Hard carbon is regarded as a promising anode material for sodium-ion batteries,while it remains a huge challenge to initial coulombic efficiency and rate performance.Numerous studies show that critical structural feat...Hard carbon is regarded as a promising anode material for sodium-ion batteries,while it remains a huge challenge to initial coulombic efficiency and rate performance.Numerous studies show that critical structural features in hard carbon,namely defects,crystallites,and close pores,are directly responsible for the electrochemical performance in sodium-ion batteries.Here,we employ bamboo-derived hard carbon to systematically regulate the defects and crystallites in hard carbon by introducing mechanical activation.Benefiting from ball milling,the intermediate product with a high specific area more easily transforms into hard carbon,which possesses abundant closed pores,effective interlayer spacing,and suitable sodium storage defects,helping to improve the sodium ion storage performance.As a result,the hard carbon ball milled for 20 min presents a high reversible capacity of 315.2 mA·h/g at 17.5 mA/g with an initial coulombic efficiency up to 79.3%,as well as good rate and cycling performances.展开更多
基金Project(2022RC3048)supported by the Science and Technology Innovation Program of Hunan Province,ChinaProject support by the Guangdong Greenway Technology Co.Ltd.,China。
文摘Hard carbon is regarded as a promising anode material for sodium-ion batteries,while it remains a huge challenge to initial coulombic efficiency and rate performance.Numerous studies show that critical structural features in hard carbon,namely defects,crystallites,and close pores,are directly responsible for the electrochemical performance in sodium-ion batteries.Here,we employ bamboo-derived hard carbon to systematically regulate the defects and crystallites in hard carbon by introducing mechanical activation.Benefiting from ball milling,the intermediate product with a high specific area more easily transforms into hard carbon,which possesses abundant closed pores,effective interlayer spacing,and suitable sodium storage defects,helping to improve the sodium ion storage performance.As a result,the hard carbon ball milled for 20 min presents a high reversible capacity of 315.2 mA·h/g at 17.5 mA/g with an initial coulombic efficiency up to 79.3%,as well as good rate and cycling performances.
基金the National Key R&D Program of China(2022YFB3206000)the National Natural Science Foundation of China(U23A20487)+1 种基金Dr.Li Dak Sum&Yip Yio Chin Development Fund for Regenerative Medicine,Zhejiang Universitythe National Natural Science Foundation of China(61975172).
文摘近红外二区(the second near-infrared window,NIR-II,900~1880 nm)荧光成像具有信号背景比高、穿透深度大的优势,在生物医学领域具有广泛的应用前景。对NIR-II成像窗口的划分有利于优化成像过程,其中,NIRIIx(1400~1500 nm)成像窗口得益于其独特的水吸收,可以有效抑制散射背景,实现高对比度成像。文章通过仿真模拟和活体实验,系统评估了NIR-IIx窗口的成像潜力。为了更好地推进NIR-IIx荧光成像的临床转化,研究采用美国食品及药物管理局(FDA)批准的有机小分子染料吲哚菁绿(Indocyanine Green,ICG)作为荧光探针,利用其延伸至NIR-II的荧光发射拖尾,实现了高对比度和清晰度的小鼠血管和肠道的NIR-IIx成像。此外,研究还结合同样通过FDA认证的亚甲基蓝(Methylene Blue,MB),成功实现了高质量的NIR-II双通道成像,精准定位小鼠的血管和淋巴结。文章进一步挖掘了NIR-IIx在生物成像上的独特优势和临床应用的潜力,并为NIR-II荧光成像的临床转化提供了重要参考。
