Stabilized lithium metal impressions coated with alloy-forming elements and method for production thereof

Abstract

The invention relates to particulate lithium metal composite materials, stabilized by alloy-forming elements of the third and fourth primary group of the PSE and method for production thereof by reaction of lithium metal with film-forming element precursors of the general formulas (I) or (II): [AR 1 R 2 R 3 R 4 ]Li x (I), or R 1 R 2 R 3 A-O-AR 4 R 5 R 6 (II), wherein: R 1 R 2 R 3 R 4 R 5 R 6 =alkyl (C 1 -C 12 ), aryl, alkoxy, aryloxy-, or halogen (F, Cl, Br, I), independently of each other; or two groups R represent together a 1,2-diolate (1,2-ethandiolate, for example), a 1,2- or 1,3-dicarboxylate (oxalate or malonate, for example) or a 2-hydroxycarboxylate dianion (lactate or salicylate, for example); the groups R 1 to R 6 can comprise additional functional groups, such as alkoxy groups; A=boron, aluminum, gallium, indium, thallium, silicon, germanium, tin, lead; x=0 or 1 for B, Al, Ga, In, Tl; x=0 for Si, Ge, Sn, Pb; in the case that x=0 and A=B, Al, Ga, In, Tl, R 4 is omitted, or with polymers comprising one or more of the elements B, Al, Ga, In, Tl, Si, Ge, Sn, Pb, at temperatures between 50 and 300° C., preferably above the melting temperature of lithium of 180.5° C., in an organic, inert solvent.

1 .- 15 . (canceled) 
     
     
         16 . A stabilized particulate lithium metal, wherein it has a core of metallic lithium which is surrounded with an outer passivating layer containing one or more elements of main groups 3 and/or 4 of the periodic table of elements that can be alloyed with lithium. 
     
     
         17 . The stabilized particulate lithium metal of  claim 16 , wherein the element that can be alloyed with lithium and is present in the outer layer is present in elemental form or as an alloy with lithium. 
     
     
         18 . The stabilized particulate lithium metal according to  claim 16  wherein it has a sodium content <200 ppm. 
     
     
         19 . The stabilized particulate lithium metal according to  claim 17  wherein it has a sodium content <200 ppm. 
     
     
         20 . The stabilized particulate lithium metal according to  claim 16 , wherein it has a sodium content <100 ppm. 
     
     
         21 . The stabilized particulate lithium metal according to  claim 17 , wherein it has a sodium content <100 ppm. 
     
     
         22 . The stabilized particulate lithium metal according to  claim 16 , wherein it has a sodium content <50 ppm. 
     
     
         23 . The stabilized particulate lithium metal according to  claim 17 , wherein it has a sodium content <50 ppm. 
     
     
         24 . The stabilized particulate lithium metal according to  claim 16 , wherein at least one element selected from B, AI, Ga, In, Tl, Si, Ge, Sn, Pb is present as the element capable of being alloyed element. 
     
     
         25 . The stabilized particulate lithium metal according to  claim 17 , wherein at least one element selected from B, Al, Ga, In, TI, Si, Ge, Sn, Pb is present as the element capable of being alloyed element. 
     
     
         26 . The stabilized particulate lithium metal according to  claim 16 , wherein it has an average particle size of max. 5000 μm. 
     
     
         27 . The stabilized particulate lithium metal according to  claim 17 , wherein it has an average particle size of max. 5000 μm. 
     
     
         28 . The stabilized particulate lithium metal according to  claim 16 , wherein it does not exhibit any exothermic effect. 
     
     
         29 . The stabilized particulate lithium metal according to  claim 28 , wherein the exothermic effect is no runaway phenomenon in contact with N-methyl-2-pyrrolidone with a water content of approx. 200 ppm for at least 15 hours at 50° C. 
     
     
         30 . A method for producing a stabilized lithium metal  17 , wherein lithium metal is brought in contact with film-forming precursors containing elements of main groups 3 and 4 of the periodic table of elements at a temperature in the range between 50 and 300° C. in an inert organic solvent. 
     
     
         31 . The method according to  claim 29 , wherein the passivating agent is of formula I or formula II:
   [AR 1 R 2 R 3 R 4 ]Li x   (I)
     or R 1 R 2 R 3 A-O-AR 4 R 5 R 6   (II)
   
       wherein
 R 1 R 2 R 3 R 4 R 5 R 6 =independently of one another alkyl (C 1 -C 12 ), aryl, alkoxy, aryloxy or halogen or two radicals R together denote a 1,2-diolate, a 1,2- or 1,3-dicarboxylate or a 2-hydroxycarboxylate dianion; 
 radicals R 1  to R 6  may contain additional functional groups, 
 A is selected from the group consisting of boron, aluminum, gallium, indium, thallium, silicon, germanium, tin and lead; 
 wherein x is 0 or 1 when A is boron, aluminum, gallium, indium, thallium; and 
 wherein x is 0 when A is silicon, germanium, tin or lead; 
 and wherein when x is 0 and A is boron, aluminum, gallium, indium or thallium, then R 4  is omitted, 
 
       or polymers containing one or more of the elements B, Al, Ga, In, Tl, Si, Ge, Sn, Pb. 
     
     
         32 . The method according to  claim 29 , wherein the molar ratio between Li metal and the passivating agent is 100:0.01 to 100:5. 
     
     
         33 . The method according to any  claim 29 , wherein inert organic solvent is selected from the group consisting of hexane, heptane, octane, decane, undecane, dodecane, toluene, ethylbenzene and cumene. 
     
     
         34 . The method according to  claim 29 , wherein an additional coating is performed at temperature <180.5° C. 
     
     
         35 . The method according to  claim 29 , wherein nonspherical lithium metal impressions, for example, lithium foil are passivated at temperatures below 180.5° C. with film-forming precursors according to the invention. 
     
     
         36 . A method comprising prelithiating an electrochemically active material with the stabilized particulate lithium metal according to  claim 16 . 
     
     
         37 . An electrode comprising the stabilized particulate lithium metal according to  claim 16 .