Cellulose as a novel precursor to construct high-performance hard carbon anode toward enhanced sodium-ion batteries

Cellulose, as it has high content and low cost along with the absence of heteroatoms, can well balance the cost and structural consistency issues raised by mass production. Herein, the cellulose-derived hard carbon as an anode material for sodium-ion batteries with high performance has been prepared by a one-step direct carbonization process using pure cellulose as a precursor in the temperature range of 900–1400 °C. Moreover, the effect of carbonization temperature on the microstructure and the sodium battery storage properties of cellulose-derived hard carbon was investigated by structural and morphological characterization, as well as electrochemical performance testing. The results show that the CHC-1300 electrode material displays a high reversible capacity of 373.2 mAh g−1 at 30 mA g−1, and exhibits a desirable cycling stability with 89.7 % capacity retention even after 200 cycles. Furthermore, cyclic voltammetry technique (CV) at different scan rates and galvanostatic intermittent titration technique (GITT) have been employed to explore the sodium storage mechanism and sodium storage kinetics of cellulose-derived hard carbon. The results exhibit that the rate performance of the electrode material would be affected by the low apparent diffusion coefficient of sodium ions in the plateau region. Besides, a full-cell has been assembled with CHC-1300 as the anode and Na0.83Mg0.11Ni0.22Mn0.63O2 (NMNM) as the cathode. The CHC-1300//NMNM full-cell shows high energy density and good cycling stability, which could verify the practical application of the cellulose-derived hard carbon.