Techno-Economical Feasibility of Biocellulose Membrane along with Polyethylene Film as a Separator for Lead-Acid Batteries

In this present investigation, we applied an eco-friendly bacterial cellulose (BC) membrane along with a polyethylene (PE) separator as a separator for lead-acid battery systems. The key factor of the research is to lower the cost of the lead-acid battery by introducing the BC membrane along with a thin PE separator. The specific surface areas of the BC membrane and the PE separator were 46.72 and 35.89 m2 g–1, respectively, with high porosity, which can enhance the electrolyte uptake and movement. The identified pore sizes of the BC membrane and the PE separator are 13.67 and 56.18 nm, respectively. The closely arranged microfibrils in the BC membrane with the smaller pore size can uptake a high amount of electrolyte, and it can hold it for a long period with the hydrogen interactions. In addition, the BC membrane and the PE separator exhibited higher thermal stabilities. The water uptake property of the BC membrane is 130% at 30 °C, which results in considerable electrolyte uptake. The ion exchange capacity of AGM, PE separator, and BC membrane are ∼0.0, ∼ 0.0, and 0.127 meq/g, respectively. The higher IEC is attributed to the presence of hydrophilic functional groups in the BC membrane, which increase the ion transportation in the membrane. The ion conductivity of the BC membrane is considerably higher than those of the AGM and PE separator. The charge and discharge performances of the AGM and BC-PE battery systems were analyzed using lead-acid battery cells. The exhibited discharge performances of both battery systems were considerably similar at 0.1 and 0.2 A discharge current. The final discharge capacities of the AGM battery and the BC-PE battery were 0.96 and 0.94 Ah, respectively, at 0.1 A under identical conditions. A considerable cyclic stability was observed in the BC-PE battery system during long-term operation. From our experimental analysis results, a cost-effective hybrid combination of a BC membrane along with a PE separator can be considered as an efficient separator for lead-acid battery systems.