294results about How to "Improve the first effect" 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 invention provides a graphite negative electrode material and a preparation method thereof, a dry-method electrode, a battery and electric equipment, and belongs to the technical field of battery manufacturing. The graphite negative electrode material is of a core-shell structure, an inner core is graphite, a shell is a polymer coating layer, the polymer coating layer can conduct ions but cannot conduct electrons, and the graphite negative electrode material can effectively inhibit PTFE from generating side reaction with lithium ions on the surface of a negative electrode, so that the first discharge gram capacity, the first effect and the cycle performance of a corresponding battery are improved.

The invention discloses a preparation method and application of a lithium-rich manganese-based positive electrode material of a lithium defect type layered spinel composite phase synthesized by a rapid thermal shock method, and the preparation method comprises the following steps: firstly, preparing a lithium-rich manganese-based precursor by using a coprecipitation method; and mixing the precursor and a lithium salt, and rapidly heating the sample by using Joule heat passing through the powder sample as a heat source to obtain the layered spinel composite phase positive electrode material with lithium defects, and the lithium-rich manganese-based positive electrode material with higher lithium deficiency, a layered spinel composite structure and more excellent performance is generated through ultrafast heating and cooling rate and short-time heat preservation. According to the preparation method disclosed by the invention, the lithium-rich manganese-based positive electrode material with the composite structure, which is relatively large in lithium deficiency, is prepared through a rapid thermal shock technology and has the advantages of high capacity, high first efficiency and long cycle stability; the preparation method is simple, the material cost is greatly reduced, large-scale production can be realized, the production efficiency is improved, and the energy consumption is reduced.

The invention discloses a sodium ion battery positive electrode material, a preparation method and a battery. The general formula of a sodium transition metal oxide of the positive electrode material is Na < x > Fe Mn M < c > Nd < LeP < f > O < 2 >, 0.7 < = x < = 0.9, 0.4 > = a > = 0.1, 0.8 > = b > = 0.4, 0.1 > = c > 0, 0.1 > = d > 0, 0.1 > = e > 0, 0.1 > = f > 0, a + b + c + d + e + f = 1, M, N, L and P are four different elements in Li, K, Mg, Ni, Zn, Ca, Cu, Al, B, La, Zr and Ti, and the four selected elements are + 1 valence, + 2 valence, + 3 valence and + 4 valence respectively. In this way, high charging capacity can be provided, and structure expansion and contraction can be suppressed; more active sites are achieved, and ultrahigh discharge capacity and ultrahigh cycling stability are achieved; the structure stability is extremely high, and the sodium ion battery has relatively high specific capacity and relatively long circulation.

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 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 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.

The invention provides an asphalt solid-phase composition for coating, a modified asphalt coated natural graphite negative electrode material, preparation of the modified asphalt coated natural graphite negative electrode material and a lithium ion battery, and the asphalt solid-phase composition for coating is used for forming an amorphous carbon coating layer coated on the surface of natural graphite and comprises coated asphalt and a modification additive, the mass ratio of the natural graphite to the coated asphalt to the modification additive is 1000: (45-80): (3-12); the modification additive comprises a saturated long-chain component, a low-molecular wax component and a component containing a modification group in a mass ratio of (2-10): (0.5-5): (0.5-7). By adding the modification additive, the softening point and viscosity of the asphalt are reduced, the wetting contact property of the asphalt to graphite is improved, the density and uniformity of a coating layer are improved, and the electrochemical performance of the natural graphite negative electrode material is further improved. The negative electrode material provided by the invention has higher first-cycle coulombic efficiency, better cycle performance, lower impedance and lower specific surface area under the condition of low asphalt addition amount.

