359results about How to "Buffer volume expansion" patented technology

The invention relates to a preparation method of a silicon/graphene laminar composite material for lithium ion battery cathode. The composite material adopts a laminar sandwich structure, silicon nano-particles are dispersed on each lamina of the grapheme, the laminas of the grapheme are separated from one another by the silicon nano-particles and the edges of the laminas are in lapped joint so as to constitute a laminar conductive network structure. The preparation method thereof comprises the steps of: formulating anhydrous silicon tetrachloride, surface active agent, sodium naphthalene and graphite oxide to tetrahydrofuran solution, adding the tetrahydrofuran solution into a reactor for reaction in vacuum at the temperature ranging from 380 to 400 DEG C, filtering the reactant to result in the product, and then washing, drying and heating the product to obtain the silicon/grapheme composite material. The preparation method of the invention has the advantages of simple preparation process and great easiness for industrial production; and the silicon/graphene laminar composite material prepared according to the method includes excellent conductivity, power performance, electrochemical activity and cycle stability, and is particularly suitable for manufacturing lithium ion battery cathode.

The invention relates to a monox/carbon composite material, comprising monox/graphene particles, organic matter pyrolysis carbon and graphite powder, wherein monox particles are adhered to the surface of a grapheme sheet; the organic matter pyrolysis carbon coats the monox/ graphene particles, and then is compounded with graphite. The preparation method of the monox/carbon composite material comprises the steps of: mixing monox particles with graphene to obtain the monox/graphene particles; coating organic carbon by obtained monox/graphene particles, thereby obtaining the monox/graphene material coated by the organic matter pyrolysis carbon; and mixing the obtained monox/graphene material coated by the organic matter pyrolysis carbon with the graphite powder, so as to obtain the monox/carbon composite material. The monox/carbon composite material is used as a lithium ion battery cathode material. Thus, the monox/carbon composite material has the characteristics of high first charge and discharge efficiency, excellent cycle performance and power charge and discharge properties, and low volume expansion effect.

The invention discloses a lithium-sulfur battery with a conductive adsorption layer, and an application of a conductive polymer film. The lithium-sulfur battery comprises a sulfur-containing positive electrode sheet, a separation film, and a lithium negative-electrode sheet. A conductive absorption layer is arranged between the sulfur-containing positive electrode sheet and the separation film. The application comprises that the conductive polymer film prepared from a conductive polymer, a conductive agent, and an adhesive is arranged as a conductive absorption layer between the sulfur-containing positive electrode sheet and the separation film of the lithium-sulfur battery, such that the lithium-sulfur battery is prepared. The prepared lithium-sulfur battery has the characteristics of high specific capacity, high coulombic efficiency, and long service life. The conductive polymer film has the advantages of low raw material cost, simple preparation method, and suitability for industrialized productions.

The invention discloses a phosphate-doping silicon carbon negative electrode material for a lithium ion battery. The phosphate-doping silicon carbon negative electrode material is formed by sinteringa phosphate-doping nanosilicon material, graphite and an organic carbon source after spray granulation. The invention also proposes a preparation method of the phosphate-doping silicon carbon negativeelectrode material for the lithium ion battery. The preparation method comprises the steps of uniformly dispersing the nanosilicon material in a phosphoric acid solution, and performing spraying anddrying to obtain the phosphate-doping nanosilicon material; performing primary sintering on the phosphate-doping nanosilicon material; and uniformly dispersing the phosphate-doping nanosilicon material subjected to primary sintering in water, adding the graphite and the organic carbon source, and performing spraying, drying and secondary sintering after complete dispersion. The preparation methodof the phosphate-doping silicon carbon negative electrode material for the lithium ion battery, proposed by the invention, has the advantages of simple process, low cost and convenient subsequent processing mode and is convenient to operate, the raw material is natural and available, mass production is easy, and the obtained negative electrode material is high in electron conductivity and small involume expansion.

