Tailoring Phosphorene Quantum Dot via Electrochemical Methods for Enhanced Capacity Na-ion Batteries

The development of advanced energy storage technologies has driven significant interest in two-dimensional (2D) materials, particularly graphene, stanene, phosphorene and their analogues, due to their unique structural and electronic properties, as well as their propensity for doping. In this work, we demonstrate an electrochemical approach for tailoring phosphorene quantum dots (PQDs) specifically optimized for sodium-ion battery (SIB) applications using benchmark cathodes and electrolytes. Sodium-ion batteries, as a promising alternative to lithium-ion systems, benefit from the tunable surface area and conductivity provided by size-optimized PQDs, which enhance ion diffusion kinetics and charge storage capabilities. The size-tuning of PQDs is achieved through a controlled electrochemical exfoliation and passivation process, resulting in quantum dots with improved stability and a higher specific capacity. For example, the PQDs coupled with Prussian white analogue (PW) exhibit superior key performance metrics, showing a high discharge capacity of 250 mAg-1 and capacity retention of 77% after 250 cycles, positioning them as a viable candidate for next-generation SIBs. This study presents a pathway for scalable production in SIBs using phosphorene-based materials, laying the groundwork for high-efficiency, sustainable energy storage solutions.