From longan peel waste to energy storage: Porous activated carbon as a cathode matrix for advanced Li/Na-selenium batteries
Mustafa Khan, Suxia Yan, Mujahid Ali, Faisal Mahmood, Yang Zheng, Xiaohui Song, Guochun Li, Junfeng Liu, Yong Wang
Abstract
This paper explores the potential of Longan peel waste (LPw) as a sustainable and cost-effective matrix for selenium-based cathodes in Li-Se and Na-Se batteries . Following activation, we created LP 2 —a designation for the carbon precursor derived from LPw, activated at a 1:2 ratio of carbonized LPw to KOH. This nomenclature, where ‘LP' stands for ‘Longan peel' and ‘2′ reflects the optimization of this ratio, led to a hierarchical porous structure with an average pore size of 3.0307 nm and a significant BET surface area of 111.9386 m 2 g -1 . Selenium was incorporated into the LP 2 matrix using a simple melt diffusion technique, yielding the composite Se@LP 2 . In Li-Se batteries, Se@LP 2 exhibited an initial discharge capacity of 1033.75 mAh g⁻ 1 at 0.1C. At a 1C rate, the composite demonstrated a capacity retention of 301.14 mAh g⁻ 1 after 550 cycles and 380.91 mAh g⁻ 1 after 100 cycles. Moreover, for Na-Se batteries, the composite showcased a capacity retention of 347.18 mAh g⁻ 1 after 100 cycles at 0.1C. These findings underscore LP 2 's potential as a viable and efficient matrix for selenium-based cathodes, revealing promising prospects for the advancement of highly efficient Li-Se and Na-Se batteries.