Increasing the Specific Energy of Environmental Friendly EDLC and Pseudocapacitors

The electrochemical storage mechanism of the electrical energy in the (electrical double layer capacitor) EDLC and respectively peseudocapacitors was studied, based on the Gouy-Chapman-Stern model. Our target is represented by the biodegradable materials for pseudocapscitors’ synthesis. In order to improve the specific energy accumulated inside the structures, a correlation between structural parameters is necessary, which can be identified by simulation methods. The HFSS program was used and Molecular Dynamics method was applied to describe the ions dynamics inside the structure, where non-faradaic and faradaic charge transfer occur. For a particular set of environmental friendly materials, the capacitance - voltage - current density dependences were pointed out, in order to illustrate the particularities of the phenomena. Materials for electrodes cellulose derivatives or based on the poly(3-hydroxybutyrrate) (PHB) natural polymer, in association with polyvinyl alcohol (PVA) biodegradable electrolyte do not perform very high charge accumulation, in comparison with other types of non-biodegradable materials, but their performance can be improved from about 20 to 26-36 $\mu \mathrm{F} / \mathrm{cm}^{2}$. Ions’ properties were correlated with the electrodes porosity and salt concentration of the electrolyte, for current maximal densities around $25 \mathrm{~A} / \mathrm{g}$. The analysis method can be applied for different type of materials, considering their structural properties and mutual interaction forces.