Hybrid Electric Energy: Self-Charging Power Cell Converts and Stores Energy in a Single Unit

[OKIsItJustMe]

http://gtresearchnews.gatech.edu/hybrid-electric-energy-self-charging-power-cell-converts-and-stores-energy-in-a-single-unit/

[font face=Serif]8/21/2012

[font size=5]Hybrid Electric Energy: Self-Charging Power Cell Converts and Stores Energy in a Single Unit[/font]

[font size=3]Researchers have developed a self-charging power cell that directly converts mechanical energy to chemical energy, storing the power until it is released as electrical current. By eliminating the need to convert mechanical energy to electrical energy for charging a battery, the new hybrid generator-storage cell utilizes mechanical energy more efficiently than systems using separate generators and batteries.

At the heart of the self-charging power cell is a piezoelectric membrane that drives lithium ions from one side of the cell to the other when the membrane is deformed by mechanical stress. The lithium ions driven through the polarized membrane by the piezoelectric potential are directly stored as chemical energy using an electrochemical process.

By harnessing a compressive force, such as a shoe heel hitting the pavement from a person walking, the power cell generates enough current to power a small calculator. A hybrid power cell the size of a conventional coin battery can power small electronic devices – and could have military applications for soldiers who might one day recharge battery-powered equipment as they walked.

“People are accustomed to considering electrical generation and storage as two separate operations done in two separate units,” said Zhong Lin Wang, a Regents professor in the School of Materials Science and Engineering at the Georgia Institute of Technology. “We have put them together in a single hybrid unit to create a self-charging power cell, demonstrating a new technique for charge conversion and storage in one integrated unit.”

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http://dx.doi.org/10.1021/nl302879t

[phantom power]

1. "stored as chemical energy using an electrochemical process" == "battery"

just sayin.

[OKIsItJustMe]

2. I hear you, and yet…

http://pubs.acs.org/doi/abs/10.1021/nl302879t

[font size="4"]Hybridizing Energy Conversion and Storage in a Mechanical-to-Electrochemical Process for Self-Charging Power Cell[/font]

…


Energy generation and energy storage are two distinct processes that are usually accomplished using two separated units designed on the basis of different physical principles, such as piezoelectric nanogenerator and Li-ion battery; the former converts mechanical energy into electricity, and the latter stores electric energy as chemical energy. Here, we introduce a fundamental mechanism that directly hybridizes the two processes into one, in which the mechanical energy is directly converted and simultaneously stored as chemical energy without going through the intermediate step of first converting into electricity. By replacing the polyethylene (PE) separator as for conventional Li battery with a piezoelectric poly(vinylidene fluoride) (PVDF) film, the piezoelectric potential from the PVDF film as created by mechanical straining acts as a charge pump to drive Li ions to migrate from the cathode to the anode accompanying charging reactions at electrodes. This new approach can be applied to fabricating a self-charging power cell (SCPC) for sustainable driving micro/nanosystems and personal electronics.

[phantom power]

3. yeah, it's a cool design - I'd call it an integrated packaging innovation

there's no "wire" -- the piezo-electrons (is that a word?) directly drive a chemical reaction, if I'm getting the explaination.