不同分子量前驱物热解硬碳负极材料的储钠性能  

Sodium storage performance of hard carbons prepared by pyrolyzing precursors with different molecular weight

作　　者：邱珅 吴先勇[1] 卢海燕[1] 艾新平[1] 杨汉西[1] 曹余良[1] 

机构地区：[1]武汉大学化学与分子科学学院,湖北武汉430074

出　　处：《储能科学与技术》2016年第3期335-340,共6页Energy Storage Science and Technology

基　　金：国家重点基础研究发展计划(973)(2015CB251100);国家自然科学基金重点项目(21333007)和面上项目(21373155)

摘　　要：硬碳已成为最具实用化钠离子电池负极材料的研究热点,然而其热解前驱物结构对储钠性能的影响仍鲜有报道。本文选择了具有相同结构单元、不同分子量的3种糖类前驱物(葡萄糖、蔗糖和淀粉)作为结构模型,系统考察了前驱物分子量对硬碳材料微观结构和储钠性能的影响。X射线粉末衍射(XRD)、透射电镜(TEM)和拉曼光谱(Raman)实验表明,硬碳材料的石墨化程度随着分子量的增大而增加;恒电流充放电测试表明,葡萄糖、蔗糖和淀粉热解硬碳的可逆储钠容量也随分子量的增大呈现出逐渐增加的趋势,其容量分别为242、275和310 m A·h/g。本工作的初步结果说明,大分子量的前驱物更容易热解形成较为规整的类石墨片层结构,从而提供了更多的嵌钠反应位点,这为选择合适的硬碳前驱体去发展高性能储钠碳负极材料提供了借鉴参考。Hard carbon anode materials have attracted wide attention for the development of practical sodium ion batteries. However, the effect of the structure of pyrolytic precursor on sodium storage performance of the hard carbon was rarely reported. In this article three different carbohydrate precursors are chosen to investigate the influence of their molecular weight on the microstructure and sodium storage property of the final pyrolyzed hard carbons. Results of X-ray powder diffraction（XRD）, transmission electron microscopy（TEM） and Raman spectroscopy（Raman） showed that the graphitization degree of the hard carbon materials increases with molecular weight of their precursors. The reversible specific capacity of the hard carbons with glucose, sucrose and starch as precursors reached 242, 275 and 310 m A·h/g respectively, indicating its proportional relationship with the molecular weight of the precursors, and a precursor with high molecular weight is easier to form a more regular graphite-sheet structure, thereby providing more fitted and more sodium reaction sites. This work provides a reference for selecting the precursor of hard carbon as anode material of sodium-ion batteries.

关 键 词：钠离子电池 硬碳 负极 糖类 分子量 

分 类 号：O646.21[理学—物理化学]