256results about How to "Improve lithium storage performance" patented technology

The invention discloses a silicon-carbon composite material with nano micropores and a preparation method as well as application thereof. The material comprises nano-silicon (Si) particles and a carbon nanofiber matrix, wherein the nano-silicon particles are dispersed in the carbon nanofiber matrix; and nano pores and micropores communicated with the nano pores are distributed in the carbon nanofiber matrix. The method comprises the steps of dissolving the nano-Si particles and polyacrylonitrile (PAN) in a solvent to prepare a mixed spinning solution, then carrying out electrostatic spinning on the mixed spinning solution, and curing spinning trickles in a coagulating bath to obtain a porous PAN-Si composite nanofiber; and then carrying out oxidation and carbonization treatment in sequence to obtain the silicon-carbon composite material with a nano micropore structure. The silicon-carbon composite material is applied to preparation of lithium ion battery cathode materials. Compared with the prior art, the silicon-carbon composite material ensures the overall electron transport capacity of the material while reserving buffer space for expansion of the nano-Si particles.

The invention discloses a silicon-carbon composite material with nano micropores and a preparation method as well as application thereof. The composite material comprises nano-silicon (Si) particles and a carbon nanofiber matrix, wherein nano pores and micropore channels communicated with each other are distributed in the carbon nanofiber matrix; the nano-Si particles are distributed in the carbon nanofiber matrix; one part of the nano-Si particles are embedded in the carbon nanofiber matrix; and the other part of the nano-Si particles are positioned in the nano pores. The method comprises the steps of carrying out electrostatic spinning on a polyacrylonitrile (PAN) spinning solution doped with the nano-Si particles and a polymer pore former (PPM) to obtain a PAN-Si-PPM composite nanofiber, and then carrying out oxidation and carbonization to obtain the silicon-carbon composite material. The silicon-carbon composite material is applied to preparation of lithium ion battery cathode materials. Compared with the prior art, the silicon-carbon composite material ensures the overall electron transport capacity of the material while reserving buffer space for expansion of the nano-Si particles.

The invention relates to an environment-friendly and efficient method for preparing an iron sesquioxide/graphene composite material. In the method, cheap and abundant soluble ferrous salt serves as an iron source and reducing agent, graphene oxide is quickly reduced into the graphene by the characteristics of microwave heating, and ferrous is oxidized and converted into iron sesquioxide so as to obtain a sesquioxide/graphene composite material. The environment-friendly and efficient method fully utilizes the characteristics of ferrite, has the advantages of simple and efficient preparation technology, no industrial three-waste pollution and stable product performance and is favorable for producing on a large scale, and a product has a wide application prospect in the cathode material of a lithium-ion secondary battery.

The invention discloses a nano-silicon material which is prepared by the following steps: using a rod-shaped nano SiO2 material with the length of 300-800nm and the width of 20-40nm, and preparing the nano-silicon material by virtue of a magnesiothermic reduction method, wherein the rod-shaped nano SiO2 material is prepared by the steps of taking attapulgite as a raw material, screening, pickling and performing high-temperature heat treatment. According to the nano-silicon material disclosed by the invention, cheap and natural attapulgite serves as a precursor, the rod-shaped nano SiO2 is purified from the attapulgite, an elemental silicon material with uniform particle size distribution is prepared in one step, amplified synthesis is easily realized in the method, gram-grade reaction can be achieved in a lab, and the cost is low; and moreover, the obtained elemental silicon material is high in yield, the elemental silicon material subjected to carbon coating treatment serves as a negative electrode material of a lithium ion battery, and excellent lithium storage performance is achieved.

The invention provides an MXene/graphene composite nanosheet, a preparation method and application thereof, an electrode plate and application thereof, and belongs to the technical field of two-dimensional materials. The invention provides the preparation method of the MXene/graphene composite nanosheet, the method comprises the following steps: mixing MAX and a hydrofluoric acid solution, and etching to obtain MXene; mixing the MXene with a tetrabutylammonium hydroxide solution, carrying out electrostatic adsorption, and then carrying out ultrasonic treatment so as to obtain a stripped MXenenanosheet; mixing the stripped MXene nanosheet with a graphene oxide suspension, and carrying out a self-assembly reaction to obtain an MXene nanosheet/graphene oxide nanosheet; and under a protectiveatmosphere, carrying out a reduction reaction on the MXene nanosheet/graphene oxide nanosheet to obtain the MXene/graphene composite nanosheet. The graphene in the MXene/graphene composite nanosheetprepared by the preparation method provided by the invention cannot be stacked again, the MXene/graphene composite nanosheet has excellent lithium storage performance, and the unique two-dimensional structure of the MXene and the graphene can be maintained.

