Method for preparing lithium iron borate serving as positive material of lithium ion battery by sol-gel technology

Abstract

The invention discloses a method for preparing lithium iron borate serving as a positive material of a lithium ion battery by a sol-gel technology. The method comprises the following steps of: dissolving a lithium source, an iron source, a borate source and a chelating agent in water according to a certain stoichiometric ratio; controlling the concentration of metal ions to be between 0.1 and 1mol/L; stirring at room temperature for 30 minutes to obtain sol; heating to 80 DEG C and keeping the temperature for 24 hours to form gel; drying the gel at the temperature of 120 DEG C and ball-milling for 2 hours; pressing into tablets under the pressure of 20MPa; sintering under the protection of argon at the temperature of between 600 and 900 DEG C for 10 hours; and naturally cooling to the room temperature to obtain the LiFeBO3. The method has the advantages of wide raw material source, simple operation process and high controllability and repeatability, the synthesis temperature of the material is effectively reduced, the preparation period of the material is shortened, and the production cost is saved. The particle size of the lithium iron borate synthesized by the method is between 60 and 600nm, and the particles have high dispersibility and crystallinity; and the lithium iron borate has higher reversible capacity and longer cycle life and can meet various requirements of the lithium ion battery during actual application.

Description

technical field [0001] The invention relates to a method for preparing a cathode material of a lithium ion battery, in particular to a method for preparing lithium iron borate, an anode material of a lithium ion battery, by using a sol-gel technology. Background technique [0002] Lithium-ion batteries are widely used in portable electronic devices, power tools, energy storage devices, electric vehicles and hybrid electric vehicles due to their advantages of high working potential, high specific energy, high specific power, long cycle life and no pollution. Lithium-ion batteries are generally composed of positive and negative active materials, electrolytes, separators, current collectors, etc. Among these components, active materials are the most important components of lithium-ion batteries and key active points for energy storage, especially It is the positive electrode material, and its cost accounts for about 40% of the entire battery. Therefore, the composition design, ...

AI Technical Summary

Problems solved by technology

[0004] Currently, the synthesis of LiFeBO 3 The main method is the high-temperature solid-state reaction method under the protection of inert gas, but this kind of preparation process has the disadvantages of complicated and changeable process, excessive energy consumption, high cost, etc., and the obtained material is not high in purity, large in particle size, Poor electrochemical performance, such as Y.Z.Dong (Y.Z.Dong, Y.M.Zhao, Z.D.Shi, X.N.An, P.Fu, L Chen, Electrochimica Acta, 2008, 53:2339.) and V.Legagneur (V.Legagneur, Y.An , A.Mosbah, R.Portal, A.Le Gal La Salle, A.Verbaere, D.Guyomard, Y.Piffard, Solid State Ionics 2001, 139: 37.) The synthetic technique reported by others and the material obtained , therefore, such methods are not conducive to the realization of large-scale industrial production

Images