Ecofriendly Synthesis of Waste-Tire-Derived Graphite Nanoflakes by a Low-Temperature Electrochemical Graphitization Process toward a Silicon-Based Anode with a High-Performance Lithium-Ion Battery
Shu‐Chi Wu, Ching‐Wei Lin, Pai‐Chun Chang, Tzu‐Yi Yang, Shin‐Yi Tang, Ding-Chou Wu, Cheng-Ru Liao, Yi‐Chung Wang, Ling Lee, Yi‐Jen Yu, Yu‐Lun Chueh
Abstract
Here, the successful transformation of graphitic carbon with a high degree of graphitization and a nanoflake structure from pyrolytic tire carbon black was demonstrated. First, amorphous carbon black with a porous structure was obtained after pyrolysis and simple preacid treatments. Subsequently, the carbon black was converted into a highly graphitic structure at a relatively low temperature (850 °C) through a facile electrochemical route using molten salt, which is ecofriendly and has high potential for large-scale graphitization compared to conventional incineration techniques. Moreover, we further improved the crystallinity and uniformity of the product simultaneously by directly mixing the metal oxide catalyst Fe 2 O 3 with a carbon precursor. The mechanism of this metal-catalyzed electrochemical graphitization has been discussed in detail. To confirm their potential in practical applications, the as-prepared graphitized nanoflakes were used as conductive additives for silicon anodes in lithium-ion batteries, which showed a performance comparable to those utilizing commercial Super-P additives, exhibiting an initial Coulombic efficiency of approximately 79.7% and a high capacity retention of approximately 45.8% after 100 cycles with a reversible capacity of 1220 mAh g –1 at a current rate of 400 mA g –1 . Hence, successfully recovered waste-tire-derived carbon black utilizing a low-temperature Fe 2 O 3 -catalyzed electrochemical process opens a pathway in low-temperature graphitization toward a sustainable value-added application in the field of energy storage.