The invention relates to a porous carbon microsphere prepared by utilizing an emulsion aggregation method. The porous carbon microsphere is simultaneously provided with a microporous structure, a mesoporous structure and a macroporous structure. When the porous carbon microsphere is applied to the lithium ion battery negative electrode material, the macroporous structure is used for providing a fast migration passage for electrolyte, the mesoporous structure is identical to size of ion in the organic electrolyte, so that the rapid adsorption and desorption of the ion can be favored; the microporous structure favors the insertion of lithium ions, so that a lithium ion secondary battery has high specific capacitance and good high-power charging-discharging performance.

The invention provides an egg-shaped dual-carbon shell layer tin-based negative electrode material of a lithium ion battery and a preparation method for the negative electrode material. The egg-shell-shaped dual-layer carbon-coated stannic oxide nanocomposite comprises a porous stannic oxide sphere kernel and a dual-layer carbon shell for coating the surface of the porous stannic oxide sphere kernel, and a hollow layer exists between the two parts; the preparation method comprises the steps of preparing the egg-shell-shaped silicon dioxide-coated porous stannic oxide sphere nanocomposite by adopting a surfactant soft template method, and then attaching an organic pyrolytic carbon raw material on the surface of the nanocomposite, and performing a hydrothermal reaction and then carrying out condensation polymerization and carbonization to obtain the egg-shell-shaped carbon-silicon dioxide-carbon-coated stannic oxide sphere nanocomposite, and finally, performing etching by adopting a sodium hydroxide alkali solution to obtain the egg-shell-shaped dual-layer carbon-coated stannic oxide nanocomposite. Finally, the invention provides the tin-based negative electrode material of the lithium ion battery with nanometer scale, high conductivity and capability of effectively suppressing the volume effect of stannic oxide, and a preparation method for the negative electrode material.

The invention belongs to the technical field of nanometer materials, and specifically relates to a three-dimensional graphene nanoribbon/carbon nanoribbon bridged aerogel material, a preparation method and application thereof. According to the invention, aerogel is prepared by assembling basic structural units formed by bridging the graphene nanoribbon stripped from the carbon nanoribbon with unstripped carbon nanoribbon and doping the basic structural units with heteroatom as needed. The preparation of the aerogel comprises the following steps: preparing a carboxylic carbon nanotube solution, wherein a proper amount of a soluble dopant is added or not added into the solution; then carrying out hydrothermal treatment so as to obtain uniform hydrogel, placing the hydrogel in an ionic impregnation agent for complete replacement, then carrying out secondary hydrothermal treatment so as to finish a stripping process; and finally, carrying out drying and carbonizing so as to obtain the graphene nanoribbon/carbon nanoribbon bridged structural aerogel. The aerogel can be used as an anode material of lithium ion battery, shows high specific capacity and excellent stability and rate performance, and has important research significance and good application prospects.

The invention discloses [alpha]-phase ferric oxide porous core-shell microspheres and a controllable synthetic preparation method thereof. The [Alpha]-phase ferric oxide microspheres having porous core-shell structures can be prepared through a hydrothermal method with an inorganic soluble ferric salt being a raw material, deionized water and anhydrous alcohol being solvents and at a certain temperature for a certain time. The microspheres are 3 [mu]m in the average diameter. Cores and shells are composed of nano particles, wherein the average diameter of the nano particles is 200 nm and the average thickness of the shells is 100nm. A plurality of pores with pore diameters being 40nm are uniformly distributed on the surface of each shell with of a plurality of pores with pore diameters being 40nm. The preparation method is free of any dispersing agent and surfactant, and subsequent processes are convenient since a template is not needed. The preparation method is simple in technology, short in reaction time, large in output, is environmental-friendly and cheap in raw materials, is beneficial to large scale industrial production and the porous core-shell microspheres can be used for a lithium ion battery electrode material and a gas-sensitive material.

The invention discloses a nano sheet self-assembled MoS2 nano hollow material and preparation and application of the MoS2 nano hollow material serving as a lithium storage electrode material. The nano sheet self-assembled MoS2 nano hollow material is obtained by mixing raw materials including molybdenum oxide, sodium fluoride and potassium thiocyanate according to the mass ratio of 0.8-0.9:0.5-0.6:1.5-2.9; adding into water-ethanol mixed solvent; placing into a reaction kettle to be sealed; reacting at 140-220 DEG C for 12-30h; and performing washing, separating and drying to obtain products. The method is simple and easy in required condition, cheap and facile in raw materials and controllable in shape and height and easily achieves industrial production. Lithium storage electrodes prepared by adopting the prepared nano sheet self-assembled MoS2 nano hollow material not only have high electro-chemical lithium storage reversible capacity and excellent cycling performance, but also have good rate capability.

