Unique nanomesh material promises battery improvements

2 min read

imec, the research and innovation hub, and KU Leuven, have presented a novel nanomesh material that they claim could mean a breakthrough in a variety of sustainable-application sectors.

The nanomesh material is a three-dimensional nanometer-scale (metal) grid structure with highly regular internal dimensions. Its combination of unique material properties and the ease of manufacturing, suggests it could become widely applicable in (sustainable) industrial applications e.g. more efficient batteries, better catalytic convertors, fuel cells and hydrogen production.

The material is a 3D structure of nanowires that are horizontally interconnected on multiple levels, showing highly regular internal spacings and dimensions. As a result, it combines high porosity with an unprecedented surface-to-volume ratio.

For each micrometre thickness, there is a 26-fold increase of available surface area. To visualize this: when filling a volume of a small can of soda, it would remain 75% empty while containing a surface area equal to the size of a football field. On top of that, the internal and external dimensions can be tuned to almost any specification, making it potentially compatible with a multitude of application requirements.

Many industrial processes build on chemical reactions that (need to) occur at a surface. The more surface available, the more reactions that can occur simultaneously, and the higher the speed or throughput of the process.

Imec’s nanomesh material can enable high-capacity and fast-charging batteries, because its large surface combined with high porosity features a high load of energy-storing material while it remains as a nanometre thin-film in close contact with the current collector. Also, in fuel cells, the metal nano-grid structure of the material could simultaneously act as a current collector and a functional catalyst.

This unique material can also be easily manufactured through cheap anodization and electroplating processes. First, a mould is formed by anodization of aluminium foil. The controlled doping of the aluminium metal creates a structure that acts as a mould in which a large variety of materials can be deposited. After consecutive chemical etching, the mould is dissolved and a self-standing nanomesh structure remains. On a macroscopic level, the self-standing nanomesh is a flexible foil, giving it another edge over its closest competitors (metal foams and aerogels), which are often more rigid or brittle.

Commenting Prof. Philippe Vereecken, scientific director at imec and professor at the bio-engineering faculty of KU Leuven, said: “We have high expectations for this new nanomaterial. Its greatest strengths lie in the regularity of its structure, the large open structure and the conformability of its dimensions. We discovered the three-dimensional nanoporous structure almost 10 years ago, but only during the PhD research of Stanislaw Zankowski, the uniqueness of this material became clear.

"The spaces between the nanowires were small when using the traditional templated nanowire processes. Stan optimised the fabrication process to obtain the large porosity, so that it can now be optimally leveraged in many applications.”