26results about How to "Reduced polarization effects" patented technology

The invention provides a silicon carbon material with a multilayer coating structure and a preparation method and application thereof, and relates to the technical field of battery materials. The silicon-carbon material with the multi-layer coating structure comprises a porous carbon core body, and a first carbon layer and a second carbon layer which sequentially coat the porous carbon core body from inside to outside, and the porous carbon core body comprises porous carbon and nano silicon particles deposited on the surface and in pore channels of the porous carbon; and a conductive nano carbon filler is dispersed in the second carbon layer. The silicon carbon material with the multilayer coating structure provided by the invention is used as a lithium ion battery negative electrode material, and has excellent specific capacity, coulombic efficiency and cycle performance. The result of the embodiment shows that when the silicon carbon material with the multi-layer coating structure is applied to the lithium ion battery, the first reversible capacity is 1882-2071 mAh / g, the first coulombic efficiency is 92.6-94.1%, and the capacity retention ratio of 100 cycles is 95.3-97.7%.

A multi-battery bidirectional charging and discharging system supporting pulse charging and discharging and a control method thereof belong to the field of power electronics, and the bidirectional charging and discharging system comprises a power factor correction (PFC) stage composed of a three-phase bridge type full-control circuit, a direct current-direct current (DC-DC) converter stage and a plurality of switching device groups. The intermittent characteristic of the pulse charging current is utilized, different battery packs are charged and discharged reasonably and alternately by staggering the conduction interval of the pulse current, the current and voltage fluctuation of the alternating current power supply side in the energy flowing process can be reduced, and the influence of the system on the stability of a power grid or other power supplies is reduced. The invention supports pulse charging and discharging, and can reduce the polarization effect of the battery, prolong the service life of the battery, improve the charging efficiency, reduce hardware equipment required by charging and reduce the cost. The system allows bidirectional flow of energy between the alternating current side and the direct current side of the system, is controllable in power, supports V2G application, and can be used for a scene in which a battery is charged or discharged by using pulse current and continuous current.

The invention provides a capacity grading method for a high-capacity battery, and the method comprises the steps: carrying out the constant-current discharge of a fully charged battery to a first discharge cut-off voltage according to a first preset current rate at a preset environment temperature, standing for a first preset time length, and enabling the first preset current rate to be smaller than or equal to the maximum continuous charging current of the battery; and performing constant-current discharge on the battery according to a second preset current rate to a second discharge cut-off voltage, standing for a second preset duration, the second preset current rate being less than or equal to the maximum continuous charging current of the battery, and the second discharge cut-off voltage being less than the first discharge cut-off voltage, so that the battery is discharged more fully, the polarization influence is reduced, and the battery quality is improved. The battery capacity obtained through capacity grading is more accurate, the battery state can be better distinguished, more microcosmic lithium is removed from the negative electrode of the battery, a part of lithium difficult to remove under high voltage can be removed, the lithium precipitation problem of the battery can be improved, the cycle life of the battery is prolonged, and the safety of the battery is improved.

The utility model provides an ultra wide band antenna, the ultra wide band antenna includes feed transmission line, ground plate, dielectric slab, radiation unit, ground plate, dielectric slab and radiation unit stack connection in proper order, feed transmission line is electrically connected with radiation unit, radiation unit includes patch antenna and via hole, and the patch antenna is electrically connected with the dielectric slab. The patch antenna is provided with the via holes, the feed transmission line is electrically connected with the patch antenna, the plurality of via holes are arranged at the edge position of the patch antenna, and the via holes penetrate through the dielectric plate and are communicated with the grounding plate. According to the patch antenna provided by the utility model, through adding the via hole, resonance which can be realized by half wave originally required can be realized with a smaller size under the condition that no slot is formed. Besides, miniaturization of the antenna area is realized, the polarization influence of the antenna is reduced, the radiation efficiency is increased, and the damage to the antenna gain is reduced, so that the positioning precision and distance are improved.

