Wolfgang Mack, vice president of business development at Capacitor Sciences, claims that lithium-ion battery technology has reached 87% of the maximum energy storage density per cell sold for commercial purposes, and questions future investments in them. He conducted the research after noticing Tesla’s presentation in which it was written that the capacity of the batteries doubles every ten years, and Elon Musk also stated that the capacity of the batteries increases roughly by about 8 to 9% every year. ). Wolfgang Mack’s research shows that in the period from 1995 to 2005 it really doubled in capacity, but from 2005 to 2015 it was not so says, capacity increased by only 16.6%. Mack argues that solar panel and battery technology is almost at its peak, adding that alternatives including supercapacitors should be considered.