4.9 Wooden Electrodes for Supercapabatteries
Nowadays, it draws more and more interest to evaluate the relevance of green and sustainable materials for electricity storage. Herein, we report a sustainable form of carbon material – charcoal – directly used as electrode for supercapacitors, and a wood aerogel supercapacitor.
These charcoal materials were prepared by burning wood in a kiln under a temperature of 500-600 oC, in absence of active agents. Thereafter the charcoal was fabricated into electrodes with help of mechanochemistry and protein nanofibrils. The characterization results from X-ray diffraction (XRD), raman spectroscopy, SEM and TEM suggest limited graphitic nature of carbon and different level of carbonization of the charcoal. Moreover, the conductive charcoal material displays a surface area of 332 m2g-1 and micropore volume of 0.1 cm3g-1, and gives a discharge capacity of 250 Fg-1. From the cyclic voltammetry, a pair of redox peaks was observed at 0.37 V and 0.1 V, versus Ag/AgCl, which was proved to originate from quinone structures. These quinone structures were further demonstrated to be in lignin, based on the elemental analysis (CHNS) and fourier transform infrared (FTIR) spectroscopy.
Moreover, another sustainable material – wood aerogel – was also used for electricity storage. The high porosity and large surface area render it a promising electrode material for supercapacitors.
In conclusion, our study is significant in the development of sustainable, low-cost and scalable production of wooden electrodes for supercapabatteries. It also argues the sustainability relevance of wood materials preparation in energy storage application.