257results 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 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 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 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 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 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.