Carbonaceous composite materials with snowball-like morphology

Abstract

The present disclosure relates to a novel process for preparing isotropic carbonaceous composite particles with favorable crystallographic, morphological & mechanical properties, wherein relatively fine carbonaceous primary particles are coated with a carbonaceous binder precursor material, agglomerated and finally heat-treated at temperatures between about 1850 and 3500° C. to convert the binder precursor material to non-graphitic or graphitic carbon, thereby resulting in stable highly isotropic carbonaceous composite materials wherein the primary particles of the aggregate are held together by the carbonized/graphitized binder. The present disclosure also relates to the isotropic carbonaceous composite particles obtainable by the process described herein. The disclosure further relates to uses of said isotropic carbonaceous composite material in various applications, including as active material in negative electrodes in lithium-ion batteries, and in secondary products containing said isotropic carbonaceous composite material.

1 - 73 . (canceled) 
     
     
         74 . A process for preparing carbonaceous composite particles, comprising:
 (a) attaching a carbonaceous binder precursor material to the surface of carbonaceous particles in the presence of a solvent, thereby forming a coating of the carbonaceous particles by the carbonaceous binder precursor material;   (b) drying the material obtained from step (a); and   (c) during or after step (a) or step (b), causing agglomeration of the coated primary carbonaceous particles.   
     
     
         75 . The process according to  claim 74 , wherein the carbonaceous composite particles are comprised of a multiplicity of aggregated primary particles, wherein said primary particles are held together by a carbonaceous binder material attached to the surface of the primary particles. 
     
     
         76 . The process of  claim 74 , wherein the carbonaceous binder precursor material is not or does not include ammonium lignosulfonate, and is not or does not include coal tar, tar pitch, and petroleum pitch. 
     
     
         77 . The process according to  claim 74 , wherein the carbonaceous particles employed in step (a) are selected from the group consisting of natural graphite, synthetic graphite, graphene, graphene nanoplatelets, graphene or carbon fibers, fullerenes, nanographite, hard carbon, soft carbon, petroleum- or coal-based coke, graphitized fine coke, char, carbon black, carbon nanotubes (CNT), including single-walled nanotubes (SWNT), multiwalled nanotubes (MWNT), carbon nanofibers (CNF) or mixtures thereof; or from non-carbonaceous materials such as silicon, silicon oxide, tin, tin oxide or tin dioxide, aluminum, bismuth, lithium titanate, or mixtures of any of the foregoing. 
     
     
         78 . The process according to  claim 74 , wherein the carbonaceous particles employed in step (a) are non-graphitic particles. 
     
     
         79 . The process according to  claim 74 , wherein the particle size distribution of said carbonaceous particles employed in step (a) is characterized by at least one of:
 i) a D90 of <35 μm,   ii) a D50 of <about 20 μm,   iii) a D90 of <25 μm, and   iv) a D50 of <about 15 μm;   (v) a sphericity Q3 [S=0.8] of equal or more than about 22%; and   (vi) a Scott density of >0.2 g/cm3.   
     
     
         80 . The process according to  claim 74 , wherein the carbonaceous binder precursor material to be used in step (a) is selected from the group consisting of polymers such as a lignin-based polymer, a polystyrene or derivative thereof, styrene-butadiene, melted phenol resin, polyvinylalcohol, polyfurfuryl alcohol, furfural, polyurethane, polystyrene-acrylate, polyacrylate, polymethylmethacrylate, polymethacrylonitrile, polyoxymethylene, poly(methyl atropate), polyisobutene, polyethyleneoxide, polypropyleneoxide, polyethylene, polypropylene, polymethylacrylate, polybutadiene, polyisoprene, polyacrylonitrile, polyaniline, tannic acid, starch, gum arabic, maltodextrin, formaldehyde phenol resins, formaldehyde tetrahydrofuran resins, nitrile butyl rubber, sucrose, glucose, or other sugars, polyethyl ether ketone, polyphenylene sulfide, polyvinyl chloride, carboxymethylcellulose, methyl cellulose, gelatins, polyvinyl pyrrolidone, polylactic acid, latexes thereof, a hydrocarbon gas such as methane, ethane, ethylene, propane, propene, acetylene, butane, benzene, toluene, xylene, or an alcohol such as ethanol, propanol, isopropanol, mixed with an inert carrier gas, and combinations thereof. 
     
     
         81 . The process according to  claim 74 , wherein the attachment of the carbonaceous binder precursor material to the surface of the carbonaceous particles is achieved by a method selected from the group consisting of:
 i) mixing to form a dispersion, optionally in the presence of a solvent and subsequent drying;   ii) melting the carbonaceous binder precursor onto the primary particles;   (iii) pyrolysis;   (iv) pitch-coating; and   (v) evaporation.   
     
