55results about How to "Inhibition of volume expansion effect" patented technology

The present invention discloses a lithium-ion battery silicon-carbon anode material and a preparation method thereof, and is to improve specific capacity and cycling performance. The material disclosed by the present invention is composed of an oxygen-containing silicon-carbon composite material and a graphite powder, wherein the oxygen-containing silicon-carbon composite material is formed by dispersing an oxygen-containing silicon-based material in a graphite powder and organic cracking carbon. Comparing the present invention with the prior art, the oxygen-containing silicon-based material is constituted by uniformly dispersing silicon particles in SiOx and a first buffer layer is formed, the oxygen-containing silicon-based material is uniformly dispersed in the organic cracking carbon and the graphite powder to form a second expansion buffer layer, thus the volume expansion effect of the silicon during charging and discharging can be effectively inhibited and cycle stability is improved. The lithium-ion battery silicon-carbon anode material is simple in preparation process, low in raw material costs, and easy for mass production.

The invention discloses a graphite/silicon@carbon core-shell structure composite spherical cathode material and a preparation method thereof. By means of the material, the volume expansion effect of silicon in the lithium de-intercalation process can be inhibited, and a high-capacity lithium iron battery silicon/carbon composite cathode material is obtained. By means of the technical scheme, a spherical graphite/silicon framework precursor serves as the core of the composite cathode material, and an amorphous pyrolytic carbon or graphite-like carbon material wrapping layer serves as the shell; nanometer or micrometer silicon is embedded in flake graphite cracks to form a graphite framework, the volume expansion effect of silicon in the lithium de-intercalation process is inhibited through the mechanical characteristics of the graphite framework, then a spherical framework is formed by mixing and granulating 3-20 wt% of nanometer or micrometer silicon, 50-80 wt% of flake graphite and 10-40 wt% of amorphous pyrolytic carbon or graphite-like carbon, and an amorphous pyrolytic carbon or graphite-like carbon spherical composite conductive carbon net structure wrapping a graphite/silicon surface is formed.

The invention provides a preparation method of a porous graphene/carbon nano tube lithium sulfur anode material. The method comprises the steps of introducing silicon dioxide microspheres as a template, mixing with a carbon nano tube dispersion liquid, dropwise adding a sodium ascorbate solution, using hydrofluoric acid for soaking for 5 to 7 days, and obtaining a porous graphene/carbon nano tube;grinding with a sulfur elementary substance, using a hydrothermal reaction kettle for heating for 10 to 15h at 140 to 160 DEG C under the argon protection, and obtaining a sulfur/porous graphene/carbon nano tube. The material prepared by the invention adopts the porous graphite/carbon nano tube composite material as a frame so as to form a three-dimensional conductive network structure, so that sulfur can be stored, and a battery performance is improved.

The invention discloses a selenium-doped ferrous disulfide carbon-coated composite material. The composition of the selenium-doped ferrous disulfide carbon-coated composite material is FeSe*S2-*@C, wherein x is 0.1-1.9. When applied to sodium ion batteries, the selenium-doped ferrous disulfide carbon-coated composite material can effectively inhibit volume expansion effects and increase actual specific capacity, rate capability and cycling performance. The invention also discloses preparation and application methods of the selenium-doped ferrous disulfide carbon-coated composite material.

The invention belongs to the technical field of lithium-sulfur batteries, in particular to a high-performance lithium-sulfur battery cathode material and a preparation method thereof. The material isporous flower-shaped CoP/C @ S composite. Using cobalt chloride dimethanol as precursor, Porous flower-like CoP/C @ S composites were synthesized by low temperature phosphating process, the porous structure of the composite can effectively coat sulfur, The porosity and nanometer size of CoP/C @ S composites endow them with superionic conductivity and larger electrode/electrolyte interface, which improves the conductivity and promotes the transport of electrons and ions. The results show that CoP/C @ S composites possess the characteristics of high porosity and nanometer size, which can inhibitthe dissolution of polysulfides and improve the utilization of active substances.

