Process for the preparation of lithium metal oxides involving fluidized bed techniques
A method of producing lithium metal oxides can include mixing lithium salt and a metal oxide to form a composition, heating the composition in a first reactor, transferring the composition to a second reactor, and passing the composition through the second reactor to anneal the composition to form lithium metal oxides. The second reactor can be a fluidized bed reactor. The lithium metal oxide can have an average crystal size of between about 5 microns and about 20 microns.
1. A process for producing a lithium metal oxide having an average crystal size of from about 5 microns to about 20 microns, the process comprising the steps of:
mixing a lithium salt and a metal compound to form a mixture;
heating the mixture in a first reactor to form a crude product; and
annealing the crude product in a second reactor to form an annealed product comprising lithium metal oxide, wherein the second reactor is a fluidized bed reactor.
2. The process of claim 1 , wherein the lithium metal oxide has an average BET surface of from about 0.5 to about 2.5 m 2 /g.
3. The process of claim 1 , wherein an oxidation state of the metal in the lithium metal oxide is from about +3 to about +4.
4. The process of claim 1 , wherein the lithium salt is selected from the group consisting of: Li 2 O, LiOH, LiCl, LiNO 3 , Li 2 CO 3 , LiSO 4 , lithium carboxylates, and mixtures thereof.
5. The process of claim 1 , wherein the metal compound comprises a metal selected from the group consisting of: B, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Zr, Nb, Mo, Ru, W, and mixtures thereof.
6. The method of claim 5 , wherein the metal compound is selected from the group consisting of: MnO, MnO 2 , Mn 2 O 3 , Mn 3 O 4 , MnOOH, MnCO 3 , MnSO 4 , Mn(NO 3 ) 2 , Mn(CHO 2 ) 2 , Mn(CH 3 COO) 2 , acetate, and mixtures thereof.
7. The process of claim 1 , wherein a gas in the fluidized bed reactor is selected from the group consisting of argon, nitrogen, and nitrogen-air mixtures.
8. The process of claim 1 , wherein the lithium metal oxide has a capacity of from about 100 mAh/g to about 140 mAh/g.
9. The process of claim 1 , wherein the first reactor is selected from the group consisting of an autoclave, pusher furnace, rotary furnace, and a calciner.
10. The process of claim 1 , wherein the step of annealing comprises annealing the crude product in the second reactor at a temperature from about 600° C. to about 1000° C. for an amount of time from about 1 to about 24 hours to form the annealed product.
11. The process of claim 10 , wherein the amount of time is less than about 8 hours.
12. The process of claim 1 , further comprising the step of:
cooling the annealed product.
13. The process of claim 12 , wherein the annealed product is cooled to a temperature at or below about 50° C.
14. The process of claim 1 , further comprising the step of:
drying the annealed product.
15. The process of claim 1 , further comprising the step of:
acid leaching the annealed product.
16. The process of claim 1 , further comprising a step of washing the crude product to remove impurities.