412 results about "Active particles" patented technology

According to the plasma aquaculture water purification method and system, a cold plasma directional screening technology is used as a core to construct a cold plasma water treatment module, a nanosecond pulse plasma generator is used for exciting a gas medium to form cold plasma, active particles are screened in situ through a directional screening assembly, and the cold plasma water treatment module is used for purifying aquaculture water. The method comprises the following steps: introducing ammonia nitrogen into a water body, guiding < 1 > O2 to be quickly injected into the water body, instantaneously completing a primary purification reaction in a gas-liquid intersection chamber, further, in order to fully utilize residual active particles, directionally converting a reaction precursor O3 of < 1 > O2 into < 1 > O2 through a catalytic dissociation module, and completing a secondary purification reaction between the < 1 > O2 and the ammonia nitrogen. Ammonia nitrogen is directionally converted into nitrogen by utilizing a 1O2-dominated non-free radical reaction path, the content of ammonia nitrogen and total inorganic nitrogen in a water body is reduced, and after purification is completed, oxidizing components in the water body and tail gas are respectively removed by adopting a by-product removal assembly, so that the use safety is guaranteed.

The invention relates to the technical field of intelligent fire extinguishing control of energy storage power stations, in particular to a method and system for plasma protection of thermal runaway of an air-cooled energy storage power station. The method comprises the following steps: processing real-time data acquired by a multi-source sensor through a dynamic risk assessment model to obtain a risk level and an early warning level; an initial control instruction for the plasma generator and the air cooling and refrigerating system is formed according to the risk level and the early warning level; the initial control instruction is processed to form a driving control signal; a control signal is subjected to cooperative execution processing to obtain a high-energy active particle jet flow, a forced airflow and a refrigeration effect. The system comprises an air cooling box body, a battery, a fan, a plasma generator, an ejector, an intelligent controller, a compressor, a gas-liquid separator, a heat exchanger, an electronic expansion valve, a drying filter, a gas sensor and a pressure sensor valve. The safety and reliability of the energy storage power station are improved.

The invention relates to the technical field of batteries, and discloses a roll core and a battery. The roll core comprises a positive plate, a negative plate and a diaphragm, a groove is formed in a positive active layer of the positive plate, and the groove is at least formed in an arc section, closest to the winding center, of the positive plate, so that the thickness of at least partial region on the arc section of the positive plate is reduced, and the risk that active particles on the positive plate pierce the diaphragm is reduced; according to the present invention, by limiting the ratio p1 / H1 between the thickness p1 of the functional layer of the diaphragm and the depth H1 of the groove to be in the range of 0.02-2, the p1 is in the range of 0.3-10 [mu] m, and the H1 is in the range of 3-40 [mu] m, such that the battery can be reduced to the preset charging cut-off current during the charging process, and the self-discharge rate of the battery can be reduced. And on the basis that the battery can reach a fully-charged state, the liquid retention capacity of the battery can be improved, the cycle performance of the battery is improved, and the battery is ensured to have relatively high volume energy density.

The invention relates to the technical field of solid-state batteries, and further relates to a solid-state battery material, a positive electrode active material layer, a positive electrode membrane, a solid electrolyte membrane, a solid-state battery, an electric device and application. The solid-state battery material comprises a coated particle, the coated particle comprises a particle body and an oxygen storage layer located on at least one part of the surface of the particle body, and the oxygen storage layer comprises an oxygen storage material; wherein the coating particles are at least one of coating positive electrode active particles and coating electrolyte particles; when the coating particles are coating positive electrode active particles, the particle body is a positive electrode active body, and the positive electrode active body comprises a positive electrode active material; when the coated particles are coated electrolyte particles, the particle bodies are solid electrolyte bodies, and the solid electrolyte bodies comprise sulfide electrolyte. When the solid-state battery material is used as a preparation raw material, the discharge capacity and the cycle performance of a sulfide solid-state battery can be improved.