The invention belongs to the technical field of electrochemical engineering, and relates to a three-dimensional electrochemical reactor which comprises a reactor shell assembly, three-dimensional electrode modules, counter electrode modules, diaphragms or polymer partition plates and an external power supply, the counter electrode modules are arranged in pairs, and the three-dimensional electrode modules are clamped between the counter electrode modules arranged in pairs; the diaphragm or the polymer partition plate is clamped between the electrode surface of the counter electrode module and the electrode surface of the three-dimensional electrode module, and the three-dimensional electrode module, the counter electrode module and the diaphragm or the polymer partition plate are arranged in an inner cavity of the reactor shell assembly; according to the invention, the fluid can flow through the interior and surface of the three-dimensional electrode, and a main electrochemical reaction field is transferred to the interior and surface of the three-dimensional electrode, so that the sufficient flow and mixing of the fluid between the electrodes are ensured while the electrode spacing is shortened as far as possible, the solution resistance is reduced, the cell voltage is reduced, and the current efficiency is improved; and energy consumption increase and equipment damage caused by overhigh voltage are avoided.

The invention discloses a zinc negative electrode protection film based on a covalent triazine framework and an in-situ electro-deposition preparation method and application thereof, and relates to the technical field of electrochemical energy storage. An organic monomer with zinc affinity is subjected to in-situ electro-deposition on the surface of a zinc metal negative electrode to form a layer of compact and uniform CTF protective film. The protective film can effectively inhibit the growth of zinc dendrites, reduce side reactions (such as hydrogen evolution reaction), improve the electrochemical stability of a zinc negative electrode and prolong the cycle life of the zinc negative electrode.

The invention discloses a dielectric barrier discharge development process dynamic simulation method based on an equivalent circuit model. The method comprises the following steps: building a DBD experiment platform to obtain electrical, optical and particle characteristics under different experiment conditions; constructing a DBD equivalent circuit model; combining electrical characteristic experimental data obtained in the experiment without the discharge air gap with a DBD static equivalent circuit model corresponding to the electrical characteristic experimental data in analogue simulation software, and solving inherent parameters in the model by utilizing an intelligent algorithm; obtaining electrical characteristic experiment data when a discharge air gap exists; substituting the inherent parameters into a DBD dynamic equivalent circuit model, and solving the dynamic change of equivalent circuit parameters in a model discharge area by using an intelligent algorithm; and comparing the parameters and dynamic changes thereof with experimental characteristics, and analyzing a DBD development process mechanism and influence factors. The method analyzes the DBD development process from the simulation result, has the advantage of simple experiment diagnosis complex work, and is also suitable for simulation and simulation research of different power supply conditions and discharge forms.

The present invention discloses a zinc negative electrode protective film based on a covalent triazine framework and an in-situ electrodeposition preparation method and application thereof, and relates to the field of electrochemical energy storage technology. An organic monomer with zinc affinity is in-situ electrodeposited on the surface of a zinc metal negative electrode to form a dense and uniform CTF protective film. The protective film can effectively inhibit the growth of zinc dendrites, reduce side reactions (such as hydrogen evolution reaction), and improve the electrochemical stability and cycle life of the zinc negative electrode.

The application discloses a bipolar square wave excitation generation and conductivity detection circuit, a direct current bias square wave generation circuit can generate direct current bias square wave excitation signals with different frequencies; a direct current bias generation circuit generates a direct current voltage excitation; the direct current bias of the direct current bias square wave is equivalent to the size of the direct current voltage, and two signals are superposed to form a bipolar square wave excitation signal. An internal reference voltage output by an ADC is used as a voltage source of the direct current bias square wave generation circuit and the direct current bias voltage generation circuit; a node voltage of an ADC acquisition circuit is collected, so that the conductivity and temperature of a medium to be measured are obtained. The excitation and detection mode provided by the application ensures that all circuit voltages are positive voltages, simplifies the structure of the excitation and sampling circuit, is high in measurement accuracy, stable in measurement, low in power consumption and capable of meeting long-term online monitoring requirements.

