Modern wearable electronic devices call for the development of energy storage solutions that match practical requisites like mechanical flexibility, safety and small environmental impact. Conventional battery architectures find limited application due to their rigid and brittle structure. 

In the Flexible Nanoelectronics Lab, we implement green manufacturing processes to fabricate flexible battery electrodes, for applications in Lithium-ion and Aluminium-ion chemistries. Natural biopolymers like nanocellulose are integrated with battery-active materials such as graphite, offering a more sustainable way forward in powering low-consumption, flexible Internet of Things devices such as healthcare and commercial wearables. In this case, the interwoven nanocellulose fibres act not only as a mechanically robust substrate, but also as short pathways promoting ion transport via a porous structure, from the electrolyte even to the bulk of graphite.

We employ structural and electrochemical characterisation methods including scanning electron microscopy, (electrochemical) atomic force microscopy, solid-state nuclear magnetic resonance spectroscopy, cyclic voltammetry, electrochemical impedance spectroscopy, galvanostatic charge-discharge and chronoamperometry to benchmark battery performance, and perform in-depth studies of the molecular-level charge storage phenomena. Finally, battery flexibility can be assessed via stress tests at various bending angles. These deformable yet efficient energy storage solutions, where performance trade-off is minimised, contribute towards a more diversified market.