Biopolymeric separator for capacitors based on porous silicon

Abstract

Biopolymers (BPs) synthesized from corn and chicken waste were studied for the first time as separator in the manufacture of capacitors based on porous silicon (pSi) as metal plate for charge storage. BPs were synthesized using easy, cheap, and sustainable thermochemical processes. The BP films (separators) were characterized by FT-IR, contact angle, surface electrical resistivity and AFM. Devices with the following pSi/BP/pSi configuration were manufactured and characterized by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) to determine their performance as capacitors and study the mechanisms that control the process at the pSi/BP interface. Likewise, the charge/discharge process of the devices was observed on an oscilloscope using a resistor-capacitor (RC) circuit. The results obtained show that the devices have the capacity to store energy in the form of an electric field with the contribution of an electrochemical double layer. Likewise, it was found that greater surface roughness and hydrophobicity in the biopolymeric separators allowed a greater energy storage capacity. The capacitance values of the charge/discharge test were in the order of 215, 296 pF, 45 and 47 nF. The synthesized biopolymers have enormous potential for use as separators in the fabrication of pSi-based capacitors.