3467results about How to "Increase capacity" patented technology

The invention provides a negative electrode material, a preparation method thereof and a battery. The negative electrode material comprises graphite and a carbon layer located on at least part of the surface of the graphite; the particle surface and the particle tangent plane of the negative electrode material are respectively tested by adopting a Raman spectrum, the ratio of the peak area of a characteristic peak D in the range of 1300 cm <-1 > to 1350 cm <-1 > to the peak area of a characteristic peak G in the range of 1500 cm <-1 > to 1580 cm <-1 > is ID / IG, the ID / IG ratio of the particle surface of the negative electrode material is A, the ID / IG ratio of the particle tangent plane of the negative electrode material is B, and 1.22 < A-B < = 2.10. The particle surface of the negative electrode material is tested through an atomic force microscope, a # imgabs0 # test area is randomly selected on the particle surface of the negative electrode material, the arithmetic mean value of the absolute value of the height deviation relative to the reference surface in the test area is S nm, and S is larger than or equal to 15 nm and smaller than or equal to 60 nm. The negative electrode material provided by the invention can comprehensively improve lithium ion transmission kinetics, first coulombic efficiency and cycle performance.

The embodiment of the invention discloses an in-memory computing circuit based on a magnetic cache, and the circuit comprises at least one magnetic cache unit, at least one in-memory computing unit, and a timer. The magnetic cache unit in the at least one magnetic cache unit is used for caching data output by the corresponding in-memory computing unit as to-be-processed data within the corresponding data retention time; the timer is used for respectively setting data retention time for the at least one magnetic cache unit; and the in-memory computing unit in the at least one in-memory computing unit is used for extracting the data to be processed from the corresponding magnetic cache unit for calculation and outputting the computed data to other magnetic cache units. According to the embodiment of the invention, the invention achieves the flexible adjustment of the data retention time of the magnetic cache unit in various in-memory calculation scenes, and achieves the provision of a high-capacity cache for the data needed by in-memory computing under the lower power consumption.

The invention discloses a transition metal nitride and amorphous carbon composite coated and modified lithium manganese iron phosphate composite material as well as a preparation method and application thereof, and belongs to the technical field of lithium ion batteries. The vanadium nitride / amorphous carbon is adopted to perform composite coating modification on the lithium manganese iron phosphate material, so that the composite positive electrode material is more stable in structure. The use of vanadium nitride reduces the coating amount of carbon, and avoids the problems of coating layer thickening caused by high carbon content and Li < + > diffusion hindering caused by reduction of tap density of active substances. Vanadium nitride not only has good conductivity, but also has good Li < + > conductivity transmission performance, Li < + > de-intercalation can be rapidly achieved, the conductivity of the material is improved, meanwhile, a Li < + > diffusion channel on the surface of the positive electrode material is further dredged and increased, and the capacity loss of the modified material is reduced.

The invention provides a sodium-ion battery positive electrode material and a preparation method thereof, a sodium-ion battery and electric equipment, and relates to the field of sodium-ion batteries. The positive electrode material of the sodium ion battery provided by the invention comprises an inner core and a shell, wherein the shell covers the inner core; the chemical formula of the inner core is NaaNixFeyMnzM1-x-y-zO2, wherein a is more than or equal to 0.9 and less than or equal to 1.05, x is more than 0 and less than 1.0, y is more than 0 and less than 1.0, z is more than 0 and less than 1.0, and 1-x-y-z is more than 0 and less than 1; the chemical formula of the shell is NaLarCa1-rO2, wherein r is more than 0 and less than 1; in the inner core, the element M comprises one or more of Al, Mg, Ti, Zr, Y, La, Ca, Zn, Cu, W, Li and B. The sodium-ion battery positive electrode material provided by the invention can reduce residual alkali on the surfaces of particles, can inhibit side reaction with an electrolyte, and improves the performance stability of the positive electrode material.

