Lithium transition-metal phosphate powder for rechargeable batteries

A process for the manufacture of a LiFePO4 powder, comprising the steps of:

• providing an equimolar aqueous solution of Li1+, Fe3+, and PO43− prepared by dissolving components which are susceptible to coexist as solutes in an aqueous system and which, upon heating at a temperature below 500° C., decompose to form a pure homogeneous Li and Fe phosphate precursor;
• evaporating water from the solution, thereby producing a solid mixture;
• decomposing the solid mixture at a temperature below 500° C. to form a pure homogeneous Li and Fe phosphate precursor;
• and
• annealing the precursor at a temperature of less than 800° C. in a reducing atmosphere, thereby forming a LiFePO4 powder of olivine structure.

A powder for use in lithium insertion-type electrodes prepared by a process comprising the steps of:

• providing an equimolar aqueous solution of Li1+, Mnn+, and PO43− prepared by dissolving components which are susceptible to coexist as solutes in an aqueous system and which, upon heating at a temperature below 500° C., decompose to form a pure homogeneous Li and M phosphate precursor;
• evaporating water from the solution, thereby producing a solid mixture;
• decomposing the solid mixture at a temperature below 500° C. to form a pure homogeneous Li and M phosphate precursor;
• and
• annealing the precursor at a temperature of less than 600° C. in an inert or reducing atmosphere, thereby forming a LiMPO4 powder of olivine structure and having an average particle size of less than 1 μm;
• wherein Mn+ is one or more of Fe2+, Fe3+, Co2+, Ni2+, and Mn2+, and M is FexCoyNizMnw, with 0≦x≦1,0≦y≦1,0≦z≦1,0≦w≦1, and x+y+z+w=1.

A battery comprising a lithium insertion electrode including a powder prepared by a process comprising the steps of:

• providing an equimolar aqueous solution of Li1+, Mn+, and PO43− prepared by dissolving components which are susceptible to coexist as solutes in an aqueous system and which, upon heating at a temperature below 500° C., decompose to form a pure homogeneous Li and M phosphate precursor;
• evaporating water from the solution, thereby producing a solid mixture;
• decomposing the solid mixture at a temperature below 500° C. to form a pure homogeneous Li and M phosphate precursor;
• and
• annealing the precursor at a temperature of less than 600° C. in an inert or reducing atmosphere, thereby forming a LiMPO4 powder of olivine structure and having an average particle size of less than 1 μm;
• wherein Mn+is one or more of Fe2+, Fe3+, Co2+, Ni2+, and Mn2+, and M is FexCoyNizMnw, with 0≦x≦1,0≦y≦1,0≦z≦1,0≦w≦1, and x+y+z+w=1.