The invention relates to the technical field of batteries, in particular to a porous carbon material, a silicon-carbon composite material and application of the porous carbon material and the silicon-carbon composite material. According to the porous carbon material, the micropore rate phi, the pore volume Pv and the compressive strength Cs meet the relational expression that (Cs * phi) / Pv is larger than or equal to 550 and smaller than or equal to 1050, and the micropore rate phi gt; and the compressive strength Cs is 600 to 850 MPa. The porous carbon material provided by the invention has high microporosity, and the microporosity phi, the pore volume Pv and the compressive strength Cs of the porous carbon material meet the relation that (Cs.phi) / Pv is more than or equal to 550 and less than or equal to 1050, so that the particle size of silicon particles can be effectively reduced, the absolute expansion of silicon in a carbon matrix is reduced, and the first effect and the cycling stability of the silicon-carbon composite material are improved.

The invention discloses a lithium cobalt oxide positive electrode material as well as a preparation method and application thereof, and relates to the technical field of lithium ion batteries. According to the lithium cobalt oxide positive electrode material provided by the invention, the O2-phase lithium cobalt oxide main body material is coated with the coating layer containing the boron compound, and the provided O2-phase lithium cobalt oxide positive electrode material after surface optimization has higher initial efficiency, capacity and cycle stability than conventional O3-phase lithium cobalt oxide. The coating method adopted by the invention can be realized only by low-temperature secondary sintering, the O2 phase structure of the bulk phase is maintained, the boron-containing compound selected for coating generates a stable interface on the surface, and on the premise of not influencing lithium ion diffusion, the side reaction of the interface is inhibited, the structure is stabilized, and the cycling stability of the material is improved.

The invention provides a current collector, a preparation method thereof and a battery. The current collector includes: a polymer layer; the metal layers are located on the surfaces of the two sides of the polymer layer; the through hole structure penetrates through the polymer layer and the metal layer along the thickness direction of the current collector; holes of the through hole structure are filled with a first lithium-philic polymer material. According to the current collector provided by the invention, the purpose of reducing weight is achieved through the synergistic cooperation of the structure and the material, the energy density of the current collector is improved, the uniform deposition of lithium is also realized, and the generation of lithium dendrites is avoided; meanwhile, the effect of reducing the occurrence probability of thermal runaway is also achieved, and the electrochemical performance of the battery is improved.

The invention discloses a high-first-effect and low-stress silicon-oxide-based all-solid-state lithium battery, and a preparation method of the high-first-effect and low-stress silicon-oxide-based all-solid-state lithium battery comprises the following steps of: introducing a pre-lithiation method in a process of preparing a silicon-oxide-based negative electrode or a process of assembling the lithium battery; the pre-lithiation method comprises a lithium-copper composite belt in-situ pre-lithiation method, a pre-lithiation additive method, a self-discharge contact pre-lithiation method, a chemical pre-lithiation method and an electrochemical pre-lithiation method. Pre-lithiation is carried out through a proper pre-lithiation method, so that the consumption of irreversible lithium in the first-circle lithiation process is reduced, and the first-circle coulombic efficiency of the battery is improved; meanwhile, the silicon monoxide-based all-solid-state lithium battery with high initial efficiency and low stress can be obtained through the method, and the method has the advantages of simple process, high universality, obvious effect and the like.

The invention discloses a battery using an adhesive for improving the first effect and circulation of a silicon negative electrode system cell, the adhesive is formed by polymerizing acrylic acid, quasi-acrylic acid and hydroxyethyl acrylate monomer, the hydroxyethyl acrylate monomer accounts for 1.5-3% of the total mass of the monomer, the acrylic acid monomer accounts for 16-58% of the total mass of the monomer, and the acrylic acid monomer accounts for 0.5-1.5% of the total mass of the monomer. The content of the acrylic monomer is 40-82%, the hydroxyethyl acrylate monomer is located in the middle of the polymer, the structural formula of the acrylic monomer is as follows: # imgabs 0 # R1 and R2 are independently selected from any one of H, carboxyl, hydroxyl, methoxyl and phenyl, R3 is selected from any one of cyano and # imgabs 1 #, R4 is selected from one or more of C1-C6 alkoxy, hydroxyl, amino, ester group, acylamino, chloroformyl and acyloxy, and n is 1-3. And R5 is selected from any one of H, carboxyl, hydroxyl, methoxyl and phenyl. The adhesive provided by the invention is strong in adhesive capacity, good in adaptability to volume expansion of a silicon negative electrode, and capable of effectively improving the cycle and the first effect of the battery, and is applied to the battery.

