STABILIZED, PURE LITHIUM METAL POWDER AND METHOD FOR PRODUCING THE SAME
The invention relates to a stabilized lithium metal powder and to a method for producing the same, the stabilized, pure lithium metal powder having been passivated in an organic inert solvent under dispersal conditions with fatty acids or fatty acid esters according to the general formula (I) R—COOR′, in which R stands for C 10 -C 29 groups and R′ for H or C 1 -C 8 groups.
1 .- 12 . (canceled)
13 . A stabilized, pure lithium metal powder, wherein the same was passivated in an organic, inert solvent under dispersal conditions with a fatty acid or fatty acid ester according to formula I
R—COOR′ (I),
wherein R denotes C 10 -C 29 moieties and R′ stands for H or C 1 -C 8 moieties.
14 . The stabilized, pure lithium metal powder according to claim 13 , wherein it has a sodium content <200 ppm.
15 . The stabilized, pure lithium metal powder according to claim 13 , wherein it has a sodium content <100 ppm.
16 . The stabilized, pure lithium metal powder according to claim 13 , wherein it has a sodium content <50 ppm.
17 . The stabilized, pure lithium metal powder according to claim 13 , wherein the same has a mean particle size of a maximum of 200 μm.
18 . The stabilized, pure lithium metal powder according to claim 13 , wherein the stabilized, pure lithium metal powder does not show any run-away phenomenon when in contact with N-methyl-2-pyrrolidone having a water content of max. 200 ppm and a minimum of 15 hours storage at 50° C., preferably storage at 100° C.
19 . A method for preparing a stabilized lithium metal powder comprising:
reacting pure lithium metal above 180° C. in an organic, inert solvent under dispersal conditions with a passivation agent containing one or a plurality of fatty acids and/or one or a plurality of fatty acid esters according to formula I
R—COOR′ (I),
wherein R denotes C 10 -C 29 moieties and R′ stands for H or C 1 -C 8 moieties.
20 . The method for preparing a stabilized lithium metal powder according to claim 19 , wherein the passivation agent is an unsaturated fatty acid selected from the group consisting of oleic acid, stearic acid, palmitic acid, lauric acid, myristinic acid, margaric acid, palmitoleic acid, linolic acid and linolenic acid.
21 . The method for preparing a stabilized lithium metal powder according to claim 19 , wherein the passivation agent is an ester of an unsaturated fatty acid selected from the group consisting of oleic acid, stearic acid, palmitic acid, lauric acid, myristinic acid, margaric acid, palmitoleic acid, linolic acid and linolenic acid.
22 . The method for preparing a stabilized lithium powder according to claim 19 , wherein the passivation agent comprises at least two unsaturated fatty acids selected from the group consisting of oleic acid, stearic acid, palmitic acid, lauric acid, myristinic acid, margaric acid, palmitoleic acid, linolic acid and linolenic acid.
23 . The method for preparing a stabilized lithium powder according to claim 19 , wherein the passivation agent comprises an ester of at least one unsaturated fatty acid selected from the group consisting of oleic acid, stearic acid, palmitic acid, lauric acid, myristinic acid, margaric acid, palmitoleic acid, linolic acid and linolenic acid.
24 . The method for preparing a stabilized lithium powder according to claim 19 , wherein the passivation agent comprises an ethylate.
25 . The method for preparing a stabilized lithium powder according to claim 19 , wherein the passivation agent comprises a triglyceride.
26 . The method for preparing a stabilized lithium powder according to claim 19 , wherein the passivation agent comprises a propanolate.
27 . The method for preparing a stabilized lithium powder according to claim 19 , wherein the passivation agent comprises a butylate.
28 . The method for preparing a stabilized lithium powder according to claim 19 , wherein the passivation agent comprises a natural oil.
29 . The method for preparing a stabilized lithium powder according to claim 19 , wherein the passivation agent comprises a natural oil selected from the group consisting of rapeseed oil, olive oil, sunflower oil and linseed oil.
30 . The method according to claim 19 , wherein the passivation agent is used in quantities of 0.1 g to 50 g per kg lithium metal.
31 . The method according to claim 19 , wherein hydrocarbons, selected from the group consisting of hexane, heptane, octane, decane, undecane, dodecane, toluene, ethylbenzene, cumene, either in the pure form thereof of as a mixture as commercially available boiling fractions, are used as inert, organic solvent.
32 . The method according to claim 19 , wherein an additional coating occurs at temperatures <180.5° C.
33 . A method comprising prelithiating an electrochemically active material with the pure lithium metal that was passivated according to claim 13 .
34 . A method according to claim 33 , wherein the electro-chemically active material is selected from the group consisting of graphite, alloy and a conversion anode for a lithium battery.