The invention belongs to the field of sodium ion batteries, and particularly discloses a positive electrode material and a preparation method and application thereof. The positive electrode material is carbon nitride coated fluorine-doped pyrophosphate sodium manganese iron phosphate, the chemical formula of the positive electrode material is NaaFe3-bMnb (PO4-x) 2F4xP2O7 / C3N4, a is larger than or equal to 3.95 and smaller than or equal to 4.1, b is larger than or equal to 0.3 and smaller than or equal to 2.4, and x is larger than or equal to 0.005 and smaller than or equal to 0.05. The sodium ferromanganese pyrophosphate is subjected to fluorine doping and carbon nitride coating, so that the electronic conductivity and the structural stability of the sodium ferromanganese pyrophosphate can be improved, the capacity of the sodium ferromanganese pyrophosphate can be well exerted, and the capacity and the voltage platform of the sodium-ion battery are improved.

The invention discloses a dynamic expansion management and control method for highway accident congestion based on an ETC portal, and relates to the technical field of traffic management and control, and the method comprises the steps: obtaining accident information; calculating the queuing length of the accident scene; the congestion duration is predicted, wherein the congestion duration is composed of rescue time, obstacle clearing time and congestion dissipation time; dilatation management and control are carried out in different areas, a control area and a buffer area are sequentially divided from the accident occurrence place along the rear, and dynamic dilatation management and control are carried out according to the actual traffic capacity of the accident road section. The method has remarkable advantages in the aspects of quick response, resource adjustment, timely rescue, accurate prediction, plan making and the like, decision scientificity is improved, effectiveness of active traffic management is improved, management strategies of active traffic management are refined, scientificity and rationality of dynamic management and control measures are improved, and the method is suitable for popularization and application. The method is of great significance in improving the emergency processing capacity of the expressway and guaranteeing traffic safety and smoothness.

The invention provides an anion-cation co-doped modified lithium manganese phosphate positive electrode material and a preparation method thereof, the lithium manganese phosphate positive electrode material comprises anion-cation doped lithium manganese phosphate and a carbon layer, the carbon layer is coated on the surface of the anion-cation doped lithium manganese phosphate, the chemical general formula is LiMn < 0.6 > Fe < 0.4-x > M < x > PO < 4-y > Fy, 0.001 < = x < = 0.03, 0.01 < = y < = 0.5, and 0 < = y < = 0.5. M is a cation, and Y is a fluorine ion. According to the preparation method, carbon layer coating and anion and cation co-doping modification of the lithium manganese iron phosphate positive electrode material are simultaneously realized through a one-step hydrothermal method, and the prepared lithium manganese iron phosphate positive electrode material is in an irregular spherical shape, relatively smooth in particle surface, and relatively high in large and small particle grading and compaction; after a performance test, compared with an electrode material which is not doped with anions and cations, the material disclosed by the invention has the advantages that the stability and the discharge capacity of the material are remarkably improved, and the electrochemical performance of the lithium manganese iron phosphate positive electrode material is effectively improved.

The invention provides a preparation method of a lithium iron phosphate material, a lithium ion battery and electric equipment, and relates to the technical field of batteries. The method comprises the following steps: mixing raw materials of an iron source, a lithium source and a phosphorus source with a reagent serving as a reducing agent and a carbon source, and grinding to obtain precursor powder; wherein the molar ratio of the lithium source to the iron source is 1.03-1.05, and the molar ratio of the iron source to the phosphorus source is 0.965-0.99; carrying out high-temperature treatment on the precursor powder in an inert atmosphere to obtain a lithium iron phosphate base material; and crushing the lithium iron phosphate base material to obtain the lithium iron phosphate material meeting the particle size requirement. The high-capacity and high-compaction lithium iron phosphate material is obtained by accurately controlling key indexes such as the iron-phosphorus ratio, the carbon content, the graphitization degree and the particle size and combining an optimized processing technology, so that the fast charging performance of a lithium ion battery is improved, and the effect of not reducing the electric quantity while the fast charging requirement is met is achieved.

The invention discloses a silicon-carbon composite material and a preparation method thereof, a pole piece and a battery. The silicon-carbon composite material comprises a cluster structure and a third carbon layer coating the cluster structure, wherein the cluster structure comprises a plurality of silicon-carbon composite particles, pores are distributed among the plurality of silicon-carbon composite particles, each silicon-carbon composite particle has a core-shell structure, each silicon-carbon composite particle comprises an inner core and an outer shell coating the inner core, each outer shell sequentially comprises a first carbon layer and a second carbon layer in the direction far away from the inner core, the first carbon layer comprises a conductive carbon material with a three-dimensional structure, an annular gap exists between the second carbon layer and the first carbon layer, and the inner core comprises porous silicon nanoparticles. The battery prepared from the silicon-carbon composite material has excellent electrochemical performance.

