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Fuel cells are promising devices for the direct conversion of chemical energy into electrical energy, with potential applications in many fields. Still, the commercialisation of the hydrogen fuel cells most frequently developed today has been hampered by the high cost of some components, such as platinum-based catalysts. Alkaline fuel cells (AAEMFCs) are being developed as a more economically viable alternative, using an anion exchange membrane (AEM) as a solid polyelectrolyte between the electrodes. Current commercially available AEMs, based on synthetic polymers, are expensive, and their preparation is usually complex and environmentally unfriendly, indicating the need to develop new highly efficient, easy-to-prepare, environmentally friendly, and economically acceptable AEMs. This doctoral dissertation focuses on the development of new chitosan-based biopolymer AEMs (CS) with organic inclusions of nanofibrillated cellulose (CNF), functionalized CNF (CNF (D), and CNF (P)), and inorganic inclusions of N-doped graphene oxide (N-GO). CNF functionalization was performed using organosilane reagent DMAOP and polycation reagent PDDA, with the aim of introducing a positive charge, contributed by quaternary ammonium groups. The obtained products CNF (D) and CNF (P), useful as inclusions, were analysed by ATR-FTIR, 13C NMR and 29Si spectroscopy, FE-SEM, TGA, DSC analysis, zeta potential measurements, and polyelectrolyte titration, and were incorporated into CS membranes. To select the most promising AEMs for inclusion in an AAEMFC, we used an experimental design and prepared a series of CS membranes with specified inclusions, which were characterised according to ionic conductivity, ion exchange capacity, fuel permeability, alkali uptake, and swelling, and were analysed through ATR-FTIR, SEM, TGA, XRD and mechanical properties determination. A cell test of the most promising AEMs in an AAEMFC showcased that the prepared CS membranes with inclusions of N-GO (Pmax = 149 mW cm-2), CNF (Pmax = 62 mW cm-2), CNF(P) (Pmax = 62 mW cm-2) and combined CNF and CNF(P) (Pmax = 65 mW cm-2) exhibited higher Pmax than the commercial Fumatech membrane (Pmax = 35 mW cm-2), thus identifying their potential for use in AAEMFCs.