1344 results about "Positive current" patented technology

The invention belongs to the technical field of lithium ion batteries, and particularly relates to a lithium ion battery with improved low-temperature charging-discharging performance and a preparation method thereof. The lithium ion battery comprises a naked core which is formed by overlapping a positive plate, an isolating membrane and a negative plate in sequence and winding along the same direction, and electrolyte thereof, wherein the positive plate comprises a positive current collector and a positive diaphragm with which the positive current collector is coated; the negative plate comprises a negative current collector and a negative diaphragm with which the negative current collector is coated; a first blank area is formed at one end of the positive current collector; a first conductive terminal is welded in the first blank area; a second black area is formed at one end of the negative current collector; a second conductive terminal is welded in the second blank area; the other end of the positive current collector and/or the negative current collector is provided with a third blank area; a third conductive terminal is arranged in the third blank area. In the lithium ion battery, the third conductive terminal is arranged on a plate, and is used for heating the battery at a low temperature, so that the battery can be kept at a normal temperature, and the charging-discharging performance of the battery at a low temperature is improved.

The invention relates to a positive plate and a lithium ion battery comprising the same. The positive plate comprises a positive current collector, a first active material layer, a buffer layer and a second active material layer, wherein the first active material layer, the buffer layer and the second active material layer are arranged on the positive current collector; the first active material layer is arranged on the positive current collector and comprises a first positive active material; the buffer layer comprises a carbon material and a binder; the second active material layer comprises a second positive active material; and the buffer layer is arranged between the first active material layer and the second active material layer. After the positive plate provided by the invention is applied to the lithium battery, the safety performance of the lithium ion battery can be improved; and the cycle performance of the lithium ion battery can be improved.

The invention provides a positive plate of a lithium ion battery. The positive plate comprises a positive current collector and a positive active substance layer, wherein the positive active substance layer is coated on the positive current collector and contains a positive active substance, a conductive agent, a binding agent and a lithium-rich compound, and the lithium-rich compound decomposes to generate lithium ions and release one or more of a gas, conductive carbon and a substance having electrochemical lithium storage activity during formation charging of the lithium ion battery. The generated lithium ions are transferred to a negative electrode from a positive electrode and take participation in reaction with the negative electrode (react with a decomposed product of an electrolyte to form an SEI film at the negative electrode) to supplement to lithium required for forming the SEI film, thus, the lithium ion consumption of the positive active substance can be reduced, and the energy density and the cycle performance of the lithium ion battery are improved. The invention also provides a preparation method for the positive plate of the lithium ion battery, the lithium ion battery applying the positive plate of the lithium ion battery and a preparation method of the lithium ion battery.

A monolithic switching device including a main semiconductor region configured to provide a current-carrying channel as in the form of two-dimensional electron gas. Disposed symmetrically on a surface of the main semiconductor region are two main electrodes to be coupled to an electric circuit for switching control, two gate electrodes for individually controlling current flow between the main electrodes through the current-carrying channel, and two diode-forming electrodes electrically connected respectively to the two main electrodes. The device operates in either Switch On Mode, Switch Off Mode, Negative Current Mode, or Positive Current Mode depending upon voltages applied to the two gate electrodes.

A composite, high-temperature resistant, non-carbon metal-based anode of a cell for the electrowinning of aluminium comprises a metal-based core structure of low electrical resistance, for connecting the anode to a positive current supply, coated with a series of superimposed, adherent, electrically conductive layers. These layers consist of at least one layer on the core structure constituting a barrier substantially impervious to monoatomic oxygen and molecular oxygen; one or more intermediate, protective layers on the oxygen barrier layer which remain inactive in the reactions for the evolution of oxygen gas; and an electrochemically active layer for the oxidation reaction of oxygen ions present at the anode/electrolyte interface into nascent monoatomic oxygen, as well as for subsequent reaction for the formation of gaseous biatomic oxygen. The active layer on the outermost intermediate layer is slowly consumable during electrolysis and protects the intermediate protective layer by inhibiting its dissolution into the electrolyte.

A controllably alternating buck mode DC-DC converter conducts cycle by cycle analysis of the direction of inductor current flow to decide whether to operate in synchronous buck mode or standard buck mode for the next successive cycle. For each cycle of the PWM waveform controlling the buck mode DC-DC converter, a mode control circuit examines and latches data representative of the direction of inductor current flow relative to the chargeable battery. If the inductor current flow is positive, a decision is made to operate in synchronous buck mode for the next PWM cycle, which allows positive current to charge the battery; if the inductor current drops to zero, a decision is made to operate the converter in standard buck mode for the next PWM cycle, so as to prevent current from flowing out of the battery and boosting the system bus.

There is provided an improved TIG welder comprising a power source for performing an AC TIG welding process across an electrode and a workpiece with a controller for creating an AC waveform. The controller having a synergic input device with an input for receiving a signal level representing a desired set current for the welding process and an output signal determining an aspect of the waveform and representing a non-linear relationship between peak positive current and peak negative current for certain desired set welding currents.

