104 results about "Constant current density" patented technology

The invention discloses a method for recycling manganese and lithium from a power type lithium manganate battery for an electric automobile, which comprises the following steps of: (1) after discharging a waste and old lithium ion battery, detaching a shell to obtain an anode part; (2) removing an organic adhesive of the anode part to obtain a power type lithium manganate anode material; (3) adding acid and a reducing agent into the inorganic material obtained in the step (2), dissolving the inorganic material and filtering to remove the undissolved substance acetylene black to obtain filter liquid; (4) carrying out electrochemical deposition for 5-8 hours by using the filter liquid obtained in the step (3) as electrolyte, using a titanium sheet as a working electrode, using a graphite rod as a counter electrode and controlling the constant current density of 300-800A/m<2> and the temperature of 60-80 DEG C to obtain a manganese dioxide solid; (5) adjusting the pH of the residual liquid in the step (4) to be 9 to 10 and filtering to obtain a sediment and filter liquid; (6) adding a sodium carbonate solution with the concentration of 30-40 percent into the filter liquid obtained in the step (5) till the filter liquid is completely deposited; and filtering, washing and drying to obtain a lithium carbonate solid. MnO2 is recycled by utilizing an electrochemical deposition method, and thereby the method has the advantage of environmental protection; and the high-purity lithium carbonate solid is recycled.

In some embodiments, the present invention provides novel methods of preparing porous silicon films and particles for lithium ion batteries. In some embodiments, such methods generally include: (1) etching a silicon material by exposure of the silicon material to a constant current density in a solution to produce a porous silicon film over a substrate; and (2) separating the porous silicon film from the substrate by gradually increasing the electric current density in sequential increments. In some embodiments, the methods of the present invention may also include a step of associating the porous silicon film with a binding material. In some embodiments, the methods of the present invention may also include a step of splitting the porous silicon film to form porous silicon particles. Additional embodiments of the present invention pertain to anode materials derived from the porous silicon films and porous silicon particles.

In some embodiments, the present invention provides novel methods of preparing porous silicon films and particles for lithium ion batteries. In some embodiments, such methods generally include: (1) etching a silicon material by exposure of the silicon material to a constant current density in a solution to produce a porous silicon film over a substrate; and (2) separating the porous silicon film from the substrate by gradually increasing the electric current density in sequential increments. In some embodiments, the methods of the present invention may also include a step of associating the porous silicon film with a binding material. In some embodiments, the methods of the present invention may also include a step of splitting the porous silicon film to form porous silicon particles. Additional embodiments of the present invention pertain to anode materials derived from the porous silicon films and porous silicon particles.

The invention relates to a method for recovering and regenerating a positive electrode material of a lithium ion battery and belongs to the technical field of recovery and circulating reuse of an electrode material. The method comprises the following steps: successively carrying out discharge, decomposition, an NMP (N-methyl-2-pyrrolidone) ultrasonic treatment and dissolution, filtration and firing on a waste lithium ion battery to obtain black solid powder; carrying out acid leaching on the black solid powder, and filtering to obtain a leachate solution containing Co<2+> and Li<1+>; and mixing the leachate solution with a LiOH solution to obtain electrolyte, stirring and reacting for 3-18 hours by using an electrochemical deposition technology at the constant current density of 5.0-9.0mA/cm<2> and the temperature of 30-90 DEG C, and directly synthesizing on a nickel substrate to obtain the regenerated lithium cobalt oxide positive electrode material, namely a regenerated positive electrode material of the lithium ion battery. By using the method, the recovery and regeneration of the lithium cobalt oxide positive electrode material of the waste lithium ion battery are realized; and the method has the advantages of low energy consumption, simple preparation process, short treatment period, obvious effect and no secondary environment pollution.

The invention provides an anode oxidation method which comprises the following steps: under the anode oxidation condition, putting light metal material in electrolyte, using the light metal material as an anode, using the conducting material which does not react with the electrolyte as a cathode, and enabling the cathode and the anode to be respectively electrically connected with a positive electrode and a negative electrode of a power source. The anode oxidation comprises constant current density anode oxidation and constant voltage anode oxidation, wherein the current density of the constant current density anode oxidation is 0.5 to 6 amperes/square decimeter, and the voltage of the constant voltage anode oxidation is 20 to 400 volts. Compared with the light metal material which is processed by the prior anode oxidation method, the corrosion resistance of the light metal material which is processed by the anode oxidation method of the invention is greatly improved, and even the light metal material which is processed by the anode oxidation method of the invention is not post-processed by plugging, the corrosion resistance of the light metal material is also stronger.