The invention discloses a silicon-carbon negative electrode material preparation method, which comprises: (S1) uniformly mixing a water-soluble resin and a transition metal salt aqueous solution, and drying to obtain a resin-loaded metal salt composite material; (S2) carrying out carbonization treatment on the resin-loaded metal salt composite material, and then carrying out reduction treatment to obtain metal-loaded porous carbon; (S3) placing the metal-loaded porous carbon in a mixed atmosphere containing carbon dioxide and acetylene, performing in-situ growth of carbon nanotubes in the porous carbon, and performing acid pickling to obtain modified porous carbon; and (S4) by taking the modified porous carbon as a substrate, sequentially carrying out silicon deposition and carbon coating to obtain the silicon-carbon negative electrode material. According to the preparation method of the silicon-carbon negative electrode material disclosed by the invention, the porous carbon is synthesized in situ, and the carbon nanotubes grow in the porous carbon in situ, so that more buffer spaces are provided for volume expansion of nano silicon particles from the angle of substrate preparation, and the long cycle stability of the silicon-carbon negative electrode material is remarkably improved.

The invention belongs to the field of energy storage of new energy materials, and relates to an asphalt-based hard carbon negative electrode material with high initial efficiency, high magnification and high capacity and a preparation method thereof. The hard carbon negative electrode material has a long and complete carbon layer edge, the specific surface area is 2-8 m < 2 > / g, and / or the aperture of the hard carbon negative electrode material is 1-12 nm. The method comprises the following steps: pre-oxidizing asphalt, mixing the pre-oxidized asphalt with a fusion repair-decomposition etching dual-function additive, and carrying out two-step high-temperature carbonization treatment in an inert atmosphere: melting metal salt in the first step of high-temperature carbonization so as to catalytically connect an edge carbon layer and repair defects; in the second step of high-temperature carbonization, the metal salt is decomposed to generate gas, pores are formed in the material, and the temperature of the first step of high-temperature carbonization is controlled to only melt the metal salt but not decompose the metal salt. Through single-additive two-step reaction, the first coulombic efficiency, the rate capability and the capacity are improved at the same time.

The invention relates to a secondary battery and an electric device. The secondary battery comprises a positive pole piece, a negative pole piece and an electrolyte, the negative pole piece comprises a negative active layer, the negative active layer comprises a negative active material and a binder, and the binder comprises polytetrafluoroethylene; the electrolyte comprises a solvent and an additive, the solvent comprises carbonic ester and carboxylic ester, and the additive comprises a silane additive. According to the secondary battery disclosed by the invention, the electrolyte is reduced on the surface of the negative pole piece early to form a stable interface protection film, so that the negative active material can be passivated well while the reduction lithium consumption of the negative binder is inhibited, and the first effect and the cycle life of the secondary battery are improved.

The invention provides a starch-based hard carbon negative electrode material, a preparation method thereof and a sodium ion battery, and belongs to the technical field of battery materials. The starch-based hard carbon negative electrode material comprises single crystal particles, the single crystal particles comprise polygonal particles with angular morphology, and the angular degree is 90-130 degrees. The single crystal particles in the starch-based hard carbon negative electrode material provided by the invention are regular in morphology and have a corner angle morphology with a specific angle, the phenomenon of particle aggregation and fusion can be avoided, the physicochemical properties of the starch-based hard carbon negative electrode material are remarkably improved, the particle size distribution is uniform, the compaction is improved, and meanwhile, the sodium storage sites are also increased; the sodium storage capacity and the first effect are favorably improved.

