Porous graphdiyne applied for sodium ion storage

Abstract

Sodium ion batteries have gained recognition as an intriguing candidate for next generation battery systems and large scale energy storage devices due to the natural abundance of sodium sources. In this study, we prepared bulk graphdiyne powder with a porous structure and explored its sodium storage properties. The assembled sodium ion batteries exhibited extraordinary electrochemical performance, including moderate specific capacity, long cycle life as well as excellent rate performance, which should be attributed to its unique three-dimensional porous structure, chemical stability and high electronic conductivity. We obtained a reversible capacity of 261 mA h g⁻¹ after 300 cycles at a current density of 50 mA g⁻¹. Even at a high current density of 100 mA g⁻¹, the as-prepared GDY electrodes delivered a moderate specific capacity of 211 mA h g⁻¹ after 1000 cycles, with an excellent capacity retention of 98.2%. The calculation results indicate that most intercalated Na cations stay in a large triangular hole in bulk material.