Complex sentence: In 1991 he described the transition from "Supercapacitor" to "Battery" behavior in electrochemical energy storage and in 1999 he coined the term supercapacitor as explanation for increased capacitance by surface redox reactions with faradaic charge transfer between electrodes and ions.
Split into simpler sentences: In 1991 he described the difference between "Supercapacitor" and "Battery" behavior in electrochemical energy storage. In 1999 he coined the term supercapacitor to explain the increased capacitance by surface redox reactions with faradaic charge transfer between electrodes and ions.