A facile and green synthesis approach to derive highly stable SiOx-hard carbon based nanocomposites for use as the anode in lithium-ion batteries

Abstract

The accomplishments of high energy and power density lithium-ion batteries (LIBs) are drawing substantial attention for commercialization in the electric vehicle and energy storage industries. Recently, silicon oxides (SiO_x) have emerged as potential anode materials owing to their abundance, sustainability, and preferable electrochemical properties. However, a few attributes such as inadequate electrical conductivity, poor cycling performance, and enormous volume variation hinder the practical usage of SiO_x. In this work, an efficient synthesis method has been employed to synthesise spherical SiO_x/hard carbon (SOHC) nano-composites with different ratios, followed by electrochemical analysis. Furthermore, nitrogen has been doped in one of the optimized composite anodes (SOHC-N) which enhances electrochemical performance considerably. Interestingly, SOHC-N exhibits improved electrochemical performance with a significant initial specific capacity of 1398.45 mA h g⁻¹ and remarkable capacity retention in comparison to all other electrodes. Besides, SOHC-N acquires an exceptional rate performance of 1139.3 mA h g⁻¹ at 1000 mA g⁻¹ and an impressive cycling stability of 1248.765 mA h g⁻¹ for over 500 cycles. Moreover, the diffusion coefficient of the mobile species (Li⁺) in the SOHC-N anode material has been calculated to be 8.28 × 10⁻¹⁰ cm² s⁻¹ to 9.75 × 10⁻⁸ cm² s⁻¹, corresponding to an outstanding kinetic performance. These values signify excellent electrochemical behaviour for next generation LIB applications.