In April 2014 this comment was made below the question What propulsion methods does the ISS use for station-keeping?:
In November they said in three years, so perhaps late 2016. Since such claims from a company seeking investment funds are always optimistic, more likely 2017 or later. – Mark Adler Apr 13 '14 at 13:05
Is there a chance the ISS will make a big step in the "all electric" direction in 2017? Is there sufficient electric power? Will the new lithium ion batteries help in any way? See also The ISS just got its first battery refresh in 18 years.