Fabrication and characterization of free-standing α-MnO₂/AC composite electrodes for Na-Ion batteries

The rapid growth of the date palm industry in the United Arab Emirates (UAE) results in significant biomass waste, particularly from leaflets and fronds. This study presents a sustainable approach to repurposing date palm biomass by synthesizing activated carbon (AC) from waste date palm leaves and integrating it with alpha-phase manganese dioxide (α-MnO₂) to fabricate a composite anode material for sodium-ion batteries (NIBs). A flexible, free-standing α-MnO₂/AC composite electrode was fabricated after a two-step hydrothermal method. Scanning electron microscope (SEM) analysis reveals the formation of nanostructured α-MnO₂ embedded within the porous AC matrix. Electrochemical testing reveals that the composite anode exhibits a discharge capacity of 466 mAh/g at a current density of 50 mA/g, with remarkable cycling stability and a consistent coulombic efficiency of 100 %. This work demonstrates a sustainable use of biomass waste for energy storage applications, providing an eco-friendly solution for high-capacity, long-cycle NIBs.