Sol–Gel-Based Synthesis of a Yolk–Shell Structured Sn@C Composite for Highly Stable Lithium Storage

Abstract

Yolk–shell structured Sn@C materials are promising candidates of anode materials for lithium-ion batteries due to their high structural stability along cycling. However, their synthesis usually suffers from complicated procedures, low efficiency and uncontrolled morphology and size. In this study, a novel yolk–shell structured composite of phenolic-resin-based Sn@hollow carbon (C) composite was effectively synthesized using tributyl(ethenyl)stannane as the tin source and hexadecyltrimethylammonium bromide as the structure-directing agent. Small Sn particles, with diameters of 10–20[Formula: see text]nm, were discovered to be encapsulated within hollow carbon spheres of about 100[Formula: see text]nm and exhibited high dispersion. Benefiting from this excellent structural design, the specific lithium-storage capacity of this composite can still retain a value of 640[Formula: see text]mAh g[Formula: see text] after 150 cycles at 0.1[Formula: see text]A g[Formula: see text]. An excellent rate performance of 280[Formula: see text]mAh g[Formula: see text] was achieved at a high current density of 1[Formula: see text]A g[Formula: see text], without decay after 600 cycles. The present study highlights the superiority of yolk–shell structure and provides a viable option for synthesizing advanced Sn-based anode materials of lithium-ion batteries.