“We are proposing that these models based on the nanoarchitecture of the material are more comprehensive, detailed, informative and accurate compared to the porous media model”Haleh Ardebili
A team from the University of Houston and Texas A&M University in the US have combined to develop a new material and an innovative approach to modeling for energy storage. They demonstrated a new structural supercapacitor electrode that is produced from reduced graphene oxide and aramid nanofiber, a breakthrough that could lead to lightweight materials for energy technologies.
With the huge and increasing use of mobile electronic devices, as well as other technologies such as electric vehicles and drones, has come great demand for lightweight materials that offer sufficient power to operate them. As reported in the paper ‘Comparison of Nanoarchitecture to Porous Media Diffusion Models in Reduced Graphene Oxide/Aramid Nanofiber Electrodes for Supercapacitors’, published in the journal ACS Nano [Aderyani et al. ACS Nano (2020) DOI: 10.1021/acsnano.9b07116], the new electrode has proven to be more robust and versatile than standard carbon-based electrodes.
Properties such as porosity, tortuosity and effective diffusivity are key to understanding the behaviour and performance of the material. The researchers also showed that modeling from the material nanoarchitecture can bring greater accuracy to research on ion diffusion and other properties in the composite electrodes than that achieved through the porous media model, which is the conventional modeling technique.
Improved accuracy in modeling methods will provide assistance in identifying new and more effective nanoarchitectured materials that offer longer battery life and higher energy while also being of lighter weight. As corresponding author Haleh Ardebili said “We are proposing that these models based on the nanoarchitecture of the material are more comprehensive, detailed, informative and accurate compared to the porous media model”.
The reduced graphene oxide and aramid nanofiber material has useful and robust electrochemical and mechanical properties. Supercapacitor electrodes are usually made of porous carbon-based materials, which provide efficient electrode performance. Although the reduced graphene oxide is mostly comprised of carbon, the aramid nanofiber provide a mechanical strength that improves the versatility of the electrode for a range of applications, including military.
While convenient, it is thought conventional, porous media-based, models do not offer sufficient precision for designing new nanoarchitectured materials, as well as for assessing these electrode materials and other energy storage devices. Porous media models tend to assume uniform pore sizes within the material, rather than measuring the different dimensions and also the geometric properties of the material. The team showed that modeling based on the material nanoarchitecture can help offer a more accurate understanding of ion diffusion and other properties in composite electrodes.