September 28, 2012 report
Komaba Group reports sodium ion battery progress
(Phys.org)—Scientists with a common goal, to figure out an alternative to the lithium ion battery, the main power source of choice, are not giving up. The quarrel is not with the lithium ion battery's performance but in its high price and looming scarcity. The objective is to be able to offer a realistic alternative to lithium ion batteries for energy storage. Numerous recipes are coming out of labs as research efforts continue. The latest team to make news in this effort is from Japan, which relies on imports for its entire supply of the rare metal lithium. The news-makers are a research group at the Tokyo University of Science, led by Associate Professor Shinichi Komaba. They have confirmed they are making progress with their focus on sodium ion batteries as a li-ion alternative.
"Actually, we've spent about seven years researching sodium ion batteries. We've gained a lot of know-how regarding electrolytes and cells for such batteries. We have all the reagents needed right here," he said.
"Sodium ion batteries can be made using iron, aluminum, and sodium, rather than cobalt or copper as before," added Prof. Komaba. "What's more, our results show that battery capacity can be increased simply by using carbon made from sugar as the anode. So high-performance batteries like expensive lithium batteries, which are an important type of rechargeable battery, may be achievable. "
They are using hard carbon obtained by pyrolyzing sucrose, the main constituent of sugar. Before it can be used as the anode in a sodium-ion battery, the sugar is turned into black, hard carbon powder by heating it in an oxygen-free oven, hot enough to produce a hard black carbon powder. The team has achieved a storage capacity of 300 mAh, which is 20 percent higher than that of conventional hard carbon.
Komaba anticipates it may take about five years to achieve a practical version, but the group is confident that this is possible. They have said that with improvements in technology and performance, it is reasonable to expect batteries that can replace lithium ion batteries with lower-priced materials that are abundant, not scarce. Other researchers beyond Japan are also interested in seeing to what extent they can progress using sodium ion technologies to the point where sodium ion batteries can be commercialized.
Argonne National Laboratory has been exploring sodium ion batteries as an alternative to lithium. Aquion Energy creates batteries that can operate at a wide range of temperatures and use sodium ions rather than lithium ions. The company has a production plant in Pittsburgh, Pennsylvania, and plans to create a high-volume production facility in the future. Sodium-based batteries are seen as an attractive path to follow as a cheap and nontoxic alternative.
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