The negative electrode material comprises an active substance and a coating layer, the coating layer is arranged on at least part of the surface of the active substance, the active substance comprises a first matrix and a second matrix, the negative electrode material is provided with pores, the pore volume of the negative electrode material is M, the pore volume measured after the negative electrode material is subjected to pressure maintaining for 1 h under the pressure of 80 Mpa is N, the particle space collapse ratio of the negative electrode material is P, P = (M-N) / M, M is larger than or equal to 0.002 cm < 3 > / g and smaller than or equal to 0.12 cm < 3 > / g, and P is larger than or equal to 0.05 and smaller than or equal to 0.85. The rigid strength of the negative electrode material is modulated by controlling the pore volume of the negative electrode material before and after pressurization, so that the electrochemical performance of the negative electrode material is improved while the structural stability of the negative electrode material is ensured.

The invention provides a silicon-based negative electrode material, a preparation method of the silicon-based negative electrode material, a dry-method electrode, a battery and electric equipment, and belongs to the technical field of battery manufacturing. The silicon-based negative electrode material is of a core-shell structure, an inner core is a silicon-based material, a shell is a cross-linked polymer layer, the cross-linked polymer layer can conduct ions but cannot conduct electrons, the silicon-based negative electrode material can effectively inhibit PTFE from generating side reaction with lithium ions on the surface of a negative electrode, and meanwhile, the service life of the silicon-based negative electrode material is prolonged. And the problems of electrode pulverization, falling and the like caused by volume expansion of the silicon-based material in the charge-discharge process can be effectively solved, so that the corresponding battery has relatively excellent first discharge gram capacity, first efficiency and cycle performance.

The invention discloses a hard carbon composite material, a preparation method and application thereof and a battery. The preparation method of the hard carbon composite material comprises the following steps: S1, heating waste phenolic resin for pre-carbonization to obtain a first precursor; the temperature rise rate of heating is 1-4 DEG C / min; s2, under a heating condition, performing alkali activation on the first precursor to obtain a second precursor; the temperature rise rate of heating is 1-4 DEG C / min; s3, carbonizing the second precursor to obtain a third precursor; and S4, carrying out carbon coating on the third precursor to obtain the hard carbon composite material. The battery assembled by the hard carbon composite material has excellent sodium storage capacity and first-week efficiency, realizes low-cost recovery and high-valued cyclic utilization of waste phenolic resin, and promotes large-scale production and preparation.

The invention belongs to the technical field of positive electrode materials, and particularly relates to an acid-washed carbon-coated lithium-rich manganese-based positive electrode material as well as a preparation method and application thereof. The invention provides a preparation method of a pickled carbon-coated lithium-rich manganese-based positive electrode material, which comprises the following steps: preparing a lithium-rich manganese-based precursor, pickling and sintering to prepare the pickled carbon-coated lithium-rich manganese-based positive electrode material, pickling with a pickling solution; the pickling solution comprises an acidic carbon-based material. The acid-washed carbon-coated lithium-rich manganese-based positive electrode material prepared by the invention has relatively high specific discharge capacity, initial efficiency and cycle retention rate.

The invention relates to the technical field of batteries, in particular to a silicon-carbon composite material and application thereof. The silicon-carbon composite material comprises a porous carbon material and nano silicon particles positioned in pores of the porous carbon material, in a dQ / dV curve of lithium intercalation for the first time of the silicon-carbon composite material, the ratio of the intensity value of a lithium intercalation peak at 0.30-0.45 V to the strongest peak value within 0-0.25 V is less than 0.05. The silicon-carbon composite material has the advantages of high compressive strength, high charge-discharge capacity and good cycle stability.

