A New Strategy by Australian Researchers Presents Improvements to Advanced Energy Storage

Today, the demand for new energy storage solutions that are clean, inexpensive, and can cope with modern challenges is higher than ever. We need it to help manage the growing proportion of renewable energy in electricity grids, move off-grid communities away from diesel and fossil fuels, and connect those that currently have no access to power. 

Researchers at the University of Technology Sydney (UTS) claim to have developed a system that stores hydrogen by bonding it with solid materials such as magnesium nanoparticles. Professor Aguey-Zinsou's new technology could provide energy at as little as two cents per kilowatt-hour and is expected to be patented within weeks,
 

A New Type of Cathode

Although lithium-ion batteries (LIBs) have many useful advantages and applications, other abundant metallic elements are available, such as sodium, zinc, potassium, and aluminum.

These elements have similar chemistries to lithium and have been extensively researched. Recent examples of innovations using them are sodium-ion batteries (SIBs), potassium-ion batteries (ZIBs), and aluminum-ion batteries (AIBs).  

However, despite the promising aspects relating to redox potential, energy density, and the batteries' potential applications, the development of these LIB alternatives (so-called 'beyond-LIBs') has been impeded by a lack of suitable electrode materials. 

"Beyond-lithium-ion batteries are promising candidates for high-energy-density, low-cost, and large-scale energy storage applications. However, the main challenge lies in developing suitable electrode materials," Professor Wang, Director of the UTS Centre for Clean Energy Technology, said.

 

Beyond-lithium-ion batteries are a promising field of investigation for low-cost, large-scale energy storage. Image credited to University of Technology Sydney

 

Interface Strain Engineering

New research by the team describes a strategy using interface strain engineering in a 2D graphene nanomaterial, which produces a new type of cathode. Strain engineering is the process of fine-tuning a material's properties by altering its mechanical or structural attributes. 

"This research demonstrates a new type of zero-strain cathodes for reversible intercalation of beyond-Li+ ions (Na+, K+, Zn2+, Al3+) through interface strain engineering of a 2D multilayered VOPO4-graphene heterostructure," Wang said. 

According to the researchers, they achieved a high specific capacity of 160 mAhg-1 d and a large energy density of ~570 W h kg-1 when applied as cathodes in K+-ion batteries. This, they claim, is the best performance to date. Moreover, the as-prepared 2D multilayered heterostructure can also be extended as cathodes for high-performance SIBs, ZIBs, and AIBs. 

 

Addressing the Greatest Challenges for Energy Storage 

Since one of the biggest challenges facing the development of advanced energy storage solutions is the absence of suitable cathode material, the team's research could prove to be a promising strategy to utilize strain engineering of 2D materials for advanced energy storage applications.

It could also be applied to many other nanomaterials for the rational design of electrode materials for applications beyond lithium-ion chemistry.