Stabilized lithium metal powder for li-ion application, composition and process

Abstract

The present invention provides a lithium metal powder protected by a substantially continuous layer of a polymer. Such a substantially continuous polymer layer provides improved protection such as compared to typical CO 2 -passivation.

1 . A stabilized lithium metal powder coated with a substantially continuous polymer layer, the polymer selected from the group consisting of polyurethanes, polytetrafluoroethylene, polyvinyl fluoride, polyvinyl chloride, polystyrenes, polyethylenes, polypropylenes, polyformaldehyde, styrene-butadiene-styrene block polymers, ethylene vinyl acetate, ethylene acrylic acid copolymers, polyethylene oxide, polyimides, polythiophenes, poly(para-phenylene), polyaniline, poly(p-phenylenevinylene), silica titania-based copolymers, unsaturated polycarboxylic acids and polysiloxanes. 
     
     
         2 . The stabilized lithium metal powder of  claim 1 , wherein the substantially continuous polymer layer has a thickness of 25 to 200 nm. 
     
     
         3 . The stabilized lithium metal powder of  claim 2  further including an inorganic coating layer. 
     
     
         4 . An anode comprising a host material capable of absorbing or desorbing lithium in an electrochemical system wherein stabilized polymer-coated lithium metal powder of  claim 3  is dispersed in the host material. 
     
     
         5 . The anode of  claim 4 , wherein said host material comprises at least one material selected from the group consisting of carbonaceous materials, silicon, tin, tin oxides, composite tin alloys, transition metal oxides, lithium metal nitrides, graphite, carbon black, and lithium metal oxides. 
     
     
         6 . The anode of  claim 5 , wherein the substantially continuous polymer layer has a thickness of 25 to 200 nm. 
     
     
         7 . A stabilized lithium metal powder coated with a substantially continuous polymer layer having a thickness of 25 to 200 nm. 
     
     
         8 . An anode comprising a host material capable of absorbing or desorbing lithium in an electrochemical system wherein stabilized polymer-coated lithium metal powder of  claim 7  is dispersed in the host material. 
     
     
         9 . A method of forming a lithium dispersion comprising the steps of:
 a) contacting lithium metal with a hydrocarbon oil;   b) heating the lithium metal and hydrocarbon oil to a temperature higher than the melting point of the lithium metal;   c) subjecting the heated lithium metal and hydrocarbon oil to conditions sufficient to disperse the lithium metal in the oil; and   d) contacting the lithium metal with a polymer selected from the group consisting of polyurethanes, polytetrafluoroethylene, polyvinyl fluoride, polyvinyl chloride, polystyrenes, polyethylenes, polypropylenes, (polyformaldehyde), styrene-butadiene-styrene block polymers, ethylene vinyl acetate, ethylene acrylic acid copolymers, polyethylene oxide, polyimides, polythiophenes, poly(para-phenylene), polyaniline, poly(p-phenylenevinylene), silica titania-based copolymers, unsaturated polycarboxylic acids and polysiloxanes at a temperature between the melting point of the lithium metal and the melting point of the polymer to provide a substantially continuous layer of polymer on the lithium metal.