Si-on-Graphite fabricated by fluidized bed process for high-capacity anodes of Li-ion batteries
Journal
Chemical Engineering Journal
Date Issued
2020
Author(s)
M?ller, J.
Abdollahifar, M.
Vinograd, A.
N?ske, M.
Nowak, C.
Chang, S.-J.
Placke, T.
Haselrieder, W.
Winter, M.
Kwade, A.
Wu, N.-L.
Abstract
Composites consisting of graphite and silicon have been considered as potential high-capacity anode materials for the next-generation Li-ion batteries (LIBs). The synthesis method is critical for determining the microstructure, which is directly related to the material performance and the cost-efficiency for making commercial electrode materials. Herein, we report the fabrication of silicon-on-graphite (Si@Gr) composites by fluidized bed granulation (FBG) for the first time. The FBG process is shown to produce composite powders comprising a uniform layer of nano-sized Si particles lodged onto the surface of micron-sized graphite particles to possess a core-shell microstructure. Adopting a suitable binder during the FBG process enables a firm adhesion of the Si nanoparticles on graphite surface during subsequent carbon-coating, where the composite particles are coated with pitch and then carbonised to form a highly electronically conductive and mechanical stabilizing layer of amorphous carbon. These carbon-coated composites exhibit a high capacity reaching over 600 mAh g−1, high rate capability and illustrates the potential of long-cycle stability in Si@Gr
Li metal cells, showing more than 70% capacity retention after 400 charge-discharge cycles even without electrolyte optimization. Furthermore, a significantly improved cycling stability is found for the carbon-coated Si@Gr materials in LiNi0.6Co0.2Mn0.2O2 (NCM-622)
Si@Gr full-cells. © 2020 Elsevier B.V.
Subjects
Fluidized bed process; High capacity anode; Pitch coating; Silicon-on-graphite composite
Other Subjects
Amorphous carbon; Amorphous silicon; Anodes; Electrolytes; Fabrication; Fluidized bed process; Fluidized beds; Graphite; Lithium compounds; Manganese compounds; Microstructure; Nickel compounds; Silicon; Silicon compounds; Carbon-coated composites; Charge-discharge cycle; Composite particles; Electrolyte optimizations; Fluidized bed granulation; High capacity anode; High rate capability; Material performance; Lithium-ion batteries
Type
journal article