85results about How to "High reversible capacity" patented technology

The invention discloses a silicon-carbon negative electrode material and a preparation method and application thereof.The silicon-carbon negative electrode material comprises a porous carbon substrate, a silicon element distributed in pore channels of the porous carbon substrate and carbon coating the outer surfaces of the porous carbon substrate and the silicon element, the porous carbon substrate is prepared after two times of activating treatment, and the silicon element is prepared after two times of activating treatment. The porous carbon has dendritic pore channels and meets at least one of the following conditions: a, the volume ratio of micropores is 10-30%; b, the volume ratio of mesopores is 60-90%; c, the volume ratio of macropores is 0-10%; d, the specific surface area is not less than 200m < 2 > / g; e, the pore volume is not less than 0.4 cm < 3 > / g; and f, the average particle size D50 is 1-20 [mu] m. By activating the porous carbon substrate, more buffer spaces can be provided for volume expansion of nano silicon particles from the angle of substrate preparation, and the cycling stability of the silicon-carbon negative electrode material is remarkably improved.

The invention belongs to the technical field of electrochemical energy storage, and relates to a nitrogen-doped MXene loaded VCo double-monatomic catalyst as well as a preparation method and application thereof. The preparation method comprises the following steps: adding a nitrogen-containing precursor into at least one layer of MXene suspension, and uniformly stirring to obtain a suspension; respectively dissolving a cobalt-containing compound and a vanadium-containing compound in water to prepare a cobalt-containing compound solution and a vanadium-containing compound solution, adding the cobalt-containing compound solution and the vanadium-containing compound solution into the suspension, and performing stirring, ultrasonic treatment and crushing to obtain a mixed solution; freeze-drying the mixed solution to obtain a precursor; and carrying out heat treatment on the precursor, and washing, centrifuging and drying the obtained powder to obtain the nitrogen-doped MXene loaded VCo double-monatomic catalyst. According to the invention, VCo double monatomic atoms are anchored on the surface of the few-layer MXene, so that the MXene serving as a sulfur carrier of the room-temperature sodium-sulfur battery can effectively adsorb and catalyze conversion of sodium polysulfide, and the room-temperature sodium-sulfur battery with excellent cycle life and capacity is obtained.

The invention relates to the field of sodium-ion batteries, and discloses a sodium-ion battery positive electrode sodium pre-treatment method and a sodium-ion battery thereof.The sodium-ion battery positive electrode sodium pre-treatment method comprises the following steps that a sodium pre-treatment material and positive electrode slurry are mixed to form sodium pre-treatment functional slurry; coating a current collector with the positive electrode slurry, and drying to form a basic function layer; coating the basic functional layer with the pre-sodium-modified functional slurry, and drying to form a pre-sodium-modified functional layer; wherein the pre-sodium-modified material is a sodium-rich material, and the sodium-rich material at least comprises at least one of Na2S, NaCrO2, Na2NiO2, Na2CO2 or Na2C4O2. According to the invention, the pre-sodium-modified functional layer is arranged on the basic functional layer, so that the first efficiency and the reversible capacity of the battery are improved, and the cycle life of the battery is prolonged.

The invention discloses a method for preparing a high-lignification biomass-based hard carbon material by water / alcohol synergistically assisted steam explosion, which comprises the following steps: soaking, washing, drying and crushing high-lignification biomass, adding water and alcohol reagents for soaking, then treating the material for 1-60 minutes under the conditions that the steam pressure is 1-3 MPa and the temperature is 150-280 DEG C, and then releasing pressure and exploding to obtain the high-lignification biomass-based hard carbon material. And performing low-temperature carbonization, impurity removal treatment, high-temperature carbonization, crushing and grading to obtain the high-lignification biomass-based hard carbon material. The invention also discloses the hard carbon material prepared by the preparation method and a sodium ion battery containing the hard carbon material. The high-lignification biomass-based hard carbon material prepared by water / alcohol synergistic auxiliary steam explosion has the advantages of high sodium storage capacity, high reversible capacity, excellent rate capability and the like when being used as a sodium ion battery negative electrode material.

