ENERGY STORAGE A new system shows potential for advanced energy storage

| Author / Editor: Luke James / Johanna Erbacher

A research team at the University of Technology Sydney claim that new types of cathodes can be developed using beyond-lithium ion batteries. Today, there is growing demand for new energy storage solutions. These solutions need to be clean, inexpensive, and robust enough to stand up to modern challenges.

Lithium-ion alternatives represent a promising solution for low-cost, large-scale energy storage
Lithium-ion alternatives represent a promising solution for low-cost, large-scale energy storage
(Source: University of Technology Sydney)

Although there are plenty of applications for these solutions, one of the most important is the storage and management of renewable energy in electricity grids which is currently an area of significant research interest.

Now, researchers at the University of Technology Sydney (UTS) claim to have developed a system that stores hydrogen by bonding it with solid materials. The team says that it expects its system, which could provide energy at a cost as little as two cents per kilowatt hour, to be patented imminently.

Developing suitable electrode materials

Although current lithium-ion battery technology has several advantages and is the backbone of electronics of the day, lithium may one day be in short supply, and other abundant metallic elements such as sodium, zinc, potassium, and aluminium are available. All these metals have similar chemistries to lithium and have been the subject of recent research.

In fact, they have even been used to develop alternatives such as sodium-ion batteries (SIBs) and potassium-ion batteries (ZIBs). However, despite the promising aspects relating to energy density and applications for these batteries beyond the scope of current lithium-ion battery technology, the development of these alternatives (‘beyond-LIBs’) has been hampered 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 the development of suitable electrode materials," Professor Wang, Director of the UTS Centre for Clean Energy Technology, said.

A new type of zero-strain cathode for high-performance alternatives

The UTS team’s research, which was recently published in Nature Communications, outlines their strategy which uses interface strain engineering in a 2D graphene nanomaterial to fine-tune its properties by altering its structural attributes. This, the researchers claim, creates a new type of cathode.

"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 multi-layered VOPO4-graphene heterostructure,” Wang said.

The researchers 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. They claim that this is the best reported performance ever to date and further, that the 2D multi-layered heterostructure can be extended and used as cathodes for high-performance SIBs, ZIBs, and other beyond-LIBs.

With the absence of suitable cathode materials representing one of the biggest challenges for the development of advanced energy storage solutions, the UTS team’s research could prove to be a promising way forward. It could also be applied to many other nanomaterials for the design of electrode materials beyond lithium-ion chemistry.