4. Conclusion
The discovery of new BPEs based on CA doped with various concentrations (0–60 wt%) of NH4NO3 have been prepared by solution casting technique. A superior ionic conductivity 1.024 × 10−3 has been achieved for the sample 50CA:50NH4NO3 at room temperature. The enhancement in mobility of proton ions and flexible structure are responsible for the improvement of ionic conductivity. The rate of increase of ionic conductivity with temperature exhibits Arrhenius behavior where the samples conductivity exclusively affected by temperature and composition of NH4NO3. The thermal profile shows the marked increase in Tg, which is an indication of interaction between H+ ion and carboxyl group of BPEs. Structural and complexation of the BPEs has been ascertained by XRD and FTIR analyses. XRD analysis displays a structural disorderliness of reduced intensity, which concludes the BPE are predominantly amorphous in nature. FTIR and Gaussian results provide an insight into possible co-ordination of interactions between CA and NH4NO3. The charge transport in these BPEs has been examined using Wagner’s polarization technique and the dominant conducting species are found to be ions rather than electrons. Thus, the optimized BPE 50CA:50NH4NO3 with high ionic conductivity has been applied for primary proton battery and PEM fuel cell application, in which their main parameters and output voltage were reported. In spite of extensive research efforts worldwide, power performance of our new polymer membrane 50CA:50NH4NO3 has to be optimized and it could satisfactorily replace Nafion. All these result suggest and believe that BPE CA:NH4NO3 may offer attractive membrane for electrochemical devices such as proton batteries and fuel cell because of its high performance, eco-friendly, economically cheap and naturally abundant.
