Characteristics of Anodes for Li-ion Batteries from Coconut Shell Activated Carbon as Environmentally-Friendly Technology

Abstract

Activated carbon is a promising material for fabricating anodes in lithium-ion batteries due to its excellent electrochemical properties. One widely available and sustainable source for producing activated carbon is coconut shell. Several key factors influence the manufacturing process of anode materials, including the mass ratio of activated carbon to lithium hydroxide (LiOH), the binder mass percentage, and the sintering temperature. This study investigates the impact of variations in binder mass ratio (w/w) and sintering temperature on the electrical conductivity of the resulting anode. The fabrication process begins by mixing activated carbon derived from coconut shell with LiOH in a 1:2 mass ratio. Carboxymethyl Cellulose (CMC) is used as a binder in varying mass percentages of 1%, 2%, 3%, 4%, and 5%. The prepared mixture is dried at 300℃ for 60 minutes before being molded into tablet form. These anode tablets are then subjected to sintering at different temperatures of 350℃, 400℃, 450℃, 500℃, and 550℃. The electrical conductivity of the fabricated anodes ranged from 3.85×10⁻¹ to 1.63×10⁻¹ S/cm. SEM analysis revealed that the anode structure consists of small, irregularly shaped, and porous particles. The highest conductivity, 3.85×10⁻¹ S/cm, was observed at 450℃ with a 1% binder ratio. However, due to brittleness, the optimal condition was determined to be 450℃ with a 2% CMC binder ratio, achieving a conductivity of 3.74×10⁻¹ S/cm while maintaining structural stability.