The invention belongs to but not limited to the technical field of electrode materials, and particularly relates to a high-tap-density lithium nickel manganese oxide positive electrode material, a preparation method and a lithium ion battery, the chemical general formula of the high-tap-density lithium nickel manganese oxide positive electrode material is LiNi < 0.5-x > Mn < 1.5-y > M < x > N < y > O < 4 >, 0.1, 0 < = y < lt >; 0.1, M and N are doping elements and comprise one or more of Mg, Co, Al, Zr, W, Sb, Ta and Ti; the material is micron-sized spherical secondary particles formed by stacking and aggregating nano-sized octahedral primary particles, and is uniformly dispersed without agglomeration; the spherical secondary particles are formed by mixing spherical secondary particles with large and small particle size distribution, and the average particle size range of the large particles is 3lt; d < 50lt >; the average particle size range of the small particles is 1lt; d < 50lt >; 2 [mu] m.

The invention provides a double-layer polymer solid electrolyte, a preparation method thereof and a lithium ion battery, and belongs to the technical field of solid electrolyte manufacturing. The first polymer solid electrolyte layer comprises the following raw materials in parts by weight: 4-30 parts of a first reactive monomer A, 5-25 parts of a first reactive monomer B, a first cross-linking agent, a first photoinitiator, a first lithium salt, 1-20 parts of a first carbonic ester plasticizer and 20-45 parts of a nitrile plasticizer; the second polymer solid electrolyte layer comprises the following raw materials in parts by weight: 4-30 parts of a second reactive monomer A, 5-25 parts of a second reactive monomer B, a second cross-linking agent, a second photoinitiator, a second lithium salt, 1-35 parts of a second carbonic ester plasticizer and 10-35 parts of a fluorine-containing plasticizer; the double-layer polymer solid electrolyte has the advantages of relatively high ionic conductivity and compatibility of a high-voltage battery positive electrode and a low-voltage lithium metal negative electrode, so that the corresponding battery has relatively excellent cycle performance and relatively high capacity.

The invention provides a hard carbon material and a preparation method thereof, and the preparation method comprises the following steps: (S1) crushing asphalt, and carrying out heat treatment in an oxidizing atmosphere to obtain a pre-oxidized precursor; (S2) uniformly mixing the pre-oxidized precursor with a cross-linking agent I, and carrying out primary cross-linking under inert atmosphere and heating conditions to obtain a cross-linked precursor I; the cross-linking agent I is a polymer of which the side chain contains carboxyl; (S3) uniformly mixing the cross-linked precursor I and a cross-linking agent II, and carrying out secondary cross-linking in an inert atmosphere under a heating condition to obtain a cross-linked precursor II; the cross-linking agent II is a micromolecular aromatic hydrocarbon compound (S4) cross-linking precursor II containing a plurality of anhydrides and / or carboxyl groups, calcining, cooling and grinding in an inert atmosphere to obtain the amorphous sodium ion battery negative electrode material. The negative electrode material obtained by the preparation method disclosed by the invention has the advantages of high capacity, high magnification, low cost, simple preparation process, adjustable disorder degree and high carbon yield, and is a carbon material suitable for large-scale production.

The invention relates to semi-bio-based polyamide containing a cross-linked structure as well as a preparation method and application of the semi-bio-based polyamide, and belongs to the technical field of polyamide preparation. The semi-bio-based polyamide containing the cross-linked structure contains a structure shown in a formula (I), 2, 5-furandicarboxylic acid taken from a bio-based material, a derivative monomer of the 2, 5-furandicarboxylic acid and aromatic diamine are used as raw materials for polycondensation, and aromatic triamine is used as a cross-linking agent. The semi-bio-based polyamide with the cross-linked structure provided by the invention has excellent thermal stability, excellent mechanical property, excellent wettability to electrolyte and outstanding chemical stability and electrochemical stability, can be applied to a lithium ion battery diaphragm, and can be used as a lithium ion battery diaphragm coating material with excellent performance and durability. The performance of the diaphragm is further improved, so that the battery capacity, the cycle and rate discharge performance, the safety and the like are improved.