This invention is related to the field of biosensors. In particular, devices and methods are described which enable the quantification of biomolecules by virtue of particle speed driven by induced-charge electrophoresis. For example, a range of biomolecules can be simultaneously detected in a highly sensitive manner from a library (e.g., combination) of active particles having different shapes or fluorescent signatures. Such biomolecules are related to conditions including, but not limited to, cancer biomarkers, viral infection biomarkers, toxins, pesticides, and small molecule drugs.

The invention relates to the technical field of plasma equipment, in particular to a plasma reactor, a plasma activated water preparation device and a plasma activated water preparation method, and the plasma activated water preparation device comprises a dielectric barrier discharge unit and a pulse discharge unit. The pulse discharge unit is arranged above the dielectric barrier discharge unit, and a mixed fluid inlet is formed in the bottom of the dielectric barrier discharge unit. And the top of the pulse discharge area is provided with a mixed fluid outlet. One is that discharge of the dielectric barrier discharge unit and pulse discharge of the pulse discharge unit are utilized to respectively provide a large amount of active oxygen and active nitrogen, and two discharge units are integrated in one plasma reactor to realize mutual dissolution promotion of the active oxygen and the active nitrogen; secondly, the multiple stages of plasma reactors are connected in series, the stages are increased according to the water demand, the plasma dosage is ensured, and plasma activated water is prepared in a non-circular circulation mode; and thirdly, the mixing time of the gas-liquid mixed fluid in the preparation device of the plasma activated water is long, so that the waste of the active particles can be prevented.

The invention discloses a preparation method and application of an oil-soluble heteropolyacid ionic liquid catalyst. The catalyst is composed of organic cations and inorganic anions, the cations are one of quaternary ammonium, imidazole and pyridine cations containing long-chain alkyl, the anions are heteropolyacid anions, the long-chain alkyl enables the catalyst to have good oil solubility, the catalyst can be efficiently dispersed in the waste grease, heteropolyacid provides active sites, and the catalyst can be used for treating the waste grease. Nano-scale active particles are formed after in-situ vulcanization, and the catalytic hydrogenation effect is achieved. The invention also provides a preparation method of the oil-soluble heteropolyacid ionic liquid catalyst, the catalyst can be prepared from tertiary amine and halogenated hydrocarbon through three-step reaction of alkylation, anion exchange and acid-base neutralization, the preparation process is simple, a highly toxic reagent is avoided, and the cost is low. The catalyst provided by the invention can be used for catalytic hydroisomerization of various waste oils and fats, has the characteristics of high conversion rate, low coking rate and high product calorific value, and has relatively high industrial application potential.

The invention relates to an antibacterial and deodorant particle which comprises an active particle and a hydrophilic film wrapping the outer surface of the active particle. The active particles comprise the following raw material components in parts by weight: 15-20 parts of SEBS, 8-15 parts of silicon dioxide, 10-20 parts of sepiolite powder, 6-16 parts of an antibacterial agent, 2-5 parts of sodium stearate, 2-5 parts of sodium citrate, 5-10 parts of beta-cyclodextrin, 18-27 parts of an adhesive and 1-3 parts of an odor neutralizer; the hydrophilic film is formed by forming a hydrophilic material. According to the antibacterial and deodorant particles, SEBS serves as a hydrophobic elastic framework of active particles, and free diffusion of active ingredients in the particles is limited through hydrophobic entanglement of molecular chains; meanwhile, a hydrophilic material is used as an outer coating film, and the release rate of the active components is controlled by adjusting the interface action of the active particles and sewage, so that the antibacterial and adsorption deodorization active components in the antibacterial and deodorization particles are stably and slowly released; it is ensured that the efficient and long-acting antibacterial and deodorizing effect can be achieved for 14 days in complex water environments such as domestic sewage treatment.

