Abstract
Si has the possibility to greatly increase the energy density of Li-ion battery anodes, though it is not without its problems. One issue often overlooked is the decomposition of Si during large scale slurry formulation and battery fabrication. Here, we investigate the mechanism of H2 production to understand the role of different slurry components and their impact on the Si oxidation and surface chemistry. Mass spectrometry and in situ pressure monitoring identifies that carbon black plays a major role in promoting the oxidation of Si and generation of H2. Si oxidation also occurs through atmospheric O2 consumption. Both pathways, along with solvent choice, impact the surface silanol chemistry, as analyzed by 1H-29Si cross-polarization magic angle spinning nuclear magnetic resonance (MAS NMR) and attenuated total reflectance Fourier transform infrared spectroscopy (ATR FTIR). An understanding of the oxidation of Si, during slurry processing, provides a pathway toward improving the manufacturing of Si based anodes by maximizing its capacity and minimizing safety hazards.
| Original language | English |
|---|---|
| Pages (from-to) | 9746-9754 |
| Number of pages | 9 |
| Journal | Journal of Physical Chemistry C |
| Volume | 122 |
| Issue number | 18 |
| DOIs | |
| State | Published - May 10 2018 |
Funding
This research was conducted at Oak Ridge National Laboratory, managed by UT Battelle, LLC, for the U.S. Department of Energy (DOE) under contract DE-AC05-00OR22725. The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan). The work was supported by the Vehicle Technologies Office, Hybrid Electric Systems Program, Battery R&D, Brian Cunningham (Technology Manager), at the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy. SEM analysis was conducted at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility. We thank Dr. Fulya Dogan (ANL) for discussions on NMR assignments, Dr. Binghong Han (ANL) and Nathan Phillips (ORNL) for experimental support, and Dr. Jagjit Nanda for use of the ATR-FTIR.
