wavelength along the coax from the second two, which couple at right angles to the first two. This matched-layer spacing cancels the reactive components of the impedances of the dipoles. Beam tilt is readily incorporated over a wide range by adjusting layer spacing to add phase taper. All dipoles are oriented parallel to the coax axis, with opposite “hot” (center coupled) dipole elements oriented oppositely to each other. A radiated signal thus has rotating phase, when viewed from above, but is vertically polarized at each azimuth. A lightweight radome, provided for weather protection, is not needed for structural integrity.

An apparatus and method for providing a power scanning in a terminal with two or more Radio Frequency (RF) chips are provided. The method includes selecting one RF chip from the two or more RF chips, performing the power scanning on a full band supported by the selected RF chip by using the selected RF chip, gathering a power scanning result obtained by performing the power scanning, and sharing the power scanning result gathered by using the selected RF chip with an unselected RF chip.

The invention relates to a carbon-clad spinel lithium titanate Li4MxTiyO12 material used as a lithium ion battery cathode material, a production method and an application thereof. The cathode material is spinel type Li4MxTiyO12 or a mono or multiple other metallic element-doped compound Li4MxTiyO12. A synthetic method comprises the following steps: mixing an organic titanium solution and lithium salt liquid to prepare sol; aging the sol to obtain a lithium titanate gel predecessor; calcining the gel predecessor, and being conversed to the spinel lithium titanate material with nano size; or comprises the following steps: dispersing the prepared lithium titanate in a carbon source organic solution, removing the solution, and calcining to obtain the spinel lithium titanate/carbon composite material with nano size. Compared with lithium titanate Li4Ti5O12 prepared by a conventional method, the spinel lithium titanate material has better multiplying power characteristic, when the spinel lithium titanate material is used as a lithium ion battery cathode, the power performance of the cell can be obviously increased.

The invention discloses a silicon-based negative electrode of a lithium ion battery and a method for preparing the silicon-based negative electrode of the lithium ion battery. The silicon-based negative electrode is prepared by coating a copper foil with negative electrode slurry. The negative electrode slurry is prepared from, by weight, 15.0-18.0 parts of graphite, 1.0-2.0 parts of nano silicon powder, 0.3-2.5 parts of conductive agent, 1.0-8.0 parts of binding agent, 1.0-1.5 parts of thickening agent and 70.0-80.0 parts of dispersing medium. By adoption of a polystyrene-polybutyl acrylate- polystyrene block polymer binding agent which is extremely high in silicon binding force and capable of providing high elasticity, volume variation of silicon in charging and discharging can be counteracted, and performances of a graphene-based negative electrode of the lithium ion battery are improved. The prepared high-energy-density negative electrode is 514mAh/g in energy density during 0.1C charging and discharging, and the power negative electrode is 349mAh/g in energy density in 2C charging and discharging. The silicon-based negative electrode of the lithium ion battery and the method for preparing the silicon-based negative electrode of the lithium ion battery have the advantages of easiness in raw material acquisition, technical simplicity and environment friendliness.

The invention discloses a torque distribution method for a four-wheel drive system of an electric automobile. The method includes the steps of collecting operation state parameters of the electric automobile, judging operation working conditions of the electric automobile according to the operation state parameters of the electric automobile, obtaining whole state information of the electric automobile, and distributing the torque of the four-wheel drive system according to the operation working conditions and the whole state information of the electric automobile. By means of the torque distribution method for the four-wheel drive system of the electric automobile, the torque of the four-wheel drive system can be automatically distributed, and the torque of one wheel can be independently controlled; the method is convenient and flexible, the power property of the electric automobile is effectively improved, fuel consumption economy and driving comfort of the electric automobile are greatly improved, and safety is high. The invention further discloses a torque distribution device for the four-wheel drive system of the electric automobile.

A switching power supply circuit uses a magnetic material that is harder to be magnetically saturated than ferrite as a core of a transformer or a choke coil and suitably protects a switching element. The circuit includes a transformer having a core made of a magnetic material of amorphous metal, a primary-side winding and a secondary-side winding. The circuit further includes a switching element for flowing current through the primary-side winding of the transformer according to a pulsive drive signal, and a primary-side current detection circuit for detecting the current flowing through the primary-side winding. The circuit further includes plural circuit elements for rectifying and smoothing a voltage generated in the secondary-side winding of the transformer to generate an output voltage, and a control circuit for generating the drive signal based on at least a detection result of the primary-side current detection circuit, and limiting a period for flowing the current in the primary-side winding.

A semiconductor power switch comprises at least a first IGBT and a second IGBT. The collectors of the first and second IGBTs are connected to each other, and the emitters of the first and second IGBTs are connected to each other. The first IGBT is an IGBT type with a comparatively low collector-emitter on-voltage and a comparatively high turn-on or turn-off switching energy. In contrast thereto, the second IGBT is an IGBT type with a comparatively high collector-emitter on-voltage and a comparatively low turn-on or turn-off switching energy. Both IGBTs receive gate signals from a control circuit for switching the power switch on during a first time interval and switching the power switch off during a second time interval. The control circuit is designed to supply an on-signal to the second IGBT during the whole first time interval and another on-signal to the first IGBT during only a part of the first time interval, which is less than the whole.