Sugar based battery developed ...o...

A Battery That Runs OnSugar Could Soon BePowering Your Electronics

DINA SPECTORJAN. 23, 2014, 9:54 AM

Nearly all living cells break down sugar to produceenergy. By mimicking what plants and animals donaturally, researchers at Virginia Tech say they havedeveloped a battery that can store the most energy for itsweight using sugar as a fuel source.

The battery technology could serve as the next generationof green power sources, researchers reported in a studypublished Jan. 21 in the journal Nature Communications.

Most gadgets today run on lithium-ion batteries, whichare costly. Lithium is a limited resource with the majorityof the world's supply found in Bolivia, China, Chile,Argentina, and Australia.

Sugars, on the other hand, are abundant in supply andsafe to use.

In the study, researchers found that the best fuel was asugar solution made of 15% maltodextrin, which is aproduct of corn starch.

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Virginia Tech College of Agriculture and Life Sciences

teries connected in a series to power a digital clock.

In a fuel cell, the maltodextrin mixture was combined withair to generate electricity with water as the mainby-product.

In animals, proteins called enzymes inside cells are usedto "burn" sugars, converting them into carbon dioxide,water, and stored energy. The reactions are carried out ina sequence known as a biological pathway, where asubstrate (sugar in this case) is converted into a productby the first enzyme. The product of the first reaction isthen handed off to another enzyme as the startingcompound for the next reaction — and so on until the finalproducts are created.

Here, researchers created a completely new enzymepathway that is not found in nature. "We put a lot ofenzymes from different sources into one pot," Y.H.Percival Zhang, the lead author of the paper and aprofessor at Virginia Tech told Business Insider via email.

Researchers have used sugar to power batteries before,but they were not able to store that much energy.

In previous cases, Zhang says, the sugar concentrationwas too high and this impacted how well the enzymescould do their jobs — not as many electrons were strippedfrom the sugar molecules.

This time, scientists came up with the right blend ofenzymes and fuel.

"The lifetime of the battery depends on the sugar


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A diagram of the enzymatic fuel cell. The purple blobsare the enzymes. The electrons flow in through thecathode and out through the anode

concentration, plus how many electrons are extracted perglucose," Zhang said.

The maltodextrin solution is unique in that it can bebroken down slowly through the synthetic enzymepathway "to generate nearly constant power output ratherthan a peak power over short time," the study authorswrote.

Basically, the system works so well because the catalysts


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convert all of the energy stored in the sugar moleculesinto energy that can be harnessed by something like yourcellphone.

The new device, which is about the size of a AAA battery,has an energy density that is 10 times higher than bothlithium-ion and previous iterations of sugar-poweredbatteries, according to the paper. The new battery couldlast at least two times longer than lithium-ions for thesame weight.

In addition, where regular batteries have to be thrownaway when the lithium gets used up, the sugar fuel cellcan be recharged by filling it with more sugar solution.

There are still challenges. Although enzymes are plentiful,

unlike metal catalysts, they don't last that long (an

enzyme in the human body, for instance, only exists for a

couple of days before being replaced by the cell). These

proteins are also extremely sensitive to temperature —

drop a few degrees and they won't work as efficiently.

To be practical in a laptop or a cellphone, the enzymeswould need to last for several months or even years.Tweaking the enzymes' structures could make thathappen.

Even though the sugar battery stores a high amount ofenergy for its mass, the maximum amount of power it canput out is still lower than that of lithium-ions, thuslimiting its potential applications to portable devices (youcouldn't use a sugar battery to run vehicles, for instance).

The team says that the sugar fuel cell could be ready tointegrate into our electronics in three years and willeventually be at least one-tenth the cost of lithium-ion


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A comparison of energy densities among different types of batteries is shownthe chart. The deep purple bar, representing a sugar solution containing 15%malodextrin was tested in the study.

batteries.

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Sugar based battery developed ...o...

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