The invention discloses a carbon-coated ferroferric oxide. The carbon coating quantity is 5-40%, and the carbon-coated ferroferric oxide is prepared by introducing an acetylene gas into Fe2O3 under Ar atmosphere at 500-700 DEG C so as to carry out reduction and carbon coating of Fe2O3, wherein the flow velocity ratio of Ar to acetylene is 100:(1-10), thereby obtaining a carbon-coated Fe3O4 composite material. The invention aims at overcoming the defect of FexOy and conducting carbon coating on FexOy. Due to the carbon coating, not only the direct contact of the active material FexOy and electrolyte overcome can be prevented and the conductivity of FexOy is improved, but also defects of volume expansion effects, the agglomeration easiness and the like of FexOy and the electrolyte are suppressed, so that the lithium storage characteristic of FexOy is improved, and the height ratio capacity characteristic of FexOy is fully exerted.

The invention provides a preparation method of a ferric oxide/carbon/carbon nanotube (CNT) lithium-ion battery negative electrode material. The preparation method comprises the following steps: step 1, after mixing carbon nanotubes and KOH powder, adding a mixture into distilled water; after stirring, drying and roasting to obtain activated carbon nanotubes; step 2, mixing a mixed solution of Fe(NO3)9 and C6H12O6 with an activated carbon nanotube dispersion solution, and reacting to obtain Fe2O3/C/CNT. According to the preparation method provided by the invention, carbon cladded ferric oxide nanoparticles and the carbon nanotubes are combined together, so that the disadvantages that the electric conductivity is low, the specific capacity is low and the coulombic efficiency is relatively low and the like when the carbon cladded ferric oxide nanoparticles are used as a lithium-ion battery negative electrode can be improved.

The invention discloses a Fe2O3 porous nanowire electrode material, and a preparation method and application thereof. The preparation method comprises the following steps of ZnO seed crystal preparation, ZnO nano array preparation and Fe2O3 porous nanowire preparation. A metal current collector or a carbon material current collector is taken as a substrate, firstly, a ZnO nano array is prepared through a hydrothermal method, the Fe2O3 porous nanowire electrode material is prepared through a second hydrothermal method, the length of the prepared Fe2O3 nanowire electrode material is about 1 [mu]m, the diameter of the Fe2O3 nanowire electrode material is within 20 nm to 80 nm, and the Fe2O3 porous nanowire electrode material is of a porous structure and is bonded firmly with a matrix. The prepared Fe2O3 porous nanowire electrode material has the characteristics of high cyclic stability and excellent rate performance, and has wide application prospects.

The invention discloses an electrolyte suitable for a silicon-carbon negative electrode and a lithium ion battery. The electrolyte comprises an electrolyte lithium salt, a non-aqueous organic solventand an additive. The additive comprises a negative electrode film-forming additive, a fluorinated phenyl boron compound and a disilyl sulfate compound. Through the synergistic effect of the fluorophenyl boron compound additive, the disilane alkyl sulfate compound additive, the negative electrode film-forming additive and the novel lithium salt type additive, the electrolyte has excellent film-forming performance on the surface of the silicon-carbon negative electrode, and the formed SEI film is relatively small in impedance and relatively stable in component and structure. By using the electrolyte, the discharge capacity, the cycling stability and the high-temperature storage performance of the silicon-carbon negative electrode lithium ion battery can be effectively improved, gas production can be inhibited, the problems of volume expansion, particle breakage and the like in the battery cycling process can be effectively solved, and meanwhile, the electrolyte has good high-temperatureand low-temperature performance.

The invention belongs to the field of material chemistry and relates to a preparation method for a cathode material of a lithium ion battery. The method comprises three steps: preparing graphene oxide, preparing foam graphene and preparing a foam graphene compound indium zinc sulfide material. The cathode material with higher charge-discharge specific capacity and better cycle performance is acquired by introducing graphene foams and indium zinc sulfide as cathode active materials; the initial charge-discharge capacity can reach up to 742.17mAh/g; after 200 times of circulation, the cathode material still has a reversible capacity of 415.23mAh/g.