The invention relates to a preparing method for aluminum foil gradient wettability surface with a nano coarse structure, which includes the steps as follows: stripped aluminum foil with the length of 5 to 20cm is ultrasonically cleaned, dried and immersed in NaOH water solution to be treated; phosphoric acid and glycerol mixed water solution is taken as electrolyte to perform anodic oxidation at a room temperature and under a constant current density mode, so as to achieve the nano coarse surface of the aluminum foil; the aluminum foil is tilted in an open empty container with the nano coarse surface facing upward, and under the condition of room temperature, the fluoroalkyl silane ethanol solution with the volume fraction of 0.14 to 0.24% is dripped in with the uniform velocity of 2.5 to 7.5ml/min within the time of 15 to 25min; and the aluminum foil taken out of the container is placed in a drying oven of 60 degrees C for 15min, then the gradient wettability of the nano coarse surface of the aluminum foil can be achieved, the gradient covering length is 5 to 15cm, the contact angle can be uniformly reduced from 155 degrees to lower than 5 degrees, and the progressive reducing amplitude is 10 to 30 degree/cm.

It is characterized in that in the case of filling a through hole formed in a substrate with a plated metal by electrolytic plating, the electrolytic plating is started by a high current density higher than Constant Current Density capable of fully filling the through hole when the electrolytic plating is performed with a current density held constant as a current density of the electrolytic plating, and the electrolytic plating is continued by being changed to a current density lower than the high current density by the time of reaching formation of a seam diameter in which an inside diameter does not decrease even when the electrolytic plating is continued after the electrolytic plating at the high current density is started.

The invention discloses a preparing method of high quality alumina photonic crystal, and the main steps of the method are as follows: an aluminum sheet, the alumina of which is dissolved by surface treatment, is treated with anodic oxidation by high constant current density first and low constant current density then, and the step is repeated, and high quality alumina photonic crystal can be obtained. As the current density is modulated periodically, the nano structure of alumina formed on the surface of the aluminum sheet changes periodically, thus forming periodical porous structure which has the periodical dielectric structure of alumina and air, therefore, the matter has the property of photonic crystal. The method has the advantages of convenient operation and low production cost, and can produce high quality one-dimensional photonic crystal of large area, and the produced photonic crystal has controllable layer number and controllable depth and position of band gap, and has deeper optical band gap on the same number of photonic crystal layers, therefore the invention has wide application prospect in the field of manufacturing optical devices.

The invention relates to a preparation method of a porous copper full-impregnated film of a three-dimensional network structure. The method comprises the following steps that (1), a basic plating solution is prepared, wherein the basic plating solution comprises 1.0mol/L of H2SO4 and 0.2mol/L of CuSO4; (2), electrochemical deposition is carried out, wherein in a depositing cell, a graphite sheet serves as a positive electrode, aluminum foil serves as a negative electrode, the basic plating solution serves as electrolytes, and an electrochemistry working station is used for carrying out constant-current density electrolytic deposition to form the porous copper film on the aluminum foil; (3), vacuum annealing treatment is carried out on the porous copper film on the aluminum foil; (4), an aluminum substrate is removed, wherein aluminum foil obtained after vacuum annealing treatment is placed in alkali liquor to have a reaction, the aluminum foil is removed, and the porous copper full-impregnated film of the three-dimensional network structure is obtained. Compared with the prior art, the porous copper full-impregnated film of the three-dimensional network structure is even in bore diameter and stable in structure and has the good filtering separation function, and meanwhile due to the large specific area, and the good toughness, the film can be used as a good catalyst carrier.

A method for electrochemically depositing discrete regions of calcium phosphate onto a medical implant. The method includes providing an implant including at least one area having a metallic surface. At least a portion of the metallic surface is contacted with an electrolyte solution comprising calcium ions and phosphate ions. The metallic surface is used as a cathode, and an electrical potential is applied between the cathode and the electrolyte solution. The electrical potential is applied with a constant current density of from about 10 to about 50 mA/cm² for a period of time of from about 1 to about 20 minutes. A plurality of discrete regions of needle-shaped hydroxyapatite crystals are electrochemically deposited onto the metallic surface.

