1215 results about "Lithium ion battery anode" patented technology

The invention belongs to the technical field of lithium ion battery negative electrode materials, and particularly relates to a method for preparing a lithium ion battery negative electrode material from sulfur-doped black phosphorus-carbon. A carbon material and sulfur powder are subjected to ball milling, uniform mixing and vacuum high-temperature calcination to obtain a sulfur-doped carbon material; and uniformly mixing the sulfur-doped carbon material with black phosphorus, and performing high-energy ball milling in an inert atmosphere to obtain the sulfur-doped black phosphorus-carbon composite negative electrode material. According to the preparation method provided by the invention, the black phosphorus, the carbon material and the sulfur are well combined, so that the high capacity of the material is ensured, the structural stability of the composite material can be improved, the polarization of the material is reduced, and the cycling stability and the rate capability of the battery are improved.

The invention discloses a preparation method of a silicon-carbon material for a negative electrode of a lithium ion battery, and relates to the technical field of lithium ion batteries, and the preparation method comprises the following steps: (1) selecting a specific silicon source solute and an organic solvent to prepare an organic silicon source solution; (2) selecting porous carbon as a substrate, and carrying out vacuum impregnation treatment in a silicon source solution; (3) carrying out solvothermal silicon deposition reaction on the porous carbon impregnated with the silicon source solution in a high-pressure reaction kettle; (4) carrying out vacuum impregnation on the deposited silicon porous carbon subjected to solvent heat treatment in a carbon source organic solvent; and (5) cracking and carbonizing the deposited silicon porous carbon impregnated with the carbon source solvent at a high temperature to form the composite silicon carbon material with carbon-coated silicon crystal particles. According to the present invention, the energy density of the lithium ion battery negative electrode material is improved while the cycle life and the rate capability are significantly improved, such that the prepared silicon-carbon material has excellent electrochemical performance, and can well meet the application requirements of the lithium ion battery on the aspects of high energy density, long cycle life, high-rate charge-discharge and the like.

The invention belongs to the technical field of energy storage materials, and particularly relates to a high-entropy oxide Fe0. 2Co0. 2Ni0. 2Cu0. 2Zn0. 2O and an ultrafast synthesis method and application thereof. According to the preparation method, ferroferric oxide, cobalt oxide, nickel oxide, copper oxide and zinc oxide with equal molar ratio are adopted as direct synthesis raw materials, toxic gases such as chlorine and nitrogen dioxide generated in the synthesis process of a metal salt precursor are avoided, and the uniformly distributed single-phase high-entropy oxide is synthesized in an ultrafast manner within 10 seconds by using a Joule heating technology; the synthesized high-entropy oxide is used as a lithium ion battery negative electrode material, and shows more excellent electrochemical performance and cycling stability compared with other high-entropy oxides prepared from transition metals with different proportions; in the preparation process, extra additives are not needed, operation is easy, the synthesis speed is high, the yield is high, element distribution is uniform, and the method has the advantages of being low in cost, high in efficiency and free of pollution and has the industrialization prospect.

Provided in the present invention are a polyacrylic acid or polyacrylate water-based binder, and a preparation method therefor and the use thereof. The polyacrylic acid or polyacrylate water-based binder is a polymer obtained by polymerizing polymeric monomers, the polymeric monomers comprising a hard monomer, a soft monomer and a functional monomer. The polyacrylic acid or polyacrylate water-based binder provided by the present invention has relatively high binding power and relatively good flexibility and electrochemical stability, and has good application prospects in the field of negative electrode sheets of lithium-ion batteries.

The present application relates to the technical field of lithium battery materials and binders, and discloses an aqueous polymeric binder, a preparation method therefor and a use thereof. The aqueous polymeric binder is obtained by copolymerizing a polymerization unit comprising an acrylic monomer, an acrylate monomer, an oil-soluble monomer, a water-soluble monomer, and an amphiphilic water-soluble monomer in an aqueous solvent; and the mass percentages of the monomers are as follows: acrylic monomer: 5%-15%; acrylate monomer: 45%-60%; oil-soluble monomer: 10%-40%; water-soluble monomer: 5%-20%; and amphiphilic water-soluble monomer: 5%-10%. The aqueous polymeric binder of the present application is mainly used for bonding of an edge coating of a negative electrode sheet of a lithium-ion battery; on the basis of the specific copolymerization monomer components and proportions, the obtained binder has excellent PP base film bonding performance and electrolyte swelling resistance; in addition, the binder avoids material mixing with a negative electrode, and has good prospects of application.

