Image courtesy of SLAC National Accelerator Laboratory
Professor Yi Cui holds a lab demonstration of the new lithium-polysulfide semi-liquid flow battery. Adding a lithium polysulfide solution to the flask containing a solid lithium metal electrode immediately produces electrical current that lights an LED.
Researchers discovered electrochemical properties of a novel lithium (Li)/polysulfide (PS) semi-liquid battery and a method to eliminate the separator membrane in flow batteries.
The novel battery design could serve as a model for low-cost, long-life batteries that enable solar and wind energy to become major suppliers to the electrical grid.
Unlike conventional batteries where the energy is stored in chemicals that make up the solid electrodes of the battery, “flow” batteries store energy in liquids which can be pumped in large quantities from external tanks into the electrical cell when needed for storing or generating electricity. Flow batteries are one of the most promising options for providing the electrical grid storage necessary to smooth out the peaks and valleys of "intermittent" power sources such as wind and solar. The new battery design is one of the early research successes from the Joint Center for Energy Storage Research (JCESR), a DOE Energy Innovation Hub. The design from research at SLAC National Accelerator Laboratory simplifies the flow battery - it uses only one stream of molecules and does not need an expensive membrane to keep the reactive components separated. When discharging, the stream of catholyte, a liquid containing lithium polysulfides, absorbs lithium ions from the solid lithium anode; when charging, the liquid stream loses the lithium ions back into the solid anode. A passivation coating on the lithium anode prevents the continuous electron transfer from lithium to polysulfide solution that would self-discharge the battery. The electrochemical parameters, such as capacity, coulomb efficiency, and reversibility, have been studied in the laboratory using research prototypes of the hybrid flow battery design fabricated as coin cells. A utility version of the new battery would have to be scaled up to store many megawatt-hours of energy, but the scientific results indicate that such a hybrid flow battery solution for large-scale electrical energy storage for the grid is both promising and potentially viable.
SLAC National Accelerator Laboratory
Argonne National Laboratory Director
Joint Center for Energy Research (JCESR)
Energy Innovation Hub
U.S. Department of Energy, Office of Science, Basic Energy Sciences program as part of the DOE Energy Innovation Hub program.
Y. Yang, G. Zheng and Y. Cui, Energy Environ. Sci., 2013, online edition, [DOI: 10.1039/c3ee00072a]
Joint Center for Energy Storage Research
Lithium-Polysulfide Flow Battery Demonstration
University, DOE Laboratory