The invention discloses a Sn-based sulfide and/or nitride modified SnO2 thin-film lithium battery negative electrode, and the negative electrode is characterized in that the negative electrode comprises a current collector, a metal buffer layer compounded on the current collector, an active substance layer compounded on the metal buffer layer and a modification layer compounded on the active substance layer; the material of the metal buffer layer is a conductive metal with the lattice constant being within the range of 3.6-4.7; the material of the active substance layer is SnO2; the material of the modification layer is SnS2 and/or SnNx, wherein x is 0.7 to 1.2. The invention also provides a preparation method and application of the negative electrode. According to the present invention, with the existence of the metal buffer layer, the active material layer having the dominant crystal face structure and the modification layer can be stably compounded without the existence of the adhesive phase; for example, SnO2 can be tightly compounded; in addition, the volume effect of the active substance in the charging and discharging process is buffered to a certain extent.

The invention provides a multilayer composite negative electrode material, a preparation method thereof, a negative electrode sheet and a lithium battery. The preparation method of the multilayer composite negative electrode material comprises the steps that silicon, silicon dioxide and carbon are used as raw materials to prepare a multilayer precursor; a silicon material is mixed with a binder toacquire a first precursor layer mixture; silicon dioxide, a carbon material and the binder are mixed to acquire a second precursor layer mixture; the carbon material is mixed with the binder to acquire a third precursor layer mixture; the first, second and third precursor layer mixtures are molded in the order of a silicon layer, a silicon dioxide/carbon mixed layer and a carbon layer, and then are sintered to acquire a multilayer precursor; and silicon dioxide in the multilayer precursor is reduced to monatomic silicon to acquire the multilayer composite negative electrode material. According to the invention, a denser solid electrolyte interface film can be generated during the first charge and discharge process; the volume expansion effect of the silicon material during the charge anddischarge process is suppressed; and the first efficiency of the battery, the specific capacity of the negative electrode and the cycle performance of the battery are improved.

The invention belongs to the technical field of materials, and particularly relates to a modified organic silicon polymer, a preparation method thereof and a lithium secondary battery. The preparationmethod comprises the following steps: carrying out a hydrosilylation reaction on side-chain hydrogen-containing silicone oil and a modifier under the action of a catalyst, and grafting amino, alkoxyor carboxyl functional groups on the modifier onto the hydrogen-containing silicone oil through the reaction to obtain the modified organosilicon polymer. The obtained modified organic silicon polymeris an elastomer containing amino, alkoxy or carboxyl functional groups on a side chain, not only has good bonding performance and self-healing performance, but also can interact with functional groups such as hydroxyl on the surface of a silicon-based negative electrode to form a self-healing three-dimensional cross-linked network, effectively inhibits the volume expansion effect of the silicon-based negative electrode active material, and maintains the integrity of the silicon-based negative electrode structure in the charging and discharging process, so that the cycling stability of the obtained lithium secondary battery is improved.

The invention belongs to the technical field of batteries, and particularly relates to an electrolyte additive, an electrolyte and a secondary battery. The structural general formula of the electrolyte additive is shown in a following formula I, and x and Y in the formula I are respectively and independently selected from one of isothiocyano group, cyclohexyl group, alkoxy group, phenyl group and halogen. According to the electrolyte additive provided by the invention, side reactions on the surface of a positive electrode can be reduced, flame-retardant phosphorus free radicals are generated, and the cycling stability and the safety performance of a pole piece are improved; and an SEI film can be polymerized on the surfaces of a positive electrode and a negative electrode, so that the elasticity of the SEI film is improved, the SEI film can better adapt to the huge volume expansion and shrinkage stress of electrode materials, such as a silicon substrate, etc., in a lithium intercalation and deintercalation process, and the cycling stability and safety of the battery are improved.