The invention discloses a porous carbon material applied to a silicon-carbon negative electrode as well as a preparation method and application of the porous carbon material, and belongs to the technical field of lithium ion batteries. Uniformly mixing asphalt and mixed acid, heating and fully reacting to obtain acid modified asphalt; dispersing the acid modified asphalt in deionized water to prepare an asphalt aqueous solution, sequentially adding melamine and KOH, uniformly dispersing to obtain a mixed solution, and drying to obtain precursor powder; carbonizing the precursor powder under the protection of nitrogen, and then introducing CO2 or water vapor or mixed gas of the CO2 and the water vapor for activation; and washing and drying the activated product to obtain the porous carbon material. The obtained material has excellent conductivity, stability and high silicon loading performance, and can be applied to the field of lithium ion battery negative electrode materials, a silicon-carbon negative electrode prepared by taking the porous carbon material as a carrier is applied to a lithium ion battery, and the technical effects of high capacity density and long circulation can be achieved.

The invention relates to the technical field of lithium ion batteries, and provides a negative plate and a lithium ion battery. The negative plate comprises a negative current collector and a negative active material layer arranged on at least one side surface of the negative current collector; the negative electrode active material layer comprises a first negative electrode active material layer and a second negative electrode active material layer, and the second negative electrode active material layer is arranged between the negative electrode current collector and the first negative electrode active material layer; the first negative electrode active material layer comprises an amorphous carbon coated graphite material, and the second negative electrode active material layer comprises a graphite material; the Dv50 of the amorphous carbon coated graphite material is recorded as P1 [mu] m, the Dv50 of the graphite material is recorded as P2 [mu] m, and P1 and P2 satisfy: P1gt; p2. The negative plate adopts a double-layer coating design to form the negative plate of which the surface layer has quick charge and the bottom layer has high energy density, so that the negative plate has both high energy density and quick charge performance.

The invention relates to the field of batteries, in particular to a preparation method and system of a silicon-carbon material, and the preparation method comprises the following steps: pretreating porous carbon, conveying the pretreated porous carbon to a fluidized bed reactor, sequentially introducing a silicon source gas and a carrier gas for silicon deposition treatment, heating, introducing a carbon source gas, adjusting the flow of the carrier gas for carbon coating treatment, and discharging and cooling to obtain a finished product, meanwhile, reaction tail gas is recycled. The preparation system comprises a gas inlet unit, a fluidized bed reactor unit, a tail gas circulation unit, a feeding preheating unit and a discharging unit. The fluidized bed reactor comprises an outer shell, an up-down stirring device, a heat exchange assembly and an air distribution assembly, and efficient reaction and temperature control can be achieved. The silicon-carbon material prepared by the method has excellent electrochemical performance and is suitable for a lithium ion battery negative electrode material. The unique porous structure and the uniform carbon coating layer effectively improve the conductivity and the structural stability of the material, and meanwhile, the volume expansion effect of silicon in the charging and discharging process is reduced.

The invention provides an amorphous copper nanolayer coated spherical porous silicon composite material and a preparation method and application thereof.The preparation method includes the step that the surface of spherical porous silicon is coated with an amorphous copper conductive nanolayer through a simple solution method.On the basis of the principle of replacement reaction, aluminum in aluminum-silicon alloy is replaced with copper to be coated on the surface of silicon, and the amorphous copper nanolayer coated spherical porous silicon composite material is obtained. And meanwhile, the rate of the replacement reaction is slowed down by utilizing different reaction activities of copper chloride in an organic solvent, so that the spherical morphology is kept, and meanwhile, the surface of silicon can be coated with a layer of amorphous copper nano layer with high conductivity. The invention also provides a preparation method of the material. Tests find that the conductivity of the material can be effectively improved due to the excellent conductivity of the copper nano layer, and the volume expansion effect of the material in the electrochemical cycle process can be effectively relieved due to the porous structure. Therefore, the combination of the two effectively improves the problems of poor conductivity and unstable structure of the silicon negative electrode material, and effectively improves the application performance of the silicon negative electrode material in the lithium ion battery negative electrode.

