稻壳基多孔硬碳的制备及其储钠性能

用稻壳做原料，不同浓度的氢氧化钾溶液做活化剂，采用水热法制备钠离子电池硬碳负极材料.利用X射线衍射（XRD）、扫描电子显微镜（SEM）、比表面积测试系统（BET）和电池性能测试系统，对其结构、形貌和电化学性能进行表征.研究结果表明，用2 mol/L浓度的氢氧化钾做活化剂制备的多孔碳材料（RHPC-1-2）具有37.633 6 m2/g的高比面积且存在大量的微孔和中孔. RHPC-1-2材料具有高的可逆比容量为285 mAh/g和初始库仑效率为72%. RHPC-1-2材料表现出优异的循环性能，在100 mA/g电流密度下，首次循环放电比容量为204 mAh/g，循环100次后容量仍有200 mAh/g，容量几乎没有衰减. RHPC-1-2材料也表现出优异的倍率性能，在25 mA/g、50 mA/g、100 mA/g、200 mA/g和500 mA/g电流密度下放电比容量分别是265 mAh/g、247 mAh/g、213 mAh/g、170 mAh/g和112 mAh/g，当电流密度又是25 mA/g时，RHPC-1-2材料的放电比容量几乎没有下降. 

Preparation and sodium-storing property of rice husk-based porous hard carbon

The hard carbon anode materials (RHPC-1-2 and RHPC-1-1) of sodium ion batteries were prepared by hydrothermal method using rice husk as the raw material and different concentrations of potassium hydroxide solution as the activator. The structure, morphology and electrochemical properties of the materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), specific surface area test system (BET) and battery performance test system. The results showed that the porous carbon material (RHPC-1-2) prepared by taking 2 mol/L potassium hydroxide as the activator had a high specific area of 37.6336 m2/g and formed a large number of micropores and mesopores. The RHPC-1-2 material had a high reversible specific capacity of 285 mAh/g and an initial coulombic efficiency of 72%. The RHPC-1-2 material exhibited excellent cycle performance: its discharge specific capacity was 204 mAh/g in the first cycle, and the capacity was still 200 mAh/g after 100 cycles at a current density of 100 mA/g, with almost no attenuation. It also displayed excellent rate performance. Its discharge specific capacities were 265, 247, 213, 170 and 112 mAh/g at different current densities of 25, 50, 100, 200 and 500 mA/g, respectively. When the current density was 25 mA/g, there was nearly no decrease found in the discharge specific capacity of RHPC-1-2 material.