Published on April 8th, 2014 | by James Ayre1
Improved, Greener Lithium-Ion Batteries With New Sticky Conductive Material
April 8th, 2014 by James Ayre
A new “sticky” type of conductive material — one that may completely eliminate the need for one of the main components of lithium-ion batteries, binders — has now been developed by researchers at the University of Delaware.
The electrodes in lithium-ion batteries typically consist of three components
active materials, conductive additives, and binders — by eliminating the need for one of these, the batteries could potentially be made to be notably cheaper, as “greener” as well.
“The problem with the current technology is that the binders impair the electrochemical performance of the battery because of their insulating properties,” states Bingqing Wei, professor of mechanical engineering. “Furthermore, the organic solvents used to mix the binders and conductive materials together not only add to the expense of the final product, but also are toxic to humans.”
The new discovery was made when the researchers observed the reality that fragmented carbon nanotube macrofilms (FCNT) can function as “adhesive conductors” — in essence, combining two functions into one material.
The University of Delaware explains:
Wei explains that FCNTs are web-like meshes with “tentacles” that are coupled with active lithium-based cathode and anode materials. They are then assembled using simple ultrasound processing. The process employs no organic solvents.
“We’ve found that the adhesive FCNT conductors actually have higher adhesion strength than PVDF, the binder traditionally used in lithium-ion battery manufacturing,” he states. “We’ve also demonstrated that these composite electrodes exhibit higher electrical conductivity than traditional materials, and we’ve achieved these benefits in a low-cost green fabrication process that replaces toxic organic solvents with just water and alcohol.”
“There is a wide market for lithium-ion batteries,” he continues, “and we see great potential for the use of this technology in vehicle applications, where quick charging and discharging are required.”
“The (new) approach could also be employed for electrode preparation for other energy storage devices such as electrochemical capacitors.”
The new findings are detailed in a paper published in the journal ACS Nano. A patent has been filed as well.
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