Disclosed is a process for producing a silicon-based composite material for a lithium ion battery cathode. The process comprises that silicon powder serves as a main material, graphite powder or flocculent carbon black serves as an auxiliary material, the main material and the auxiliary material are mixed and placed in a ball-grinding steel tank, argon serves as a shielding gas, the ball-grinding steel tank inflated with the shielding gas is placed in a planetary ball mill, and powder with granularity of less than 20 mum, which is the silicon-based composite material for the lithium ion battery cathode, is obtained after the mixture is subjected to ball milling at 500 revolutions/minute for 80 hours. The process has the advantages that the silicon material having the good lithium-storing capacity is mixed with the carbon material having the good electrical conductivity, atomic-grade mixing of the silicon material and the carbon material is achieved in a mechanical alloying mode, the electrical conductively of the silicon matrix is fully improved, and the inert carbon material can reduce volume expansion caused by the processes of lithium intercalation and lithium deintercalation of the silicon material in the processes of charging and discharging of the inert carbon material, so that the cycle performance of the silicon material is improved, the electrical conductivity and the cycle performance of the carbon-doped material are better than those of the pure silicon material.

The invention provides a metallic 1T molybdenum disulfide nano-sheet array as well as a preparation method and application thereof. The method comprises the following steps: carrying out thermal treatment on a substrate to obtain a functionalized substrate; carrying out solvothermal reaction on the functionalized substrate, molybdate and a sulfur compound in a solvent to obtain the metallic 1T molybdenum disulfide nano-sheet array. According to the method disclosed by the invnetion, the thermal treatment on the substrate is carried out firstly, so that the wettability of the surface of the substrate is improved; then through the one-step solvothermal reaction, the metallic 1T molybdenum disulfide nano-sheet array can be obtained on the surface of the substrate. The preparation method disclosed by the invention has simple steps, is low-cost, is high in yield and meets a requirement on environment protection; the prepared metallic 1T molybdenum disulfide nano-sheet array has excellent lithium storage performance, and has wide application prospect in lithium ion batteries.

The invention relates to a graphite compound modification method, which mainly comprises the graphite oxidative modification technology and the graphite coating modification technology. The graphite oxidative modification technology further comprises the following steps: graphite is smashed and subject to ball milling and oxidation reaction together with concentrated nitric acid in a certain temperature. The graphite coating modification technology further comprises the following steps: a surface finishing solvent containing asphalt is prepared; graphite is coated in the surface finishing solvent; and the graphite and asphalt mixture is subject to heat treatment. The prepared compound modified graphite serves as an active material to further prepare an electrode material for a lithium ion battery. According to the method provided by the invention, the capacity per gram and cycle life of natural graphite are effectively improved and prolonged respectively.

The invention relates to a tin selenide @ carbon nano fiber composite material, and a preparation method and application thereof, and solves the technical problems that the existing material preparation method is complex and the cost is high. In-situ generated tin selenide is uniformly dispersed in carbon nano fiber, and the diameter of the carbon nano fiber is 300-400 nanometers. The invention also provides the preparation method and application of the tin selenide @ carbon nano fiber composite material. The tin selenide @ carbon nano fiber can be widely used in the field of preparation of electrode materials.

The invention discloses a preparation method and application of a rubidium lithium nickel-cobalt manganate material. The chemical formula of a rubidium-doped high-nickel ternary positive pole materialis Li1-xRbxNiyCozMn1-y-zO2, wherein y is not less than 0.6, x is more than 0 and not more than 0.1, and z is more than 0 and less than 0.4. The preparation method of the rubidium-doped high-nickel ternary positive pole material comprises the following steps of mixing nickel-cobalt-manganese ternary material precursor, a Li source and a Rb source to acquire a mixture; pre-sintering under the an oxygen atmosphere after grinding, and then sintering at high temperature, thus acquiring the rubidium lithium nickel-cobalt manganate material. The rubidium lithium nickel-cobalt manganate material provided by the invention is uniform in particle, has the micro-nano size and is low in positive ion mixing degree; when the rubidium lithium nickel-cobalt manganate material is applied to the lithium ionbattery, the acquired lithium ion battery is high in specific discharge capacity, high in rate capability, good in cycle performance and long in service life.

