Enhanced capacities of carbon nanosheets derived from functionalized bacterial cellulose as anodes for sodium ion batteries

Abstract

We studied carbon nanosheets prepared from bacterial cellulose (BC) and 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) oxidized-BC through carbonization at temperatures ranging from 900 to 1100 °C. Based on experimental results, we propose a comprehensive perspective of Na storage for BC based anode material. The pyrolysis TEMPO-oxidized BC delivers the highest capacity at annealing temperature of 1000 °C under different current densities, and displays excellent rate capability and cyclability. The superior electrochemical performance is attributed to the increasing interlayer distance, rich porous structure and oxygen-containing functional groups. The experimental studies reveal that the introduction of carboxyl is an effective strategy to enhance the specific capacity and cycling stability for Na-ion storage.