Department of Materials Science & Engineering Seminar Series: Chunsheng Wang

Description

Chunsheng Wang from the Center for Research in Extreme Batteries at the University of Maryland, will give a talk titled "Electrolytes for High-Energy Li-ion and Li Metal Batteries" for the Department of Materials Science & Engineering. Learn more about the speaker online.

This event will also be online; for Zoom Information, please email dmse@jhu.edu. All in-person events at Johns Hopkins must follow university COVID-19 policies. See current guidelines online.

Abstract:

Electrolytes are critical enabling components for Li-ion batteries to safely operate within a wide temperature range, under extreme fast charging, and under intense abuse conditions without sacrificing energy density and cycle life. Current electrolytes cannot satisfy these requirements. We developed advanced all-fluorinated electrolytes, water-in-sale (WIS) electrolytes, and solid-state electrolytes aiming to simultaneously enhance cell energy density and safety.

Guided by the electrolyte design principle for high-capacity electrodes with large volume changes, we developed serval organic liquid electrolytes suitable for micro-sized Si and Li metalanodes and NMC cathodes. We also reduced the salt concentration of water-in-salt electrolytes from 21 m to 4.5m and extended the electrochemical stability window from 3.0V of WIS to 3.4V. These improved electrolytes enable LiMn2O4/Li4Ti5O12 pouch cells with an areal capacity of 2.5 mAh/cm2 and a P/N capacity ratio of 1.14 to achieve a long cycle life of 500. For solid state electrolyte Li metal batteries, we suppressed the Li dendrite growth and reduced the interface resistance by constructing a lithionphobic-lithiophoilic interlayer between solid electrolyte and Li metal anodes. The critical role of solid electrolyte interphase in accommodating electrode volume changes was also investigated.