Protective coatings for lithium anodes

1. A method for forming protective coatings on lithium (Li) anodes, comprising:

(a) reacting a Li surface with an aluminum-containing precursor or a first zinc-containing precursor to form a first monolayer;

(b) purging excess aluminum-containing precursor or first zinc-containing precursor and reaction by-product;

(c) reacting the first monolayer with a first oxygen-containing precursor selected from the group consisting of water (H 2 O), ozone (O 3 ), and oxygen (O 2 );

(d) purging excess first oxygen-containing precursor and reaction by-product;

wherein steps (a) to (d) constitute a first cycle that forms a film of a first material on the Li surface;

(e) reacting the film of the first material with a second zinc-containing precursor to form a second monolayer;

(f) purging excess second zinc-containing precursor and reaction by-product;

(g) reacting the second monolayer with a second oxygen-containing precursor comprising HO(CH 2 ) n OH, where n is an integer in the range of 2 to 10;

(h) purging the second oxygen-containing precursor and a second reaction by-product;

wherein steps (e) to (h) constitute a second cycle that forms a zincone film on the film of the first material;

(i) reacting the zincone film with a Li-containing precursor to form a third monolayer

(j) purging excess Li-containing precursor and a third reaction by-product;

(k) reacting the third monolayer with a third oxygen-containing precursor selected from the group consisting of water (H 2 O) and HO(CH 2 ) n OH, where n is an integer in the range of 2 to 10;

(l) purging the third oxygen-containing precursor and reaction by-product;

wherein steps (i) to (l) constitute a third cycle that forms a film of Li-containing material on the zincone film such that the protective coating comprises a first material/zincone/Li-containing material film having a thickness.

2. The method of claim 1 , wherein the aluminum-containing precursor comprises at least one of trimethylaluminum (Al(CH 3 ) 3 ) (TMA), triethylaluminum ((C 2 H 5 ) 3 Al) (TEA), triethyl(tri-sec-butoxy)dialuminum ((C 2 H 5 ) 3 Al 2 (OC 4 H 9 ) 3 ), aluminum chloride (AlCl 3 ), aluminum isopropoxide (Al((OCH(CH 3 ) 2 ) 3 ), dimethylaluminum isopropoxide ((CH 3 ) 2 AlOCH(CH 3 ) 2 ), tris(2,2,6,6-tetramethyl-3,5-heptanedionato)aluminum (Al(TMHD) 3 ), tri-isobutylaluminum ((C 4 H 9 ) 3 Al), aluminum hexafluoroacetylacetonate (Al(CF 3 COCHCOCF 3 ) 3 ), aluminum ethoxide (Al(OC 2 H 5 ) 3 ), aluminum s-butoxide (Al(OC 4 H 9 ) 3 ), or aluminum acetylacetonate (Al(CH 3 COCHCOCH 3 ) 3 ).

3. The method of claim 1 , wherein an even number of cycles of the first cycle, the second cycle and/or the third cycle are performed.

4. The method of claim 3 , wherein an odd number of cycles of the first cycle, the second cycle and/or the third cycle are performed.

5. The method of claim 1 , wherein the protective coating has a thickness in the range of 1 nm to 10 nm.

6. The method of claim 1 , wherein each of the first zinc-containing precursor and the second zinc-containing precursor comprises diethyl zinc.

7. The method of claim 1 , wherein the Li surface is reacted with the aluminum containing precursor such that the first material comprises alumina or lithium doped alumina.

8. The method of claim 1 , wherein the Li surface is reacted with the first zinc containing precursor such that the first material comprises zinc oxide or lithium doped zinc oxide.

9. The method of claim 1 , wherein the Li-containing precursor comprises lithium tert-butoxide.