The invention discloses a preparation method of plasma activated water based on a micro-nano bubble synergistic effect, and mainly solves the technical problems that the generation efficiency of liquid-phase active particles in the plasma activated water prepared by the existing method is low, the chemical activity of the plasma activated water is difficult to maintain and the like. The preparation method comprises the following steps: introducing micro-nano bubbles into pure water until the pure water is saturated to obtain micro-nano bubble water; then performing plasma activation treatment on the micro-nano bubble water within 3 minutes to obtain plasma activated water based on the micro-nano bubble synergistic effect; the gas adopted by the micro-nano bubbles is one of air, oxygen, nitrogen or helium. The chemical activity of the plasma activated water is enhanced, the maintenance time of the activity of the activated water is greatly prolonged, efficient production and long-acting storage of the plasma activated water are facilitated, and the method has great significance in biomedical application of the plasma activated water.

The invention relates to the technical field of batteries, in particular to an electrode assembly, a preparation method and a lithium ion battery, the electrode assembly comprises a positive pole piece, a negative pole piece and a diaphragm, the positive pole piece comprises a positive current collector and a positive active material layer, and the positive active material layer comprises a positive active material layer and an inorganic coating; the positive electrode plate comprises a positive electrode current collector and a positive electrode active material layer, the positive electrode active material layer comprises a positive electrode active material, and the positive electrode active material comprises a ternary positive electrode material of which the core nickel content is more than 80 at% and the shell manganese content is 10-20 at%; the negative active material comprises silicon-based active particles and a three-dimensional elastic conductive network layer coating at least part of the surface of the silicon-based particles, and the positive active material and the negative active material are improved, so that various properties of the electrode assembly are good and stable, the overall electrical property and safety of the battery are improved, and the cycle life of the battery is prolonged.

The invention belongs to the technical field of neutralization treatment, and discloses a coal gasification slag and tail gas neutralization treatment device based on amino catalysis, which comprises a working frame, when amino-catalyzed coal gasification slag particles and tail gas are mixed and float upwards, the particles are arranged by the conical surface of a conical block; amino-catalyzed coal gasification slag particles move towards the periphery of the inner wall of a fixed shell, then the amino-catalyzed coal gasification slag particles slide to the top of a lifting table along the inclination angle of a conical annular plate in the natural falling process, and active particles fall into a sedimentation shell through filter holes. In the process, the particles can be screened and separated through floating and falling, when the particles with high activity are mixed with the tail gas, chemical reaction or harmful substance adsorption can be more effectively carried out, and the active particles can fall back to the settling shell through the filter holes to be further treated. Therefore, the cyclic utilization of the particulate matters is ensured.

The invention provides a refrigerator plasma ozone yield regulation and control system and method based on temperature and humidity control. The system comprises a temperature sensor, a humidity sensor, a plasma device and a control unit. The temperature sensor is arranged in the center of the interior of a refrigerator body and used for detecting real-time temperature data in the refrigerator body. The humidity sensor is arranged around a discharge electrode of the plasma device and is used for collecting humidity data of a discharge area in real time; the plasma device is used for generating ozone active particles; the control unit is electrically connected with the temperature sensor, the humidity sensor and the plasma device and used for receiving data of the temperature sensor and the humidity sensor and controlling the working state of the plasma device according to a preset control model. The problem that the ozone yield of plasma carried by the refrigerator is difficult to accurately control is solved.

The invention relates to a multistage self-adaptive plasma excitation and closed-loop feedback processing system, and relates to the field of environmental engineering. After waste gas enters the system, parameters such as odor concentration, temperature and humidity, ozone and the like are detected in real time by a sensor array, and data are fed back to a control center. The method comprises the following steps: decomposing organic high-molecular compounds by pre-ionization, exciting high-density active particles by a main reaction to thoroughly degrade peculiar smell, and decomposing ozone and small-molecular byproducts by using a nano-catalyst in a deep purification stage. The system adopts PID self-adaptive control, parameters can be automatically optimized according to real-time monitoring data, the removal rate is effectively improved, and the energy consumption is reduced. The processed gas is analyzed again through the secondary detection unit, data are uploaded to the cloud model, energy efficiency and processing strategies are continuously optimized through reinforcement learning, and intelligent and closed-loop management is achieved. The device can be widely applied to the field of industrial waste gas treatment, and has the outstanding advantages of efficient removal, low energy consumption, intelligent self-adaption and the like.

