A method for preparing nanoscale lithium iron phosphate by self-sacrificing template method

Abstract

The invention relates to a self-sacrificing template method for preparing nanoscale lithium ferrous phosphate used as a cell cathode material and belongs to the field of electrochemistry. The method comprises the following specific steps: dissolving inorganic compound raw materials containing Fe<3+> and PO4<3+> in an aqueous solution, adjusting the pH value of the solution to 1-6, reacting at thetemperature of 60-150 DEG C for 3-10 hours, filtering, washing to obtain amorphous nano iron phosphate, and then baking at the temperature of 450-750 DEG C in air atmosphere for 4-16 hours to obtain a crystalline nano iron phosphate template; and on the basis of utilizing crystalline nano iron phosphate as a template, dissolving iron phosphate, a Li<+>-containing compound and a carbon-containing organic matter in water, stirring and mixing uniformly, after spray-drying, and baking at the temperature of 450-800 DEG C in a / an nitrogen / argon protective atmosphere furnace to prepare a grey-black lithium ferrous phosphate (LiFePO4) / C material. The preparation method provided by the invention is simple and low in cost; and the prepared lithium ferrous phosphate material has the advantages of high purity, good consistency, integral crystal structure, small and uniform particles and excellent electrochemical performance.

Description

technical field [0001] The invention relates to a preparation method of lithium ferrous phosphate, a positive electrode material of a lithium ion battery, in particular to a method for preparing nanoscale lithium ferrous phosphate by a self-sacrificing template method, which belongs to the field of electrochemistry. Background technique [0002] The continuous deterioration of the global environment and the continuous shortage of energy supply are two major problems that mankind must face in the 21st century. The development and application of new energy and renewable clean energy has become an urgent task. Renewable resources such as wind energy, solar energy, and tidal energy are increasingly being used for power generation by humans, and green and environmentally friendly batteries as storage units for electric energy have also become research hotspots at home and abroad. Lithium-ion secondary battery, as a new type of green battery, has developed quite rapidly since it c...

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Problems solved by technology

However, based on the limitation of the high-temperature solid-state reaction itself, due to the long-term heat treatment at high temperature, the LiFePO prepared by the high-temperature solid-state method 4 Large particle size, uneven distribution, and difficult to control particle shape

Preparation of LiFePO by liquid phase methods such as hydrothermal method 4 The advantages and disadvantages of the method are obvious: the advantages are that the raw materials are mixed between molecules, the mixing uniformity reaches the molecular level, the synthesis temperature is low, the product particles after roasting are small and uniform, and the size distribution range is narrow, which has incomparable advantages compared with the solid phase method. , and the disadvantages are: complex and difficult preparation process, high requirements for reaction equipment, high cost, and the iron source in the raw material is usually soluble ferrous salt, which is easy to introduce Fe 3+ Impurities, poor product consistency

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