New polymer gel for cheaper, flexible lithium ion batteries
A newly-developed gel could make lithium batteries cheaper and more damage-tolerant, and allow them to be made in a variety of shapes and sizes
Lithium-ion batteries have certainly been a boon to electronic devices, offering much longer run times than their alkaline counterparts. There is still room for improvement, however. Existing lithium batteries can short circuit, they don't stand up to damage, and they can only be made in a limited variety of shapes. Now, scientists from the University of Leeds have developed a polymer gel that could be used to make lithium batteries with none of those shortcomings - plus, they should be cheaper.
Traditional lithium-ion batteries consist of sealed cells that each contain a porous polymer film separator and a liquid chemical electrolyte. The pores in that separator allow charged lithium ions to flow between the electrodes, while acting as a barrier that keeps those electrodes from contacting one another and shorting out.
That separator isn't needed with the new gel. In a patented high-speed extrusion/lamination process, the gel is sandwiched between an anode and a cathode. The result is a highly-conductive strip, that is nanometers thick. It is flexible, damage-tolerant, and can be cut to any size. Its fully-automated production process is said to be cost-effective and safe, as it doesn't result in any excess flammable solvents or liquid electrolytes.
The gel itself contains about 70 percent liquid electrolyte which is mixed with a polymer. The two liquids are mixed with hot water, and set into a gelatinous consistency as they cool.
The technology was developed by Ian Ward, a Research Professor of Physics at Leeds. It has been licensed to American company Polystor Energy Corporation, which is in the process of conducting trials in preparation for commercialization.
About the Author
An experienced freelance writer, videographer and television producer, Ben's interest in all forms of innovation is particularly fanatical when it comes to human-powered transportation, film-making gear, environmentally-friendly technologies and anything that's designed to go underwater. He lives in Edmonton, Alberta, where he spends a lot of time going over the handlebars of his mountain bike, hanging out in off-leash parks, and wishing the Pacific Ocean wasn't so far away.
All articles by Ben Coxworth
I still remember a video taken of the thinnest lithium ion battery ever made, they recorded it as the battery was charged and it twisted and turned from the stresses, indicating that it\'s actually physical stresses built up over charge/discharge cycles that cause Li-Ion batteries to lose capacity. Since this new system is flexible, that should no longer be a problem. This should start a new wave of devices where the batteries are built more snugly into the casing, or other places you couldn\'t normally fit a battery.
Sounds interesting but how is this different than what they tried a decade ago? Is this the same company?
Small U.S. company takes foot steps in Li-ion battery production
Polystor Corporation, a privately held company based in Livermore, California, developed and manufactured rechargeable Li-ion and Li-ion polymer batteries in small volumes for mobile devices and portable elec-tronic products. Polystor developed a nickel cobalt oxide cathode that delivered the highest capacity and energy density in the industry at one point.
The firm was founded in 1993 to bring to the market technology that was developed by its founders while at the Lawrence Livermore National Laboratory. The firm pursued development of Li-ion technologies for the Strategic Defense Initiative program. In the 1990s, with assistance in R&D funding from a TRP grant, sev-eral SBIR grants, and a grant from the U.S. Advanced Battery Consortium, the company sought to spin the technology out for commercial use.
PolyStor\'s Li-ion cell was tested by Motorola and other major manufacturers and reached production by 1996. PolyStor made the cell components in the U.S. and shipped them to Korea for assembly.
In 2000, PolyStor won an award from the Advanced Technology Program to help develop a safe, ultrahigh capacity next-generation rechargeable battery based on Li-ion polymer gel technology.
After suffering a sharp decline in demand for its products in 2001, tied to a global decline in the demand for cell phones, PolyStor ceased operations in 2002.
Source: Steve Peng. \"Mold to Fit Battery.\" Edgereview.
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