Current graphite anodes in Li-ion batteries have a capacity of 372 mAh g^-1 whereas silicon has a theoretical capacity 10x higher. In spite of this immense advantage, bulk silicon is not used as anode due to its large volumetric change during (de)lithiation (up to 300%) leading to internal stresses and pulverization after only a few cycles. Here, we explore additively- manufactured architectures for sintered Si which can withstand these internal stresses.

Additive manufacturing of metals is usually done via selective laser melting (SLM) or selective laser sintering (SLS). However, SLM is very difficult for silicon given its high thermal conductivity, high reflectivity and a high tendency to form oxides, while SLS is unattractive because of silicon's slow sintering kinetics. Therefore, we use an extrusion-based method (direct ink writing) to create Si anode with porous architectures, and we investigate both steps of ink printing of Si powders and their subsequent sintering.

Related Publications

1. Calvo M, Jakus AE, Shah RN, Spolenak R, Dunand DC. Microstructure and Processing of 3D Printed Tungsten Microlattices and Infiltrated W-Cu Composites. Advanced Engineering Materials. 2018;20(9):1800354.
2. Reyes Tirado FL, Huang J, Dunand DC. Ice-templated silicon foams with aligned lamellar channels. MRS Communications. 2017;7(4):928-32.

Funding support

1. Laboratory of Nanometallurgy (ETH Zurich)