The invention relates to a silicon-carbon composite material with a porous structure and a preparation method thereof, and the silicon-carbon composite material with the porous structure comprises an N / P co-doped porous carbon skeleton with micropore, mesopore and macropore channel networks, and amorphous or low-crystalline nanometer silicon particles which are uniformly loaded in the porous carbon skeleton and have the average particle size of 15-40nm, the mass percent of silicon in the composite material is 40-60%, and good interface bonding is formed between silicon and carbon. The preparation method mainly comprises the following steps: firstly, preparing an N / P co-doped porous carbon skeleton through a template method in combination with high-temperature carbonization and N / P source co-pyrolysis; and hydrolyzing an organic silicon source in the carbon skeleton to form silicon dioxide, and performing low-temperature metal thermal in-situ reduction to obtain the nano-silicon loaded composite material. Through a unique porous carbon skeleton design and a precise in-situ composite strategy of nano silicon, the prepared material shows high specific capacity, high initial coulombic efficiency and excellent cycling stability and rate capability when being used as a negative electrode of a lithium ion battery.

The invention discloses a silicon-carbon negative electrode material, a preparation method thereof and a lithium ion battery, and relates to the technical field of lithium ion battery negative electrode materials. The material sequentially comprises a porous silicon core, a transition layer and a shell from inside to outside, the transition layer is a nitrogen-doped SiC / C composite layer, the shell comprises a graphene / carbon nanotube skeleton and MXene quantum dots, the MXene quantum dots are embedded in the graphene / carbon nanotube skeleton, boric acid ester bonds exist between carbon nanotubes and graphene, and the MXene quantum dots are embedded in the graphene / carbon nanotube skeleton. The silicon-carbon negative electrode material is based on dual-network dynamic bonding and stress gradient regulation and control, the cycle performance of the material can be remarkably improved, and the service life of the material can be remarkably prolonged.

The invention discloses a lithium ion battery negative pole piece, a preparation method thereof and a lithium ion battery, and belongs to the technical field of lithium ion battery electrode materials. The lithium ion battery negative electrode plate provided by the invention comprises a negative electrode current collector; the graphite layers are arranged on the surfaces of the two sides of the negative electrode current collector; the graphite layer comprises graphite particles, a conductive agent and a binder; the hard carbon layer is arranged on the surface of one side, far away from the negative electrode current collector, of the graphite layer; the hard carbon layer comprises hard carbon particles, a conductive agent and a binder; wherein the graphite layer and the hard carbon layer meet the relational expression: 1.4 < = rho1 * D1 + rho2 * D2 + PD < = 1.75. According to the invention, through proper design of the composite layer structure, the surface density, the compaction density and the particle sizes of the graphite particles and the hard carbon particles, the rapid charging performance of the lithium ion battery is improved, and meanwhile, relatively high energy density is kept; and the negative pole piece also has relatively good flexibility, so that the problems of breakage and powder falling in the processing process are relieved.

The invention relates to the technical field of lithium ion battery negative electrode materials, in particular to a silicon-carbon negative electrode material, a preparation method thereof and an electrochemical device. The silicon-carbon negative electrode material comprises nano silicon slurry and organic carbon, and the mass ratio of a silicon material to the organic carbon is (1: 0.1)-(1: 2); the nano silicon slurry is prepared by wet grinding and comprises micron silicon powder, dispersion liquid, a dispersing agent, an antioxidant and an ammonia-containing conditioning agent, and the mass ratio of the micron silicon powder to the dispersion liquid to the dispersing agent to the antioxidant to the ammonia-containing conditioning agent is (1-4): (10-20): (0-1): (0-1): (0-1). According to the nanometer silicon grinding formula and the preparation method of the silicon-carbon negative electrode material provided by the invention, the ammonia-containing tempering agent is added in the physical grinding process, so that the dispersity of nanometer silicon in the slurry is improved, the grinding efficiency is improved, the particle size of the nanometer silicon is reduced, the grinding energy consumption can be remarkably saved, the production cost is reduced, and commercialization is promoted.

