Composite carbon materials comprising lithium alloying electrochemical modifiers

Abstract

The present application is generally directed to composites comprising a hard carbon material and an electrochemical modifier. The composite materials find utility in any number of electrical devices, for example, in lithium ion batteries. Methods for making the disclosed composite materials are also disclosed.

1 . A composite material having a first cycle insertion of at least 700 mAh/g and a first cycle efficiency in the absence of ex situ prelithiation of greater than 70% when the composite material is incorporated into an electrode of a lithium based energy storage device, wherein the composite material comprises a carbon material and a lithium alloying electrochemical modifier. 
     
     
         2 . The composite material of  claim 1 , wherein the first cycle insertion is at least 1000 mAh/g and the first cycle efficiency in the absence of ex situ prelithiation is greater than 80%. 
     
     
         3 . The composite material of  claim 1 , wherein the first cycle insertion is at least 2400 mAh/g and the first cycle efficiency in the absence of ex situ prelithiation is greater than 80%. 
     
     
         4 . The composite material of  claim 1 , wherein the first cycle efficiency in the absence of ex situ prelithiation is greater than 90%. 
     
     
         5 . The composite material of  claim 1 , further comprising a first cycle extraction of at least 600 mAh/g and a fifth cycle retention of greater than 99%. 
     
     
         6 . The composite material of  claim 5 , wherein the first cycle extraction is at least 1200 mAh/g. 
     
     
         7 . The composite material of  claim 1 , wherein the lithium alloying electrochemical modifier is silicon, tin, germanium, nickel, aluminum, manganese, Al 2 O 3 , titanium, titanium oxide, sulfur, molybdenum, arsenic, gallium, phosphorous, selenium, antimony, bismuth, tellurium or indium or combinations thereof. 
     
     
         8 . The composite material of  claim 7 , wherein the lithium alloying electrochemical modifier is silicon. 
     
     
         9 . The composite material of  claim 1 , wherein the composite material comprises particles having a core-shell structure, wherein the shell comprises substantially the carbon material and the core comprises substantially the electrochemical modifier. 
     
     
         10 . The composite material of  claim 1 , wherein the composite material comprises particles having a core-shell structure wherein the core comprises substantially the carbon material and the shell comprises substantially the electrochemical modifier. 
     
     
         11 . The composite material of  claim 1 , wherein the composite material comprises particles of the carbon material, the carbon material particles encapsulating a plurality of particles of the lithium alloying electrochemical modifier. 
     
     
         12 . The composite material of  claim 1 , wherein the electrochemical modifier comprises nanoparticles. 
     
     
         13 . The composite material of  claim 1 , wherein the electrochemical modifier comprises particles having a particle size ranging from 10 nm to 500 nm. 
     
     
         14 . The composite material of  claim 1 , wherein a ratio of carbon material to electrochemical modifier ranges from 40:1 to 1:99 on a mass basis. 
     
     
         15 . The composite material of  claim 1 , wherein a ratio of carbon material to electrochemical modifier ranges from 19:1 to 1:9 on a mass basis. 
     
     
         16 . The composite material of  claim 1 , wherein the composite material further comprises an efficiency enhancing electrochemical modifier. 
     
     
         17 . The composite material of  claim 16 , wherein the efficiency enhancing electrochemical modifier comprises phosphorus and is present in the composite material at 3-13% by weight as measured by TXRF. 
     
     
         18 . The composite material of  claim 1 , wherein the composite material comprises a total of less than 200 ppm of all elements having atomic numbers ranging from 11 to 92, excluding any intentionally added electrochemical modifier, as measured by TXRF. 
     
     
         19 . The composite material of  claim 1 , wherein the carbon material is a hard carbon material. 
     
     
         20 . A composite material having a first cycle extraction of at least 1900 mAh/g and a first cycle efficiency in the absence of ex situ prelithiation of greater than 80% when the composite material is incorporated into an electrode of a lithium based energy storage device, wherein the composite material comprises silicon and carbon material in a ratio ranging from about 8.5:1 to about 9.5:1 by weight and further comprises 3-13% by weight phosphorus. 
     
     
         21 . A method for preparing a composite material, the composite material comprising a carbon material and a lithium alloying electrochemical modifier, the method comprising:
 A) copolymerizing one or more polymer precursors in the presence of the electrochemical modifier or a compound comprising the electrochemical modifier to obtain a polymer gel; and   B) pyrolyzing the polymer gel to obtain the composite material.   
     
     
         22 - 27 . (canceled) 
     
     
         28 . An electrode comprising the composite material of  claim 1 . 
     
     
         29 . A device comprising the electrode of  claim 28 . 
     
     
         30 . An electrical energy storage device comprising:
 a) at least one anode comprising a composite material according to  claim 1 ;   b) at least one cathode comprising a metal oxide; and   c) an electrolyte comprising lithium ions.   
     
     
         31 - 32 . (canceled)