38results about How to "Increase the specific capacity of lithium storage" patented technology

The invention relates to the technical field of lithium-ion cathode material, in particular to silicon cathode material coated with graphene and a preparation method of the silicon cathode material coated with the grapheme. The preparation method comprises the following steps: A, preparing oxidized graphene suspension liquid; B, preparing nanometer silicon particle suspension liquid; and C, preparing silicon cathode material coated with grapheme. The preparation method adopts the electrostatic self-assembly synthetic technology and is wide in source of raw material, low in price, simple in synthetic method, easy for control of process conditions, strong in operability and good in repeatability. The silicon cathode material coated with grapheme is high in specific capacity and good in cycle performance and rate capability, wherein the specific discharge capacity for the first time under the electric current density of 0.01-1.2V, 200mA/g can reach 2746mAh/g, and the specific discharge capacity after 100 times of cycles can maintain 803.8mAh/g.

The invention provides a method for preparing a titanium dioxide nanosheet coated graphene anode material of a lithium ion battery. The method comprises the following steps: a, preparing graphene oxide suspension: preparing graphite oxide by adopting a hummer method, and ultrasonically peeling graphite oxide in isopropanol to form graphene oxide suspension; and b, preparing the titanium dioxide nanosheet coated graphene material: adding a certain amount of diethylenetriamine into the graphene oxide suspension, uniformly stirring, adding butyl titanate, uniformly stirring, putting in a closed reaction kettle to perform solvothermal reaction, washing a solvothermal reaction product by using ethanol, drying, and processing at high temperature under the protective atmosphere so as to obtain the titanium dioxide nanosheet coated graphene anode material. By means of the preparation method disclosed by the invention, aggregation and overlapping in the reducing process of graphene can be effectively prevented; therefore, the electronic conductivity of the titanium dioxide nanosheet coated graphene anode material of the lithium ion battery is increased; and a research thought is provided for seeking the novel anode material of the lithium ion battery.

The invention relates to preparation and application of an anode material of a lithium battery and aims to provide preparation and the application of a conductive carbon film-coated calcium nitride compound serving as the anode material of the lithium battery. The preparation method comprises the following steps of: after calcium metal is molten, spraying into polyethylene glycol liquid by using high purity nitrogen, and performing a reaction of the calcium fog drops and nitrogen in an nitriding atmosphere to obtain Ca3N2 microspheres so as to obtain a carbon-coated calcium nitride material primary product; and after filtering out a carbon-coated calcium nitride material, calcining for 2 to 3 hours again in the high purity nitrogen atmosphere and carrying out refining to obtain carbon-coated Ca3N2, or calcining for 2 to 3 hours again in vacuum to obtain a carbon-coated Ca3N2-Ca2N mixture. In the invention, a conductive carbon film is formed on the surface of Ca3N2 or Ca3N2-Ca2N, is favorable for stability of an electrode structure, has high heat stability and low cost, is easy to prepare and has no pollution. The conductive carbon film prepared by a spraying method has the advantages of uniform thickness and high conductivity. The electrode polarization is reduced. The speed and the capacity of the lithium battery are improved.

The invention discloses a nano silicon alloy based composite negative pole material. The nano silicon alloy based composite negative pole material has a three-shell layer structure, wherein a core layer is a nano carbon material coated nano silicon alloy core layer, and a three-shell layer is of a three-shell layer structure and is a conductive polymer film layer which is prepared by taking Fe3O4 nano-microspheres as sacrificial templates. The invention further discloses a preparation method of the nano silicon alloy based composite negative pole material. According to the preparation method, firstly, a nano silicon alloy material is prepared by a ball milling method and is subjected to wet grinding with a nano carbon material, then, hot coating is carried out so as to form the nano carbon material coated nano silicon alloy core layer, and then, the conductive polymer film layer with the three-shell layer structure is formed on the surface of the core layer by using a sacrificial Fe3O4 microsphere template method, so that the volume expansion of the nano silicon alloy material is effectively buffered. The nano silicon alloy based composite material disclosed by the invention has the advantages of high specific capacity, excellent cycle performance and rate performance, high tap density, and the like. The preparation method of the negative pole material, provided by the invention, is simple, environmentally friendly and pollution-free.