The invention provides a lithium-mixed coated modified ternary positive electrode material as well as a preparation method and application thereof, and relates to the technical field of lithium battery raw materials. Various lithium sources are mixed according to a certain proportion to prepare a ternary positive electrode, co-doping modification is carried out through cooperation of Li3PO4 and a W / Al / Zr / Y / B-containing compound, double-layer coating modification is carried out through cooperation of the Li3PO4 and a Ti / Al-containing compound for primary coating and cooperation of an anhydrous Li compound and TiP2O7 or Ti3 (PO4) 4 for secondary coating, and a double-gradient fast ion conductor coating layer is constructed. The structural stability, the thermal stability, the first discharge capacity and efficiency, the multiplying power, the circulation and storage performance and the like of the single-crystal or polycrystal ternary positive electrode material under different voltage and power conditions are improved; the lithium-mixed multi-element composite ternary positive electrode provided by the invention has the advantages of more stable layered structure, higher safety, higher electronic conductivity, better multiplying power, high specific capacity and long cycle performance.

The invention provides a method for cyclically regenerating a positive electrode active material by using magnesium sulfate, which comprises the following steps: 1) burdening and mixing waste lithium battery black powder, magnesium sulfate and a carbon source, and roasting the mixture in a vacuum or inert atmosphere to obtain a roasted product; (2) adding the roasted product into water to carry out water leaching treatment, and carrying out suction filtration to obtain a lithium sulfate solution and water leaching residues; 3) adding the lithium sulfate solution into the saturated sodium carbonate solution for lithium precipitation to obtain a lithium carbonate precipitate; (4) drying the water leaching residues, adding dilute sulphuric acid to carry out acid leaching treatment, filtering to obtain acid leaching residues and a magnesium sulfate solution, and then carrying out evaporative crystallization treatment on the magnesium sulfate solution to obtain a magnesium sulfate precipitate; 5) mixing the acid leaching residues with lithium carbonate, and sintering to obtain the regenerated ternary positive electrode active material.According to the method, the recovery rate of obtained lithium reaches 99% or above, loss of important elements in the regeneration process can be avoided, cyclic utilization of magnesium sulfate is achieved, and consumption of chemical reagents and secondary pollution are reduced.

The invention discloses a solid electrolyte coated porous microcrystalline graphite composite material, a composite negative electrode and a preparation method and application of the composite negative electrode. The solid electrolyte coated porous microcrystalline graphite composite material comprises porous microcrystalline graphite with a porous structure; the particle size compounded inorganic solid electrolyte comprises a gathering part filled in a porous structure, and coating parts distributed among particles of porous microcrystalline graphite and on the surface of the porous microcrystalline graphite. The composite negative electrode comprises a current collector, a solid electrolyte coated porous microcrystalline graphite composite material arranged on the surface of the current collector and metal compounded on the surface of the composite material. The surface of the porous microcrystalline graphite is coated with the compounded solid electrolyte with different particle sizes, so that the ionic conductivity of the material can be greatly improved, and uniform deposition and dissolution of metal are facilitated; and the prepared composite negative electrode has lower expansion, the porous microcrystalline graphite can contribute higher reversible capacity, and the composite negative electrode has the advantages of high capacity and high compaction.

The invention discloses a negative plate, a lithium ion battery and electric equipment. The negative plate comprises the negative plate, the lithium ion battery and the electric equipment. The negative plate comprises a negative current collector and a negative active material layer located on at least one side of the negative current collector, the negative active material layer comprises a negative active material, and the negative active material comprises a graphite material, a hard carbon material and a silicon-based material; the particle size D50 of the graphite material, the particle size D '50 of the hard carbon material and the particle size D' '50 of the silicon-based material meet the conditions that 1.5 < = D50 / D' 50 < = 2.5 and 1.1 < = D '50 / D' '50 < = 3. According to the scheme, through the matching of the sizes and the particle sizes of the graphite, the hard carbon and the silicon-based material, the short plate of low compaction density of the hard carbon is effectively improved, the overall compaction density of the negative pole piece is improved, the energy density of the battery is favorably improved, the infiltration of electrolyte is facilitated, the liquid retention of the pole piece is improved, the rapid embedding of lithium ions is also facilitated, and the rate capability is improved.

The embodiment of the invention discloses a lithium ion battery and a power utilization device, the lithium ion battery comprises an electrolyte, the electrolyte comprises metal ions, and the reduction potential of the metal ions is higher than that of lithium ions; and in the low CB value region, the CB value of the lithium ions in the low CB value region satisfies the following conditions: 0 < CB < 1, and the CB value is the ratio of the capacity of the negative electrode active material per unit area to the capacity of the positive electrode active material per unit area. The lithium ion battery provided by the invention can effectively improve the problem of lithium precipitation in a low CB value region.

