Preparation of hard carbons derived from rambutan peel as anodes for sodium ion battery

Abstract

In this work, hard carbons were prepared from the Indonesian rambutan peel using the combination method of hydrothermal carbonization and KOH activation (RPHC). Based on the morphology and physical characterizations, RPHC had a naturally nitrogen doping, a highly porous structures with surface area of 2145 m2/g, a large interlayer spacing (d002) and honey comb like morphology. The RPHCs were then utilized as anode materials for sodium ion batteries (SIBs). The electrochemical characterizations were then studied by cyclic voltammetry (CV), galvanostatic charge discharge and electrochemical impedance spectroscopy. The RPHC electrodes demonstrated a stable cycle performance, showing a specific capacity of 252 mAhg-1 after 100 cycles at a current density of 100 mA g-1. It was attributed to the unique morphology of hard carbons, large interspacing and defect carbon structures due to the naturally nitrogen doping.