Metal fluoride and phosphate nanocomposites as electrode materials

Abstract

The present invention relates to primary and secondary electrochemical energy storage systems. More particularly, the present invention relates to such systems as battery cells, especially battery cells utilizing metal fluorides with the presence of phosphates or fluorophosphates, which use materials that take up and release ions as a means of storing and supplying electrical energy.

What is claimed is: 
     
         1 . A battery cell comprising:
 (a) a positive electrode comprising a nanocomposite; and   (b) a solid electrolyte,   wherein the positive electrode is characterized by a specific capacity of about 100 mAh/g to 600 mAh/g at a voltage of about 2 volts to about 4 volts when measured against a Li/Li+ reference potential,   wherein the nanocomposite comprises a metal fluoride component and a conductive matrix,   wherein the metal fluoride component is characterized by a particle size about 1 nm to about 100 nm,   wherein the metal fluoride component is selected from the group consisting of CuF2, BiF3, CoF3, AgF, MnF3, NiF2, and FeF3, and   wherein the conductive matrix comprises sulfur.   
     
     
         2 . The battery cell according to  claim 1 , wherein the conductive matrix is from about 5% to about 50% weight of the nanocomposite. 
     
     
         3 . The battery cell according to  claim 1 , wherein the nanocomposite is x-ray amorphous. 
     
     
         4 . The battery cell according to  claim 1 , wherein the conductive matrix comprises intercalation compounds. 
     
     
         5 . The battery cell according to  claim 1 , wherein the metal fluoride component is FeF3. 
     
     
         6 . The battery cell according to  claim 1 , wherein the nanocomposite further comprises carbon or oxygen. 
     
     
         7 . The battery cell according to  claim 1 , further comprising a negative electrode, wherein the negative electrode comprises lithium. 
     
     
         8 . The battery cell according to  claim 1 , wherein the positive electrode is rechargeable. 
     
     
         9 . An electrochemical cell comprising:
 (a) a positive electrode comprising a nanocomposite;   (b) a negative electrode comprising lithium; and   (c) a separator disposed between the negative electrode and positive electrode,   wherein the positive electrode is characterized by a specific capacity of about 100 mAh/g to 600 mAh/g at a voltage of about 2 volts to about 4 volts when compared to a Li/Li+ reference potential,   wherein the nanocomposite comprises a metal fluoride component and a conductive matrix,   wherein the metal fluoride component is characterized by a particle size about 1 nm to about 100 nm, and wherein the conductive matrix comprises a sulfur material.   
     
     
         10 . The electrochemical cell according to  claim 9 , wherein the metal fluoride component is FeF3. 
     
     
         11 . The electrochemical cell according to  claim 9 , wherein the separator comprises a solid electrolyte. 
     
     
         12 . The electrochemical cell according to  claim 9 , wherein the positive electrode further comprises sulfur. 
     
     
         13 . An electrochemical cell comprising:
 (a) a positive electrode comprising a nanocomposite;   (b) a negative electrode, the negative electrode comprising lithium; and   (c) a solid electrolyte,   wherein the positive electrode being characterized by a specific capacity of about 100 mAh/g to 600 mAh/g at a voltage of about 2 volts to about 4 volts when compared to a Li/Li+ reference potential,   wherein the nanocomposite comprises an iron fluoride component and a conductive matrix,   wherein the iron fluoride component is characterized by a particle size about 1 nm to about 100 nm, and   wherein the conductive matrix comprises sulfur.   
     
     
         14 . The electrochemical cell according to  claim 13 , wherein the nanocomposite further comprises phosphate. 
     
     
         15 . The electrochemical cell according to  claim 13 , wherein the nanocomposite is characterized by a particle exhibiting an X-ray diffraction (XRD) distribution into at least a first phase and a second phase, wherein the first phase comprises the iron fluoride component in the form of iron fluoride nanocrystallites. 
     
     
         16 . The electrochemical cell according to  claim 15 , wherein the second phase comprises an iron fluorophosphate. 
     
     
         17 . The electrochemical cell according to  claim 13 , wherein the nanocomposite is amorphous.