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

The invention relates to the technical field of lithium ion battery negative electrode materials, and discloses a preparation method and application of a high-efficiency silicon-carbon composite graphite material, and the preparation method comprises the following steps: S1, carrying out porosity and size regulation and control on silicon particles: carrying out ball milling on industrial-grade silicon powder to obtain nano silicon particles, and carrying out acid etching to form a porous structure; s2, functional surface treatment and interface optimization: introducing functional molecules to the surfaces of the silicon particles and coating a layer of ultrathin SiO2 protective film; and S3, carbon coating and flexible protection layer construction: performing pyrolysis on the porous silicon particles by using a carbon source to form a uniform carbon coating layer which is applied to a lithium ion battery negative electrode material, and the lithium ion battery is used for an electric vehicle, a power grid energy storage system and portable electronic equipment. Through the collaborative design of the flexible protection layer, the double-layer carbon coating and the gradient coating, the technical bottlenecks of the silicon-based negative electrode material in the aspects of long cycle stability, high rate performance and interface chemical stability are systematically solved.

The invention belongs to the technical field of lithium ion battery negative electrode materials, and particularly relates to a spinel type metal oxide coated hard carbon composite material based on a lattice matching mechanism, and a gradient doping preparation method of the spinel type metal oxide coated hard carbon composite material can overcome the defects that a hard carbon material is low in initial coulombic efficiency (about 50%), low in lithium ion transmission rate and poor in rate capability. According to the invention, magnesium salt, aluminum salt, copper salt and other metal salts are mixed with hard carbon, a precipitant is added, and a hydrothermal method is combined with a calcination process to obtain the core-shell structure composite material with hard carbon coated with a spinel structure. The technology has the following three obvious advantages: (1) lattice adaptive design of the spar type metal oxide and the hard carbon, (2) molybdenum-copper gradient doping repair of the SEI film, and (3) stable circulation of more than 5000 times at the capacity of 350mAh / g.

The invention discloses acrylic resin, a preparation method and application thereof, lithium ion battery negative electrode slurry and a negative electrode plate, and belongs to the technical field of lithium ion batteries. The invention provides acrylic resin which comprises the following raw materials in percentage by mass: 40-70% of A-type monomer, 10-30% of B-type monomer, 10-30% of C-type monomer and 10-30% of cross-linking agent, and the total mass of the monomers is 100%. The dosage of the monomer B is 10%-40%; the use amount of the class C monomer is 10%-40%; the dosage of the cross-linking agent is 0.5%-3% of the total mass of the monomer. The acrylic resin disclosed by the invention is good in thickening and dispersing performance, good in bonding performance and good in flexibility in a negative electrode slurry system with graphite as an active substance, and can completely replace a traditional thickening agent CMC, and a lithium ion battery negative electrode pole piece prepared from the acrylic resin has excellent thick coating anti-cracking performance and can be applied to lithium ion batteries. And the peeling strength of the pole piece can be greatly improved.

The invention relates to the technical field of lithium ion battery negative electrode materials, in particular to a coating modification method of a negative electrode material, the negative electrode material and application of the negative electrode material, and the negative electrode material sequentially comprises a silicon core, a gradient interface layer, a self-repairing elastic layer and a hierarchical porous carbon skeleton from inside to outside; the gradient interface layer coats the surface of the silicon core and sequentially comprises an amino silane coupling agent modification layer and a conductive polymer layer from inside to outside; the self-repairing elastic layer covers the outer side of the gradient interface layer and comprises a dynamic covalent bond cross-linked network; the hierarchical porous carbon skeleton coats the outer side of the self-repairing elastic layer, a strongly-combined gradient interface layer is firstly constructed on a silicon core through hydroxylation, amino silane coupling and conducting polymer in-situ polymerization, then a reversible cross-linked network is formed outside the gradient interface layer based on Diels-Alder dynamic covalent bonds, and in-situ crack repairing is achieved. And finally, biomass carbon and CVD carbon nanotubes are compounded, and a micropore / mesopore synergistic conductive buffer structure is formed outside the reversible cross-linked network, so that the cycling stability of the battery is improved.