     
         82 . The process according to  claim 74 , wherein the agglomeration of step (c) is achieved by spray-drying a dispersion comprising the primary carbonaceous particles and the carbonaceous binder precursor material. 
     
     
         83 . The process according to  claim 74 , wherein the drying of step (b) and the agglomeration of step (c) is achieved by at least one of:
 spray-drying a dispersion comprising the primary carbonaceous particles and the carbonaceous binder precursor material obtained from step (a) in a spray dryer;   vacuum-drying a dispersion comprising the primary carbonaceous particles and the carbonaceous binder precursor material obtained from step (a) in a heatable vacuum reactor;   freeze-drying a dispersion comprising the primary carbonaceous particles and the carbonaceous binder precursor material obtained from step (a) in a stirred freeze dryer;   flash-drying a dispersion comprising the primary carbonaceous particles and the carbonaceous binder precursor material obtained from step (a) in a flash dryer;   drying a fluidized dispersion comprising the primary carbonaceous particles and the carbonaceous binder precursor material obtained from step (a) in a fluidized bed dryer, optionally in combination with a spray system;   disc drying a dispersion comprising the primary carbonaceous particles and the carbonaceous binder precursor material obtained from step (a) in a disc dryer; and   paddle drying a dispersion comprising the primary carbonaceous particles and the carbonaceous binder precursor material obtained from step (a) in a paddle dryer.   
     
     
         84 . The process according to  claim 74  further comprising:
 (d) carbonizing said carbonaceous binder precursor material attached to the surface of the agglomerated particles from step (c) by a thermal decomposition under vacuum or an inert atmosphereat temperatures ranging from 400° C. to 3500° C. 
 
     
     
         85 . The process according to  claim 84 , wherein prior to the carbonizing of step (d), the coated agglomerated carbonaceous particles are subjected to a pre-treatment performed under vacuum, air, nitrogen, argon or CO 2  atmosphere at temperatures of below 1000° C. 
     
     
         86 . The process according to  claim 84 , wherein the particles obtained from step (d) are subjected to an additional heat treatment in a gas atmosphere selected from one of: nitrogen, argon, mixtures of nitrogen with hydrocarbons like acetylene, propane or methane, or with oxidative gases such as air, steam, or CO 2  to adjust the morphology and surface chemistry of the carbonaceous composite particles. 
     
     
         87 . The process according to  claim 84 , wherein the particles obtained from step (d) are subjected to an additional heat treatment performed by contacting the particles with an oxidant either in a gaseous/solid phase process with air, carbon dioxide, water vapor, oxygen, ozone, or any combination thereof, or, alternatively, in a liquid/solid phase process with aqueous hydrogen peroxide or other oxidants present in said liquid phase. 
     
     
         88 . A process for preparing carbonaceous composite particles, comprising:
 (a) attaching a carbonaceous binder precursor material to the surface of carbonaceous particles thereby forming a coating of the carbonaceous particles by the carbonaceous binder precursor material; and   (b) during or after step (a), causing agglomeration of the coated primary carbonaceous particles.   
     
     
         89 . The process according to  claim 88 , wherein the particle size distribution of said carbonaceous particles employed in step (a) is characterized by at least one of:
 i) a D90 of <35 μm,   ii) a D50 of <about 20 μm,   iii) a D90 of <25 μm, and   iv) a D50 of <about 15 μm;   (v) a sphericity Q3 [S=0.8] of equal or more than about 22%; and   (vi) a Scott density of >0.2 g/cm3.   
     
     
         90 . The process according to  claim 88 , wherein the agglomeration of step (b) is achieved by spray-drying a dispersion comprising the primary carbonaceous particles and the carbonaceous binder precursor material. 
     
     
         91 . The process according to  claim 88  further comprising: (c) carbonizing said carbonaceous binder precursor material attached to the surface of the agglomerated particles from step (b) by a thermal decomposition under vacuum or an inert atmosphere at temperatures ranging from 400° C. to 3500° C. 
     
     
         92 . The process according to  claim 91 , wherein prior to the carbonizing of step (c), the coated agglomerated carbonaceous particles are subjected to a pre-treatment performed under vacuum, air, nitrogen, argon or CO 2  atmosphere at temperatures of below 1000° C. 
     
     
         93 . The process according to  claim 91 , wherein the particles obtained from step (c) are subjected to an additional heat treatment by one of:
 i) heating the particles in a gas atmosphere selected from one of: nitrogen, argon, mixtures of nitrogen with hydrocarbons like acetylene, propane or methane, or with oxidative gases such as air, steam, or CO 2  to adjust the morphology and surface chemistry of the carbonaceous composite particles;   ii) heating the particles in the presence of an oxidant in a gaseous/solid phase process with air, carbon dioxide, water vapor, oxygen, ozone, or any combination thereof; and   iii) heating the particles in the presence of an oxidant in a liquid/solid phase process with aqueous hydrogen peroxide or other oxidants present in said liquid phase.