The invention discloses a silicon substrate lithium ion battery negative electrode material and a preparation method thereof. The negative electrode material comprises an amorphous silicon substrate and a plurality of monocrystalline silicon cores, wherein the monocrystalline silicon cores are embedded in the amorphous silicon substrate and are covered by the amorphous silicon. The preparation method comprises the following steps: firstly, removing a silicon oxide layer on the outer surface of the amorphous silicon by adopting a chemical etching method; calcining the amorphous silicon material at high temperature under inert atmosphere; realizing the nucleation and growth of monocrystalline silicon in the amorphous silicon material; controlling the calcining time and the calcining temperature, thereby realizing the regulation for the inner silicon core size. The first specific discharge capacity of the compound material is above 1500mAh/g and the specific discharge capacity after 35 times of repeated charging and discharging circulation still can be kept above 1150mAh/g.

The invention relates to a preparation method of a tin oxide-hard carbon composite negative electrode material. The preparation method comprises the following steps: mixing and stirring a phenolic monomer, an aldehyde monomer, tin salt, a sacrificial template agent and water to prepare a precursor solution; granulating the precursor solution by a spray drying method to obtain precursor particles;and calcining the precursor particles to obtain the tin oxide-hard carbon composite negative electrode material. The tin oxide-hard carbon composite negative electrode material is prepared according to the preparation method. The invention discloses an application of a tin oxide-hard carbon composite negative electrode material in a lithium ion battery. The preparation method has the beneficial effects that hard carbon and tin oxide with high specific capacity are compounded by using the spray drying method, so that the test specific capacity of the lithium ion battery is improved and is muchhigher than that of a commercial graphite material; and the cycling stability of the lithium ion battery is improved.

The invention relates to a lithium ion battery anode material LiSi2N3 and a method for preparing the material. The technical scheme is as follows: the method comprises the following steps that 10-30wt% of elementary-substance silicon powder, 25-45wt% of trimeric cyanamide, 35-55wt% of a lithium precursor and 0.5-15wt% of halide powder are uniformly mixed to prepare a mixture; the mixture is placed in a tubular electric furnace, and heated up to 900-1200 DEG C at the heating rate of 2-10 DEG C /min under nitrogen atmosphere, and the temperature is kept for 2-6 hours; the prepared product is repeatedly washed by de-ionized water and titrated by respectively using AgNO3 and Ca(NO3)2 solutions until no white precipitates appear; and finally the prepared product is dried for 10-24 hours at 110 DEG C and thus the lithium ion battery anode material LiSi2N3 is prepared. The preparation method is low in reacting temperature and cost, easy to control, high in productivity, and applied to industrial production; the prepared lithium ion battery anode material LiSi2N3 is high in activity, large in specific surface area, high in purity and specific capacity, and steady in performance.

The present invention provides a rare earth hydride-carbon nano composite material and a preparation method and application thereof, a rare earth hydride is prepared by high temperature and high pressure, and the rare earth hydride and a carbon material are uniformly mixed in a certain proportion at room temperature by low rotation speed ball milling. The method is simple and quick, high in yield, low in cost, easy to enlarge, the reaction product is mixed evenly, particle size is small, purity is high, and the reaction product has a specific synergistic effect and has high lithium storage specific capacity. The rare earth hydride-carbon nano composite material has remarkable advantages, and has great industrial application prospects.