The invention discloses a zinc oxide-metal lithium composite negative electrode and a preparation method thereof, and a metal lithium secondary battery. The zinc oxide-metal lithium composite negativeelectrode has a three-dimensional structure and comprises foamy copper and metal lithium and zinc oxide compounded in the foamy copper. The negative electrode utilizes combination of foamy copper andmetal lithium, utilizes three-dimensional foamy copper as a skeleton, utilizes a hydrothermal method to deposit a layer of a zinc oxide nano-layer on the foamy copper surface, and utilizes the lithium loving performances of the zinc oxide nano-layer to melt the solid lithium metal into liquid lithium spontaneously adsorbed into the three-dimensional foamy copper skeleton. Compared with the lithium sheet negative electrode, the three-dimensional metal lithium negative electrode has a large specific surface area and can effectively reduce the current density during charging and discharging. Theporous structure can well limit lithium in the internal space, reduce the volume expansion of the lithium negative electrode during charging and discharging, and effectively inhibit the growth of dendrites.

The invention discloses a preparing method for a silicon-carbon composite negative electrode material for a lithium ion battery. The preparing method includes the following steps that 1, flake graphite, a polymer solution and nanometer silicon dispersion liquid are evenly mixed, dried and carbonized in a protective atmosphere; 2, pitch and spherical graphite are mixed, ground, placed in an inert protective atmosphere, and subjected to heat treatment to obtain modified spherical graphite; 3, a binder, the modified spherical graphite and the mixed material obtained after carbonization in the step 1 are added into solvent, dispersed evenly and dried to obtain a precursor material; 4, the precursor material is carbonized to obtain the silicon-carbon composite negative electrode material. In the process of the preparing method, it is unnecessary to add special dispersant, nanometer silicon is evenly dispersed in the graphite by means of some ionic groups existing in the polymer solution and high viscosity, the polymer solution has certain stability, and the possibility of nanometer silicon aggregation in the drying process is reduced.

The invention discloses a boron-doped silicon-based negative electrode material used for a lithium ion battery. The boron-doped silicon-based negative electrode material is prepared from a boron-doped nanometer silicon material and graphite in a compounding manner, wherein the mass percentage of the boron-doped nanometer silicon material is 3-100%, and the balance is graphite. Diboron trioxide is gradually diffused to the silicon negative electrode material in a high-temperature sintering process to replace a part of silicon atoms to form displacement type doping, so that vacancy carrier concentration in the nanometer silicon material is improved, thereby improving the intrinsic electron conductivity of the silicon material; volume expansion of the silicon material can be buffered by graphite; and the boron-doped silicon-based negative electrode material has simple preparation process, convenience in operation, natural and easily available raw materials, low cost, convenience in subsequent processing mode, and easy realization of large-scale production.

The invention discloses a method for preparing a tin dioxide/graphene-compounded anode material of a lithium ion battery. The method comprises the following steps: uniformly mixing choline chloride, ethylene glycol and graphene oxide to obtain a mixed solution, adding stannous chloride to the mixed solution, performing ultrasonic oscillating reaction, and performing post-processing to obtain the product. According to the method for preparing the tin dioxide/graphene-compounded anode material of the lithium ion battery, a normal-pressure and normal-temperature one-step method is adopted, the adopted raw materials are simple in components and common and easy to obtain, the reaction conditions are mild and controllable, the reaction can be performed at normal temperature and normal pressure, and the preparation process is simple and practicable, has low requirements for equipment so as to be free from geographical restrictions, and is suitable for large-scale industrial production. The prepared tin dioxide/graphene-compounded anode material of the lithium ion battery has excellent electrochemical properties, and can be used as an active electrode substance for preparing an anode of the lithium ion battery so as to have a wide market application prospect.

The invention discloses a core-shell structure nanometer silicon-Mxene composite cathode material and a preparation method thereof. During preparation, the core-shell structure nanometer silicon-Mxenecomposite cathode material comprises the following steps: (1) using a ceramic phase precursor MAX as a raw material, etching the ceramic phase precursor MAX by using HCl+LiF and using deionized waterto wash the ceramic phase precursor MAX to obtain an MXene material; (2) adding the MXene material to a nanometer silicon suspension liquid; carrying out high energy ball milling and dispersing on the MXene material so as to obtain a nanometer silicon-Mxene composite turbid liquid; and drying the nanometer silicon-Mxene composite turbid liquid to obtain a nanometer silicon-Mxene composite powder;and (3) coating the nanometer silicon-Mxene composite powder by using asphalt, and carbonizing the nanometer silicon-Mxene composite powder to prepare the core-shell structure nanometer silicon-Mxenecomposite cathode material. The core-shell structure nanometer silicon-Mxene composite cathode material disclosed by the invention has the advantages that the nanometer silicon and the Mxene with a two-dimensional layer structure are combined by using a high energy ball milling method, and a core-shell structure of a porous network is designed; and therefore, volume expansion in the nanometer silicon particle charging and discharging process can be effectively buffered, direct contact between electrolyte and a silicon interface is stopped, the electrical conductivity of an active substance isimproved, so that the specific capacity and cycling stability of a lithium ion battery are improved in a coordinated manner.

