Modification of lithium ion electrode materials via atomic layer deposition techniques
A method for coating of lithium ion electrode materials via atomic layer deposition. The coated materials may be integrated in part as a dopant in the electrode itself via heat treatment forming a doped lithium electrode.
1. A method of modifying a cathode comprising:
providing a lithium carbonate or lithium hydroxide cathode precursor in a reactor; and
depositing on the cathode precursor a first material by atomic layer deposition process including at least one cycle of:
pulsing a first metal precursor into the reactor for a first metal precursor pulse time;
exposing the cathode precursor to the first metal precursor for a first metal precursor exposure time and at a first partial pressure and binding the first metal precursor;
purging the reactor of the first metal precursor;
pulsing a co-reactant precursor into the reactor for a first co-reactant pulse time;
exposing the cathode precursor to the co-reactant precursor for a co-reactant precursor exposure time and at a second partial pressure, the co-reactant precursor reacting with the bound first metal precursor therein to form the first material; and
purging the reactor of the co-reactant precursor;
wherein the cathode precursor prior to deposition is non-calcinated and non-lithiated.
2. The method of claim 1 , further comprising calcinating the cathode precursor after depositing of the first material.
3. The method of claim 2 , wherein the calcinating is at a temperature in the range of 300° C. to 1000° C.
4. The method of claim 1 , wherein the cathode precursor comprises a metallic element with a first oxidation state.
5. The method of claim 4 , wherein the cathode precursor comprises LiCoO 2 or LiOH.
6. The method of claim 4 , wherein the first material comprises an ALD deposited metallic element having the first oxidation state.
7. The method of claim 5 , wherein the first material comprises aluminum.
8. The method of claim 1 , depositing a second material by atomic layer deposition process including at least one cycle of:
pulsing a second metal precursor into the reactor for a second metal precursor pulse time;
exposing the cathode precursor to the second metal precursor for a second metal precursor exposure time and at a second metal precursor partial pressure and binding the second metal precursor;
purging the reactor of the second metal precursor;
pulsing a second co-reactant precursor into the reactor for a second co-reactant pulse time;
exposing the cathode precursor to the second co-reactant precursor for a second co-reactant precursor exposure time and at a second partial pressure, the co-reactant precursor reacting with the bound first metal precursor therein to form the second material and
purging the reactor of the co-reactant precursor.
9. The method of claim 8 , wherein the second material comprises an ALD deposited metallic element having the second oxidation state that is different from the first oxidation state.
10. The method of claim 8 , wherein following calcination, the first material forms a first material dopant within the cathode precursor bulk and the second material is not a dopant.
11. The method of claim 1 , further comprising, following or during calcination, lithiation of the coated cathode precursor to form a modified cathode.
12. The method of claim 1 , wherein the cathode precursor comprises a manganese-rich layered-layered spinel carbonate, a nickel-rich hydroxide, or a mixture thereof.