From waste to energy storage: calcinating and carbonizing chicken eggshells into electrode materials for...

The presented study aims to explore the potential sources of common bio-wastes that could be successfully processed without any leftovers into materials for energy conversion and storage devices. We used chicken eggshells as an environmentally friendly precursor for electrode fillers in electrochemical capacitors (calcinated OS₆₀₀ and OS₉₀₀) and anode materials in Li-ion batteries (carbonized EM₆₀₀ and EM₉₀₀). Both groups of materials were obtained at two different temperatures to investigate the influence of their composition and properties on the electrochemical performance. Electrochemical capacitors with OS₆₀₀ and OS₉₀₀ substituted for 10 wt% of commercial activated carbon supplied similar capacitances, with OS₆₀₀ stabilizing the long-term performance of the device. Also, both obtained anode materials are suitable for operation in Li-ion batteries, supplying a capacity of around 280 mA h g^-1. Notably, EM₉₀₀ is characterized by a well-developed structure, and as an anode, it exhibited better capacity retention of over 84%.