The invention discloses a method for preparing an aluminum alloy colored composite film. The method comprises pretreatment and direct-current electrolytic coloring; the direct-current electrolytic coloring adopts composite electrolyte consisting of H2SO4, CuSO4, EDTA and water, wherein the H2SO4 is 1,000 to 1,200g/L, the CuSO4 is 200 to 300g/L, the EDTA is 40 to 55g/L, the balance is water, and the pH value of the solution is less than or equal to 4.5; the coloring is performed at the constant current density of 0.5 to 0.6A/cm<2> and the temperature of between 20 and 30 DEG C, and the area ratio of a cathode to an anode is (1.5-2): 1; and a direct-current anode oxidation step can be added before the direct-current electrolytic coloring. The method has the advantages of simple preparation process, safe production operation and low production cost; and the obtained colored film has good corrosion resistance, and meets the decorative requirement.

The surface ceramizing treatment process for pipe of non-valve metal or non-metal includes the following steps: 1. forming valve metal layer of 50-150 micron thickness in the inner and outer surface of the pipe through composite filming process; and 2. fixing electrode rod connected to negative pole of DC power source in the inner cavity of the pipe, connecting the pipe to the positive pole of the power source, soaking the pipe into alkali treating liquid inside treating tank, and maintaining constant current density to treat for proper period. The treatment process of the present invention is suitable for the surface ceramizing of pipe unsuitable for being ceramized in micro plasma process and has the problem of ceramizing the inner surface of pipe solved.

The invention discloses a sodium-perfluorocarbon primary battery and relates to a sodium battery. The sodium-perfluorocarbon primary battery is provided with a positive electrode, a negative electrode, a diaphragm and an electrolyte solution, wherein the positive electrode takes perfluorocarbon as an active substance; a main body of the perfluorocarbon is (CFx), and x is ranged from 0.2-1.2; the active substance comprises 20-100 percent of perfluorocarbon by mass; the electrolyte consists of a solvent, an electrolyte and an additive. The commercial perfluorocarbon, including carbon monofluoride, fluoride petroleum coke, fluoride carbon nano tube, fluoride carbon fibers, fluoride graphene and the like, is used as a main body active substance of the positive electrode of the sodium-perfluorocarbon primary battery; the sodium metal is used as the negative electrode; the electrolyte solution which takes an organic solution as the solvent and contains the sodium salt electrolyte and the diaphragm form a primary battery system which discharges at the constant current density of 20mA/g, and the mass specific capacity can be more than 800mAh/g. The sodium-perfluorocarbon primary battery has the characteristics of high discharging capacity, steady discharging level, environment friendliness and the like.

A method and apparatus for providing a uniform current density across an immersed surface of a substrate during an immersion process. The method includes the steps of determining a time varying area of an immersed portion of the substrate during the immersion process, and supplying a time varying current to the substrate during the immersion process, wherein the time varying current is proportional to the time varying area and is configured to provide a constant current density to the immersed portion of the substrate.

The invention relates to a treatment method of an aluminium foil bionic nanostructured super-hydrophobic anti-condensation functional surface. The method comprises the following steps: firstly performing ultrasonic cleaning of an aluminium foil with acetone and deionized water, blowing to dry, soaking the aluminium foil into a 1 mol/L NaOH aqueous solution for treatment for 30-60 s, cleaning with ethanol and deionized water in order, blowing to dry so as to keep in reserve; soaking the pretreated aluminium foil in liquid which adopts a mixed aqueous solution of phosphoric acid and glycerol as an electrolyte, performing anodization under a room-temperature condition in a constant current density mode for 120-150 min; after the anodization is completed, taking the aluminium foil out, cleaning with ethanol and deionized water, blowing to dry; soaking the anodized aluminium foil in liquid stearic acid at 70 DEG C for 1 h, rinsing in hot ethanol with a temperature of 70 DEG C, curing in an oven with a temperature of 80 DEG C for 30 min so as to prepare the aluminium foil bionic nanostructured super-hydrophobic anti-condensation functional surface. The invention has a simple preparation process, no pollution, less substrate damage, excellent surface quality, and is applicable to popularization and application.

The invention is an apparatus and method for forming highly uniform layers of metal on a substrate by electro-deposition. The substrate is electroplated in a bath composed of a quiescent (i.e., no external agitation) electrolyte solution using an effective constant current density carefully selected to match the chemical composition of the electrolyte.