5 results about "Vanadate" patented technology

The invention relates to a method for preparing a ferric vanadate-graphene negative electrode composite material. The method comprises the following steps: dispersing sheet layers of graphene, forming ferric vanadate on the surface of graphene, growing and performing after-treatment on the ferric vanadate attached to the surface of graphene. According to the method disclosed by the invention, the sheet layers of graphene are dispersed, so that the ferric vanadate is uniformly attached to the surface of the graphene. Therefore, the ferric vanadate-graphene negative electrode composite material is uniform in texture and high in dispersity, the performance is greatly improved, and hydrogen peroxide is added into graphene turbid liquid, so that reaction is carried out on the surface of the uniformly dispersed graphene, functional groups are generated, a negative ion state is formed, ferrous iron ions are easily adsorbed, the reaction rate is accelerated, the adsorption rate is increased, and the ions react with vanadate on the graphene surface so as to form uniform particles. The ferric vanadate-graphene negative electrode composite material disclosed by the invention has low discharge voltage and extremely high discharge capacity, the raw materials are wide in source, and the cost is reduced.

The invention discloses a preparation method of ferric vanadate photocatalysts. According to the method, firstly, a direct current electrolysis method is used; by controlling the current density, the electrolyte concentration and the temperature, ferric vanadate with different appearance structures and particle diameters is prepared; then, products obtained at an anode are cleaned and filtered; obtained filter cake is dried for 4 to 6h at the temperature of 80 DEG C to 100 DEG C; natural cooling is performed to room temperature; finally, at the air atmosphere, the temperature is raised to 500 to 700 DEG C at the temperature rise speed of 2.5 to 10 DEG C/min; high-temperature roasting is performed for 3 to 5 h; the ferric vanadate with high purity and high cleanness degree can be obtained; the composition is FeVO4. The product obtained by controlling the corresponding conditions has the main appearance of ball-shaped particles and micro nanometer lines.

The invention discloses a positive plate capable of improving lithium nickel manganese oxide battery capacity. The positive plate comprises the following components based on mass percentage: 0.1-10% of compound, 1-20% of conductive agent, 2-10% of binder, and the balance beinga positive electrode active material consisting of lithium nickel manganese oxide, wherein the compound is lithium titanate, lithium iron phosphate, lithium vanadate or lithium peroxide. The positive plate capable of improving the lithium nickel manganese oxide battery capacity and the lithium nickel manganese oxide battery applying the positive electrode plate have the beneficial effects as follows: the compound consisting of lithium titanate, lithium iron phosphate, lithium vanadate or lithium peroxide is added to the positive plate; the lithium titanate, lithium iron phosphate, lithium vanadate or lithium peroxide are materials capable of realizing lithium ion intercalation under a relatively low voltage; therefore, active lithium ions are released in the initial charging process within charging-discharging voltage sections of the high-voltage lithium nickel manganese oxide battery; the lithium ion absorption is not continued in the subsequent discharging process of the lithium nickel manganese oxide battery; and therefore, the capacity of the lithium nickel manganese oxide battery is improved.

The invention discloses a graphene and ammonium vanadate composite material and a preparation method thereof. In the graphene and ammonium vanadate composite material, graphene accounts for 5 to 20 mass percent, and the rest is ammonium vanadate; the ammonium vanadate is uniformly distributed on a graphene sheet layer in a belt shape; the width of the ammonium vanadate is 20 to 60nm. The preparation method of the graphene and ammonium vanadate composite material is mainly characterized in that the graphene and ammonium vanadate composite material is synthesized by using sodium dodecyl benzene sulfonate by a soft template method. The ammonium vanadate in the graphene and ammonium vanadate composite material is uniformly distributed on the graphene sheet layer; the condition of ammonium vanadate particle aggregation is avoided; the charging and discharging capacity of a lithium battery is improved.