Progress on the Quest for Better Energy Storage

There are several recent headlines in the scientific press about discoveries made by different research institutions in their search for better ways to store energy when the sun isn't shining and the wind isn't blowing.  Here is a little digest of a few of these stories:

SILICON TRUMPS GRAPHITE

Science Daily reported on October 29, 2009 that researchers at the Institute for Chemistry and Technology of Materials at Graz University of Technology in Austria have found that the darling material of the late 20th and early 21st century, silicon, can provide storage capacity of ten times higher than the graphite substrate which has previously been used in lithium-ion batteries. Their findings were made public as part of the "NanoPoliBat" EU project and have been submitted to the patent office by the researchers, together with their partner, Varta Microbattery. 

Source: TU Graz (2009, October 29). Battery Of The Future: New Storage Material Improves Energy Density Of Lithium-ion Battery. ScienceDaily. 

NANOPARTICLES ENABLE LARGE-SCALE STORAGE APPLICATIONS

Nature Communications has published a paper entitled, "Copper hexacyanoferrate battery electrodes with long cycle life and high power" by Colin D. Wessells, Robert A. Huggins and  Yi Cui of the Department of Materials Science and Engineering at Stanford University in Stanford, California. These researchers have discovered that crystalline nanoparticles of copper hexacyanoferrate can be used as a battery electrode in inexpensive aqueous electrolytes. The implication is for a low-cost, scalable technology that lends itself to use in large-scale energy storage systems.

Source:  Nature Communications 2, Article number: 550 doi:10.1038/ncomms1563. Published: 22 November 2011

Additional affiliation: Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California

STANDARDIZING STORAGE METRICS

Did you ever wonder why some of your personal electronic gadgets have batteries that run down quickly and some seem to last longer? One recent paper  entitled, "True Performance Metrics in Electrochemical Energy Storage", published in Science, by authors Dr. Yury Gogotsi, head of the A.J. Drexel Nanotechnology Institute and Dr. Patrice Simon of the Université Paul Sabatier in Toulouse, France suggests that international standards for the measurement and reporting of electrochemical energy storage (EES) capacity of batteries be created.

While their article focuses primarily on electrochemical capacitors (ECs) also called supercapacitors or ultra-capacitors, their considerations also apply to lithium-ion batteries. 

Science Daily reports on the paper saying, "The issue that Gogotsi and Simon bring to light is the idea that current metrics for grading energy storage devices, including the Ragone plot, may not provide a complete picture of the devices' capability. According to the researchers, other metrics, such as a device's cycle lifetime, energy efficiency, self-discharge, temperature range of operation and cost, must also be reported."

Sources:

Science  18 November 2011: Vol. 334 no. 6058 pp. 917-918 DOI: 10.1126/science.1213003

Drexel University (2011, November 29). Efficiency metrics for energy storage devices need standardization. ScienceDaily