The use of activated carbon from biomass as an electrode for lithium-ion batteries is promising because of the low cost, natural abundance, and environmentally friendly. Chicken feather is a biomass that has the potential to be a source of activated carbon, because it contains keratin. The activation process affects the quality of activated carbon, thereby increasing battery performance. In this study, chicken feather waste was chemically activated using KOH and combined with physical activation at temperature variations of 750, 850 and 950 °C. The activation process significantly influenced electrochemical properties because of the difference in their microstructure. The activated carbon pyrolyzed at 850 °C (CFCA-850) shows the highest discharge capacity of 285.78 mAhg⁻¹, good cycling stability and rate performance due to its higher interlayer spacing and large surface area. Furthermore, electronic conductivity and ion increase, thus improve battery performance.