10.1021/acsami.5b11628.s001 So Yeun Kim So Yeun Kim Jaewoo Lee Jaewoo Lee Bo-Hye Kim Bo-Hye Kim Young-Jun Kim Young-Jun Kim Kap Seung Yang Kap Seung Yang Min-Sik Park Min-Sik Park Facile Synthesis of Carbon-Coated Silicon/Graphite Spherical Composites for High-Performance Lithium-Ion Batteries American Chemical Society 2016 capacity retention Si nanoparticles mass production cycle performance Facile Synthesis electrochemical reaction 100 cycles carbon layer encapsulating Si nanoparticles storage capability multicomponent structure 2016-04-26 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Facile_Synthesis_of_Carbon_Coated_Silicon_Graphite_Spherical_Composites_for_High_Performance_Lithium_Ion_Batteries/3363727 A high-performance Si/carbon/graphite composite in which Si nanoparticles are attached onto the surface of natural graphite by carbonization of coal-tar pitch is proposed for use in lithium-ion batteries. This multicomponent structure is favorable for improving Li<sup>+</sup> storage capability because the amorphous carbon layer encapsulating Si nanoparticles offers sufficient electric conductivity and strong elasticity to facilitate relaxation of strain caused by electrochemical reaction of Si during cycles. The Si/carbon/graphite composite exhibits a specific capacity of 712 mAh g<sup>–1</sup> at a constant current density of 130 mA g<sup>–1</sup>, and maintains more than 80% of its initial capacity after 100 cycles. Moreover, it shows a high capacity retention of approximately 88% even at a high current density of 5 C (3250 mA g<sup>–1</sup>). On the basis of electrochemical and structural analyses, we suggest that a rational design of the Si/carbon/graphite composite is mainly responsible for delivering a high reversible capacity and stable cycle performance. Furthermore, the proposed synthetic route for the Si/carbon/graphite composite is simple and cost-effective for mass production.