Fungal exopolysaccharides as a bio-binder for conductive pigment/reduced graphene oxide/nano‑cobalt composite: an eco-friendly solution for anode rechargeable batteries.

Abstract

The rapid increase in population has driven the demand for fossil fuel energy, contributing to increased carbon emissions that ultimately accelerate global warming and climate change. Battery storage systems have many advantages over conventional energy sources. However, they face limitations such as energy storage, cost, and environmental hazards that come with the use of chemical binders. This study presents a novel application of Talaromyces atroroseus co-produced exopolysaccharides (EPS)-pigment complex for their bio-binding and conductivity properties that can replace chemical binders in the preparation of rechargeable anode batteries. The EPS-pigment complex was combined with reduced graphene oxide (rGO) and nano‑cobalt (CoNPs) to fabricate a hybrid conductive composite on nickel foam mesh. The composite was characterized using Energy Dispersive X-ray (EDX) and X-ray diffraction (XRD), both confirmed the presence of C, O, and Co. Electrochemical characterization of the composite elements showed a cathodic peak at 0.2 V and an anodic peak at 0.414 V. At the same time, the specific capacitance reached 400 F/g for the composite. The results also demonstrated a good rate of charge and discharge. Compared to chemical binders, fungal EPS showed good binding strength and environmental benefits due to its bio-based nature.