Biopolymers materials have garnered much attention in energy storage technology due to their renewable properties and inert to the environment. Cellulose based biopolymers derivative such as carboxymethyl cellulose (CMC) are an attractive material since it is easily available and has the potential to be used as solid biopolymer electrolyte (SBE) material. This research aim is to develop a high conducting CMC SBE as potential electrolyte for proton battery. Two CMC biopolymer electrolytes were developed where the first system is by doping the CMC biopolymer with various ammonium formate (AFT) composition (CMC–AFT). The second SBE system is by adding propylene carbonate (PC) plasticizer (CMC–AFT–PC). Both SBEs systems were prepared through solution casting technique where the obtained SBEs are physically stable. Both SBE was investigated for their respective electrical, structural and ionic transport properties. The highest ionic conductivity of the CMC–AFT SBE is 1.47 ± 0.15 (× 10-4) Scm-1 when added with 50wt.% of AFT. It was then improved to 2.40 ± 0.08 (× 10-3) Scm-1 with addition of 6 wt.% of PC plasticizer for the CMC–AFT–PC SBE. At elevated temperature, the ionic conductivity behavior of both SBEs appears to follow Arrhenius relations where the activation energy of each SBEs is the lowest for the highest conducting SBE film. The dielectric properties follow non-Debye behavior. The chemical structure of both SBEs shows that the amorphous phase affected the ionic conductivity improvement significantly. The complexation between CMC and proton (H+) from AFT salt was also seen from the theoretical analysis via Gaussian analysis software and the experimental infrared data. The ionic conductivity improvement in CMC–AFT SBE was understood to depend on the number of mobile ions (η), ionic mobility (μ) and diffusion coefficient (D) while for the latter two parameters is described for CMC–AFT–PC SBE as the contributing factors. Ion is the main contributing charge in both SBEs due to high the transference number (tion) obtained. The mechanism in which the ions transfer within the SBE bulk structure can be explained from the non-overlap small polaron tunnelling for the CMC–AFT SBE and the quantum mechanical tunneling for the CMC–AFT–PC SBE. Primary proton battery was fabricated with the highest conducting sample from CMC–AFT SBE (50wt.%) and CMC–AFT–PC SBE (6wt.%) through Zn|| SBE || MnO4 configuration. The open circuit potential for both batteries are > 1.40 V and the battery with CMC–AFT–PC SBE was selected to be fabricated into rechargeable battery (Zn|ZnSO4 || SBE || MnO4) since it shows the highest discharge capacity. The battery shows good rechargeability for 20 cycles with efficiency between 50% to 80% depending on the discharge current. This suggests that the CMC–AFT–PC SBE has good potential to be applied in proton battery applications.