The invention provides a catalyst composition, including a mixture of catalytically active particles and a magnetic material, such as superparamagnetic iron oxide nanoparticles, capable of inductive heating in response to an applied alternating electromagnetic field. The catalytically active particles will typically include a base metal, platinum group metal, oxide of base metal or platinum group metal, or combination thereof, and will be adapted for use in various catalytic systems, such as diesel oxidation catalysts, catalyzed soot filters, lean NOx traps, selective catalytic reduction catalysts, ammonia oxidation catalysts, or three-way catalysts. The invention also includes a system and method for heating a catalyst material, which includes a catalyst article that includes the catalyst composition and a conductor for receiving current and generating an alternating electromagnetic field in response thereto, the conductor positioned such that the generated alternating electromagnetic field is applied to at least a portion of the magnetic material.

The invention relates to the technical field of lithium ion battery manufacturing, and discloses a preparation method of a silicon-containing silicon oxide-phenolic resin-artificial graphite composite negative electrode material, which comprises the following steps: grafting phytic acid on the surface of silicon-containing silicon oxide to construct a protonated acidic site, mixing modified silicon-containing silicon oxide, phenolic resin and artificial graphite, and keeping at a constant temperature to obtain the silicon-containing silicon oxide-phenolic resin-artificial graphite composite negative electrode material. Preferentially carrying out pre-polycondensation by utilizing phytic acid catalysis interface resin to form a gel layer, and rapidly removing a solvent to obtain a precursor; according to the preparation method disclosed by the invention, interface chemical anchoring is established before solvent volatilization by utilizing a dynamic competitive mechanism, so that the problem of stripping of resin and active particles caused by solvent volatilization in a traditional process is solved, and the structural stability and the electric conduction continuity of the material in a battery circulation process are improved.

The present application relates to an electrode assembly, a battery, and an electric device. The electrode assembly comprises a negative electrode sheet, a separator, and a positive electrode sheet. The separator is arranged on one side of the negative electrode sheet; the separator comprises a base material and a bonding layer; the bonding layer is arranged on the surface of the base material; the bonding layer comprises first polymers; and the first polymers are copolymers of vinylidene fluoride and hexafluoropropylene. The positive electrode sheet is arranged on the side of the separator facing away from the negative electrode sheet; the positive electrode sheet comprises a current collector layer and an active material layer which are stacked; the active material layer is arranged on the surface of the current collector layer and faces the bonding layer; the active material layer comprises active particles and second polymers; the second polymers are granular; the second polymers are dispersed in the active particles; and the second polymers are bonded to the first polymers.

The application provides a battery positive plate and a battery, the battery positive plate comprising a positive active material and a binder, the binder being a product obtained by cross-linking a polyacrylic compound modified by a phenylboronic acid compound and a hydroxylated carbon nanotube.The battery positive plate of the application adopts a three-dimensional conductive network binder based on cross-linking of a polyacrylic compound modified by a phenylboronic acid compound and a hydroxylated carbon nanotube, the binder forming a special three-dimensional conductive network structure by a multiple cross-linking mechanism between the phenylboronic acid group, the hydroxylated carbon nanotube (OHCNT) and the positive active particles, and self-cross-linking between the phenylboronic acids to form a boroxin structure, improving the mechanical strength, the electrical conductivity of the binder, the cycle performance and the stability of the battery; the discharge performance and the ability of fast charging and discharging of the battery can be improved, and the consumption of electrolyte can be reduced, thereby prolonging the cycle life of the battery.