The invention relates to the technical field of sodium ion battery research and development, and particularly discloses a strong-oxidizing acidified asphalt-based hard carbon negative electrode material and a preparation method and application thereof, concentrated nitric acid or concentrated sulfuric acid is introduced into asphalt as a cross-linking agent, so that the cross-linking reaction among molecules can be promoted under a low-temperature condition, and the structural stability of the material is greatly improved. Compared with a traditional method, the method has the advantages that the technological process is simplified, only one-step pretreatment is needed before carbonization, and energy consumption and pollution caused by high temperature can be avoided. According to the liquid phase cross-linking strategy, through reconstruction of chemical bonds, the low-softening-point asphalt can form a more compact carbon precursor network structure at low temperature, and formation of a high-performance hard carbon material in the subsequent carbonization process is facilitated.

The invention discloses a watermelon structure-imitated silicon-carbon negative electrode material as well as a preparation method and application thereof. The preparation method comprises the following steps: step 1, liquid phase coating: adding nano silicon particles into a carbon source solution containing organic matters, uniformly stirring, filtering and drying to obtain an organic carbon source-coated nano silicon material; step 2, stirring and calcining the material obtained in the step 1 in the atmosphere of introducing protective gas, then heating, and introducing the protective gas to obtain an intermediate material; and 3, introducing a carbon source gas into the intermediate material obtained in the step 2, and collecting a product after carbon deposition on the surface of the intermediate material is completed, wherein the product is the silicon-carbon negative electrode material with the watermelon-like structure. According to the silicon-carbon negative electrode material disclosed by the invention, a gap is reserved between the carbon layer and the silicon, so that a space can be provided for volume expansion of the silicon, the carbon layer and the deposited carbon can provide buffer for the volume expansion of the silicon and inhibit the volume expansion of the silicon, so that a stable SEI film is formed on the outer side of the material, and the consumption of lithium ions is reduced.

The invention discloses a rock pore three-dimensional reconstruction method and system based on an adaptive hierarchical cube algorithm, and a storage medium, relates to the technical field of rock structure measurement, and aims to solve the problems of low extraction execution efficiency, ambiguity and poor reconstruction precision of an existing moving cube algorithm. According to an image segmentation model based on RefineNet, the model adopts three 3 * 3 convolution cascading to replace 7 * 7 convolution, and a coordinate attention mechanism is introduced behind each block of an encoder to improve the segmentation precision and efficiency of a key area; dividing the cube into tetrahedrons by adopting a saddle point-adaptive layered downward subdivision method, solving intersection point coordinates and normal vectors, and constructing a triangular patch index; determining the contour surface shape penetrating through the cube by adopting a cube lookup table, and merging triangles of all tetrahedrons to form a complete contour surface; and creating a new triangular patch by using the vertex of the edge of the hole and the newly generated vertex, and repairing the hole to obtain the accurately reconstructed three-dimensional hole of the rock.

The invention discloses a water-based lithium battery positive electrode adhesive, a preparation method and application. The adhesive is of a single-layer or multi-layer shell core-shell structure formed by polar monomers such as acrylic acid, acrylate monomers, cross-linking monomers, self-emulsifying monomers and water through core-shell emulsion polymerization; by controlling the mass percent of acrylate monomers, polar groups and the like in the core layer structure and the shell layer structure and selecting proper types and dosages of cross-linking monomers and self-emulsifying monomers, the adhesive has proper surface tension, shows excellent adhesion and wettability to the current collector, has high peel strength, and is suitable for the current collector. According to the present invention, the lithium ion battery pole piece has the low glass-transition temperature so as to ensure the high toughness, the high surface density, the excellent electrolyte resistance, the excellent electrical property, the excellent coating property and the like of the pole piece, and the raw materials are all non-fluorine materials so as not to produce hydrogen fluoride and other harmful gases during the lithium battery recovery; water is used as a solvent, recycling is not needed, environment friendliness and low carbon are achieved, the manufacturing process is simplified, and the application range is widened.

