We herein report the preparation of SIBs using carbon anodes based on spray-dried cellulose nanocrystals (CNCs) carbonized over a wide temperature range (i.e., 800–2500 °C). The structural variations in the CNC-based carbon anodes are correlated with the sodiation mechanism by investigating the galvanostatic voltage profiles, and it is found that Na ion adsorption takes place in the less-ordered carbonaceous structures followed by intercalation into the more ordered internal carbon structure with an average interlayer spacing of >0.37 nm. Among the various anodes examined, the CNCs carbonized at 1500 °C (C1500) deliver the highest reversible specific capacity of 311 mA h g⁻¹ at a current density of 10 mA g⁻¹, and exhibit an outstanding rate capability (273 mA h g⁻¹ at 400 mA g⁻¹). In addition, they also possess an excellent specific capacity retention of 92.3% even after 400 cycles at 100 mA g⁻¹, along with an initial coulombic efficiency of 85%. Density functional theory (DFT) calculation exhibits that the energy barrier for Na ion intercalation of C1500 (0.20 eV) is almost a half that of the CNCs carbonized at 2500 °C (0.39 eV).

我们在此报告了基于碳阳极的SIB的制备，所述碳阳极基于在宽温度范围（即800–2500°C）下碳化的喷雾干燥纤维素纳米晶体（CNC）。通过研究恒电流电压曲线，将基于CNC的碳阳极的结构变化与成膜机理相关联，发现Na离子吸附发生在无序碳质结构中，然后插入到更有序的内部碳结构中平均层间间距> 0.37 nm。在各种不同的阳极检查中，CNC控制器在1500碳化℃（C1500）递送311毫安汞柱的最高可逆比容量^-1 以10mA g的电流密度^-1，并表现出杰出的速率能力（273毫安汞^{- 1个} 在400 mA g ^-1时）。此外，它们甚至在100 mA g ^-1下经过400次循环后仍具有92.3％的出色比容量保持率，以及85％的初始库仑效率。密度泛函理论（DFT）计算表明，C1500中Na离子嵌入的能垒（0.20 eV）几乎是在2500°C（0.39 eV）碳化的CNC的一半。