The invention discloses a sodium ion button type half cell and also discloses a preparation method of the button type half cell, and the preparation method comprises the following steps: cleaning and drying amygdalus pedunculata shells, crushing the amygdalus pedunculata shells, and sieving the amygdalus pedunculata shells with a 100-mesh sieve to obtain amygdalus pedunculata shell powder; removing impurity ions in the powder by using excessive hydrochloric acid, filtering out the hydrochloric acid, and cleaning and drying the powder; carrying out cell disruption on the powder, freezing and then freeze-drying; carbonizing the obtained powder in an Ar atmosphere to obtain an amygdalus pedunculata shell-based hard carbon material; preparing a negative plate by taking the hard carbon material as a negative electrode material; the negative plate is used as a negative electrode, a sodium plate is used as a positive electrode, a glass fiber diaphragm is adopted, and a sodium ion button half cell is assembled; and carrying out sodium ion accelerated desolvation treatment on the assembled button type half cell to obtain the sodium ion button type half cell. The button half cell has the characteristics of high reversible capacity and high first-cycle coulombic efficiency.

The invention discloses an organic conjugated fused ring polymer positive electrode material, and relates to the technical field of batteries. The molecular structural formula of the organic conjugated fused ring polymer positive electrode material is # imgabs0 #. The invention also provides a preparation method of the organic conjugated fused ring polymer positive electrode material and application of the organic conjugated fused ring polymer positive electrode material in a wide-temperature-range aqueous zinc ion battery. The raw materials used in the invention are green and environment-friendly, the price is low, the preparation process is simple, and when the positive electrode material is used as an aqueous zinc ion battery positive electrode material, excellent electrochemical properties such as high magnification, high cycle stability and excellent weather resistance can be realized. Therefore, the method is very suitable for large-scale popularization and application.

The invention belongs to the technical field of sodium batteries, and particularly relates to a ferric sodium pyrophosphate positive electrode material as well as a preparation method and application thereof. The ferric sodium phosphate pyrophosphate positive electrode material obtained by the invention has uniform particle size, good conductivity and high structural stability, and the raw materials are crushed to micron-scale to nano-scale through two key steps of ball milling and ultrasonic treatment, so that the problem of insufficient solid-phase reaction caused by adopting ferric phosphate as the raw material is solved. When the material is applied to a sodium battery, the problem of nitrogen oxide pollution in industrial preparation of ferric sodium pyrophosphate is solved, and the reversible capacity and the cycling stability can be further improved.

The invention is applicable to the technical field of materials, and provides a high-rate hard carbon material, a preparation method thereof and a sodium ion battery, and the preparation method comprises the following steps: reacting a hard carbon precursor subjected to pre-carbonization treatment with alkali at 800-900 DEG C for 1-2 hours to obtain a porous carbon material; the alkali is KOH or K2CO3; the mass ratio of the hard carbon precursor to the alkali is 1: (0.05-0.2); the porous carbon material is subjected to acid pickling treatment through an acid solution, and a low-ash carbon material is obtained; the low-ash carbon material is filled with a carbon filler through liquid-phase impregnation to obtain a filled carbon material, and the filled carbon material is carbonized at high temperature to obtain the low-ash carbon material. The addition amount of the carbon filler is 5-10 wt% of the mass of the low-ash carbon material. According to the invention, a closed pore structure with a proper pore diameter is accurately constructed in hard carbon, so that high reversible capacity, high first coulombic efficiency and high multiplying power are realized.

This invention belongs to the field of hard carbon technology, specifically relating to a bamboo-based and lignin-based hard carbon composite material, its preparation method, and its applications. The process involves pretreating raw materials to obtain pretreated material; pretreating the pretreated material with an acidic oxidant to obtain acidic oxidant pretreated material; pre-oxidizing the acidic oxidant pretreated material to obtain pre-oxidized material; pre-carbonizing the pre-oxidized material under a protective atmosphere to obtain pre-carbonized material; pulverizing the pre-carbonized material to obtain pulverized material; acid washing followed by water washing to obtain purified material; soaking the purified material in acid, filtering, and drying to obtain soaked material; mixing the soaked material with a modifier, and high-temperature coating and carbonizing under a protective atmosphere to obtain bamboo-based coated hard carbon or lignin-based coated hard carbon. Mixing the two types of hard carbon and carbon coating yields a bamboo-based and lignin-based hard carbon composite material, which is used in negative electrode sheets and batteries. When applied to batteries, the hard carbon composite material of this invention can improve battery energy density.

