Researchers Combine Salt with Metal Oxides to Dramatically Increase Energy Storage Capacity

Daniel Butler
Sun, 27 May 2018
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An international consortium of US and Chinese researchers has discovered that increasing the surface area of metal oxides with the addition of salt significantly increases their energy storage capability.

The team consists of researchers from Drexel University in the US, Huazhong University of Science and Technology (HUST) and Tsinghua University in China. The findings of their research were published in the scientific journal Nature Communications.

The findings show that salt crystals can be used as the foundation to grow thin sheets of conductive metal oxides, allowing the materials to form in larger and more chemically pure molecules. This makes them better adapted to collecting ions and, therefore, storing energy.

 “The challenge of producing a metal oxide that reaches theoretical performance values is that the methods for making it inherently limit its size and often foul its chemical purity, which makes it fall short of predicted energy storage performance,” explained Jun Zhou, a leading author of the study.

“Our research reveals a way to grow stable oxide sheets with less fouling that are on the order of several hundreds of times larger than the ones that are currently being fabricated,” added Zhou, who is also a professor at HUST’s Wuhan National Laboratory for Optoelectronics.

A Long Way To Go

In principle, the ideal materials in this context would be very thin sheets of metal oxides as their chemical arrangement and high surface area make it easy for electrically charged ions to attach, which is the essence of energy storage.

However, according to the research, the metal oxide sheets that have been developed so far still have a way to go before they reach their theoretical potential.

“The trick in this work is that the crystal structure of salt must match the crystal structure of the oxide, otherwise it will form an amorphous film of oxide rather than a thin, strong and stable nanocrystal. This is the key finding of our research – it means that different salts must be used to produce different oxides,” added Gogotsi.

Although this development is in the early stages of real-world application, it signifies a massive breakthrough in improving energy storage capacity. “Energy storage is becoming an increasingly integral part of electrical supply, transmission and distribution systems because of its cost saving and grid stabilising potential” explains Kenneth Melvin, Head of Energy at Challenge Advisory. “Any progress in increasing energy storing capacity only makes it a more attractive venture for developers, therefore intensifying the expansion of energy storage in the energy industry.”