KAIST researchers developed a hybrid aqueous energy storage device

By Warren Miller,
contributing writer

Longer lasting, more quickly chargeable batteries are in
higher demand than ever before. Lithium-ion batteries are in everything from
cell phones to electric vehicles, but they aren’t the only game in town, and
there may be some new competition on the horizon. Researchers at the Korean
Advanced Institute of Science and Technology (KAIST) have created a hybrid aqueous battery that is
capable of fully charging in 20 seconds or less
.

The aqueous hybrid capacitor is essentially a small amount
of liquid electrolyte held between an anode and a cathode. The anode is made up
of graphene-like polymer chain materials which have a high surface area, and
therefore higher capacitance. The cathode is a blend of nickel oxide nanoparticles
applied to graphene – the nickel oxide increases the rate of atom-by-ion redox
reactions, while the graphene increases capacitance. The net result is an
aqueous battery that is significantly more stable than its predecessors,
maintaining almost 100% of its energy capacity over 100,000 charging cycles.

“This eco-friendly technology can be easily manufactured and
is highly applicable. In particular, its high capacity and high stability,
compared to existing technologies, could contribute to the commercialization of
aqueous capacitors,” said Professor Jeung Kang, leader
of the team from KAIST’s Graduate School of Energy, Environment, Water, and
Sustainability. “The device can be rapidly charged using a low-power charging
system, and thus can be applied to a portable electronic device.” 

Image source: KAIST.

Another major benefit of the aqueous hybrid capacitor is
safety because it doesn’t use any dangerous chemicals or solvents, it is safer
for both people and the environment. Previous iterations of aqueous batteries
have low energy density and poor storage capacity, but the KAIST team has
seemingly eliminated these drawbacks with their innovative new design. The
battery can be fully charged using a low-power charging system (like a phone
charger you plug into the wall or a USB port) in about 20 to 30 seconds.

This is a good example of the ways in which complex polymer
chain molecules, nanotubes and molecules with even more complex topologies can
replace scarce or environmentally unfriendly materials. Will we be able to find
even more fantastic applications for complex structures made out of common
materials like carbon, silicon, oxygen, and hydrogen? And can we meld the
structural capabilities of these materials with energy generation, energy
storage, and electro-mechanical movement to create entire self-sufficient
systems?

In the near term, however, just a more efficient battery can
be a dramatic improvement. What could this mean for the future of portable
electronics? A battery that is not only safer but more effective than its
lithium-ion-based counterparts would seem like a pretty good bet to make a big
splash on the market — if and when it becomes commercially available, that
is. In the long run, we might see aqueous batteries incorporated into electric
cars at some point in the future. Can you imagine charging your Tesla in 30
seconds?