The invention belongs to the technical field of batteries, and particularly relates to a composite negative plate and a preparation method thereof, and a secondary battery. The composite negative plate comprises a current collector and a carbon active layer combined on the surface of the current collector, a plurality of micropores are formed in the surface, deviating from the current collector, of the carbon active layer, the micropores are filled with a second active material, and the specific capacity of the second active material is higher than that of a carbon material in the carbon active layer; and the opening depth of the micropores is lower than the thickness of the carbon active layer. According to the composite negative plate disclosed by the invention, through the synergistic effect of the carbon active layer and the second active material which is filled in the micropores and has higher a specific capacity, the capacity of the composite negative plate can be improved so that the capacity density of the battery is improved, and the volume expansion effect of the active material can be relieved or even inhibited through the carbon active layer; and the microporous structure is also beneficial to improving the ion migration transmission efficiency, improving the electrolyte retention capacity of the pole piece and improving the electrochemical performance of the composite pole piece.

The invention provides a preparation method and an application of a transition metal oxide/graphitized mesocarbon microbead composite material. The preparation method comprises the steps of firstly preparing surface oxidized graphitized mesocarbon microbeads, then adding the surface oxidized graphitized mesocarbon microbeads into an aqueous solution of transition metal chloride, slowing drippinga precipitating agent, stirring, carrying out pumping filtration, drying, and carrying out calcining heat treatment in an inert atmosphere. The material can directly serve as an anode material for lithium ion batteries, and has excellent rate performance and cycle performance. The whole preparation process of the composite material is simple to operate, and the reaction conditions are easy to control.

The invention discloses a silicon-carbon composite material and a preparation method and application thereof. A chemical vapor deposition method is adopted for preparing a graphene foam body which is subjected to in-situ toughening through a carbon nano toughening agent and has carbon nano tubes growing on the surface of the graphene foam body, and then the Si powder or SiOx powder with the carbon nano tubes or carbon nano sheets growing on the surface of the Si powder or SiOx powder is loaded in the graphene foam body, so that a flexible electrode based on the silicon-carbon composite material with a novel structure is prepared and is used as a negative electrode of a semi-solid, quasi-solid or all-solid-state battery. The silicon-carbon composite material prepared by the invention has the characteristics of high capacity and high cycle stability, has excellent interface wettability, stability and ion/electron conductivity with solid electrolyte, does not need a current collector, and remarkably improves the energy density and power density of the solid-state battery.

The invention discloses a preparation method of a pole sheet for improving the performance of a silicon-based negative electrode lithium ion battery. The method comprises the following steps: dissolving a modified additive into deionized water/absolute ethyl alcohol in a certain proportion to obtain a modified additive solution, and fully mixing a silicon-based negative electrode material, a conductive agent, a binder and the modified additive solution in a certain mass ratio to form a slurry-like substance, wherein the modified additive is a plurality of aromatic organic matters and must contain one of aromatic acid or aromatic aldehyde and one of aromatic alcohol or aromatic amine; and then uniformly coating the surface of a copper foil with the slurry-like substance, and respectively carrying out drying at 50-80 DEG C for 30-60 minutes and vacuum drying at 100-150 DEG C for 10-20 hours to obtain the silicon-based negative pole sheet. According to the invention, the poor contact property caused in the silicon particle expansion process is effectively improved, the problems of lattice volume expansion, silicon particle pulverization, repeated growth of SEI films on the surfaces of silicon particles, electrolytic solution consumption and the like after the silicon-based material is charged and discharged are solved, and the first efficiency, rate discharge and cycle performance of the prepared battery are improved.

The invention discloses a preparation method of a copper-zinc-tin sulfide-selenide (CZTSSe) thin film and application of the thin film in a lithium ion battery. By means of a magnetron sputtering method, by means of copper foil treated with Se, the atmosphere with Se and S plasma is created in a sputtering cavity, and a Cu-Zn-Sn-S-Se precursor is synthesized through reactive sputtering. The thin film is arranged in the protective atmosphere, and after high-temperature annealing, the CZTSSe thin film is obtained. The preparation method is simple and effective, the uniformity and the stability of the preparation material are guaranteed, meanwhile, the material integrates the advantages of metal sulfide-selenide and has high energy density and circulating stability, and the discharge performance of the battery is effectively improved.