Study of cassava starch as coating for zinc in zinc-air fuel cell

Fuel cell is an electrochemical device that convert chemical energy to electrical energy. There a lots types of fuel cell which are polymer electron membrane, solid oxide and zinc-air fuel cell. There are numerous studies on Zn-air fuel cell have been conducted in order to improve the performance of Zn-air fuel cell by modification of the anode. The modification of anodes with some additives will give some effect to the electrochemical of zinc anodes. Therefore, in this study, cassava starch was prepared as conductive biodegradable material on zinc anode in Zn-air fuel cell by using electrochemistry method. Cassava starch had been chosen due to it is a natural polymer that gives friendly environmental material that can be used as biofuel with safe. Moreover, cassava has their own unique characteristic which is, it has own value of natural conductivity. The characterization of cassava starch was studied, this is including physical observation, functional group, morphology observation, conductivity and discharge. Successful formation of cassava on zinc anode had been prepared by using different concentration of cassava starch solution by coding C1, C2, C3 and C4 with 66, 83, 100 and 116 g/L was tested by its conductivity using four-point probe instrument. It had been proven the enhancement of conductivity of anode after the deposition of cassava starch. From conductivity analysis, it was shown the increment 30% of conductivity values from original conductivity of pure zinc (0.079 to 0.097, 0.072, 0.112 and 0.071 Scm-1). Successful formation of CS on Zn anode as the appearance of significant peaks from raw materials (ZnP and CS) was observed in the spectrum of ZnC. The data before and after the experiment still show the peaks of C-H and O-H. Moreover, SEM analysis exhibits the morphology of cassava coated on zinc plate with distinct particle structure was observed, proving the successful formation of cassava layer via electrochemical method. This is due to the existence of cassava starch granules that can be seen in before and after the cassava starch coated anode undergo the discharge in the Zn-air fuel cell. The higher the concentration of CS resulted in the increasing of the voltage. But, in term of the best voltage is C3 and C4 with value of 1.556V. While, the longest time to discharge is C3 with 126 hours. In conclusion, cassava starch can be used as coated on the anode.