The Collaborative International Dictionary of English v.0.48:

Electro-chemistry \E*lec`tro-chem"is*try\, n.
   That branch of science which treats of the relation of
   electricity to chemical changes.
   [1913 Webster]

WordNet (r) 3.0 (2006):

electrochemistry
    n 1: branch of chemistry that deals with the chemical action of
         electricity and the production of electricity by chemical
         reactions