UMD Engineers Discover Root Cause of Solid-State Battery Failure
The use of a lithium metal anode in rechargeable batteries could significantly increase the energy density of conventional batteries, but combined with solid electrolytes (SEs) presents a challenge due to the formation of dendrites. Dendrites – a mass of crystal resembling a crown of broccoli – form inside electrolytes, causing batteries to fail. The cause of dendrite growth in solid electrolytes remained a mystery until recently.
The University of Maryland (UMD) research team - consisting of Chunsheng Wang, a professor of Chemical and Biomolecular Engineering (ChBE); Howard Wang, a visiting research professor of Materials Science and Engineering (MSE) and Nancy Dudney of Oak Ridge National Laboratory - discovered that high electronic conductivity of solid electrolytes is the root cause of dendrite formation in solid-state batteries. If the electronic conductivity can be reduced, dendrites are less likely to form, boosting the battery’s longevity. The results of their study were published in Nature Energy on January 14, 2019. Fudong Han – a ChBE post-doctoral associate – served as the paper’s first author.
“Using a unique and powerful technique called in-situ neutron depth profiling (performed at beam line NG5 of the NIST Center for Neutron Research), we can directly see the formation of dendrites inside the solid electrolytes,” said Han.
“Future research should focus on developing methods to reduce the electronic conductivity while simultaneously increasing, or at least, maintaining, the ionic conductivity of SEs,” said Chunsheng Wang.
The results will aid in the development of safe, high-performance solid-state batteries, which can be utilized for clean energy storage in portable electronic devices (e.g., mobile phones and laptops) and electric vehicles.
This work is supported by Army Research Office, NSF, DOE and NIST.
For additional information:
Han, F., Westover, A.S., Yue, J., Fan, X., Wang, F., Chi, M., Leonard, D.N., Dudney, N.J., Wang, H., and Wang, C. (2019). “High electronic conductivity as the origin of lithium dendrite formation within solid electrolytes.” Nature Energy, DOI: 10.1038/s41560-018-0312-z.
January 14, 2019