The invention relates to an alkaline earth metal ion doped titanium-based phosphate composite material as well as a preparation method and application thereof, and belongs to the technical field of sodium ion batteries. The chemical formula of the alkaline earth metal ion doped titanium-based phosphate composite material is KxMyTiOPO4 / C, M is selected from one or more of beryllium, magnesium, calcium, strontium and barium, x is larger than or equal to 0.8 and smaller than or equal to 0.95, y is larger than or equal to 0.001 and smaller than or equal to 0.1, and the values of x and y meet the charge balance of the chemical formula. By doping alkaline earth metal ions, the lattice structure is effectively stabilized, and the exchange of K-Na ions is avoided, so that the cycling stability of the battery is remarkably improved, and the service life of the battery is remarkably prolonged.

The invention belongs to the technical field of sodium ion battery electrode materials, and discloses a full-concentration gradient layered oxide positive electrode material and a preparation method and application thereof. According to the material, from the core to the surface layer, the relative content of the nickel element and the iron element is continuously reduced, the relative content of the manganese element is continuously increased, and the full-concentration gradient change of nickel and iron ions in the radial direction from the secondary particle core to the surface layer of the material is constructed; while the overall characteristics of high nickel and high capacity of the material are maintained, the side reaction between the material and an electrolyte is inhibited through a low-nickel-iron surface layer, the actual reversible capacity and cycling stability of the material are improved, and the lattice volume change difference generated in the repeated charging and discharging process of heterogeneous components is buffered through gradient change of element concentration. The mechanical integrity of the material particles in the process is enhanced, so that the cycle life of the material particles is further prolonged.

The invention discloses a sodium-rich positive electrode material, a preparation method thereof and a sodium ion battery, the component of the positive electrode material is represented as NaxM1yFe1 / 3Sb1 / 3O2, and the element M1 is one or more of inactive metal elements without oxidation-reduction activity, such as Li, Na, Mg, Zn, Ca and the like. Wherein 1 < = x < = 4 / 3, 0 < = y < = 1 / 3. The positive electrode material is rich in sodium ions and has a special superlattice structure, a sodium ion battery prepared from the positive electrode material is high in reversible capacity and relatively high in capacity retention ratio, the problem that the capacity of the positive electrode material in the sodium ion battery is not high is solved, and the energy density of the battery is improved.

The invention is suitable for the technical field of sodium ion batteries, and provides a Zn monatomic modified hard carbon material and a preparation method and application thereof.The preparation method comprises the steps that an electrode plate is prepared through a Zn-N4 carbon nanosheet, and the electrode plate is cut to obtain a circular electrode plate; the circular electrode plate is used as a negative electrode, a metal sodium plate is used as a counter electrode, and the sodium ion battery is assembled together with a diaphragm and electrolyte. The Zn-N4 carbon nanosheet prepared by the invention is used as a sodium ion battery negative electrode material, and shows extremely high reversible capacity (321.4 mAh g <-1 > under 0.05 A g <-1 >), excellent rate capability (190.2 mAh g <-1 > under 5A g <-1 >) and ultra-long cycle life (the capacity is maintained at 92.1% after 4000 cycles under 2A g <-1 >). The monatomic modification method provided by the invention provides a reasonable and effective solution for challenges of slow storage dynamics and poor cycling stability of the anode of the sodium-ion battery.

The invention relates to the technical field of lithium battery negative electrode materials, and discloses a nano composite negative electrode material and a preparation method thereof. The molybdenum disulfide-carbon nanotube composite material comprises the following components in parts by weight: 3-4 parts of carbon nanotubes, 135-150 parts of concentrated nitric acid, 315-330 parts of concentrated sulfuric acid, 600-650 parts of diluted hydrochloric acid, 30-40 parts of absolute ethyl alcohol, 7.5-10 parts of polyethyleneimine, 25-30 parts of molybdenum disulfide, 10-12 parts of a surfactant and 3325-3600 parts of deionized water. A modified MoS2 nanosheet layer and MWCNTs are subjected to self-assembly in a solution by adopting an electrostatic force assisted self-assembly method to obtain a MoS2 / PVP / PEI / MWCNTs quaternary compound, and finally heat treatment is performed to obtain the final MoS2 / MWCNTs nano composite negative electrode material which has relatively high reversible capacity and relatively good cycling stability and rate capability. In addition, the preparation method does not need high-temperature and high-pressure conditions and is efficient, convenient, energy-saving and environment-friendly.