The invention relates to the technical field of battery materials, in particular to a method for regulating and controlling a biomass-based hard carbon microstructure through vapor deposition, a biomass-based hard carbon negative electrode material and application of the biomass-based hard carbon negative electrode material. The method comprises the steps that biomass-based shells are subjected to pre-oxidation treatment to obtain pre-oxidized shells, and the pre-oxidized shells are subjected to heat treatment in an inert atmosphere containing organic molecules to obtain the biomass-based hard carbon negative electrode material. A hard carbon material precursor is obtained; and finally carrying out carbonization treatment on the hard carbon material precursor. Inert gas is used as carrier gas to be mixed with gaseous organic molecules, the atmosphere of high-temperature sintering of hard carbon is changed, and the organic molecules are deposited on the surface of a hard carbon precursor, so that a relatively ordered surface structure is controllably formed in the carbonization process of a lignin-rich fruit shell biomass base; hard carbon surface defects are modified to obtain the biomass-based hard carbon negative electrode active material, so that a solid electrolyte interface generated by the biomass-based hard carbon negative electrode active material in contact with an electrolyte in a charging and discharging process is thinner and has stable chemical properties, and the first-circle coulombic efficiency is improved on the premise of keeping high capacity.

The invention discloses a zinc negative electrode protective layer material of an aqueous zinc ion battery as well as a preparation method and application of the zinc negative electrode protective layer material. The method comprises the following steps: dispersing a carbon material in an acidic liquid, stirring at room temperature, and fully mixing to obtain a uniform suspension; adding manganese salt into the mixed solution, stirring at room temperature, and then performing constant-temperature water bath; washing, centrifuging, drying and calcining a product obtained by the reaction to obtain expanded graphite; uniformly dispersing expanded graphite in a solvent, and stirring to obtain a dispersion liquid; adding a titanium-containing organic compound into the dispersion liquid and stirring; adding deionized water into the dispersion liquid and refluxing; and centrifuging, washing, drying and calcining to obtain the protective layer. According to the composite material, expanded graphite is prepared firstly, and then titanium dioxide quantum dots are anchored on the expanded graphite. Due to excellent zinc ion rate, compared with the prior art, the material has lower interface resistance and good cycling stability and rate capability, and the problems of interface dendritic crystal growth and the like are solved.

The utility model discloses a flow measuring device, which comprises a weighing balance, the liquid collecting container is arranged on the weighing balance; the capillary receiving tube comprises a first tube section and a second tube section which are communicated with each other, the inner diameter of the second tube section is larger than that of the first tube section, a liquid receiving opening is formed in the end of the first tube section, and a liquid discharging opening corresponding to the liquid collecting container is formed in the end of the second tube section; a liquid outlet is formed in the end portion of the liquid outlet pipe, the end face of the liquid outlet corresponds to the end face of the liquid receiving opening, and a first distance is formed between the end face of the liquid outlet and the end face of the liquid receiving opening, so that liquid discharged from the liquid outlet is sucked into the liquid receiving opening at intervals, and the liquid discharging opening drips the liquid into the liquid collecting container at intervals. According to the utility model, the liquid containing capacity is increased by utilizing the second pipe section with the increased inner diameter, the dripping frequency of the liquid from the liquid outlet is reduced, the evaporation capacity of the liquid is reduced, and meanwhile, the evaporation capacity of the liquid in the first pipe section can also be reduced when the inner diameter of the first pipe section is small.

The invention relates to the technical field of electrochemistry, in particular to a high-entropy Prussian blue analogue positive electrode material, a preparation method and application. Preparing manganese source, iron source, cobalt source, nickel source and copper source solutions; the preparation method comprises the following steps: dispersing a potassium ferrocyanide precursor and a potassium citrate chelating agent in deionized water, adding quantitative manganese source, iron source, cobalt source, nickel source and copper source solutions after uniformly dispersing, and continuously stirring in the adding process until all the solutions are dropwise added; centrifugally washing the obtained mixed solution by using deionized water and absolute ethyl alcohol; drying the centrifugally washed colloid in a vacuum drying box; the obtained solid particles are ground into uniform powder, and the high-entropy Prussian blue analogue positive electrode material is prepared by adopting the preparation method; the material can be used as a sodium ion battery positive electrode material. The content of crystal water is reduced, and side reactions in the electrochemical process are reduced. Excessive crystal defects are improved; the structural stability is improved; and the sodium ion diffusion barrier is reduced.

