Method for drying organic liquid electrolytes

Abstract

A method is described for removing water and other protic impurities from an organic liquid electrolyte, wherein the organic liquid electrolyte is brought into contact with one or more insoluble alkali metal hydride(s) and the insoluble reaction by-products formed thereby are separated off.

1 . Method of removing water and other protic impurities from an organic liquid electrolyte, characterised in that the organic liquid electrolyte is brought into contact with one or more insoluble alkali metal hydride(s) and the insoluble reaction by-products formed thereby are separated off.  
     
     
         2 . Method according to  claim 1 , characterised in that LiH and/or NaH is used as the alkali metal hydride.  
     
     
         3 . Method according to  claim 2 , characterised in that LiH alone is used as the alkali metal hydride.  
     
     
         4 . Method according to any one of  claims 1  to  3 , characterised in that the content of protic compounds in the liquid electrolyte to be dried is <0.6 mmol/g.  
     
     
         5 . Method according to any one of  claims 1  to  4 , characterised in that the temperature is from −20 to 150° C.  
     
     
         6 . Method according to  claim 5 , characterised in that the temperature is from 0 to 90° C.  
     
     
         7 . Method according to any one of  claims 1  to  6 , characterized in that the amount of metal hydride corresponds at least to the stoichiometric amount of protic impurities.  
     
     
         8 . Method according to  claim 7 , characterised in that the amount of metal hydride corresponds to from 2 to 100 times the stoichiometric amount of protic impurities.  
     
     
         9 . Method according to any one of  claims 1  to  8 , characterised in that the metal hydride is activated by milling under an inert gas atmosphere.  
     
     
         10 . Method according to any one of  claims 1  to  9 , characterized in that the liquid electrolyte is stirred with the metal hydride.  
     
     
         11 . Method according to any one of  claims 1  to  9 , characterised in that the liquid electrolyte passes over a fixed bed containing the metal hydride.  
     
     
         12 . Method according to any one of  claims 1  to  11 , characterised in that the insoluble reaction by-products are separated off by filtration or centrifugation.  
     
     
         13 . Use of the organic liquid electrolyte dried according to any one of  claims 1  to  12  for electrolytic cells or supercapacitors.  
     
     
         14 . Use of the organic liquid electrolyte dried according to any one of  claims 1  to  12  for lithium batteries.