Method and apparatus for preparation of spherical metal carbonates and lithium metal oxides for lithium rechargeable batteries
A number of materials with the composition Li 1+x Ni α Mn β Co γ M′ δ O 2−z F z (M′=Mg,Zn,Al,Ga,B,Zr,Ti) for use with rechargeable batteries, wherein x is between about 0 and 0.3, α is between about 0.2 and 0.6, β is between about 0.2 and 0.6, γ is between about 0 and 0.3, δ is between about 0 and 0.15, and z is between about 0 and 0.2. Adding the above metal and fluorine dopants affects capacity, impedance, and stability of the layered oxide structure during electrochemical cycling. Another aspect of the invention includes materials with the composition Li 1+x Ni α Co β Mn γ M′ δ O y F z (M′=Mg,Zn,Al,Ga,B,Zr,Ti), where the x is between 0 and 0.2, the α between 0 and 1, the β between 0 and 1, the γ between 0 and 2, the δ between about 0 and about 0.2, the y is between 2 and 4, and the z is between 0 and 0.5.
1. A method of preparing a mixed nickel-cobalt-manganese carbonate comprising the steps of:
dissolving in distilled water about 0.01M to about 2M of a metal solution comprising:
a nickel compound selected from the group consisting of Ni-acetate, Ni-nitrate, Ni-sulfate and combinations thereof;
a cobalt compound selected from the group consisting of Co-acetate, Co-nitrate, Co-sulfate, and combinations thereof; and
a manganese compound chosen from the group consisting of Mn-acetate, Mn-nitrate, Mn-sulfate, and combinations thereof;
adding the metal solution to an aqueous solution of about 0.1M to about 5M of a carbonate chosen from the group consisting of ammonium hydrogen carbonate, sodium carbonate and combinations thereof;
aging the precipitates in the solution at a temperature increased from about 20° C. to about 65° C. wherein the solution is reacted at each temperature for about 1 h to about 24 h.
2. The method of preparing a mixed nickel-cobalt-manganese carbonate of claim 1 , wherein the steps of reacting and aging are carried out with constant stirring.
3. The method of preparing a mixed nickel-cobalt-manganese carbonate of claim 1 further comprising the steps of, after aging, filtering and drying the coprecipitate powders.
4. The method of preparing a mixed nickel-cobalt-manganese carbonate of claim 1 , wherein the carbonate solution has a pH which is varied from about 7 to about 10 using a hydroxide selected from the group consisting of ammonium hydroxide, sodium hydroxide, and combinations thereof.