The invention relates to a negative electrode material, a preparation method thereof and a lithium ion battery, the negative electrode material comprises a silicon-based material and a coating layer located on at least part of the surface of the silicon-based material, the silicon-based material comprises silicon oxide and lithium silicate, and the material of the coating layer comprises a carbon material; the method comprises the following steps: dissolving 20 mg of a negative electrode material in 10 ml of deionized water to form slurry, carrying out a Zeta potential test on the slurry by adopting a nanometer particle size and Zeta potential analyzer, in a Zeta potential test distribution diagram of the slurry, the intensity of a first characteristic peak of the slurry in a Zeta potential interval of-50 mV to-40 mV is I1, the intensity of a second characteristic peak of the slurry in a Zeta potential interval of-65 mV to-50 mV is I2, and the first characteristic peak and the second characteristic peak are shown in the specification. The intensity of the third characteristic peak in the Zeta potential interval of-35mV to-25mV is I3, and the relation among I1, I2 and I3 meets the conditions that I2 / I1 is greater than or equal to 0 and less than or equal to 2.0, and I3 / I3 is greater than or equal to 0 and less than or equal to 1.0. According to the negative electrode material, the volume expansion of the negative electrode material can be reduced, and the rate capability and the cycle performance of the negative electrode material are improved.

The invention provides a negative electrode plate and a lithium ion battery, the negative electrode plate comprises a negative electrode current collector, a first negative electrode active layer and a second negative electrode active layer, the negative electrode current collector comprises a first region and a second region, the first region is arranged on the negative electrode current collector, the second region is located between the edge of the negative electrode current collector and the edge of the first region, the first negative electrode active layer is arranged in the first region, and the second negative electrode active layer is arranged in the second region; the Young's modulus of the second negative electrode active layer is greater than the Young's modulus of the first negative electrode active layer. According to the negative electrode plate provided by the invention, the second negative electrode active layer is arranged in the second region of the negative electrode current collector, the Young modulus of the second negative electrode active layer is greater than that of the first negative electrode active layer, and the relatively large Young modulus can inhibit volume expansion generated by the edge of the negative electrode plate in the charging and discharging process, so that the extension stress in the width direction of the negative electrode plate is reduced; the condition of corner damage caused by excessive extension of the negative plate is improved, so that the safety performance of the lithium ion battery is improved.

The invention discloses a preparation method and application of a carbon-interspersed superfine silicon network composite structure. According to the method, a carbon skeleton with a low specific surface area is used as a carrier, after high-temperature air oxidation pretreatment, nano silicon particles are loaded through vapor deposition or a mixing method, and the battery is assembled for in-situ electrochemical induction. In the induction process, silicon particles are subjected to lithiation fusion-lithium removal bonding to form a continuous network, a carbon phase is interspersed in the continuous network to limit silicon agglomeration, and a double-phase interspersed structure with a silicon network skeleton size of 5-40nm is obtained. According to the embodiment of the invention, as a lithium ion battery negative electrode, the specific capacity reaches 1507mAhg <-1 > under 0.2 Ag <-1 >, the 100-time cycle capacity retention ratio reaches 94.8%, and the 50-time cycle capacity retention ratio of a whole battery matched with LiFePO4 is 98.1%. A high-cost porous carbon carrier is abandoned, the problems of nano silicon agglomeration and side reaction are solved, and the method is compatible with industrial production.

The invention belongs to the technical field of lithium battery materials, and particularly relates to a lithium trifluoromethanesulfonate in-situ doped graphdiyne composite material and a preparation method and application thereof. The preparation method of the lithium trifluoromethanesulfonate in-situ doped graphdiyne composite material adopts a one-step in-situ synthesis method, and specifically comprises the following steps: adding hexaacetylene benzene and lithium trifluoromethanesulfonate into a solvent, mixing, adding a catalyst, carrying out a heating reaction, and carrying out post-treatment on the obtained reactant to obtain the lithium trifluoromethanesulfonate in-situ doped graphdiyne composite material. Finally, the lithium trifluoromethanesulfonate in-situ doped graphdiyne composite material is obtained. The preparation method of the lithium trifluoromethanesulfonate in-situ doped graphdiyne composite material provided by the invention is simple in process, the prepared composite material is good in interface stability, and when the composite material is applied to a negative electrode of a lithium ion battery, the electrochemical performance of the battery can be improved, and the service life of the battery can be prolonged.

