Oxidation Tuned Cu_1.94S Nanostructures for Ultrafast Charge and Discharge

Morphological control is an effective approach to enhance the rate performance of nanostructured electrode materials, offering a promising solution for alleviating energy concerns. We have utilized a seed-mediated growth method to synthesize hexagonal djurleite (Cu_1.94S) nanoplates and nanoflowers under N₂ and air, respectively. The influence of the morphology on the ion interaction has been investigated in the storage process through half-cell electrochemical energy storage. Cu_1.94S nanoplates performed a higher specific capacity of 193 mAh g⁻¹ at a high rate of 8 A g⁻¹ than nanoflowers and showed excellent cycle stability over 4,000 cycles with capacity retention of 80.8%. The relationship between morphology and electrochemical performance was explored through further electrochemical characterization. It is found that the stacking of hexagonal surfaces of nanoplates increases the contact area of the electrode material and reduced resistance, leading to faster ion migration and a more complete redox process, ultimately contributing to a higher specific capacity. Our study has enhanced the understanding of structure–property relationships for electrode material, providing an insightful approach for the preparation of electrode materials suitable for ultrafast charge and discharge.