Replacing lithium-ion batteries with seawater batteries is a little more complicated than going out to scoop a little seawater and returning home to cook up a battery according to a Dec. 7, 2016 American Chemical Society news release (also on EurkeAlert),
With the ubiquity of lithium-ion batteries in smartphones and other rechargeable devices, it’s hard to imagine replacing them. But the rising price of lithium has spurred a search for alternatives. One up-and-coming battery technology uses abundant, readily available seawater. Now, making this option viable is one step closer with a new report on a sodium-air, seawater battery. The study appears in the journal ACS Applied Materials & Interfaces.
Sodium-air — or sodium-oxygen — batteries are considered one of the most promising, and cost-effective alternatives to today’s lithium-ion standby. But some challenges remain before they can become a commercial reality. Soo Min Hwang, Youngsik Kim and colleagues have been tackling these challenges, using seawater as the catholyte — an electrolyte and cathode combined. In batteries, the electrolyte is the component that allows an electrical charge to flow between the cathode and anode. A constant flow of seawater into and out of the battery provides the sodium ions and water responsible for producing a charge. The reactions have been sluggish, however, so the researchers wanted to find a way to speed them up.
For their new battery, the team prepared a catalyst using porous cobalt manganese oxide nanoparticles. The pores create a large surface area for encouraging the electrochemical reactions needed to produce a charge. A hard carbon electrode served as the anode. The resulting battery performed efficiently over 100 cycles with an average discharge voltage of about 2.7 volts. This doesn’t yet measure up to a lithium-ion cell, which can reach 3.6 to 4.0 volts, but the advance is getting close to bridging the gap, the researchers say.
Here’s a link to and a citation for the paper,
A Metal–Organic Framework Derived Porous Cobalt Manganese Oxide Bifunctional Electrocatalyst for Hybrid Na–Air/Seawater Batteries by Mari Abirami, Soo Min Hwang, Juchan Yang, Sirugaloor Thangavel Senthilkumar, Junsoo Kim, Woo-Seok Go, Baskar Senthilkumar, Hyun-Kon Song, and Youngsik Kim. ACS Appl. Mater. Interfaces, 2016, 8 (48), pp 32778–32787
DOI: 10.1021/acsami.6b10082 Publication Date (Web): November 14, 2016
Copyright © 2016 American Chemical Society
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