Blended 1D carbon nanostructures synergistically enhance electron and ion transport in silicon nanoparticle electrodes

Abstract

Carbon additives in lithium-ion battery electrodes are needed to provide electrical conductivity through the electrode but also can have a strong influence on the electrode morphology that dictates ion transport. For conversion-type electrodes, both electron and ion transport properties are key parameters determining cycling performance. Understanding the effect of carbon on change transport properties in electrodes is critical for rational electrode design. In this work, we study the impact of the 1-dimensional (1D) carbon aspect ratio on the electron and ion transport properties in silicon nanoparticle-based composite electrodes. We demonstrate that 1D carbon nanostructures provide a platform to decouple electron and ion transport and optimize each property separately. Furthermore, we show that combining different carbon nanostructures in a single composite provides a cumulative improvement in both ionic and electronic conductivity. This promising electrode architecture strategy becomes especially useful in thick composite electrodes with mass loadings >1.5 mg cm−2.