Stabilization of microsized Sn anode with carbon coating and fluoroethylene carbonate additive for high-performance Li-ion batteries

Abstract

Metallic Sn is one of the promising alternatives to graphite for lithium-ion batteries because of its high theoretical capacity, low lithium alloying voltage, and high conductivity. However, the huge volume expansion due to repeated alloying-dealloying makes it unsuitable for commercial applications. Herein, we have proposed a single-step synthesis of carbon-coated Sn by catalytic decomposition of acetylene over Sn microparticles using the chemical vapor deposition technique. This modification of Sn has successfully controlled the volume expansion due to the higher availability of pores, resulting in very low capacity fading. Further, adding fluoroethylene carbonate (FEC) as an electrolyte additive results in very high structural stability. Postmortem studies carried out have confirmed the same. A specific discharge capacity of 390 mAh g−1 at a high current density of 0.5A g−1 is achieved for Sn/C in the presence of FEC additive, along with high rate capability and cyclic stability. The structural reconstruction in the presence of FEC additive, with superior capacity and stability, can pave the way for further building of Sn-based anodes for next-generation high-performance LIBs.