Coating and lithiation of inorganic oxidants by reaction with lithiated reductants

Abstract

A method for producing conductive carbon coated particles of an at least partially lithiated electroactive core material comprises the step of premixing an oxidant electroactive material with a metallated reductant followed by chemically reacting the oxidant electroactive material with the metallated reductant, said reductant being a coating precursor, said metal being at least one alkaline and/or at least one alkaline earth metal, and said chemically reacting being performed under conditions allowing reduction and metallation of the electroactive material via insertion/intercalation of the alkaline metal cation(s) and/or the alkaline earth metal cation(s) and coating formation via a polymerisation reaction like polyanionic or radicalic polymerisation of the reductant.

1 - 11 . (canceled) 
     
     
         12 . A coated at least partially metallated particulate electroactive material that is crystalline or amorphous, obtained by a process comprising:
 premixing an oxidant electroactive material with a metallated reductant, followed by chemically reacting the oxidant electroactive material with the metallated reductant, wherein:   the metallated reductant is a coating precursor comprising an alkali metal, an alkaline earth metal, or both, and   the chemically reacting is performed under a condition allowing reduction and metallation of the oxidant electroactive material via insertion or intercalation of the alkali metal and/or the alkaline earth metal and coating of the metallated electroactive material with a coating formed from the metallated reductant.   
     
     
         13 . An electrode comprising:
 the coated at least partially metallated particulate electroactive material of  claim 12 ,   an optionally electronically conducting binder, optionally in particulate form, and   optionally a conductive additive.   
     
     
         14 . A method for producing an electrode comprising the coated at least partially lithiated particulate electroactive material of  claim 12 , the method comprising mixing the coated particulate material with an optionally electronically conducting binder, optionally in particulate form and optionally in the presence of a conductive additive in an aprotic solvent followed by drying. 
     
     
         15 . A battery comprising;
 the electrode of  claim 13  as cathode,   an anode, and   an electrolyte.   
     
     
         16 . The coated at least partially metallated particulate electroactive material of  claim 12 , wherein the condition comprises applying energy in at least one form selected from the group consisting of heat energy, tribological energy, ultrasonic energy, and microwave energy. 
     
     
         17 . The coated at least partially metallated particulate electroactive material of  claim 12 , wherein the metallated reductant comprises an alkali metal comprising lithium and optionally sodium and/or potassium. 
     
     
         18 . The coated at least partially metallated particulate electroactive material of  claim 12 , wherein the reductant of the metallated reductant is oxygen free. 
     
     
         19 . The coated at least partially metallated particulate electroactive material of  claim 12 , wherein the coating formed from the metallated reductant is selected from the group consisting of:
 carbon formed from Li 2 C 2 ;   boron nitride formed from Li 3 BN 2 ;   carbon nitride formed from Li 2 CN 2 ;   carbon boride formed from Li 4 BCB;   carbon boron nitride formed from a lithium pyrazine precursor;   polymeric sulfur nitride formed from Li 9 NS 3 ; and   polyacetylene formed from LiHC 2 .   
     
     
         20 . The coated at least partially metallated particulate electroactive material of  claim 12 , wherein the oxidant of the oxidant electroactive material is selected from the group consisting of a transition metal oxide, a hydrated transition metal oxide, a transition metal oxynitride, a transition metal phosphate, a transition metal oxide glass, S, Se, and Si. 
     
     
         21 . The coated at least partially metallated particulate electroactive material of  claim 20 , wherein the oxidant of the oxidant electroactive material is in the form of microparticles or nanoparticles having an average particle size below 10 μm, and wherein the metallated reductant is in the form of microparticles with an average particle size of less than 10 μm. 
     
     
         22 . The coated at least partially metallated particulate electroactive material of  claim 12 , wherein the coating has an average thickness of 0.5 nm to 30 nm. 
     
     
         23 . The coated at least partially metallated particulate electroactive material of  claim 12 , wherein the condition allowing reduction and metallation of the oxidant electroactive material and coating deposition comprises applying tribological energy by ball milling at a rotation speed of 200 to 1500 rpm for 15 to 45 minutes, wherein a ratio between the weight of the balls and the weight of the sample is in the range from 6:1 to 4:1. 
     
     
         24 . The coated at least partially metallated particulate electroactive material of  claim 12 , wherein the condition allowing reduction and metallation of the oxidant electroactive material and coating deposition comprises a heat treatment with a heating profile providing a slow heating rate of between 50 to 70 K/h for about at least the last hour before reaching the reaction temperature. 
     
     
         25 . The coated at least partially metallated particulate electroactive material of  claim 24 , wherein the heating profile comprises a fast heating rate of 180 K/h until about 60 K below the reaction temperature, followed by a slow heating rate of about 60 K/h.