In our ongoing search for renewable energy resources, one of the least attainable thus far has been our own motion. But now, researchers at MIT seem prepared to change that — in a new paper published in Nature Communications, the team details how it developed a “novel class of mechanical energy harvesters via stress–voltage coupling in electrochemically alloyed electrodes,” or in English, motion-powered batteries.
Using electrochemical technology, the researchers have found a way to generate alternating current from the process of bending the new material back and forth. Essentially, the “battery” works by moving lithium ions between two electrodes. “You can think of it as two water tanks, each containing a lot of lithium,” Sangtae Kim, the MIT researcher who authored the recent paper told takepart.com. “In between the tanks we have this layer of electrolyte where only lithium ions can pass. In a conventional battery we move the lithium ions by supplying electricity. In this case, we press one water tank, or electrode, and that moves the lithium ions from the one electrode to the other.”
This new method of energy production, Kim says, has the potential to be far more efficient than say, piezoelectrics, which refers to the generation of electricity from applied pressure. “For piezo, in almost all cases they are made of ceramic materials, which indicate that they don’t really conduct electricity,” Kim said. “So a vast amount of the electricity generated becomes heat.”
And while this new electrochemical method is currently just 15 percent efficient, Kim has high hopes that it could one day become 100 percent efficient.
The new tech is still a ways away from being implemented in real-life situations, however. “Currently it’s only a laboratory version that tests the mechanisms and demonstrates the principles,” Kim noted. “Our next step would be to stack these into the right engineering shape so that this can actually be used in real-life applications.”
So who knows — maybe one day you can charge your phone just by taking it for a walk.