The invention relates to a porous carbon material used in a cathode of a lithium ion battery, and a preparation method of the porous carbon material. The slit-type porous carbon material which mainly comprises micropores and mesopores is prepared by mixing layered plate-shaped magnesium-aluminum hydrotalcite used as a template with a carbon source, curing, carbonizing and performing acidification treatment. The preparation process is simple, the cost is low, and the specific surface area is adjustable. The slit-type porous carbon provided by the invention has good electrochemical properties when being used as a lithium ion electrode material.

The invention discloses an amorphous tetratin triphosphate/phosphorus/few-layer graphene negative material for lithium ion batteries and a preparation method and an application thereof. The negative material is formed by coating amorphous tetratin triphosphate and phosphorus with a few layers of graphene carbon. The preparation method includes the following steps: mixing and ball-milling tin powder and phosphorus powder to obtain tin triphosphate; and mixing the obtained tin triphosphate with expanded graphite and carrying out ball-milling to obtain the amorphous tetratin triphosphate/phosphorus/few-layer graphene negative material. The negative material prepared in the invention is matched with a lithium iron phosphate positive material, and a lithium ion battery assembled by using the negative material and the lithium ferrous phosphate positive material has the advantages of high capacity and stable cycle and has application potential. The preparation method of the invention has theadvantages of simple process, good repeatability, less time consumption and environment friendliness, and is conducive to actual industrial production.

The invention discloses a preparation method of a polyhedral metal-organic framework compound ZIF-67. The preparation method comprises the following steps: preparing a solution from Co(NO3)2.6H2O, 2-methylimidazole and methanol, mixing and stirring, reacting at a normal temperature, performing centrifugal washing, drying and the like. The ZIF-67 presents bluish violet, is in the shape of rhombic dodecahedron, and has the particle size of 300-920nm. The prepared ZIF-67 is in the shape of rhombic dodecahedron, the particle size of the framework is small and uniform and can be controlled to be about 300nm, the specific surface area is large, and the overall distribution is uniform. The material disclosed by the invention is high in degree of crystallinity, has high specific surface area and porosity, homogeneous distribution can be formed, the prepared framework is small in particle size, and the overall distribution is uniform. Meanwhile, the compound is high in electric shock capacity and long in service life, has excellent lithium storage property, and can avoid attenuation after 200 charge-discharge cycles at most. The stability in the application is excellent, the condition thatthe current is unstable is avoided, and the product purity is high. The yield of the preparation method is high and can reach 70% or higher, and the preparation process is simple and feasible and worthy of market popularization.

The invention provides a preparation method of graphene. According to the method, a nano-scale metal and/or metal oxide catalyst is attached on a rotatable reaction deposition part, a carbon source which can be decomposed into carbon and hydrogen is introduced, and the carbon source is cracked into the graphene under the action of the nano-scale catalyst; as the reaction deposition part is rotatable, the carbon source is in three-dimensional and dynamic contact with the catalyst, and more graphene can be deposited; in addition, the catalytic efficiency of the nano-scale catalyst to the carbon source is higher, and the preparation of the high-quality graphene even in thickness and controllable in number of layers can be effectively realized. The method is simple in process; the problems of less deposited graphene, large catalyst scale and low catalytic efficiency due to the static placement of the catalyst in the existing chemical vapor deposition technology are solved. The invention also provides a graphene; the layers of the graphene are bent to form a hollow cloth bag shape; the graphene of the structure has excellent hydrogen storage and lithium storage functions.

The invention discloses a method for preparing a LiNi1/3Co1/3Mn1/3O2 fibrous material by electrostatic spinning and belongs to the technical field of lithium ion battery electrode materials and preparation thereof. The method includes: taking deionized water as a dissolvent, regulating solution viscosity through polyvinylpyrrolidone, then adding a lithium source, a nickel source, a cobalt source and a manganese source to prepare a spinning solution, preparing a nanofiber film by a electrostatic spinning technique, and then sintering the nanofiber film to obtain the LiNi1/3Co1/3Mn1/3O2 fibrous material. The fibrous material prepared by the method is smooth in surface, small in fibre diameter and large in specific surface area and has good charge and discharge performance and large storage capacity, the preparation method is simple in technology, reaction condition parameters are easy to control, sintering temperature is low, and large-scale industrialization of cathode materials of lithium nickelate, lithium cobaltate and lithium manganate are benefited.