The global demand for efficient, reliable, and environmentally friendly energy storage systems has accelerated the development of advanced materials for lithium-ion capacitors (LICs). Among these, biomass-derived activated carbon is a good choice because it is sustainable and its properties can be adjusted. This study presents an effective and simple strategy of applying freeze pretreatment at -60 °C to biomass-derived activated carbon. Structural, physisorption, and electrochemical analyses reveal that freezing significantly restructures the pore structure of the activated carbon, leading to enhanced microporosity (increasing from 45.3% to 57.1%) and a higher specific surface area (686.73 m2g-1). X-ray diffraction (XRD) investigation shows enhanced graphitic arrangement, while (Brunauer-Emmett-Teller) BET and isothermal statistics verify the shift toward more confined and accessible pores. These physical modifications directly translate into superior electrochemical performance of the activated carbon (AC), as demonstrated by increased capacitance and improved ion transport, as validated by cyclic voltammetry (CV). These results affirm that strategic thermal control during synthesis is significantly improved AC properties, providing a practical and scalable method for optimizing carbon-based LIC electrodes. The findings demonstrate that thermal control during carbon synthesis plays a vital role in tailoring material characteristics, offering a practical and scalable approach to improving LIC electrodes. Beyond technical merits, this work highlights how simple adjustments in preparation conditions can significantly influence the real-world performance of sustainable energy storage devices. © Published under licence by IOP Publishing Ltd.