Grey Sedge as Potential Source for Biomass-Derived SiO<sub>x</sub>/C Anode in Lithium-Ion Battery

Lithium-ion batteries (LIBs) are widely used in various applications such as portable devices and electric vehicles due to their long lifespan and high energy density. However, current LIBs have limited capacity, which can be attributed to the low theoretical capacity of graphite anode (~372 mAh/g). To enhance LIBs performance, silicon-based materials can be used as an alternative anode, offering a higher theoretical capacity of up to 4200 mAh/g. Nonetheless, silicon-based anodes in LIBs still face challenges of high-volume expansion and low electrical conductivity. To overcome these issues, combining silicon-carbon in the form of SiO x /C has been developed to mitigate the effect of volume expansion and enhance the conductivity of the anode. Moreover, SiO x /C can be directly synthesized from biomasses as they can serve as both silicon and carbon sources, providing a sustainable synthesis approach. In this study, SiO x /C materials were synthesized from grey sedge, an abundant biomass in tropical and humid areas of Indonesia. The synthesis of grey sedge-derived SiO x /C involved the activation using ZnCl 2 and one-step pyrolysis, resulting in carbon-rich SiO x /C anode with an initial discharge capacity of 1595 mAh/g in pre-lithiation. The grey sedge-derived SiO x /C anode demonstrated a higher actual capacity than graphite anodes, with 68% capacity retention after 85 charge-discharge cycles at 200 mA/g. These findings highlight the potential of grey sedge-derived silicon-carbon materials as the anode for next-generation LIBs, supporting the global transition to renewable energy sources.