Eggshells can act as electrodes to power batteries

A researcher who recently received the Higher Doctorate award from Flinders University has developed high-performance sustainable electrode materials from crushed eggshells, marking a significant step towards an advancement in sustainable energy storage and production.

Dr Manickam Minakshi Sundaram’s discovery could reduce landfill by transforming discarded biowaste — such as eggshells — into an economic asset. The research could also address the critical challenge of reshaping how we generate, store and access energy efficiently. Minakshi found that chicken eggshells can be used as electrodes — a conductor of electricity — to power batteries. Eggshells contain a high level of calcium carbonate and when they are baked and crushed, their chemical compositions change and they become a more efficient electrode and conductor of power, according to Minakshi.

“The current lithium-ion batteries used for renewable energy storage typically use fossil fuels. Repurposing a bio-waste product like eggshells could add considerable value to the renewable energy market. They also offer a potentially safer option, as the current lithium battery technologies are high-cost and potentially unsafe in the event of catastrophic failure,” Minakshi said.

Supervisor and Associate Professor of Chemistry Dr Zhongfan Jia said Minakshi’s research findings could have a game-changing impact on the energy sector.

“Dr Minakshi’s work provides deeper insights into organic and inorganic hybrid electroactive materials for energy storage and renewable energy generation, crucial for the transition to a sustainable society. He is to be congratulated for shining a light on the significance of organic materials in creating a smarter, greener future,” Jia said.

The study focused on the development of sustainable electrodes in aqueous-based energy storage technology. Minakshi said that although chicken eggs and related products are used in large quantities in the food processing and manufacturing sectors, along with many other sectors, their shells are typically sent as solid waste to landfill.

“However, eggshell and shell membranes contain a range of active chemical compounds that can be used. The reversibility of this new approach allows for efficient energy storage and retrieval. The study demonstrates that highly conductive aqueous lithium and sodium electrolytes with varying salt concentrations have the potential to replace existing non-rechargeable primary batteries. The discovery holds the promise of high energy capacity, long cycle life and affordability in aqueous batteries,” Minakshi said.

The research also highlights the potential to extend this technology to other waste materials, such as wheat straw, grape marc and mango seeds, all of which could open doors to a new era of environmentally stable batteries.

Image credit: iStock.com/Gearstd