ExFolia - Powerful, printed & recyclable batteries made from leaves

Duration: 01 June 2024 - 30 November 2025

Funding amount: €249,062.91

Funding by: SAB / EFRE

Summary:

The rapid development of electronics over the last 50 years has formed the basis for the digital transformation of our everyday lives and work environments, as well as driving global economic growth. In particular, electronics is a key economic factor in Saxony, and its importance is expected to grow in the future. However, the electronics industry also represents unsustainable economic practices: environmental damage due to harmful extraction methods, environmentally hazardous manufacturing processes, and the rapid increase in electronic waste are major challenges. This problem is further exacerbated by new applications such as the Internet of Things (IoT).

A key technology for sustainable IoT circuits, such as energy-autonomous sensors and communication systems, is rechargeable, recyclable thin-film batteries. Without these batteries, it is impossible to integrate IoT components into a sustainable life cycle. Thus, these batteries represent a central future technology in the electronics industry.

At the Institute of Applied Photophysics (IAPP) at TU Dresden, we have been developing innovative materials and processes for years to enhance resource efficiency in electronics. A key focus is on substrate materials made from leaf skeletons, which are derived from nature and can be fully composted. On these leaves, we have successfully fabricated, disassembled, and recycled functional circuits. In addition, we have developed the prototypes of thin-film batteries on leaf substrates.

In the ExFolia project, our research aims at the production and optimization of printed, rechargeable thin-film batteries based on functionalized leaf membranes. The leaf not only serves as a substrate but also acts as an ion-selective membrane, which enhances the energy density and stability of the batteries. Our goal is to develop batteries with a voltage of >3.7V, a capacity of 80mAh, and a lifespan of more than 100 charge cycles. Additionally, a recycling protocol will be developed to ensure the compostability of all components.

This project targets the growing thin-film battery market, which is projected to reach $1.8 billion by 2031. With our innovation, we aim to introduce the first fully sustainable battery, offering a cheaper and more environmentally friendly alternative to current options.