The invention discloses a preparation method of a low-dislocation high-efficiency GaN substrate for a laser. The preparation method comprises the following steps: providing a heterogeneous substrate; a layer of mask is deposited on a heterogeneous substrate, the mask is further subjected to uniform glue etching to be patterned, a GaN single-crystal crystal column is grown on the basis of the patterned mask in a heteroepitaxial mode through an HVPE method, and the GaN single-crystal crystal column is subjected to linear cutting and polishing to form a product. And the GaN crystal column top layer can be used as the original substrate, and is repeatedly used after being subjected to wet etching. The method has the advantages that through mask HVPE epitaxial growth, special treatment of homogeneous epitaxy and wet etching can be utilized, so that lattice mismatch does not exist in homogeneous epitaxy, pits are formed in dislocation positions through wet etching, the epitaxy disappears during regrowth, and in addition, along with continuous increasing of the thickness, the thickness of the epitaxy is gradually increased. Dislocation extending from an original substrate interface layer can be continuously annihilated and disappeared; the top layer of the GaN crystal column generated in each cycle can be repeatedly used; the dislocation density is reduced, so that the polarization effect of the blue-green laser is reduced.

The embodiment of the invention provides a charging control method, a charging circuit and a battery module, and the method comprises the steps: determining a charging stage of a target object, the target object comprising one of a single cell, a battery module, or a battery pack; controlling a pulse charging circuit to execute charging / discharging operation on the target object at a target charging / discharging rate based on the charging stage; wherein in different charging stages, the target charging multiplying powers configured for the pulse charging circuit are different.

The invention relates to a stepped charging optimization method, a charging control device and a computer storage medium. According to a preset charging comparison table, the polarization degree of the charging process is judged in combination with a charging SOC-OCV curve, necessary shelving steps are set to eliminate the polarization influence, and overvoltage cut-off in advance is avoided. Meanwhile, the shelving time and the charging current of the next stage are controlled, and the preset charging comparison table is optimized. The optimized stepped charging scheme not only can ensure the charging efficiency of the battery, but also can avoid polarization accumulation in the battery as much as possible, so that the charging and discharging cycle is smoothly carried out. Battery loss caused by charging is reduced, and battery life is prolonged.

The application relates to a diaphragm and an electrochemical device and an electronic device comprising the same, and belongs to the technical field of electrochemical energy storage. The diaphragm comprises a porous substrate and a porous coating on at least one side surface of the porous substrate, and the porous coating comprises fibrous fillers; the fibrous fillers comprise a core layer and a shell layer on the surface of the core layer, the core layer comprises at least one of Mxene and an oxide thereof, MOFs and an oxide thereof, black phosphorus and an oxide thereof, and carbon; the shell layer comprises at least one of silicon dioxide and a lithiumophilic metal oxide; the mass ratio of the shell layer to the core layer of the fibrous fillers is M; the thermal conductivity of the diaphragm is lambda W / (m.K), the specific heat capacity is Cp J / (g.K), and the density is rho g / cm 3 ; the following relationships are satisfied: 0.010 <= (M*lambda) / (2Cp) <= 0.017 and 0.4 <= lambda / (rho*Cp) <= 1.0. The diaphragm can improve the safety performance, cycle life and rate performance of a battery.

