A high performance direct borohydride fuel cell employing cross-linked chitosan membrane

Abstract

A cross-linked chitosan (CCS) membrane has been prepared by a solution casting method using sulfuric acid as cross-linking agent. The CCS membrane was used as the polymer electrolyte and separator in a direct borohydride fuel cell (DBFC). Ionic conductivity and borohydride crossover rate have been measured for the CCS membrane. The DBFC used in this study employed nickel-based composite as anode catalyst and Nafion® as anode binder. The power performance of the CCS membrane-based DBFC was compared with a similar DBFC employing Nafion® 212 (N212) membrane as electrolyte /separator. The CCS membrane-based DBFC exhibited better power performance as compared to N212 membrane-based DBFC. Encouraged by this result, chitosan chemical hydrogel (CCH) was prepared and used as binder for anode catalysts. A DBFC comprising CCS membrane and CCH as anode binder was studied and found to exhibit even better power performance at all temperatures in this study. A maximum peak power density of 450mWcm−2 was observed at 60̊C for DBFC employing CCS membrane and CCH binder-based anode. The chitosan-based DBFC was operated continuously for 100h and its performance stability was recorded.