The invention discloses a resin-based hard carbon composite material and application thereof in button type half-cell preparation. The method comprises the following steps: melting phenol, and adding a formaldehyde solution to prepare a mixed solution A; dispersing the carbon nano tube powder and hexadecyl trimethyl ammonium bromide in pure water, and grinding to obtain carbon nano tube dispersed slurry B; and adding the carbon nanotube dispersion slurry B into the mixed solution A to obtain a mixed solution C, adjusting the pH value to prepare a phenolic resin precursor solution, carrying out cross-linking curing to prepare a phenolic resin cured precursor, carrying out mechanical grinding, and putting the phenolic resin cured precursor into a tubular furnace to finally prepare the resin-based hard carbon composite material. Conductive carbon is introduced to the condensation polymerization end of phenol and formaldehyde, a communicated conductive network is formed in the composite material by regulating and controlling the material composition, the electron transmission distance between particles is shortened, the intrinsic conductivity of original resin carbon is improved, and the composite material has the advantages of high capacity, high first efficiency, high magnification and low ash content; wide application prospects are realized in the field of lithium ion battery negative electrode materials.

The invention provides a sodium ion battery negative electrode hard carbon material and a preparation method and application thereof, and the preparation method comprises the following steps: carbonizing a co-pre-oxidation raw material in an oxygen-containing atmosphere, mixing the carbonized co-pre-oxidation raw material with starch to form a mixed raw material, carrying out first-stage heat treatment in air, and carrying out second-stage heat treatment in a protective atmosphere to obtain the sodium ion battery negative electrode hard carbon material. Wherein the co-pre-oxidation raw material is any one or a mixture of more of biomass and carbonized raw materials. According to the preparation method, the thermal stability of starch pre-carbonization is effectively improved, the effect of inhibiting expansion of starch is achieved, and the problems of low structural damage capacity and the like caused by expansion due to the characteristics of starch raw materials are solved.

The invention relates to a secondary battery and an electric device. The secondary battery comprises a positive pole piece, a negative pole piece and an electrolyte, the negative pole piece comprises a negative active material layer and a solid electrolyte interface film formed on the surface of the negative active material layer, and the solid electrolyte interface film comprises lithium fluoride, fluorine-containing lithium phosphate and a substance containing a fluorocarbon bond; an X-ray photoelectron spectrometer is adopted for testing after the sputtering etching time is 10 minutes, based on the total substance amount of fluorine atoms in a solid electrolyte interfacial film, the molar content of fluorine atoms in lithium fluoride is a, the molar content of fluorine atoms in fluorine-containing lithium phosphate is b, the molar content of fluorine atoms in a substance containing fluorocarbon bonds is c, a + b is larger than or equal to 85% and smaller than or equal to 100%, and c is larger than or equal to 0 and smaller than or equal to 15%; in addition, the negative electrode active material layer further comprises a binder, and the binder comprises polytetrafluoroethylene. The secondary battery of the present application can improve the first efficiency and cycle life.

The invention belongs to the technical field of sodium ion batteries, and particularly relates to a soft and hard carbon composite material and preparation and application thereof.The soft and hard carbon composite material is of a double-sulfur-rich core-shell structure with soft carbon coated with hard carbon, the soft carbon serving as an inner core is sulfur-doped mesocarbon microbead-based secondary pore carbon, and the sulfur-doped mesocarbon microbead-based secondary pore carbon serves as an outer core; the hard carbon serving as the shell is sulfur-doped PEDOT (poly (3, 4-ethylenedioxythiophene))-based hard carbon. The core-shell structure is constructed by means of surface chemical modification, pore structure regulation and control, soft and hard carbon compounding and the like of the mesocarbon microbeads, the technical problem that the sodium storage capacity of the pitch-based soft carbon anode needs to be improved is solved, considerable intercalation capacity can be obtained by means of widened carbon layer spacing, and the sodium storage capacity of the pitch-based soft carbon anode can be improved. And abundant sodium storage sites can be obtained to realize large-proportion surface capacitance storage, so that the first charge-discharge capacity, the first efficiency and the cycle performance of the sodium ion battery (sodium battery) are improved.