The invention provides an all-solid-state battery capacity grading method which comprises the following steps: placing a battery in a capacity grading cabinet, and controlling the internal temperature of the capacity grading cabinet to reach a first preset temperature; performing low-current discharging operation on the battery at the first preset temperature, so that the voltage of the battery is reduced to a first preset voltage; low-current charging operation is carried out on the battery, so that the voltage of the battery is increased to a second preset voltage, and the second preset voltage is larger than the first preset voltage; the internal temperature of the capacity grading cabinet is controlled to be reduced to a second preset temperature, large-current charging operation is carried out on the battery, the voltage of the battery is made to be increased to a third preset voltage, and the third preset voltage is larger than the second preset voltage; controlling the internal temperature of the capacity grading cabinet to rise to a first preset temperature, discharging the battery, and reducing the voltage of the battery to a first preset voltage; and charging the battery to enable the voltage of the battery to meet the preset K value test voltage, and ending the capacity grading operation. By applying the method, the internal polarization degree of the battery in the charge-discharge process during capacity grading can be reduced, and the capacity grading process time is shortened.

The present invention relates to a millimeter wave switchable MIMO antenna unit, comprising a top layer, a first metal layer, a second metal layer, a third metal layer, a fourth metal layer and a bottom layer arranged in sequence from top to bottom, and also having through holes penetrating the six metal layers and four blind holes; the top layer contains 11 radio frequency switching chip patches, adopts a three-layer multiplexing structure, the first metal layer is a ground layer, the second metal layer is a control signal layer, the third metal layer is a power layer, and the fourth metal layer is a ground layer. A millimeter wave switchable MIMO antenna array comprises antenna units as above arranged in a 1×32 linear array, the polarization mode adopts vertical polarization, and the center frequency is 38.5GHZ. Compared with the prior art, the present invention has the advantages of small coupling, high reliability, clear and compact structure, high switching frequency, low cost, and can fit actual large-scale antenna base stations.

The invention discloses a method for improving the performance of a flexible solid-state battery discharge detection device based on ultrasonic catalysis. Belongs to the technical field of mutual intersection of ultrasound, fluid driving and flexible batteries, and comprises a battery bracket, a substrate, an electrolyte accommodating cavity cover, a flexible solid-state battery, an electrolyte accommodating cavity, an electrolyte, an ultrasonic transducer and an ultrasonic transducer driving circuit, according to the invention, ultrasonic waves generated by vibration of the ultrasonic vibration excitation unit are utilized to drive electrolyte flow, so that the oxidation-reduction reaction on the surface of the flexible solid-state battery electrode is catalyzed. By applying ultrasound to the flexible solid-state battery and the array battery pack, the mass transfer and electrochemical reaction rate can be effectively improved, so that the discharge performance of the flexible solid-state battery and the array battery pack is greatly improved.

Provided is a hybrid DC chain energy storage converter and a control method thereof. The hybrid DC chain energy storage converter comprises: a positive DC bus; a negative DC bus; a main circuit inductor; at least one high-frequency submodule, comprising a first switch circuit and a first capacitor connected in parallel; a plurality of low-frequency submodules, each comprising a second switch circuit and an energy storage element connected in parallel, the main circuit inductor, at least one high-frequency submodule and a plurality of low-frequency submodules are connected in series to form a series branch, and the series branch is respectively connected to the positive DC bus and the negative DC bus; a controller, coupled to the first switch circuit of at least one high-frequency submodule and the second switch circuits of the plurality of low-frequency submodules, respectively, for controlling the action of the first switch circuit of at least one high-frequency submodule according to the current of the main circuit inductor, and controlling the action of the second switch circuits of the plurality of low-frequency submodules according to the voltage of the first capacitor of at least one high-frequency submodule and the voltage of the plurality of energy storage elements.

The present invention relates to a battery bidirectional pulse charging and self-heating circuit and control method, comprising a charging and discharging circuit driven by a pulse width modulation signal and a charging circuit controlled by a charging control signal; the charging and discharging circuit driven by the pulse width modulation signal charges the battery pack when the pulse width modulation signal is at a high level, and discharges the battery pack when the pulse width modulation signal is at a low level; the charging circuit controlled by the charging control signal is turned off at low temperatures, so that the charging amount and the discharging amount of the battery pack in each pulse width modulation signal cycle are the same, and heat energy is generated inside the battery pack. The present invention can enable the battery pack to realize bidirectional pulse charging, and has the function of heating the battery pack by generating positive and negative pulse currents to the battery pack at low temperatures.

