High-Performance Electrolytes Compatible with Avocado Carbon–Calcium Batteries

The escalating demand for lithium-ion batteries has intensified the search for new energy storage solutions that are both high-performing and cost-effective. Calcium-ion batteries (CIBs) have emerged as a promising alternative due to calcium's natural abundance and lower cost compared to lithium. However, the development of suitable electrodes and electrolytes for rechargeable calcium batteries remains a significant challenge. In this study, we convert avocado peels into high-purity, porous hard carbon powder through a simple and sustainable process. This avocado-derived hard carbon serves as an effective anode material for CIBs. This study also develops high-performance electrolytes that enhance compatibility with the hard carbon anode. Electrochemical tests show that the avocado-derived hard carbon anode delivers robust calcium-ion storage capabilities, exhibiting stable cycling performance over 80 charge-discharge cycles. These results indicate that using biomass-derived hard carbon from avocado peels is a viable and environmentally friendly approach for advancing calcium-ion battery technology, contributing to the development of sustainable energy storage systems.