Recrystallized lead and lead alloy positive current collectors and connectors such as straps and lugs for use e.g. in lead acid batteries and electrowinning anodes, having an increased percentage of special grain boundaries in at least part of the microstructure, which have been provided by a process comprising of (i) cold or hot rolling or cold or hot extrusion or (ii) steps of deforming the lead or lead alloy, and subsequently annealing the lead or lead alloy. Either a single cycle of working and annealing can be provided, or a plurality of such cycles can be provided. The amount of deformation, the recrystallization time and temperature, and the number of repetitions of such steps are selected to ensure that a substantial increase in the population of special grain boundaries is provided in the microstructure, to improve resistance to creep, intergranular corrosion and intergranular cracking of the current collectors and connectors during battery service, and result in extended battery life and the opportunity to reduce the size and weight of the battery.

A composite high voltage schottky rectifier is revealed that provides a forward voltage slightly larger than a low voltage schottky rectifier combined with a high voltage breakdown capability. The composite rectifier can be formed from the combination of a low voltage schottky rectifier, a high voltage mosfet, and a few small passive components. A quarter bridge primary switching network similar in some ways to a half bridge primary switching network is revealed. The quarter bridge network consists of four switches with voltage stress equal to half the line voltage and the network applies one quarter of the line voltage to a primary magnetic circuit element network thereby reducing the number of primary winding turns required to one quarter by comparison to a common full bridge network. A synchronously switched buck post regulator is revealed for multi-output forward converters. The synchronously switched buck post regulator accomplishes precise independent load regulation for each output and reduced magnetics volume by using a coupled inductor with a common core for all outputs plus a second smaller inductor for each output except the highest voltage output. An improved capacitor coupled floating gate drive circuit is revealed that provides an effective drive mechanism for a floating or high side switch without the use of level shifting circuits or magnetic coupling. The capacitor coupled floating gate drive circuit is an improvement over prior art capacitor coupled floating gate drive circuits in that the new circuit uses a positive current feedback mechanism to reject slowly changing voltage variations that cause unintentional switch state changes in prior art capacitor coupled floating gate drive circuits.

The storage cell comprises a flat roll electrode that includes a strip of positive electrode having a positive electrode current collector foil and a positive electrode layer formed thereon, a strip of negative electrode having an electrode current collector foil and a negative electrode layer formed, and a strip of electrically insulated separator, the strip of positive electrode and the strip of negative electrode being wound into a flat roll configuration with the strip of electrically insulated separator sandwiched therebetween; a sealed casing that hermetically seals the flat roll electrode impregnated with an electrolyte; a positive terminal and a negative terminal each electrically insulated from the sealed casing, connected to the positive current collector foil and the negative current collector foil, respectively.

Systems and methods for determining self-discharge currents in an energy storage cell and detecting internal shorts are disclosed. A system includes a DC voltage source configured to provide a constant test voltage selected to be less than an open-circuit voltage of an energy storage cell to the energy storage cell. The system also includes a current measuring device operably coupled between the DC voltage source and the energy storage cell, and control circuitry operably coupled to the current measuring device. A method includes applying the constant test voltage, and measuring the test current flowing between the DC voltage source and the energy storage cell until after the test current switches from a negative current to a positive current. The method also includes determining a self-discharge current of the energy storage cell by analyzing the measured test current with computational models that capture physical processes tied to the test methods.

The invention discloses a lithium-rich manganese-based power battery which comprises a positive plate, a negative plate and a diaphragm, wherein the positive plate comprises a positive current collector and a positive pole material coated on the positive current collector, the negative plate comprises a negative current collector and a negative pole material coated on the negative current collector, the positive pole material comprises a positive pole active substance, a positive pole conductive agent and a positive pole binding agent, the positive pole material further comprises a toughener and an activating agent, the positive pole active substance is of lithium-rich manganese-based, and the general formula of the lithium-rich manganese-based power battery is xLi2MnO3.(1-x) LiYO2, wherein Y is one or more of Co, Mn, Ni and Cr, x is more than 0 and less than 1, and the compacted density and the electric capacity of the battery are high. The invention further discloses a preparation method of the lithium-rich manganese-based power battery, and the lithium-rich manganese-based power battery prepared by the preparation method disclosed by the invention has the advantages of high energy density, high discharge capacity and the like.

The invention discloses a forward-flyback converter with an active clamping circuit. The secondary side output of the converter comprises a flyback sub-circuit operating in a continuous conduction mode and a forward sub-circuit operating in a non-continuous conduction mode. Under over-load output, the converter uses a zero voltage switching mechanism of an active clamping flyback sub-circuit to provide sufficient resonance current; and under light-load output, the converter prolongs the time that the resonance current is converted from negative current into positive current to ensure that a switch realizes zero voltage switching, and reversal of biasing of a diode of the flyback sub-circuit is designed, so that the sub-circuit can not continue to work and unnecessary element power loss canbe reduced. Thus, the converter can simultaneously take account of the conversion efficiencies of over-load output and light-load output under a wide load fluctuation range.

