Monolithic Composite Electrodes Comprising Silicon Nanoparticles Embedded in Lignin‐derived Carbon Fibers for Lithium‐Ion Batteries

Abstract

AbstractWe report direct manufacturing of high‐capacity carbon/silicon composite fiber electrodes for lithium‐ion batteries produced via a flexible low‐cost melt processing route, yielding low‐cost stable silicon particles coated in situ by a 10 nanometer thick protective silica layer. The core–shell silicon/SiO2 islands are embedded in electrochemically active and electronically conductive carbon fiber derived from lignin precursor material. The silicon–silica–carbon composites exhibit capacities exceeding 700 mAh g−1 with Coulombic efficiencies in excess of 99.5 %. The high efficiency, stability, and rate capability are linked to the nanocrystalline structure and abundant, uniform nanometer‐thick SiO2 interfaces that are produced during the spinning and subsequent pyrolysis of the precursor blend.