Multiscale Engineered Si/SiOx Nanocomposite Electrodes for Lithium-Ion Batteries Using Layer-by-Layer Spray Deposition

Abstract

Si-based high-capacity materials have gained much attention as an alternative to graphite in Li-ion battery anodes. Although Si additions to graphite anodes are now commercialized, the fraction of Si that can be usefully exploited is restricted due to its poor cyclability arising from the large volume changes during charge/discharge. Si/SiOx nanocomposites have also shown promising behavior, such as better capacity retention than Si alone because the amorphous SiOx helps to accommodate the volume changes of the Si. Here, we demonstrate a new electrode architecture for further advancing the performance of Si/SiOx nanocomposite anodes using a scalable layer-by-layer atomization spray deposition technique. We show that particulate C interlayers between the current collector and the Si/SiOx layer and between the separator and the Si/SiOx layer improved electrical contact and reduced irreversible pulverization of the Si/SiOx significantly. Overall, the multiscale approach based on microstructuring at the electrode level combined with nanoengineering at the material level improved the capacity, rate capability, and cycling stability compared to that of an anode comprising a random mixture of the same materials.