The invention discloses a preparation method for a negative electrode material with a core-shell coated structure and for a lithium ion battery. The preparation method is simple in process and easy to control. The preparation method comprises the following steps: preparing a graphene oxide material; then preparing a core-shell-structured carbon-coated silicon material from nanometer silicon; blending graphene oxide with carbon-coated silicon powder according to a certain ratio; after uniform blending, carrying out pumping filtration so as to obtain a two-dimensional film; and then carrying out thermal reduction so as to obtain the core-shell-structured carbon-coated silicon/graphene composite material. The electrode material prepared by using the method has initial charge and discharge capacities of 835.8 mAh/g and 1452.3 mAh/g respectively when current density is 200 mA/g and has charge and discharge capacities of 705.1 mAh/g and 710.9 mAh/g respectively after 100 cycles, so the electrode material has a capacity retention rate of 84.4% and good cycle stability.

Preparation method for negative electrode material with core-shell coated structure and for lithium ion battery

The invention provides a preparation method of an N-doped mesoporous carbon-coated ternary cathode material of a lithium ion battery The preparation method comprises the following steps: (1) performing ultrasonic dispersion on a ternary cathode material into water, adding a phenylamine monomer, performing ultrasonic dispersion and adding acid solution, so as to obtain precursor solution; (2) adding ammonium persulfate solution into the precursor solution, heating and stirring the mixture, washing and settling twice or more than twice after centrifugal separation and performing vacuum drying,so as to obtain a polyaniline-coated ternary cathode material of the lithium ion battery; (3) placing the polyaniline-coated ternary cathode material into a tube furnace, calcining the polyaniline-coated ternary cathode material in an inert atmosphere, and naturally cooling to room temperature, so as to obtain the N-doped mesoporous carbon-coated ternary cathode material The particle size of theN-doped mesoporous carbon-coated ternary cathode material of the lithium ion battery, which is obtained by the method, is 5-15mum, and an N-doped mesoporous carbon-coated layer is uniform and is 3-20nm in thickness; the N-doped mesoporous carbon-coated ternary cathode material is assembled into the battery and has comparatively good cycling stability and large rate discharge performance The method is low in cost and simple in process, therefore, the method is suitable for large-scale industrial production

Preparation method of N-doped mesoporous carbon-coated ternary cathode material of lithium ion battery

The invention discloses a nitrogen-doped and carbon-coated iron trioxide anode material for a lithium ion battery and a preparation method of the nitrogen-doped and carbon-coated iron trioxide anode material. The preparation method comprises the following steps: coating the outer surface of nano-fusiform iron trioxide with a silicon dioxide layer to serve as a precursor; then coating the outer surface of the silicon dioxide layer with one layer of conducting polypyrrole; finally, annealing to carbonize the polypyrrole, and etching to remove a silicon dioxide interlayer, thus obtaining the nitrogen-doped and carbon-coated iron trioxide anode material with an interlayer void structure. The nitrogen-doped and carbon-coated iron trioxide anode material for the lithium ion battery, provided by the invention, can keep high cycling capacity, excellent cycling stability and high multiplying power (high current density charging and discharging) within a wider temperature range including room temperature, as well as good application prospect.

Nitrogen-doped and carbon-coated iron trioxide anode material for lithium ion battery and preparation method of nitrogen-doped and carbon-coated iron trioxide anode material

The invention discloses a nitrogen-doped silicon carbon composite negative electrode material, which includes a nanometer Si core layer and a nitrogen-doped carbon layer coating the nanometer Si core layer, wherein the mass content of silicon is (27.32+/-0.2)%. The nitrogen-doped silicon carbon composite negative electrode material is smooth and regular in sphere shapes and good in dispersion, and can be used as an active substance of a negative electrode material of a lithium ion battery. According to an electrochemical performance test which is carried out with the current density being 100 mA/g and the voltage being 0.02-1.5 V, the composite material has superior specific capacity and cycling stability than those of a pure silicon negative electrode and is high in capacity retention ratio. The preparation method is mild in condition, short in reaction time, easy to operate and high in nitrogen content.

Nitrogen-doped silicon carbon composite negative electrode material and preparation method thereof

The invention discloses a silicon/activated charcoal composite cathode material and a preparation method thereof. The preparation method comprises the following steps: 1) dispersing nanosilicon spheres in a hydrochloric acid solution to obtain a turbid liquid, the concentration of which is 3-11g/L; 2) adding a dispersant into the turbid liquid obtained in the step 1) to obtain a mixture A; 3) adding a phenylamine monomer into the mixture A obtained in the step 2) to obtain a mixture B; 4) in a stirring state, dropwise adding ammonium persulfate into the mixture B to perform a polymerization reaction for 8-24h to obtain a silicon/polyaniline compound; 5) transferring the silicon/polyaniline compound obtained in the step 4) to a tubular furnace to be carbonized under inert gas shielding; and 6) heating the tubular furnace to the activating temperature under inert gas shielding, then introducing activating gas to activate for 0.5-3h, converting the gas in the tubular furnace into inert gas, and cooling the tubular furnace to room temperature to obtain the silicon/activated charcoal compound.

Silicon/activated charcoal composite cathode material and preparation method thereof

The invention discloses an anode material for Li-ion batteries and a preparation method thereof. The anode material for Li-ion batteries is characterized in that silica nanoparticles are taken as raw materials, and firstly the surface of the silica nanoparticles is coated with a SiO2 coating to obtain a precursor Si@SiO2; then the surface of the precursor is coated with a PANI coating to obtain a compound material Si@SiO2@PANI; then the PANI is carbonized into porous carbon through calcining the compound material, a compound material Si@SiO2@NOC is obtained; finally SiO2 is removed through mechanical erosion with a hydrofluoric acid, and a compound material Si@SiO2@NOC is obtained to be the anode material for Li-ion batteries. According to the method, the discharged Anode material for Li-ion batteries can be charged, the problem of volume dilation of batteries is effectively solved, circulation property and rate property of batteries are improved; the preparation method is simple, and large scale production can be achieved.

Zhang Chaofeng

Papers

Anode material for Li-ion batteries and preparation method thereof