Hydrothermal process for the production of LiFePO₄powder

摘要

The present invention relates to a process for the production of LiFePO4 powder, comprising the steps: a) providing an aqueous solution of an organic surfactant; b) providing an aqueous solution of an iron (II) salt and mixing said aqueous iron (II) salt solution with an aqueous solution of a phosphate, to provide a mixed iron (II) salt/phosphate solution having a stoichiometric ratio of Fe2+:phosphate of about 1:1; c) adding the mixed iron (II) salt/phosphate solution to the surfactant solution under constant stirring; d) providing an aqueous solution comprising a lithium salt, adding said aqueous solution comprising a lithium salt to said mixed iron (II) salt/phosphate solution to provide a mixture having a stoichiometric ratio of Fe2+:phosphate:lithium salt of about 1:1:3 and stirring the resulting mixture; e) heating the resulting mixture at 80-200° C.; f) washing the resulting precipitate to remove excess surfactant, filtering and drying the precipitate; and g) heat treating the dried precipitate in an inert atmosphere by firing at 550-850° C. for at least 2 hours, wherein a co-solvent is added during or after any one of steps (a) to (d).

主权项

1. A process for the production of LiFePO4 powder, comprising the steps:
a) providing an aqueous solution of an organic surfactant; b) providing an aqueous solution of an iron (II) salt and mixing said aqueous iron (II) salt solution with an aqueous solution of a phosphate, to provide a mixed iron (II) salt/phosphate solution having a stoichiometric ratio of Fe2+:phosphate of about 1:1; c) adding the mixed iron (II) salt/phosphate solution to the surfactant solution under constant stirring; d) providing an aqueous solution comprising a lithium salt, adding said aqueous solution comprising a lithium salt to said mixed iron (II) salt/phosphate solution to provide a mixture having a stoichiometric ratio of Fe2+:phosphate:lithium salt of about 1:1:3 and stirring the resulting mixture; e) heating the resulting mixture at 80-200° C.; f) washing the resulting precipitate to remove excess surfactant, filtering and drying the precipitate; and g) heat treating the dried precipitate in an inert atmosphere by firing at 550-850° C. for at least 2 hours, wherein a co-solvent is added during step (a) to provide a solution of organic surfactant in a mixture of water and co-solvent.