The invention provides an iron-cobalt bimetal selenide nanomaterial and a preparation method thereof, and a lithium ion battery. The preparation method of the iron-cobalt double-metal selenide nanomaterial comprises the following step: carrying out a heating reaction on ferric acetylacetonate, cobalt acetylacetonate and dibenzyl diselenide in a solvent to form the Fe2CoSe4 nanomaterial. Accordingto the method, specific ferric acetylacetonate, nickel acetylacetonate and dibenzyl diselenide are used as precursor sources and undergo a reaction in a solvent system, so the Fe2CoSe4 nanomaterial can be directly synthesized in one step; and thus, operation is greatly simplified, and the crystallinity and purity of the Fe2CoSe4 nanomaterial can be effectively improved. When the Fe2CoSe4 nanomaterial prepared by the method is used as a negative electrode material of the lithium ion battery, the specific lithium storage capacity, the rate capability and the cycle performance of the battery canbe improved.

The invention relates to the technical field of electrochemical materials, in particular to a preparation method for an ordered macroporous titanium dioxide, which includes the following steps: titanium halide and hydrolytic titanate are respectively added into absolute ethanol and uniformly agitated, so that titanium dioxide precursor solvent is obtained; carboxylic acid type polystyrene spheres are dispersed into absolute ethanol, so that carboxylic acid type polystyrene sphere suspension is obtained; the titanium dioxide precursor solvent and the carboxylic acid type polystyrene sphere suspension are mixed together and dried in an oven, so that titanium dioxide precursor is obtained, the titanium dioxide precursor is calcined under high temperature, and thereby the ordered macroporous titanium dioxide is obtained. The template method is adopted by the preparation method, the process conditions are simple and easy to control, operability is high, and repeatability is good; the produced product has an ordered macroporous structure, which enlarges the specific surface area of the titanium dioxide and is favorable for the increase of the specific lithium storage capacity of the product and the permeation of electrolyte, consequently, the electronic conductivity of the ordered macroporous titanium dioxide used as a lithium ion electrode material is increased, and moreover, safety is high.

The invention discloses a nano titanium dioxide/graphene negative electrode material and a preparation method thereof, and belongs to the field of electrochemical materials. According to the preparation method of the nano titanium dioxide/graphene negative electrode material, titanium dioxide with nano morphology is generated on graphene oxide through in-situ assembly of a hydrothermal method, meanwhile, dominant crystal faces are selectively generated by titanium dioxide through addition of fluoroborate, the particle size morphology of titanium dioxide in the prepared material composition is effectively limited, the prepared material is uniformly dispersed and free of agglomeration, the contact resistance is reduced, and the permeation of electrolyte is facilitated, and a final product has high capacity and excellent rate discharge performance; and the preparation method is simple to operate and high in repeatability. The invention also discloses the nano titanium dioxide/graphene negative electrode material prepared by the method and a lithium ion battery further prepared from the nano titanium dioxide/graphene negative electrode material.

The invention relates to the preparation technology of a gel lithium ion battery, and aims to provide a preparation method for a gel-state polymer lithium ion battery. The preparation method comprises the steps of performing ball milling and mixing on glucose monohydrate, melamine, metaboric acid and NaCl-KCl eutectic salt, and heating the mixture in a nitrogen atmosphere for three times and then cooling to the room temperature; cleaning off salt content by deionized water and performing vacuum drying; performing mixing and grinding on obtained graphene-loaded nanometer boron and acetylene black, and Nafion-PEO co-mixed resin solution, and mixing the mixture into paste shape to coat foamed nickel; drying in the shade and pressing and shaping to obtain a negative electrode; performing arrangement on a positive electrode, a diaphragm and the negative electrode in sequence and performing pressing and shaping, and then carrying out heat treatment in a nitrogen atmosphere to obtain a film electrode, and immersing the film electrode in an electrolyte for 2h to obtain a cell; and assembling a button type gel-state polymer lithium ion battery by the cell. By adoption of the preparation method, a free-state electrolyte does not exist, so that the safety of the lithium ion battery can be remarkably improved, the electrode structural stability can be improved, high-current discharge can be promoted, and a safe and reliable high-energy power battery can be provided for an electric vehicle.