Two Birds with One Stone: Micro/Nanostructured SiOxCy Composites for Stable Li‐Ion and Li Metal Anodes

Abstract

AbstractDeveloping stable silicon‐based and lithium metal anodes still faces many challenges. Designing new highly practical silicon‐based anodes with low‐volume expansion and high electrical conductivity, and inhibiting lithium dendrite growth are avenues for developing silicon‐based and lithium metal anodes, respectively. In this study, SiOxCy microtubes are synthesized using a chemical vapor deposition method. As Li‐ion battery anodes, the as‐prepared SiOxCy not only combines the advantages of nanomaterials and the practical properties of micromaterials, but also exhibits high initial Coulombic efficiency (80.3%), low volume fluctuations (20.4%), and high cyclability (98% capacity retention after 1000 cycles). Furthermore, SiOxCy, as a lithium deposition substrate, can effectively promote the uniform deposition of metallic lithium. As a result, low nucleation overpotential (only 6.0 mV) and high Coulombic efficiency (≈98.9% after 650 cycles, 1.0 mA cm−2 and 1.0 mAh cm−2) are obtained on half cells, as well as small voltage hysteresis (only 9.5 mV, at 1.0 mA cm−2) on symmetric cells based on SiOxCy. Full batteries based on both SiOxCy and SiOxCy@Li anodes demonstrate great practicality. This work provides a new perspective for the simultaneous development of practical SiOxCy and dendrite‐free lithium metal anodes.