The application discloses a method for regulating solidification structure of aluminum-silicon-iron alloy by gas-phase synergistic double-melt blending. CH4 gas is introduced into high-temperature aluminum-titanium alloy liquid, C-containing active particles are decomposed from the CH4 gas in the alloy melt and gas-liquid reaction occurs between the C-containing active particles and Al and Ti particles to generate intermediate phases such as Al4C3 and Ti3AlC and unstable TiC particles, and the intermediate phases react to generate thermodynamically stable TiC nanoparticles. Meanwhile, aluminum-silicon alloy melt and aluminum-iron alloy melt with significant difference in volume and temperature are blended in a controlled diffusion manner to obtain aluminum-silicon-iron melt. During the gas-liquid blending process, due to the opposite directions of solid / liquid interface advancing direction and solute diffusion direction during melt solidification, there exist non-local micro temperature and concentration fluctuations, and grain refinement is realized by controlling the solidification nucleation and diffusion growth process. The gas-liquid casting technology is a new process with multiple processes in synergistic action, and multiple processes can have a superposition effect under synergistic action, so that the synergistic refinement of aluminum-silicon-iron alloy second phase and aluminum grains is realized.

The application provides a high-flexibility dielectric positive electrode binder and a preparation method thereof and a solid-state battery positive electrode. The high-flexibility dielectric positive electrode binder comprises a fluoropolymer matrix and a fast ion conductor; the fluoropolymer matrix is a copolymer of vinylidene fluoride (VDF) and a fluorine-containing comonomer, the fast ion conductor is in a one-dimensional nanowire shape and is dispersed in the fluoropolymer matrix; and the mass fraction of the fast ion conductor is 1% to 20% based on the fluoropolymer matrix. The application can simultaneously solve three core problems of physical continuity of an ion conduction path in the positive electrode, inhibition of a space charge layer at an interface and mechanical coating of active particles, thereby significantly improving the rate performance, cycle stability and actual energy density of the solid-state battery.

The invention relates to a method for preparing a rapid hydrochromic mesoporous tungsten oxide film based on a plasma etching technology. The preparation method comprises the following steps: mixing an amphoteric block copolymer template agent with a tungsten source precursor, and coating the surface of a substrate with obtained sol to construct an organic-inorganic hybrid film; then introducing oxygen-containing plasma to etch the hybrid film; and finally loading a catalyst layer on the surface of the film. By utilizing the synergistic effect of high-energy active particles and active oxygen species in the plasma, through coupling of physical bombardment and chemical oxidation / volatilization reaction, the rapid removal of the organic template is realized under a low-temperature condition, meanwhile, the structural integrity of a mesoporous skeleton is kept, and the pore collapse and the specific surface area loss caused by traditional high-temperature calcination are avoided. The obtained mesoporous WO3 thin film has a high specific surface area and abundant surface active sites, and hydrogen diffusion and interface reaction kinetics can be effectively improved, so that the coloring / fading response is remarkably accelerated, and the hydrogen-induced discoloration performance is improved.

This invention discloses a portable low-temperature plasma device based on a Laval nozzle structure and its application, belonging to the field of plasma technology application technology. Specifically, it includes (1) the construction of the device; and (2) the use of the device for fungal eradication treatment and transdermal drug delivery enhancement treatment. The beneficial effects achieved by this invention are as follows: This invention is the first to apply the Laval nozzle structure to a portable low-temperature plasma device. The results show that the device can effectively improve the plasma jet performance and active particle content, significantly improve the treatment effect of fungal infections of the skin and nails and the transdermal drug penetration efficiency, while solving the problems of large size, reliance on external power supply, and complex operation of traditional plasma devices. Therefore, using this invention for the treatment of fungal infections of the skin and nails and for enhanced transdermal drug delivery has advantages such as ease of operation, high safety, non-invasiveness, and high efficiency, and thus has potential application prospects in the field of skin disease treatment and transdermal drug delivery.