This invention discloses a hard carbon material with ultra-high platform capacity, its preparation method, and its applications. The hard carbon material is prepared by hydrothermal reaction and high-temperature carbonization, with a particle size of 2-4 μm, a pore size of 0.4-200 nm, and a specific surface area of ​​no more than 15 m². 2 / g, with a platform capacity ratio of not less than 40%; the preparation method of hard carbon material is as follows: S1: Add surfactant to pectin aqueous solution for hydrothermal reaction, and obtain hard carbon microspheres after filtration and drying; S2: Carbonize the hard carbon microspheres of S1 at high temperature under an inert atmosphere, and obtain hard carbon material with ultra-high platform capacity after cooling. The hard carbon material of the present invention can be used as a negative electrode material for lithium-ion batteries, which can significantly improve the platform capacity ratio.

The invention belongs to the technical field of sodium ion batteries, and particularly relates to a large-scale safe preparation method of a sodium ion positive electrode material assisted by a water reducing agent. The preparation method comprises the following steps: putting a sodium source into a water reducing agent, then adding deionized water, finally adding an iron source, a phosphorus source and a carbon source into the mixed solution, and repeatedly grinding to obtain a homogeneous solution; drying the homogeneous solution to obtain a precursor; and carrying out staged sintering treatment on the precursor to finally obtain the NaxFex-1 (PO4) x-2P2O7 / C powder. The Na4Fe3 (PO4) 2P2O7 / C can be prepared in batches by limiting the types and process parameters of the sodium source, the iron source, the phosphorus source and the carbon source, and the reversible capacity of the obtained Na4Fe3 (PO4) 2P2O7 / C under the multiplying power of 0.2 C can reach up to 110 mAh. G <-1 >.

The invention discloses a gel-resistant positive electrode slurry and porous electrode preparation. The positive electrode slurry in the invention gels slowly, and the surface and the inside of the electrode after drying have pores, which are helpful to increase the electrode liquid retention, improve the rate performance of the battery core, and reduce the polarization of the electrode. The invention uses glycolic acid, acetic acid, anhydrous oxalic acid, and anhydrous citric acid as pore formers. The pore formers are added after part of the organic solvent has been added to the stirring tank, which can avoid the corrosion of the tank body by the acidic pore former. The pore former can be miscible with N-methylpyrrolidone to ensure the uniformity of the dispersion of the pore former in the slurry. By controlling the drying temperature of the electrode, controlling the volatilization speed of glycolic acid and acetic acid and the decomposition speed of anhydrous oxalic acid and anhydrous citric acid, the porosity of the electrode is improved, and the structure of the electrode is ensured not to be destroyed. The pore former used in the present invention is a weakly acidic substance, which can neutralize the residual alkali on the surface of the positive electrode material, adjust the pH of the slurry, and has the effect of alleviating the gelation of the slurry.

The invention discloses a method for recovering a lithium resource in a waste lithium battery for lithium supplement of a negative electrode of the lithium battery, and belongs to the technical field of lithium battery recovery. An anode of a waste lithium battery is recycled, a circuit is externally connected to control the amount of electrodeposited lithium on an aluminum foil, a layer of aluminum-lithium alloy is formed on the surface of the aluminum foil, and the aluminum-lithium alloy is used as a modification layer on the surface of a cathode of the lithium ion battery, so that a lithium supplementing effect is provided for lithium loss caused by an SEI film formed on the cathode, and the aluminum-lithium alloy can also be used as a part of a cathode material; and high reversible capacity is provided. The recycling method is easy to operate, invalid waste of the positive electrode in the waste battery is avoided, compared with a common negative electrode lithium supplementing method, the pre-lithiation degree can be accurately controlled, the used aluminum foil is low in price, the production cost is reduced, operation is easy, and potential safety hazards are small.

The present invention belongs to the field of electrochemical energy storage technology, and discloses a porous sulfide bond functionalized carbon material, a preparation method and an application. The preparation method comprises: mixing sodium chloride, glucose, thiourea and water and stirring them evenly to obtain a solution A; freezing, vacuum freeze drying and grinding the solution A in sequence to obtain a precursor powder; pyrolysis carbonization treatment, washing, vacuum drying and grinding the precursor powder in sequence to obtain a porous sulfide bond functionalized carbon material. The present invention can assemble the prepared porous sulfide bond functionalized carbon material into a sodium battery as an active electrode material. The porous sulfide bond functionalized carbon material of the present invention has great application potential in safe, low-cost, high-energy and long-life (RT) Na-S batteries.

