The nanomesh material is a three-dimensional nanometer-scale metal grid structure with highly regular internal dimensions that can be used for more efficient batteries, better catalytic convertors, fuel cells and hydrogen production.
The 3D nanowires are horizontally interconnected on multiple levels, showing highly regular internal spacings and dimensions. As a result, it combines high porosity with a 26-fold increase in surface-to-volume ratio. The internal and external dimensions can be tuned to almost any specification, making it potentially compatible with many applications.
"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," said Prof. Philippe Vereecken, scientific director at imec and professor at the bio-engineering faculty of KU Leuven.
The higher surface area means more reactions can occur simultaneously, and the higher the speed or throughput of a process, such as transforming lithium into lithium ions in a battery electrode. This will suport fast charging batteries with higher capacity, as the high porosity also provides a high load of energy-storing material while it remains as a nanometer thin-film in close contact with the current collector. Also, in fuel cells, the metal nano-grid structure of the nanomesh material could simultaneously act as a current collector and a functional catalyst. For example, in the electrolytic production of hydrogen from water, a few-micron of the new
nanomesh material was shown to outperform a 300 times thicker nickel foam of about one millimeter thick.
The material can be quite easily manufactured through cheap anodization and electroplating processes. First, a mold is formed by anodization of aluminum foil. The secret for the regular perforation at the nanoscale lays in the controlled doping of the aluminum metal. The resulting structure acts as a mold in which a large variety of materials can be deposited. After consecutive chemical etching, the mold is being 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 metal foams and aerogels, which are often more rigid or brittle.
"We discovered the three-dimensional nanoporous structure almost