The application relates to a diaphragm and a preparation method thereof, a lithium ion battery and a power utilization device. The diaphragm comprises a base film, a lithium supplementing material and a coating. The base film has opposite first and second surfaces in the thickness direction thereof, the first surface has a convex structure, the convex structure has a through hole, the second surface has a recess on the surface opposite to the convex structure, the through hole and the recess are communicated, the inner diameter of the recess at the second surface is greater than the hole diameter of the through hole, the convex structure is multiple, and the multiple convex structures are arranged at intervals; the lithium supplementing material is located in the recess; and the coating is coated on the second surface and covers the recess. The diaphragm has the functions of liquid retention and lithium supplementing, can not only inhibit the capacity attenuation of the lithium ion battery but also reduce the falling risk of the lithium supplementing material.

The invention discloses an aqueous solution conductivity monitor, which comprises a main processor, a conductivity acquisition circuit, a display unit and a square wave excitation circuit, and is characterized in that the conductivity acquisition circuit, the display unit and the square wave excitation circuit are respectively connected with the main processor; the square wave excitation circuit comprises a power conversion circuit, a square wave control circuit, a square wave amplitude switching circuit and a current amplification circuit which are connected in sequence; the conductivity acquisition circuit is connected to a conductivity electrode, and the conductivity electrode is connected with the current amplification circuit. According to the aqueous solution conductivity monitor, based on the arrangement of the square wave excitation circuit, the frequency and amplitude of the square wave voltage signal of the square wave excitation circuit can be controlled through a program of the main processor, and the aqueous solution conductivity monitor has a variable frequency adjustment function, so that conductivity online monitoring can be switched back and forth in different frequency bands; according to the invention, other measured pulse signals can be effectively distinguished, and the polarization effect of the conductivity electrode can be reduced.

The invention provides a pole piece preform, a pole piece and a battery, and aims to solve the technical problem of concentration polarization in the pole piece. The pole piece preform comprises a current collector, a first initial active material layer and a second initial active material layer which are sequentially stacked; a first pore-forming agent with the mass content of w1 is dispersed in the first initial active material layer, and the average particle size of the first pore-forming agent is d1; a second pore-forming agent with the mass content of w2 is dispersed in the second initial active material layer, and the average particle size of the second pore-forming agent is d2; wherein # imgabs0 #

The present invention discloses a silver electrode material with an ordered straight-through pore structure, wherein a columnar structure array composed of silver nanoparticles is distributed on the surface of the silver electrode material, and the gaps between the columnar structures are straight or approximately straight straight-through pores in the direction perpendicular to the surface of the silver electrode material; wherein the lateral size of the columnar structure is 0.1 to 20 μm, the height of the columnar structure is 0.2 to 1.4 mm, and the gaps between the columnar structures are 0.01 to 10.0 μm. The straight-through pore structure is conducive to improving the diffusion rate of the electrolyte, improving the exchange rate of reactants and products on the electrode surface during the electrochemical reaction, and improving the reaction rate; at the same time, the conductivity of the columnar structure composed of nanosilver is higher than that of the ordinary silver powder electrode, which is conducive to the transmission of electrons in the electrode body. Therefore, the polarization effect and overpotential of the silver electrode material in the present invention are lower, and the electrochemical performance is better. In addition, the present invention also provides a preparation method of the silver electrode material, which is simple in process, easy to operate, convenient in parameter control, more flexible in process, and higher in preparation efficiency.

