A NOVEL HIGH-PERFORMANCE AND LOW-COST 3D SILICON NANOSTRUCTURES ANODE FOR LITHIUM-ION BATTERIES

New, higher capacity materials are required in order to address the fast growing need for greater energy density, longer cycle life and safer high-power operation batteries for both mobile and vehicle applications.

We present the study of a scalable low-cost chemical vapor deposition (CVD) synthesis and characterization of a novel 3D-architecture high-capacity silicon anode for lithium ion battery. The formation and growth of solid electrolyte interphase (SEI) and anode degradation mechanisms have been examined as a function of the composition and structure of the active anode material. Our research efforts have culminated in the outstanding performance of 3D silicon anode: high areal capacity of 3−5 mAh/cm², high gravimetric capacity of up to 2000mAh/gr-Si and a very low irreversible capacity (7-15%). Cycle life over 500 full charge-discharge cycles was demonstrated in Si/Li half-cells. Pairing the 3D silicon anode with a commercial cathode resulted in a full lithium- ion battery with cycle life over 200 cycles. The developed anodes have the potential to increase the energy density of lithium ion batteries for electric vehicles, storage devices and portable applications by 60%. Due to high melting points of lithium-rich silicon compounds, and higher working potentials (vs. Li) these batteries are safer than both Li-ion and lithium-metal cells.