The invention provides a lithium manganese iron phosphate material as well as a preparation method and application thereof. The lithium manganese iron phosphate material sequentially comprises a lithium manganese iron phosphate matrix inner core, a first coating layer and a second coating layer from inside to outside, the first coating layer comprises a carbon material, the second coating layer comprises a composite material, and the composite material comprises carbon nitride and a conductive polymer. Through doping and coating of the carbon material in the first coating layer and synergistic cooperation of the conductive polymer and the carbon nitride in the second coating layer, the conductivity of the lithium manganese iron phosphate material is improved, and the cycling stability, the capacity and the rate capability of the lithium manganese iron phosphate material are improved.

The invention discloses a mountain gravity energy storage system and method for continuous operation of multiple weight blocks. The mountain gravity energy storage system comprises an inclined rail, a cableway support, a truck, standardized weight blocks, a high-altitude automatic loading and unloading platform, a low-altitude automatic loading and unloading platform, a motor generator set, a transmission mechanism and a control system. Standardized weight blocks serve as weight carriers, charging and discharging of the energy storage system are achieved through mutual conversion of gravitational potential energy and electric energy of the standardized weight blocks, rail transportation and cable transportation modes are combined, an automatic weight loading and unloading platform is arranged, and the carrying capacity of the weight carriers can be increased on the basis that the system operation continuity is guaranteed; the power and the capacity of the energy storage system are improved, manual establishment of a sand warehouse or a complex transferring and stacking mechanism is avoided, the cost is reduced, and the energy circulation efficiency of the system is further improved.

The invention discloses a ferric sodium pyrophosphate positive electrode material, a preparation method thereof and a battery, and relates to the technical field of batteries. Pre-sintering is performed; sanding and spray drying; and high-temperature sintering. Wherein the pH value of the reaction is controlled by using a Tris-HCl buffer solution in the hydrothermal reaction, so that the precursor is uniformly crystallized and has high crystallinity, and low-temperature segmented presintering is adopted later, so that the compaction density of the material can be controlled, and the related electrical properties of the material are relatively good. In the preparation process, a carbon source and a doping element are supplemented twice, so that carbon coating is uniform in the sintering process, the compaction density of the NFPP positive electrode material is further improved, the properties such as theoretical specific capacity of the positive electrode material are better through doping and carbon coating modification, and the high-compaction and high-capacity ferric sodium pyrophosphate positive electrode material is obtained.

The invention relates to the technical field of batteries, in particular to a negative plate and a lithium ion secondary battery. The negative plate comprises a negative current collector and a negative active material layer positioned on at least one side surface of the negative current collector; the negative electrode active material layer comprises a first coating close to the negative electrode current collector and a second coating deviating from the negative electrode current collector; the thickness of the negative plate is 30-1000 [mu] m; the first coating comprises a first negative electrode active substance, the second coating comprises a second negative electrode active substance, and the second negative electrode active substance comprises a second graphite material and hard carbon; the ratio of the average particle size of the second negative electrode active material to the average particle size of the first negative electrode active material is L, 1lt; l < = 2.5; the outer surface of the negative electrode active material layer has a recess. The negative plate disclosed by the invention has excellent lithium ion conduction capability and capacity exertion, and the lithium ion secondary battery comprising the negative plate disclosed by the invention has relatively high energy density and rapid charging capability.

The invention discloses a preparation method and application for preparing a cobalt-doped manganese dioxide material by taking Co3 [Co (CN) 6] 2 as a hard template, and belongs to the technical field of electrode material preparation. The preparation method comprises the following steps: firstly, preparing a Co3 [Co (CN) 6] 2 type Prussian blue nano cubic material through a liquid phase coprecipitation reaction method; and then preparing the cobalt-doped manganese dioxide material with a loose porous structure by taking the Co3 [Co (CN) 6] 2 type Prussian blue nano cubic material as a hard template and potassium permanganate as a reaction raw material and adopting a hydrothermal synthesis method, specifically, forming a submicron cube with the size of 200-700nm by combining nanosheets with the thickness of about 10-20nm, and preparing the cobalt-doped manganese dioxide material with the loose porous structure by adopting a hydrothermal synthesis method. And an optimization strategy of Co atom doping of manganese dioxide and nanosheet morphology control is synchronously completed. When the material is used as an electrode material, the conductivity of the manganese dioxide electrode material is greatly improved, the capacity of an aqueous zinc ion battery is improved, and the material has excellent charge-discharge cycle stability.

