A team of researchers at the University of Maryland Energy Research Center (UMERC) recently was awarded a $1.25 million grant from the Department of Energy (DOE) for research to develop better, safer Lithium-ion battery technology.
UMD’s award is part of a total of $57 million in DOE funding for 35 projects aimed at reducing the cost and improving the efficiency of plug-in electric, alternative fuel, and conventional vehicles. The Department of the Army is contributing an additional $2.2 million through the Advanced Vehicle Power Technology Alliance to support projects specifically focused on advanced high-voltage electrolytes for batteries and advanced engine and powertrain technologies to improve vehicle fuel efficiency. The UMERC project and most of the other 34 projects will support the goals of EV Everywhere, a DOE program that aims to make plug-in electric vehicles (PEVs) as affordable and convenient as gasoline-powered vehicles by 2022.
UMD’s DOE-funded project is to design “self‐healing, 3‐D conformal solid state electrolytes to prevent dendrite formation and achieve high battery cycle life.” Researchers have long known that lithium-ion batteries that currently power electric vehicles, laptops and smartphones could have significantly higher energy if their graphite anodes (electrodes) were replaced by lithium metal anodes. Hampering this change, however, has been the so-called dendrite problem. Over the course of several battery charge/discharge cycles microscopic fibers of lithium, called “dendrites,” sprout from the surface of the lithium electrode and spread like kudzu across the electrolyte solution until they reach the battery’s other electrode (cathode). An electrical current passing through these dendrites can short-circuit the battery, causing it to rapidly overheat and in some instances catch fire.
UMERC researchers already are rapidly developing safer, higher capacity and longer lasting lithium batteries based on a number of different technological approaches. The new DOE-funded project will build on technology developed by UMERC Director Eric Wachsman and Department of Materials Science and Engineering professors Liangbing Hu and Yifei Mo.
This team has already shown breakthroughs in developing the first flexible, solid-state, ion-conducting membrane based on a 3D Li-ion conducting ceramic nanofiber network. In June in the Proceeding of the National Academy of Sciences (PNAS), they published research on the development of a flexible solid battery electrolyte with superior thermal stability and electrochemical stability to high voltage.
“This technology is unique in its ability to replace current flammable organic liquid electrolyte systems in lithium-ion batteries with a solid electrolyte that enables both higher energy density lithium-metal anodes and the use of conventional battery manufacturing facilities,” says Wachsman.
Hu adds that “the 3D interconnected network with percolated garnet nanofibers can lead to high ion conductivity and great flexibility, which are important for safe, solid state battery fabrications and operations.”