Electrospun SiOC ceramic fiber mats as freestanding electrodes for electrochemical energy storage applications

Polymer-derived-ceramics (PDCs) and PDC-based fibers are being studied as potential high capacity electrode materials for electrochemical energy storage applications. Among these, silicon oxycarbide (SiOC) has shown most promise, especially as electrodes in lithium ion batteries (LIB). The study of PDCs for supercapacitor electrodes is, however, very limited. This work investigates the fabrication of SiOC-based PDC fiber mats via electrospinning and pyrolysis of three commercial pre-ceramic silicone resins (MK, H44, RSN) of varying composition, and their use as supercapacitor and LIB electrodes. Electron microscopy, Fourier transform infrared spectroscopy and Raman spectroscopy was performed to study the effect of precursor chemical composition, pyrolysis time and temperature on the morphology, polymer to ceramic transformation and free carbon content. As supercapacitor electrodes, the H44 (a methyl-siloxane) derived SiOC showed the best performance with maximum specific capacitance of 50 F g-1 with capacity retention of ~100% after 2000 cycles. Similarly, as LIB electrodes, H44 derived SiOC fiber mat showed highest reversible capacity of 578 mAh g-1 at a current density of 50 mA g-1.