Energy release from RuO2//RuO2 supercapacitors under dynamic discharge conditions

In this study, RuO 2 was deposited on tantalum (Ta) substrates by electrochemical plating and then assembled into supercapacitors RuO 2 //RuO 2 . The output energies of the as-obtained RuO 2 //RuO 2 under dynamic conditions were evaluated through a designed measuring circuit. The specific capacitance of electrodes in RuO 2 //RuO 2 was calculated from the experimental results of the discharge current and the potential of positive/negative electrodes during discharge. Also, the energy of the positive/negative electrodes and RuO 2 //RuO 2 with respect to time were derived. The results showed the positive electrode energy was partly transferred into the load R to generate joule heat and the other was used to elevate the potential of the negative electrode during discharge. The decrease in mass of negative electrode ( m − ) $m_{-})$ could extend the potential window, resulting in an enhancement of the energy of RuO 2 //RuO 2 . The energy of RuO 2 //RuO 2 with m − = 103 μ g $m_{-}=103\mu \mathrm{g}$ was elevated by 138.7% compared to that with m − = 200 μ g $m_{-}=200\mu \mathrm{g}$ . Further decrease in mass of the negative electrode would deteriorate the energy of RuO 2 //RuO 2 .