The present invention belongs to the field of atmospheric pressure glow discharge and relates to a low-temperature plasma processing device controlled by a transverse magnetic field. The device comprises a power supply unit, a discharge unit with a built-in high-voltage spike electrode, an annular ground electrode, and an electromagnetic coil, a gas unit, a gas control unit, a magnetostrictive unit, and a sample unit for holding a treatment liquid or collecting gaseous products processed in the discharge unit. The discharge end of the high-voltage spike electrode is a pointed tip, and the radially inner side of the annular ground electrode is prefabricated with an axially symmetrical cut angle. A magnetic core is provided on the inner surface of the outer cylinder, and the magnetic core includes a first annular magnetic core and a second annular magnetic core. The device improves the efficiency of generating high-energy active particles in the low-temperature plasma by significantly increasing the discharge area. It can either utilize the discharge process of a specific dielectric gas to generate high-energy active particles for subsequent liquid treatment, or directly mix the gas to be treated with the dielectric gas in a certain proportion in the gas unit and then complete the treatment directly in the discharge unit.

The invention discloses a multi-dimensional carbon structure negative electrode material, and belongs to the field of lithium battery materials. The multi-dimensional carbon structure negative electrode material comprises a core layer, a middle layer and a shell layer which are sequentially arranged from inside to outside, the core layer comprises a three-dimensional conductive skeleton loaded with active particles; the material of the middle layer comprises amorphous carbon; the material of the shell layer comprises a metal oxide. The negative electrode material with the core-shell structure is obtained by preparing the multi-layer structure containing the core layer, the middle layer and the outer layer and optimizing the material of each layer. The outer layer and the middle layer can effectively inhibit disordered deposition of metal lithium on the outer surface, active particles of the core layer serve as lithium-loving sites to guide lithium to be nucleated and deposited in fiber coils preferentially, the uniformity and directionality of lithium deposition can be improved through cooperation of the three layers, and therefore growth of lithium dendrites is effectively inhibited; and the safety performance and the cycling stability of the prepared battery are enhanced.

The embodiment of the invention provides an active particle track processing method and device, electronic equipment and a storage medium, and belongs to the technical field of image processing. The method comprises the steps that a plurality of active particles are continuously shot, an image sequence is obtained, and the image sequence comprises a plurality of images; according to the image sequence, multiple track fragments of the multiple active particles and the motion time period of the active particles corresponding to each track fragment are obtained, and the track fragments are obtained by the fact that the motion tracks of the active particles are fractured due to the fact that the active particles are shielded by other active particles in the motion process of the active particles; identifying N track fragments belonging to the same active particle from the plurality of track fragments of the plurality of active particles, wherein N is a positive integer greater than 1; and for N track fragments of the same active particle, splicing the N track fragments according to the motion time period corresponding to each track fragment to obtain a first track of the active particle. The embodiment of the invention can improve the track quality of the active particles.

The invention discloses a levetiracetam sustained-release granule and a preparation process thereof, and relates to the technical field of pharmaceutical preparations. The preparation method specifically comprises the following steps: S1, preparing levetiracetam active particles; s2, preparing a transition coating solution and a slow-release coating solution; and S3, coating the levetiracetam active particles with a transition layer and a sustained-release layer in sequence to obtain the levetiracetam sustained-release particles. Wherein the transition coating liquid is prepared by mixing the following raw material components in parts by weight: 3-5 parts of sodium alginate, 1-1.5 parts of a plasticizer and 100 parts of purified water; wherein the molecular weight of the sodium alginate is 50000 to 100000; the slow-release coating solution is prepared by mixing the following raw material components in parts by weight: 5-8 parts of silicon dioxide modified chitosan, 3-5 parts of sodium alginate, 1.5-3 parts of a plasticizer and 200 parts of purified water; wherein the molecular weight of the sodium alginate is 150000 to 200000.

