Composite electrolytes with binders

Abstract

Functionalized polymeric binders for electrolyte and electrode compositions include a polymer having a polymer backbone and functional groups. In some embodiments, a polymer includes a non-polar polymer backbone and a functional group that is 0.1 to 5 wt % of the polymer. In some embodiments, a polymer includes a polar backbone and a functional group that is 0.1 to 50% weight percent of the polymer. Also described are composites for electrolyte separators and electrodes that include argyrodite ion conductors and polar polymers.

1 . A composite comprising:
 inorganic ionically conductive particles of an alkali metal argyrodite wherein the alkali metal argyrodite is a structural analog to the mineral Argyrodite (Ag 8 GeS 6 ) with alkali metal cations occupying Ag +  sites of the mineral and PS 4   3−  occupying GeS 4   4−  sites of the mineral;   and   an organic phase comprising a polar polymer binder.   
     
     
         2 . The composite of  claim 1 , wherein composite has an ionic conductivity of at least 0.2 mS·cm −1  at 25° C. 
     
     
         3 . The composite of  claim 1 , wherein the composite has an ionic conductivity of at least 0.25 mS·cm −1  at 25° C. 
     
     
         4 . The composite of  claim 1 , wherein the composite has an ionic conductivity of at least 0.3 mS·cm −1  at 25° C. 
     
     
         5 . The composite of  claim 1 , wherein the inorganic ionically conductive argyrodite-containing particles are no more than 90 wt % of the composite. 
     
     
         6 . The composite of  claim 1 , wherein the inorganic ionically conductive particles are no more than 85 wt % of the composite. 
     
     
         7 . The composite of  claim 1 , wherein the inorganic ionically conductive particles are no more than 80 wt % of the composite. 
     
     
         8 . The composite of  claim 1 , wherein the composite has an ionic conductivity of at least 0.5 mS·cm −1  at 25° C. 
     
     
         9 . The composite of  claim 1 , wherein the composite has an elongation at break of at least 10%. 
     
     
         10 . (canceled) 
     
     
         11 . The composite of  claim 1 , wherein the composite has an elongation at break of at least 20%. 
     
     
         12 . (canceled) 
     
     
         13 . The composite of  claim 1 , wherein the polymer binder is poly(acrylonitrile-co-styrene-co-butadiene) (ABS), poly(ethylene-co-vinylacetate), poly(styrene-co-acrylonitrile) (SAN), poly(styrene-co-maleic anhydride), poly(meth)acrylates, poly(alkyene glycols), poly(butadiene-co-acrylate), poly(butadiene-co-acrylic acid-co-acrylonitrile), Poly(ethylene-co-acrylates), polyethers, polyesters of dialkyl phthalates, or poly(vinyl chloride) (PVC). 
     
     
         14 . The composite of  claim 1 , wherein the polymer binder comprises a first polymer modified with functional groups, the functional groups being between 0.1 and 5 wt. % of the first polymer. 
     
     
         15 . The composite of  claim 1 , wherein the polymer binder comprises a first polymer modified with functional groups, the functional groups being between 0.1 and 50 wt. % of the first polymer. 
     
     
         16 . The composite of  claim 15 , wherein the first polymer unmodified is insoluble in solvents having polarity indexes below 3.5. 
     
     
         17 . The composite of  claim 16  wherein the first polymer modified is soluble in the solvents having polarity indexes below 3.5. 
     
     
         18 . The composite of  claim 15 , wherein the first polymer unmodified is insoluble in solvents having polarity indexes below 3.5 and the first polymer modified is soluble in the solvent having polarity indexed below 4.5. 
     
     
         19 . (canceled) 
     
     
         21 . The composite of  claim 1 , wherein the polar polymer binder comprises a first polymer modified with functional groups, the functional groups being between 0.1 and 5 wt. % of the first polymer. 
     
     
         22 . The composite of  claim 21 , wherein the functional groups are selected from: 
       
         
           
           
               
               
           
         
       
       where R, R 1 , R 2 , R 3  are independently for each occurrence selected from —CN, —H, —OH, Me + , —OMe + , optionally substituted aryl, optionally substituted alkoxy, optionally substituted alkyl, optionally substituted alkenyl, and optionally substituted alkynyl; and X is independently for each occurrence selected from —F, —Cl, —Br, and —I; and n is an integer from 1 to 10.