The invention provides a conjugated naphthalenone diimide compound, which belongs to the technical field of electrochemical energy storage and energy conversion, and the structural formula of the compound is shown as any one of formulas 1-3. An electrode material prepared from the compound has excellent electrochemical stability, high specific capacity, good rate capability and excellent cycle life, and is suitable for novel energy storage systems such as zinc ion batteries and aluminum ion batteries. The invention also provides a preparation method and application of the conjugated naphthalenone diimide compound.

The present application provides a silicon-containing negative electrode active material, and a negative electrode plate, a secondary battery, and an electrical device including the same. The silicon-containing negative electrode active material includes a silicon-based material and a conductive layer, located on the surface of the silicon-based material, including a polymer and a one-dimension conductive material, wherein, the polymer includes polar functional group(s) including one or more selected form carboxylic acid group, hydroxyl group, amide grous, amino group, carbonyl group, and nitro group; and the polar functional group(s) in the polymer have a mass percentage content as A1, and silicon in the silicon-based material has a mass percentage content as A2, the silicon-containing negative electrode active material satisfies: A2 is from 5% to 100% and A2 / A1 is from 0.2 to 8. The silicon-containing negative electrode active material according to the present application has good electronic conductivity and small volume expansion effect and simultaneously has high reversible capacity and first coulombic efficiency; moreover, it still has good electronic conductivity after being prepared into negative electrode plates.

The invention belongs to the technical field of hard carbon materials, and particularly relates to a preparation method and application of a polyurethane-based hard carbon material. The preparation method comprises the following steps: carrying out roasting carbonization and post-treatment on a solid polyurethane material at 900-1400 DEG C to obtain a powdery polyurethane-based hard carbon material; the solid polyurethane material is a polyurethane product prepared from reaction raw materials including isocyanate, non-phosphorus-containing polyol and phosphorus-containing polyol through a reaction. According to the invention, the polyurethane material is prepared by adding the phosphorus-containing polyol, and the polyurethane material is applied to the field of batteries as a negative electrode raw material, so that high carbonization yield can be maintained, and excellent performances such as initial coulombic efficiency, energy density, cycle capacity retention rate and the like of the battery can be realized.

The application relates to a sodium titanate nanofiber / reduced graphene oxide composite electrode material and a preparation method and application thereof. The composite electrode material has a two-dimensional sheet structure, the particle size is 1-6 mu m, the thickness is 10-20 nm, is composed of a few-layer reduced graphene oxide and sodium titanate nanofibers with a diameter of 5-10 nm loaded on the reduced graphene oxide, and is prepared by taking the few-layer reduced graphene oxide as a template, uniformly loading titanium dioxide particles, and then carrying out hydrothermal treatment in an alkali solution. Compared with the prior art, the synthesis method is simple in process, easy to scale up, and high in controllability. As a negative electrode of a sodium ion battery or a positive electrode of a sodium battery, the sodium titanate nanofiber / reduced graphene oxide composite electrode material has the advantages of high initial coulomb efficiency, low working voltage, high capacity, excellent rate characteristics and cycle stability, and has a broad market application prospect.

The invention relates to the technical field of batteries, in particular to a graphite composite material and a preparation method and application thereof. The graphite composite material comprises a base material layer and a coating layer, and the coating layer comprises a first material layer and a second material layer; the base material layer comprises graphite; the first material layer comprises an amorphous carbon material, and the amorphous carbon material is doped with a first nitrogen element; the second material layer comprises a graphite material, and the graphite material has a porous structure and is doped with a second nitrogen element; the concentration of the first nitrogen element is greater than that of the second nitrogen element. According to the graphite composite material, the first material layer can ensure the reversible capacity and the rate capability of the material; the graphitization degree of the carbon material in the second material layer is high, the irreversible capacity can be reduced, the low nitrogen concentration is beneficial to improving the conductivity, and the porous structure can shorten an ion diffusion channel, so that the energy storage capacity and the rate capability are improved.

The present application provides a carbon material, a preparation method therefor and the use thereof, a negative electrode plate, a secondary battery, and a power consuming device. The carbon material comprises a porous carbon substrate and an amorphous carbon layer provided on at least part of a surface of the porous carbon substrate. When the carbon material is used as a negative electrode active material, it can make full use of the abundant porous structures in the porous carbon substrate for lithium / sodium precipitation or lithium / sodium intercalation and avoid the side reactions due to the contact between the abundant active sites on the surface of the porous carbon substrate and an electrolyte solution, such that the initial coulombic efficiency and the actual capacity of a secondary battery can be improved.