The invention discloses a preparation method and application of heteroatom-doped asphalt-based hard carbon, and relates to the field of sodium-ion battery negative electrode materials. The preparation method comprises the following steps: mixing asphalt with a catalyst, a cross-linking agent and a solvent, and performing cross-linking modification in a reflux state to obtain a liquid precursor I; heating and pre-carbonizing the precursor I in air to obtain a precursor II; and washing the precursor II to be neutral, drying, and performing high-temperature carbonization in inert gas to obtain the heteroatom-doped asphalt-based hard carbon material. Asphalt is used as a precursor, chemical crosslinking and doping methods are used, Friedel-Crafts reaction of the asphalt is realized, and a large number of oxygen-containing functional groups and other heteroatoms are introduced. In the high-temperature carbonization process, the introduced oxygen-containing functional group and other heteroatoms can weaken or destroy the pi-pi interaction between asphalt aromatic hydrocarbons and inhibit the graphitization of asphalt of the asphalt-based carbon material, so that the carbon material forms a three-dimensional cross-linked structure, the interlayer spacing is increased, the closed pore volume is increased, and the capacity, the cycle performance and the rate capability are further improved.

The invention relates to the technical field of electrode materials, in particular to porous carbon, a silicon-carbon negative electrode material, an electrode plate, a lithium ion battery and an electric appliance. The porous carbon has micropores and mesopores, and the percentage of the pore volume of pores with the pore diameter smaller than 3 nm in the total pore volume is higher than 85%; the percentage of the pore volume of pores with the pore diameter less than 0.7 nm in the total pore volume is less than 15%; the pore size distribution of the porous carbon is in a Koelreuteria-type distribution, and the Koelreuteria-type distribution is that Dv / Dw of a pore size distribution curve is greater than 0.05 cm < 3 >. G <-1 >. Nm <-1 > in a pore size interval of 1-3nm. The porous carbon provided by the invention is micro-mesoporous porous carbon, is distributed in a koelreuteria shape, is low in pore resistance, can improve the silicon loading efficiency, ensures the adsorption capacity and also ensures the de-intercalation of lithium ions, and the silicon-carbon negative electrode material prepared from the porous carbon is high in capacity and efficiency and lower in expansion performance.

The invention provides a quick-charge and quick-discharge type lithium battery and a preparation method thereof, and belongs to the technical field of lithium battery preparation. The preparation process comprises the following steps: preparing a fluorinated carbon nanotube based on biomass carbon; preparing a positive electrode plate; preparing the dendritic mesoporous silicon dioxide nano particles; preparing a cerium oxide-loaded two-dimensional hierarchical porous composite material; preparing a negative electrode plate; and assembling the lithium battery. According to the preparation method, the eutectic and the carbon fluoride nanotubes are added in the preparation of the positive electrode plate, and the cerium oxide-loaded two-dimensional hierarchical porous composite material and the carbon fluoride nanotubes are added in the preparation of the negative electrode plate, so that the prepared positive electrode plate and the prepared negative electrode plate have relatively high conductivity; and moreover, the ion transmission efficiency is improved, the rapid ion transmission is beneficial to reducing the polarization phenomenon of the battery, improving the charging and discharging rate and the power performance of the battery, enhancing the structural stability of the electrode, improving the performance and the safety of the battery, and being more beneficial to rapid charging and rapid discharging.

The invention discloses a high-conductivity bridged silicon-carbon composite material as well as a preparation method and application thereof, and belongs to the technical field of lithium ion batteries. The high-conductivity bridged silicon-carbon composite material comprises a core-shell structure with an inner core and an outer shell, the inner core is porous carbon and a carbon nano tube growing on the surface of the porous carbon in situ, and a nano silicon layer is attached to pores and surfaces of the porous carbon and the carbon nano tube; and the shell is a carbon coating layer. According to the high-conductivity bridged silicon-carbon composite material provided by the invention, the carbon nanotubes are grown on the surface of the porous carbon in situ, and contact among particles is similar to bridging, so that a point-line conductive network is formed, the intrinsic conductivity of the composite material is improved, and the electron transfer rate is accelerated. Meanwhile, the carbon nanotubes have extremely high strength and hardness, the mechanical strength of the porous carbon substrate can be remarkably improved by introducing the carbon nanotubes into the porous carbon material, expansion of nano silicon in the charging and discharging process can be better restrained, and the performance of high capacity, high first efficiency, long circulation and high magnification is shown.