The invention relates to the technical field of preparation of a lithium ion battery negative electrode material, in particular to a metal organic framework coating for improving the performance of an iron oxide negative electrode lithium ion battery and a preparation method of the metal organic framework coating. The metal organic framework coating mainly comprises the step of coating the iron oxide by growing a metal organic framework on the surface of the iron oxide in situ. According to the invention, in-situ synthesis of a metal organic framework material on the surface of iron oxide is innovatively proposed, and the iron oxide material is coated in a hollow structure through a structure provided by an organic framework, so that volume expansion and shrinkage of iron oxide in charge and discharge processes are effectively buffered. By regulating and controlling the mass ratio of the organic framework to the ferric oxide, the high-rate discharge performance and the specific discharge capacity of the ferric oxide negative electrode are improved.

The invention belongs to the technical field of lithium ion battery electrode materials, and particularly relates to a fluorine-doped long-circulation silicon-based negative electrode material as well as a preparation method and application thereof. The silicon-based material is doped and modified by using the fluoride, the doping and modification of the fluoride on the silicon-based particles are realized by using simple and convenient dry mixing and heat treatment means, F doping can be performed on the silicon-based particles by introducing the fluoride, and a high-strength solid electrolyte interface (SEI) rich in LiF is continuously formed in the expansion and pulverization process of the silicon-based particles. And meanwhile, the mass transfer rate is improved through bulk phase doping elements, uneven lithiation and stress concentration are reduced, and the cycling stability of the silicon-based composite negative electrode material is comprehensively improved. The preparation method disclosed by the invention is simple to operate, cheap in raw materials and easy for large-scale production, has a good application prospect in lithium ion battery negative electrode materials, and has a relatively high commercial value.

The invention provides a graphite composite material, a preparation method thereof and a secondary battery, and relates to the technical field of lithium ion battery negative electrode materials. The graphite composite material comprises an inner core and a shell layer, the inner core comprises metal element doped metal oxide and graphite, the metal element doped metal oxide is embedded between sheet layers of the graphite, the shell layer comprises multi-walled carbon nanotubes and amorphous carbon, and the multi-walled carbon nanotubes are distributed in the amorphous carbon in a 3D net shape. According to the invention, by introducing the doping element, the lithium intercalation active sites of the metal oxide are increased, so that the lithium storage performance of the graphite composite material is improved; through the construction of a core-shell and intercalation structure, the volume expansion of the metal oxide is inhibited, so that the cycling stability of the graphite composite material is improved.

The invention discloses a preparation method and application of a silicon-carbon lithium ion battery negative electrode, and the preparation method comprises the following steps: carrying out carbon coating on a single-walled carbon nanotube through a hydrothermal reaction to obtain a carbon-coated single-walled carbon nanotube; performing chemical etching and pore forming on the carbon-coated single-walled carbon nanotube to obtain a porous carbon-coated single-walled carbon nanotube; and adding the porous carbon coated single-walled carbon nanotube into a lithium ion battery negative electrode material containing a silicon negative electrode to obtain the silicon-carbon lithium ion battery negative electrode. Volume expansion is inhibited through the porous carbon coated silicon negative electrode, the micro-mesopore composite porous carbon coated single-walled carbon nanotube is prepared to replace a pure single-walled carbon nanotube to serve as a main conductive agent in a silicon-doped negative electrode formula, the cycle life of a lithium battery is prolonged, and the rate capability of the lithium battery is improved.