The invention discloses a porous silicon-carbon composite material and a preparation method thereof. The porous silicon-carbon composite material is formed by bonding a silicon-based material and a carbon-based material. The silicon-based material comprises silicon, a silicon oxide and silicate, and the silicate is dispersed in a silicon oxide substrate. The carbon-based material comprises a carbon material and an amorphous carbon coating material. The carbon material and the silicon-based material are in contact with each other and are bonded together to form a porous structure, and the amorphous carbon coating material coats the surface of the porous structure. The condition is that the total mass of the porous silicon-carbon composite material is 100%, and the mass percentage content ofsilicate is 5%-30%. The porous silicon-carbon composite material shows an extremely low expansion rate when used as a lithium ion battery negative electrode material, and has high specific capacity,high initial coulombic efficiency, excellent cycle performance and excellent rate capability. In addition, the preparation method is simple, and is a method suitable for industrial large-scale production of the silicon-carbon composite material for lithium ion batteries.

The invention relates to a sodium ion battery negative electrode material containing nitrogen and carbon coated bimetallic sulfide and a preparation method thereof. The preparation method provided bythe invention comprises the steps: firstly, the surface of a bimetallic Prussian blue complex is coated with a nitrogen-containing polymer by an in-situ polymerization method, and then the product isnitrided, carbonized and vulcanized through one-step high temperature annealing. The method has the beneficial effects that the bimetallic Prussian blue complex is coated with nitrogen and carbon, anda bimetallic ion hybrid structure is retained, so that two metal sulfides are formed in the subsequent vulcanization process, and the electrochemical performance of the negative electrode material can be improved by the synergistic action of the two metal sulfides; nitrogen and carbon elements are effectively introduced into the negative electrode material, on one hand, the coated nitrogen and carbon can improve the electrical conductivity of the negative electrode material; on the other end, volume expansion of the negative electrode material in a sodium disembedding process is buffered. Inconclusion, the invention provides the high-performance sodium ion battery negative electrode material.

The invention discloses a carbon-coated porous manganese monoxide core-shell structure composite material and a preparation method and an application thereof. The preparation method comprises the following steps: firstly, with styrene as a carbon source and potassium peroxodisulfate as an initiator, carrying out soap-free emulsion polymerization to obtain a polystyrene microsphere template, and then carrying out surface modification on microspheres with concentrated sulfuric acid; with common manganese sulfate as a manganese source, preparing manganese carbonate particles embedded with a plurality of polystyrene microspheres by a liquid phase deposition method, and then adding a shell layer material to coat the particle surfaces with a carbon layer; and finally, carrying out high-temperature carbonization to obtain a novel carbon-coated porous manganese monoxide core-shell structure composite material. The composite material is spherical particles with uneven surfaces; and the spherical particles comprise manganese monoxide grains, multi-scale holes and the carbon layer. The special structure with the carbon layer and the multi-scale holes can play a role in buffering volume expansion of manganese monoxide in the repeated charging and discharging processes. The composite material disclosed by the invention has excellent cycling stability and rate capability as an anode material for a lithium-ion battery.

The invention provides a cathode active material of a lithium-ion battery, wherein, the cathode active material comprises a tin base alloy with an amorphous and nanocrystal dual-phase structure. The tin base alloy with the amorphous and nanocrystal dual-phase structure of the invention comprises tin (1); inactive elements (2) which are chosen from one or a plurality of the kinds of iron, cobalt, nickel, copper, titanium, manganese, vanadium and chromium and are not easy to be alloyed with the metal lithium; and carbon (3). The tin base dual-phase alloy of the invention has high specific capacity and good cycling; the maximum reversible capacity can reach 706Ah/g, and the capacity conservation rate keeps more than 96% after 20 cycles. In addition, the invention further provides a method for preparing the cathode active material.

