Search

A series of natural-biogum-deprived carbon composites Si@GAC, Si@GGC and Si@XGC anode materials have been constructed, among which Si@GAC shows the best initial Coulombic efficiency (ICE) resulting from conformal carbon layer containing heteroatoms and covalent interactions with Si core. Based on this result, artificial graphite (AGr) and natural graphite (NGr) are added during the preparation process of Si@GAC to further elevate ICE and cycling stability. This strategy successfully realizes simultaneous and effective improvement of ICE and cycling performance, which could ultimately provide inspiration for high-performance silicon-based anodes. [Display omitted] • Si@C@Graphite materials with enhanced ICE and cycling stability are synthesized. • N, O render dominant capacitive Li+ storage mechanism and faster Li+ transfer. • Artificial graphite better enhances overall electrochemical performance. • Covalently-attached C layer with heteroatoms is conducive to cycling stability. Regarded as one of the most prospective anode materials for lithium-ion batteries (LIBs), silicon (Si) exhibits the highest theoretical capacity (4200 mAh g−1) among various anode materials while generally suffers from huge volume change, resultant rapid capacity fading and low initial Coulombic efficiency (ICE). Here, the ICE and cycling performance of Si-based anode have been simultaneously improved through preparing Si@C@Graphite materials where the conformal carbon modifiers derived from natural biopolymer binders covalently attached to Si particles could enhance the cycling stability, among which GA-derived carbon layer with N, O heteroatoms could best ameliorate the Li+ transport kinetics and thereby rendering superior electrochemical properties, while artificial graphite (AGr) could significantly promote the overall ICE and more effectively elevate the reversible capacity. An excellent ICE (86.4%), a prominent rate performance (1240.6 mAh g−1 at 2000 mA g−1) and a promoted cycling stability (1320.5 mAh g−1 at 800 mA g−1 after 100 cycles) could be presented by Si@GAC@AGr anode. This research provides an effective strategy of simultaneously improving ICE and cycling performance of Si-based anodes and inspires rational design of high-energy–density LIB anodes. [ABSTRACT FROM AUTHOR]