The invention provides a copper-nickel alloy foil and a preparation method and application thereof, and belongs to the technical field of lithium ion battery negative electrode current collectors, and the preparation method comprises the following steps: preparing a copper-nickel composite electrolyte, and adding a coordination agent, a pH buffer agent and an additive into the copper-nickel composite electrolyte to obtain a mixed electrolyte; the coordination agent comprises a main coordination agent and an auxiliary coordination agent, and the main coordination agent comprises at least one of trisodium citrate, potassium sodium tartrate and sodium pyrophosphate; the auxiliary coordination agent comprises at least one of ammonia water, glycine and triethanolamine; and a cathode and an anode are placed in the mixed electrolyte, the pH of the mixed electrolyte is controlled to be 6-10, direct current is applied for electrochemical deposition, and the copper-nickel alloy foil is obtained. According to the method, the alkalescence system is adopted, the main coordination agent and the auxiliary coordination agent are used, full coordination of free Cu < 2 + > and Ni < 2 + > is achieved, precipitation is avoided, the hydrogen evolution phenomenon is greatly reduced, and the alloy foil quality is improved.

The invention discloses a method for preparing a silicon-carbon composite negative electrode material through an electrostatic self-assembly technology, and belongs to the technical field of lithium ion battery negative electrode materials. According to the invention, lignin is used as a biomass carbon source and lauryl sodium sulfate (SDS) and poly (diallyldimethylammonium chloride) (PDDA) are used as activators through a simple electrostatic self-assembly technology; a proper amount of nano silicon and PDDA are subjected to in-situ adsorption, and lignin and SDS are subjected to in-situ adsorption; a self-assembly process is carried out through the positive and negative charge attraction effect among colloidal particles, so that effective compounding of the nano silicon particles and the biomass carbon is realized; and performing vacuum drying, and performing one-stage sintering in a tubular furnace to obtain the silicon-carbon composite negative electrode material. Based on the problems of non-uniform particle size, easy agglomeration and great abrasion of a silicon-carbon composite material in a traditional mechanical synthesis technology, the invention improves the compounding efficiency of the silicon-carbon material and improves the problems of volume expansion of a silicon negative electrode, slow migration rate of lithium ions, poor cycle performance and the like.

The invention relates to the technical field of lithium ion battery negative electrode materials, in particular to a preparation process of a silicon-carbon coated negative electrode material which takes bamboo wood as a biomass carbon source and is combined with nano silicon and a dual carbon coating technology, and the preparation process comprises the following steps: step a, sol loading, step b, vacuum impregnation, step c, interface bonding, step d, inner layer coating and step e, outer layer coating. A silicon-carbon interface in-situ bonding technology and a double-layer carbon coating technology are utilized, a sol-gel method is adopted to construct a Si-O-C chemical bond on the surface of bamboo-based carbon, molecular-level anchoring of silicon particles (20-50 nm) on the surface of a carbon skeleton is achieved, the interface separation problem of traditional mechanical mixing is solved, meanwhile, inner-layer amorphous carbon (2-3 nm) is generated in cooperation with bamboo wood pyrolysis gas, and the surface of the bamboo-based carbon is separated. Then bamboo vinegar is carbonized to form an outer graphitized carbon shell (5-8nm), and the double carbon layers cooperate to inhibit volume expansion of silicon, so that the problem of volume expansion of silicon is solved, and the first charge-discharge efficiency of the battery and the capacity retention rate after circulation are effectively improved.

The invention relates to the field of electrochemical energy storage electrode materials, in particular to a method for preparing a coal-based carbon material through chemical crosslinking coupling high-temperature carbonization and application of the coal-based carbon material. The method comprises the following steps: crushing and deliming raw material coal to obtain ultra-pure coal powder; then dissolving the ultra-pure coal powder and a cross-linking agent in an organic solvent, under the action of a catalyst, inducing methyl, ethyoxyl, aldehyde and other groups to uniformly introduce polycyclic aromatic hydrocarbon molecules, and finally forming a super-cross-linked structure; and performing high-temperature carbonization to recombine the coal into closed pores, thereby forming the disordered coal-based carbon material with small microcrystal size. The method has the advantages that the raw material source is stable, the cost is low, the carbon yield is high, the treatment process is simple, large-scale preparation of the high-performance coal-based carbon material is easy to realize, and the like; and the prepared coal-based carbon material shows excellent electrochemical performance as a sodium ion / lithium ion battery negative electrode.