A nickel-zinc battery cell is formed with a negative can, a positive cap, and a jelly roll of electrochemically active positive and negative materials within. The inner surface of the can is protected with an anticorrosive material that may be coated or plated onto the can. Good electrical contact between the jelly roll and the cap is achieved through folding the nickel substrate over to contact a positive current collection disk.

A rapid charge lithium-ion battery comprises a positive plate, a negative plate, a separator disposed at intervals between the positive plate and the negative plate, and an electrolyte. The positive plate includes a positive current collector and a positive active material layer disposed on a surface of the positive current collector; the positive active material layer includes a positive active material, a positive conductive agent and a positive adhesive; the positive active material includes a component A and a component B; the component A is selected from at least one of lithium nickel cobalt aluminum oxide (NCA), lithium nickel cobalt manganese oxide (NCM), lithium manganese oxide (LMO) and lithium cobalt oxide (LiCoO₂); the component B is selected from at least one of lithium iron phosphate (LFP) and lithium titanium oxide (LTO); and the component B accounts for 5 to 90 percent by mass of the positive active material.

The invention refers to the electrodes of lithium ion battery and making method, as well as the lithium ion battery. Mix positive and/or negative active substrate powder 85-98%, electric agent 0.5-10%, and water-based adhesive 1.5-10% according to weight percentage, add in water to adjust into 4000-12000mPa*s plasm; smear the plasm on two surfaces of positive current collector aluminum foil and/or negative current collector copper foil; roll and slice to obtain the electrodes. It can be widely applied to the making field of lithium ion battery.

The invention relates to a switch control circuit, a power supply including the same, and a method for driving the power supply. The power supply includes: a first switch; a second switch coupled in series to the first switch; a transistor coupled to a node where the first switch and the second switch are coupled; a resonance capacitor coupled between the transformer and a primary side ground and to which a resonance current flows; a sense circuit generating a first sense voltage that depends on the resonance current when the resonance current is a positive current; and a switch control circuit detecting a zero voltage switching failure by sensing the resonance current using the first sense voltage at a turn-off time of the first switch for every switching cycle of the first and second switches.

The invention relates to a solid oxide fuel battery cathode material and a preparation method thereof. The chemical formula of the material is MxA(1-x)M`yB(1-y)O(3-Delta). The material is prepared by adopting an EDTA-citrate combination and complexation method or a glycine combustion method. The cathode material can be smeared onto the electrolyte surface by screen printing, spraying, dip coating or flow casting, and then calcined at high temperatures to obtain a cathode catalyst layer. The catalyst layer is in the working state, that is, the negative current passes through the electrode, so that the precious metal oxides can obtain electrons to take the reduction reaction, emerge out of the lattice of the perovskite or perovskite-like ceramic material to enrich on the surface of the material and to form the precious metal-ceramic composite cathode. The precious metals can be re-oxidized and enter the ceramic oxide lattice when the positive current passes through the electrode.

The invention provides an aqueous rechargeable magnesium/zinc ion capacitor battery. A positive plate comprises a positive current collector and a coating layer, wherein the coating layer is coated on the positive current collector and contains a positive active substance which is lambda-MnO2 in a three-dimensional tunnel spinel structure. A negative plate comprises a negative current collector and a coating layer, wherein the coating layer is coated on the negative current collector and contains a negative active substance which is a carbon-based material of an ion-adsorption/desorption super-capacitor in a porous structure. An electrolyte solution is a water solution containing magnesium ions or zinc ions. The concentration of the magnesium ions or the zinc ions in the electrolyte solution is 0.5mol/L to 10mol/L. By virtue of the aqueous electrolyte solution, the cost is reduced, the safety performance is improved, and environmental pollution is avoided; the aqueous rechargeable magnesium/zinc ion capacitor battery is long in cycle life, large in energy density and applicable to large-current charge and discharge, and is power storage equipment with wide application prospect.

A flyback converter implements a Forced Zero Voltage Switching (ZVS) timing control by detecting a positive current excursion of the secondary winding current as the synchronous rectifier turn off trigger. The synchronous rectifier switch is turned on near the end of the switching cycle or the on duration is extended to develop a current ripple on the secondary winding current. The control circuit of the flyback converter detects a positive current excursion on the secondary winding current to turn off the synchronous rectifier and to start the next switching cycle. At this point, the voltage across the primary switch has been discharged and the primary switch can be turned on with zero drain-to-source voltage. In other embodiments, zero voltage switching for the off-transition of the primary switch is realized by coupling a capacitor across the primary switch or by coupling a capacitor across the primary winding, or both.