摘要
碳量子点独特的量子限域效应、小尺寸效应以及丰富的表面缺陷及官能团,为其在电极材料的设计和构筑中提供了多元的可能性。以褐煤为原料,采用化学氧化法制备碳量子点(CQDs)。以CQDs为基本结构单元,采用冰模板法构筑二维炭片(CSs),经后续炭化改性制备改性炭片(CSs-t)。对样品的形貌及微观结构进行了系统表征并采用恒流充放电及循环伏安测试探究CSs-t用作钠离子电池负极材料的电化学性能。结果表明:借助冷冻干燥过程中冰模板的作用,可实现零维CQDs到二维炭片的定向组装。在后续炭化过程中,炭化温度对CSs-t的微观结构有重要影响。当炭化温度为700℃时,CSs-700片层结构发育完整,横向尺寸可达微米级,具有适宜的表面杂原子含量(11.13%)。在连续导电网络作用下,CSs-700展示出优异的循环稳定性和良好的倍率性能。在50 mA/g的电流密度下首次充电比容量为161 mAh/g,对应的首次库伦效率为42.8%,当电流密度增大到2 A/g时,仍能保持63 mAh/g的比容量,在1 A/g大电流密度下经历1000次循环后容量保持率为101.6%。
The unique quantum-limited effect,small size effect,abundant surface defects and functional groups of carbon quantum dots provide diversified possibilities in the design and construction of electrode materials.Carbon quantum dots(CQDs)were prepared by chemical oxidation method using lignite as raw material.The two-dimensional carbon sheets(CSs)were constructed by ice template method with CQDs as the structural units,combined with subsequent carbonization treatment to obtain modified carbon sheets(CSs-t).The morphology and microstructure of the samples were characterized systematially,and the electrochemical performances applied as anode for sodium-ion batteries(SIBs)of CSs-t were further investigated via galvano-static charge-discharge(GCD)and cyclic voltammetry(CV)tests.The results show that the directional assembly from zero-dimensional CQDs to two-dimensional carbon sheets can be realized by applying the effect of ice template in the freeze-drying process.In addition,the carbonization temperature is an important factor affecting the microstructure of CSs-t.When the carbonization temperature is 700℃,CSs-700 owns a well-developed lamellar structure with micron-level dimensions and a suitable surface hetero-atom content of 11.13%.When used as anode materials for SIBs,CSs-700 exhibits excellent cycling stability and acceptable rate performance owing to the effect of continuous conductive networks.In particular,the optimal CSs-700 electrode can deliver an initial charge capacity of 161 mAh/g at a current density of 50 mA/g,and the initial coulombic efficiency is 42.8%.At a higher current density of 2 A/g,the reversible capacity is maintained at 63 mAh/g.Moreover,after 1000 cycles at a high current density of 1 A/g,the capacity retention rate can be up to 101.6%.
作者
王俊冰洁
邢宝林
张兆华
赵会会
蒋振东
张文豪
张越
张传祥
WANG Junbingjie;XING Baolin;ZHANG Zhaohua;ZHAO Huihui;JIANG Zhendong;ZHANG Wenhao;ZHANG Yue;ZHANG Chuanxiang(College of Chemistry and Chemical Engineering,Henan Polytechnic University,454003 Jiaozuo,China;Collaborative Innovation Center of Coal Work Safety and Clean High Efficient Utilization Jointly Built by the Ministry and the Province,454000 Jiaozuo,China;Henan Key Laboratory of Coal Green Conversion,454000 Jiaozuo,China)
出处
《煤炭转化》
CAS
CSCD
北大核心
2023年第2期53-63,共11页
Coal Conversion
基金
国家自然科学基金资助项目(52074109,52274261,51974110)
河南省高校科技创新人才支持计划项目(21HASTIT008)
国家级大学生创新创业训练计划项目(202110460011,S202110460065).
关键词
褐煤
碳量子点
炭片
钠离子电池
负极材料
lignite
carbon quantum dots
carbon sheets
sodium-ion batteries
anode materials
作者简介
第一作者:王俊冰洁,硕士生,E-mail:wjbjhpu@163.com;通信作者:张传祥,博士、教授,E-mail:zcx223@163.com;邢宝林,博士、教授,E-mail:baolinxing@hpu.edu.cn。