The invention provides a negative electrode active material for a lithium-ion/sodium-ion secondary battery, a negative electrode and a battery, belonging to the technical field of electrochemistry and batteries. The negative electrode active material comprises a phosphorus-germanium compound, or/and a first complex formed by the phosphorus-germanium compound and elementary P or/and elementary Ge, or/and a second complex formed by the phosphorus-germanium compound and conductive components, or/and a third complex formed by the first complex and conductive components. The negative electrode provided by the invention comprises the negative electrode active material. The negative electrode has the advantages of high specific capacity, high initial Coulomb efficiency, small charge-discharge voltage platform difference and good high-current charge-discharge performance.

The invention relates to a preparation method of a nickel ion doped cobalt sulfide/conductive substrate composite material. The preparation method of the nickel ion doped cobalt sulfide/conductive substrate composite material relates to the technical field of lithium ion batteries, and aims to solve the technical problem that the negative material of an existing lithium ion battery is poor in cycling stability and low in rate capability. The method comprises the following steps of (1) treating a substrate; (2) preparing a solution; (3) preparing a precursor; (4) heat treating. The electrode material prepared by the invention can be used as the negative material to be directly assembled to form the lithium ion battery. The electrode material is directly used as an electrode without adding any conductive agent and binding agent. The electrode preparation process is simplified, the preparation cost is reduced, and the capacity, the power density performance and the cycling stability of the battery are improved.

The invention discloses a preparation method for a sodium-ion battery antimony/carbon anode composite material with a yolk-shell structure. The preparation method comprises the following steps: preparing nano antimony particles through a reduction method; sequentially coating the surfaces of the nano antimony particles with a silicon dioxide layer and a poly-dopamine layer; carbonizing, and removing the silicon dioxide layer through an etching method to obtain the antimony/carbon anode composite material with the yolk-shell structure. The antimony/carbon anode composite material is good in mechanical stability and thermal stability, and can be used to prepare a sodium-ion battery with high mass ratio capacity and good rate capability. The preparation method is simple in operation, easy to operate, low in cost and suitable for being applied to industry and mass production.

The invention provides a silicon-carbon composite lithium ion battery negative electrode material and a preparation method thereof. The preparation method comprises the following steps of adding micron silicon and a dispersing agent into a solvent, and grinding to obtain nano silicon slurry 1; adding a carbon matrix into the nano silicon slurry 1, and stirring to obtain mixed slurry 2, wherein thecarbon matrix is one or more of flattened artificial graphite, flattened natural graphite and flattened mesocarbon microbeads; and drying the mixed slurry 2, adding into a fusion machine for fusion,mixing with a coating agent, granulating, carrying out heat treatment in a protective atmosphere, carrying out high-temperature carbonization treatment in the protective atmosphere, crushing, gradingand demagnetizing to obtain the silicon-carbon composite negative electrode material. According to the present invention, the structure with better volume expansion can be buffered, the dispersion andcomplete coating of the nano silicon on the carbon matrix are realized, and the direct contact between the nano silicon and the electrolyte is isolated, so that the composite material can form a stable SEI film, and the service life of the battery is greatly prolonged.

The invention discloses a silicon-carbon composite material as well as a preparation method and application thereof. The silicon-carbon composite material comprises nanometer silicon, graphite and lithium carbonate. The nanometer silicon, graphite and lithium carbonate are encapsulated by polymers and carbonized so as to obtain the silicon-carbon composite material. The preparation method comprises the following steps: mixing graphite, lithium carbonate and nanometer silicon so as to obtain a lithium carbonate/silicon/graphite mixture; dispersing the lithium carbonate/silicon/graphite mixture into a polymer solution, and drying to obtain a precursor material; carbonizing the precursor material, thereby obtaining the silicon-carbon composite material. The silicon-carbon composite material disclosed by the invention has high electrical conductivity and excellent cycling stability and can be applied to preparing lithium ion batteries.

A preparation method of cathode active material includes the steps of firstly, adding 60-100 parts, by weight, of graphite oxide into water for ultrasonic dispersion so as to obtain evenly dispersed 1g/L graphite oxide solution; secondly, adding 1-20 parts of silicon nanoparticles into the graphite oxide solution to obtain suspension; thirdly, placing mixture obtained by dewatering the suspension in reducing atmosphere, raising the temperature to 200-1200 DEG C, heating for 1-10 hours, and cooling to obtain silicon-graphene composite; and fourthly, subjecting the silicon-graphene composite and 30-50 parts of carbon nanotubes to ball milling to obtain the cathode active material. The cathode active material prepared by the preparation method is high in energy density. In addition, a preparation method of a capacitor using the cathode active material is provided.