The rapid development of renewable energy resources has triggered tremendous demand for large-scale, high-density, and cost-efficient stationary energy storage systems, and presents a challenge to the energy transition. However, researchers at the Sydney University of Technology may have potentially overcome it.
Lithium-ion batteries (LIBs) have many advantages, but there are much more abundant metallic elements available, such as sodium, potassium, zinc and aluminium, which have similar chemistries.
According to the university, they have seen these elements investigated in the form of potassium-ion, aluminium-ion, sodium-ion, and zinc-ion batteries, with exciting technologies like graphene and vanadium-based storage holding promise. However, tapping the true potential of these technologies relies on until-now-elusive electrode materials.
New research led by Professor Guoxiu Wang from the University of Technology Sydney, and published in Nature Communications, describes a 2-dimensional (2D) graphene nanomaterial, made using interface strain engineering to produce a new type of cathode. Strain engineering involves the tuning of a material’s properties by altering its mechanical or structural attributes.
“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,” explains Professor Wang, Director of the UTS Centre for Clean Energy Technology.
“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 2-D multilayered VOPO4-graphene heterostructure.
“When applied as cathodes in K+-ion batteries, we achieved a high specific capacity of 160 mA h g-1 and a large energy density of ~570 W h kg-1, presenting the best-reported performance to date. Moreover, the as-prepared 2-D multilayered heterostructure can also be extended as cathodes for high-performance Na+, Zn2+, and Al3+-ion batteries.”
The researchers say this work represents a promising opportunity to utilise strain engineering of 2D materials for advanced energy storage applications.
“The strategy of strain engineering could be extended to many other nanomaterials for rational design of electrode materials towards high energy storage applications beyond lithium-ion chemistry,” Professor Wang said.