The invention relates to the technical field of batteries, in particular to a modified hard carbon material, a preparation method thereof, a negative plate and a battery. A modified hard carbon material comprises a carbon matrix and doping elements, the doping elements are distributed among carbon layers of the carbon matrix, and the doping elements comprise an N element; the modified hard carbon material is obtained by heat treatment of a carbon source modified by a modifier, and the modifier comprises poly (diallyldimethylammonium chloride). The preparation method of the modified hard carbon material comprises the following steps: mixing a carbon source solution and a modifier to obtain a mixture; mixing the mixture with a solvent, reacting at a first temperature for a first time, and drying to obtain a precursor; performing heat treatment on the precursor to obtain a modified hard carbon material; wherein the modifier comprises poly (diallyldimethylammonium chloride). The problems of low initial efficiency, low capacity and the like of the existing hard carbon material can be relieved, and the reversible specific capacity, the initial efficiency and the cycling stability of the hard carbon material can be obviously improved.

The invention discloses a modified porous silica negative electrode material of a lithium ion battery and a preparation method and application of the modified porous silica negative electrode material, the modified porous silica negative electrode material comprises an inner core layer and a shell layer coating the inner core layer, and the inner core layer is a pre-magnesium silica material, namely porous SiO; the shell layer comprises a carbon nano tube growing on the surface of the porous SiO in situ and a carbon nano tube-nitrogen-doped conductive coating and repairing carbon layer, and the carbon nano tube is embedded in a porous channel of the porous SiO. The modified porous silica negative electrode material is prepared by constructing porous defects on the surface of silicon monoxide, modifying in-situ catalytic growth of carbon nanotubes and doping, coating and repairing a structure; according to the method, the carbon nanotubes can be quickly and uniformly grown on the surface of the porous silica powder and in pore channels, so that firm connection between the inner core layer and the outer shell layer is formed; meanwhile, the electronic conductivity and the ionic conductivity of the material are improved through the point-line-point connection mode. The obtained modified porous silica negative electrode material for the lithium ion battery has relatively high first efficiency, excellent conductivity and cycle rate capability.

The invention relates to the technical field of battery negative electrode materials, and particularly discloses an artificial SEI film coated negative electrode material as well as a preparation method and application thereof. The artificial SEI film coated negative electrode material comprises a negative electrode material matrix and an artificial SEI film coated on the surface of the negative electrode material matrix; a raw material of the artificial SEI membrane is an artificial SEI membrane glue solution, and a preparation method of the artificial SEI membrane glue solution comprises the following steps: introducing carbon dioxide and hydrogen fluoride into a hydroxymethyl cellulose lithium glue solution until the pH value of a system is 5.5-7.0 to obtain the artificial SEI membrane glue solution. According to the invention, CMC-Li is used as an organic lithium salt component of the artificial SEI membrane, a compact inorganic lithium salt component is introduced by introducing CO2 and HF, and the artificial SEI membrane is similar to a natural SEI membrane in component, so that the first effect and reversible capacity of the negative electrode material are remarkably improved, the rate rapid charge performance and cycle performance are improved, and the commercial value is relatively high.

The invention belongs to the field of waste graphite regeneration, and particularly relates to a preparation method of a regenerated graphite active material, which comprises the following steps: carrying out first-stage gas-solid treatment on waste graphite powder in an atmosphere A in advance to obtain a first-stage material; the first-stage material is placed in an aqueous solution containing a solute a and a solute b for second-stage solvent heat treatment, and a second-stage material is obtained through separation; and mixing the second-stage material, an auxiliary agent and a carbon source, carrying out negative pressure heat treatment at the temperature T1, cooling to the temperature T2, directly contacting with a cooling medium, and carrying out cold quenching treatment to obtain the regenerated graphite active material. The invention also comprises the material prepared by the preparation method and application of the material in a battery. The graphite material regenerated by the method disclosed by the invention has excellent quick charge and long cycle performance.