The invention provides a method for improving the thermal stability of a high-nickel ternary positive electrode material of a lithium ion battery and a functional material of the high-nickel ternary positive electrode material, and the functional material specifically comprises a multifunctional ceramic skeleton constructed by taking Ce < 3 + > doped BaTiO3 (Ba1-xCexTiO3, 0.01 < = x < = 0.05) as a core, and the multifunctional ceramic skeleton is tightly compounded with the high-nickel positive electrode material by adopting a nano-powder coating, low-temperature sintering or atomic layer deposition mode, so that the thermal stability of the high-nickel ternary positive electrode material of the lithium ion battery is improved. And a positive electrode protection system with thermal response current limiting and structure supporting functions is constructed. The resistance can be suddenly increased within the range of 130-160 DEG C, so that internal current limiting of the positive electrode is realized; meanwhile, due to the excellent thermal stability and high melting point, a supporting framework is formed in the early stage of thermal runaway, and active particle aggregation and structural collapse are effectively retarded. Meanwhile, the technological process for preparing the functional material is covered, precursor selection, sintering conditions and coating process paths of Ce < 3 + >-doped BaTiO3 powder are defined, reversible doping elements such as Pr < 3 + >, Nd < 3 + > and Mn < 2 + > and ceramic systems such as SrTiO3 and CaTiO3 are further expanded, and the functional material has wide adaptability and application potential.

The present application provides a negative electrode active particle, a preparation method therefor, a negative electrode sheet, a battery, and an electronic device. The negative electrode active particle of the present application comprises a matrix particle, and a plurality of carbon microspheres, wherein the plurality of carbon microspheres are distributed on the surface of the matrix particle, and the average particle size d1 of the carbon microspheres and the average particle size d2 of the matrix particle satisfy the following relational expression: 0.001≤d1 / d2≤0.5. The negative electrode active particle of the present application have good cycle performance.

This invention provides an electronic nose. [Solution] An electronic nose is provided, comprising a substrate containing a carbon precursor and a gas-active substance precursor, and an olfactory sensor array including a plurality of olfactory sensors formed by irradiating the substrate with lasers of different parameters, wherein each olfactory sensor includes a laser-induced graphene layer formed from the carbon precursor by laser irradiation of one parameter, and gas-active particles formed from the gas-active substance precursor and embedded in the laser-induced graphene layer, and the plurality of olfactory sensors react to different types of gaseous substances.

The present invention belongs to the technical field of batteries. Provided are a positive electrode active material and a preparation method therefor, a positive electrode sheet, a battery and an electric device. The positive electrode active material comprises an active material body and a boride, wherein the active material body comprises a plurality of agglomerated active particles; the inner core of each active particle comprises NaaRb(PO4)2P2O7, where a is 3.5-4.5, b is 2.5-3.5, and R comprises at least one of Mg, Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Cr, Nb, Mo, In, Ga, Sn, Hf, Ta, W and Pb; and the shell layer of each active particle comprises a carbon coating layer. By converting residual alkali on the surface of the positive electrode active material into a boride, a reduction in residual alkali on the surface of the positive electrode active material is achieved. The boride has a more stable structure, and is not prone to reacting during the production and use of a battery, thereby ameliorating the problems of gas production, etc., of the battery.

The invention discloses a dual-functional-layer gradient composite binder for a negative electrode and a preparation method of the dual-functional-layer gradient composite binder, and relates to the technical field of batteries. The dual-functional-layer gradient composite binder is gradient composite slurry loaded on the surfaces of negative electrode active particles; the gradient composite slurry sequentially comprises inner-layer anchoring slurry and outer-layer buffering slurry from inside to outside; the method specifically comprises the following steps: adding graphene quantum dots and hydroxylated carbon nanotubes into a lithium polyacrylate solution, and performing ultrasonic dispersion to obtain inner-layer anchoring slurry; the preparation method comprises the following steps: adding an ionic conductive elastic polymer into a solvent, stirring and swelling at a high speed to obtain a suspension, and carrying out stepped heating and stirring to obtain outer-layer buffer slurry; taking negative electrode active particles, and stirring and mixing the negative electrode active particles with a conductive agent, the inner-layer anchoring slurry and the outer-layer buffering slurry to obtain negative electrode slurry mixed with the dual-functional-layer gradient composite binder; through the gradient structure design, the two binders with complementary functions are organically combined, so that the interface impedance is reduced, and the cycling stability of the battery is remarkably improved.