Enhanced sodium storage kinetics of nitrogen rich cellulose-derived hierarchical porous carbon via subsequent boron doping

Abstract

Doping engineering is of great importance in adjusting the electronic conductivity, structural defects and energy storage performance of carbonaceous materials. Herein, a stepwise heteroatoms doping engineering is designed to modify cellulose-derived hierarchical porous carbons (HPC) with rich nitrogen (N@HPC) and subsequent boron (B@N@HPC). The effect of boron doping on nitrogen rich HPC is investigated to reveal the evolution of microstructures, porosity, surface area, and chemical groups. It is found that boron doping cannot further change the interlayer distance of nitrogen-rich HPC, but B@N@HPC exhibits excellent electrochemical performance as an anode in sodium ion batteries (SIBs). Compared with N@HPC, B@N@HPC anodes show a larger capacity of 308 mAh g−1 at 0.02 A g−1, which is 137% larger than that of nitrogen doped HPC. Electrochemical Kinetics analysis through galvanostatic intermittent titration technique (GITT) and electrochemical impedance spectroscopy (EIS) suggests a capacitive-dominated process combined with a higher Na+ diffusion coefficient and lower charge transfer resistance for the B@N@HPC than that of N@HPC. The effect of boron doping on the carbon anodes can be taken to explore an enhanced performance for SIBs.