There is great interest in one-dimensional (1D) nanostructures that allow lateral relaxation and can be used to reduce pulverization of a silicon-based anode material. However, the growth of high density arrays of silicon nanowires (SiNWs) on metal current collectors using a chemical vapor deposition (CVD) processing is challenging due to competing metal silicide formation during the Si nanowire growth process. An issue with the metal silicide formation is that Si is consumed and this reduces the overall specific capacity as well as the rate capability of a silicon nanowire-based anode material. Here, we demonstrate high density, electrically contacted Si nanowire growth on stainless steel substrates (metal current collectors) with minimal unwanted substrate-silicide formation for high Li ion battery performance. These high-purity silicon nanowire-based anodes show average high specific capacities of 3670 mA h g -1 at 0.2 C and 3448 mA h g -1 at 0.5 C over 40 cycles. Moreover, the high-purity silicon nanowires are demonstrated to reach extremely high capacities at high cycle rates (1912 mA h g -1 and 997 mA h g -1 at 10 C and 20 C, respectively).
Bibliographical noteFunding Information:
This material is based upon work supported as part of the Nanostructures for Electrical Energy Storage, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DESC0001160. The work was performed, in part, at the Center for Integrated Nanotechnologies, a U.S. Department of Energy, Office of Basic Energy Sciences user facility. Los Alamos National Laboratory, an affirmative action equal opportunity employer, is operated by Los Alamos National Security, LLC, for the National Nuclear Security Administration of the U.S. Department of Energy under contract DE-AC52-06NA25396.
- Chemical vapor deposition
- Lithium-ion battery
- Metal silicide
- Silicon nanowire