The invention belongs to the field of organic thin film packaging materials, and particularly discloses a photosensitive resin composition for packaging a photoelectron component and a use method of the photosensitive resin composition, and the photosensitive resin composition comprises the following components in parts by mass: 20-50 parts of an ultraviolet curable monomer, 2-8 parts of a photo-crosslinking initiator and 5-30 parts of functional dispersion liquid. Wherein the ultraviolet light curable monomer is formed by mixing (methyl) acrylate containing a long carbon chain and a bridged ring light curable monomer according to a specific mass ratio; the functional dispersion liquid comprises a monofunctional group reaction monomer and hollow microspheres, and the surfaces of the hollow microspheres are connected with organic modification groups. The photosensitive resin composition is excellent in comprehensive performance, the viscosity and surface tension of the photosensitive resin composition meet the range of ink-jet printing requirements, the photosensitive resin composition has high curing rate, light transmittance and refractive index, especially the dielectric constant can be controlled to be 2 or below, and the photosensitive resin composition has excellent mechanical property and water and oxygen isolation capacity and provides material support for packaging of related electronic components.

The invention relates to the technical field of preparation of electrochemical power supply materials, in particular to a vanadium-chlorine co-doped lithium iron phosphate material and a preparation method thereof. The preparation method comprises the following steps: step 1, mixing all materials into a parent raw material; 2, ball-milling and drying the raw materials to obtain a precursor; according to the vanadium and chlorine co-doped lithium iron phosphate material and the preparation method thereof, the method for preparing the vanadium and chlorine co-doped lithium iron phosphate material is simple, mature and low in cost, a V-Cl doped LiFePO4 sample is prepared by a simple carbon thermal reduction method, and the crystallinity is good; what's more important is that lattice of LiFePO4 is distorted, Li < + > mobility is increased due to reduction of Li-O bond energy in the lattice, meanwhile, structural stability of the material is improved due to increase of P-O bond energy, electrochemical test shows excellent cycling stability and rate capability, polarization effect is weakened, Li < + > diffusion coefficient is increased, and especially, vanadium and chlorine are doped, so that the performance of the material is greatly improved. And high-speed rapid charging and discharging are realized.

This invention belongs to the field of battery cathode material technology, specifically relating to a high-rate manganese-based cathode material, its preparation method, and its application. The material, from the inside out, consists of a manganese-based active core, a mesoporous fast-ion conductor shell, and a pretreatment layer formed in situ from boron-containing compounds coated on the surface of the manganese-based active core. A functionalized carbon nanotube three-dimensional conductive network permeates the active core and shell. This invention achieves this by pretreating the manganese-based active core with boron-containing compounds in a liquid phase to form a surface pretreatment layer, sequentially oxidizing and functionalizing the carbon nanotubes and then lithium-modifying them to construct an embedded three-dimensional conductive network, followed by ball milling and ultrasonic dispersion to prepare a precursor sol and coating it to form a fast-ion conductor shell, and finally, template-assisted calcination to construct a mesoporous structure, thus obtaining a high-rate manganese-based cathode material. This invention effectively inhibits manganese ion dissolution and material structure collapse through multi-structure synergy, improving the high-rate performance and cycle stability of the material, and possesses good industrialization prospects.

The invention discloses an ultrapure water total organic carbon real-time monitoring method and system based on bidirectional excitation, and relates to the field of organic carbon monitoring. Firstly, reference conductivity is obtained through default frequency, and then adaptive matching is performed on an excitation mode by using a bidirectional feedback regulation mechanism; therefore, the polarization effect in ultrapure water measurement is eliminated, and the signal acquisition quality is optimized. Aiming at the influence of environment temperature fluctuation, nonlinear correction is carried out on actually measured conductivity and temperature parameters through temperature sensing verification and data cleaning, and the limitation of traditional linear compensation is overcome. In addition, according to the method, ignition parameters of the ultraviolet lamp are brought into a calculation model, the oxidation efficiency correction coefficient is dynamically adjusted according to the accumulated working time, and measurement errors caused by light source aging are effectively counteracted. And finally, standard curve inversion and multi-channel differential operation are combined to realize high-stability and high-precision total organic carbon real-time monitoring.