Synthesis and Electrochemical Characterization of Porous Si-C Composite as an Anode for Li-Ion Battery

Abstract

Silicon is one of the most promising anode materials for replacing conventional graphite-based anode for Li-ion batteries due to its high gravimetric capacity and a volumetric capacity.However, Si undergoes volume change upto 4 times its initial volume during the lithiation/delithiation process, which leads to severe mechanical strain on the particles and which resultsinto various capacity detoriating factors. To overcome such problems, in this work we demonstrate the synthesis of porous structured Si-C composite by using Si nanoparticles, SiO2as asacrificial template, and phenolic resin as a carbon source, followed by a carbonization process at 1000° C and the subsequent removal of the SiO2template to obtain pores. In the porousnanostructured Si-C composite, the porous carbon structure is expected to absorb the mechanical strain creating due to the lithiation/delithiation process and also improve the overallelectronic conductivity of the system. Several characterization techniques, such as XRD, Raman spectroscopy, BET, XPS, FE-SEM, and TEM, are used to evaluate the phase, structure, andmicrostructure of the Si-C composite. The prepared porous Si-C composite delivered a good initial discharge capacity of 1410 mAh g−1 and retains a stable discharge capacity of 750 mAhg−1 over 100 cycles at 100 mA g−1 retaining a coulombic efficiency of more than 99 %.