In order to improve the adhesion of the middle frequency magnetic sputtered zirconium coating on a polyurethane film,an anode layer source was used to pretreat the polyurethane film with nitrogen and oxygen ions.SEMs ...In order to improve the adhesion of the middle frequency magnetic sputtered zirconium coating on a polyurethane film,an anode layer source was used to pretreat the polyurethane film with nitrogen and oxygen ions.SEMs and AFM roughness profiles of treated samples and the contrast groups were obtained.Besides,XPS survey spectrums and high resolution spectrums were also investigated.The adhesion test revealed that ion bombardment could improve the adhesion to the polyurethane coating substrate.A better etching result of oxygen ions versus nitrogen predicts a higher bonding strength of zirconium coating on polyurethane and,indeed,the highest bonding strengths are for oxygen ion bombardment upto 13.3 MPa.As demonstrated in X-ray photoelectron spectroscopy,the oxygen ion also helps to introduce more active groups,and,therefore,it achieves a high value of adhesion strength.展开更多
钾离子电池(PIBs)面临的一个关键问题是设计具有先进结构的负极材料,以实现快速电荷传输以提高钾的存储性能.采用碳二亚胺铁(FeNCN)作为阳极,由于其含有一定数量的共价键且在分子水平上具有稳定的结构,使得储钾系统能够实现优异的电化...钾离子电池(PIBs)面临的一个关键问题是设计具有先进结构的负极材料,以实现快速电荷传输以提高钾的存储性能.采用碳二亚胺铁(FeNCN)作为阳极,由于其含有一定数量的共价键且在分子水平上具有稳定的结构,使得储钾系统能够实现优异的电化学性能.FeNCN阳极具有高导电性,带隙接近0 eV,并且由于其共价键结构具有良好的结构稳定性.此外,无定形反应产物也为离子扩散提供了多种途径.因此,FeNCN阳极表现出高可逆比容量(在50 mA g^(-1)电流密度下具有600 mA h g^(-1)比容量),显著的倍率性能和长寿命循环(电流密度为500 mA g^(-1)时拥有400 mA h g^(-1)比容量且超过300次循环).通过理论模拟、X射线原位衍射分析和X射线光电子能谱分析揭示了Fe^(2+)和K^(+)之间的转化反应机理.此外,将FeNCN负极与苝-3,4,9,10-四羧酸二酐正极材料匹配,组装成的全电池在198.6 Wkg^(-1)的功率密度下实现了184.7 W h kg^(-1)的超高能量密度,明显高于以往所有铁基负极的PIBs或钾离子混合电容器.展开更多
The coupling between electrochemically active material and conductive matrix is vitally important for high efficiency lithium ion batteries （LIBs）. By introducing oxygen groups into the nanoporous carbon framework, ...The coupling between electrochemically active material and conductive matrix is vitally important for high efficiency lithium ion batteries （LIBs）. By introducing oxygen groups into the nanoporous carbon framework, we accom- plish sustainably enhanced electrochemical performance for a SnO2/carbon LIB. 2-5 nm SnO2 nanoparticles are hydro- thermally grown in different nanoporous carbon frameworks, which are pristine, nitrogen- or oxygen-doped carbons. Compared with pristine and nitrogen-doped carbon hosts, the SnO2/oxygen-doped activated carbon （OAC） composite ex- hibits a higher discharge capacity of 1,122mAhg^-1 at 500 mA g^-1 after 320 cycles operation and a larger lithium storage capacity up to 680 mAhg-I at a high rate of 2,000 mA g^-1. The exceptional electrochemical performance originated from the oxygen groups, which could act as Lewis acid sites to attract electrons effectively from Sn during the charge process, thus accelerating reversible conversion of Sn to SnO2. Meanwhile, SnO2 nanoparticles are effectively bonded with carbon through such oxygen groups, thus preventing the electrochemical sintering and maintaining the cycling stability of the SnO2/OAC composite anode. The high electrochemical performance, low biomass cost, and facile preparation renders the SnO2/OAC composites a promising candidate for anode materials.展开更多
文摘In order to improve the adhesion of the middle frequency magnetic sputtered zirconium coating on a polyurethane film,an anode layer source was used to pretreat the polyurethane film with nitrogen and oxygen ions.SEMs and AFM roughness profiles of treated samples and the contrast groups were obtained.Besides,XPS survey spectrums and high resolution spectrums were also investigated.The adhesion test revealed that ion bombardment could improve the adhesion to the polyurethane coating substrate.A better etching result of oxygen ions versus nitrogen predicts a higher bonding strength of zirconium coating on polyurethane and,indeed,the highest bonding strengths are for oxygen ion bombardment upto 13.3 MPa.As demonstrated in X-ray photoelectron spectroscopy,the oxygen ion also helps to introduce more active groups,and,therefore,it achieves a high value of adhesion strength.
基金financially supported by the National Natural Science Foundation of China(52074113,22005091 and 22005092)Hunan University Outstanding Youth Science Foundation(531118040319)+4 种基金the Science and Technology Innovation Program of Hunan Province(2021RC3055)Changsha Municipal Natural Science Foundation(43184)the CITIC Metals Ningbo Energy Co.,Ltd.(H202191380246)Chongqing Talents:Exceptional Young Talents Project(CQYC202105015)Shenzhen Virtual University Park Basic Research Project of Free exploration(2021Szvup036)。
文摘钾离子电池(PIBs)面临的一个关键问题是设计具有先进结构的负极材料,以实现快速电荷传输以提高钾的存储性能.采用碳二亚胺铁(FeNCN)作为阳极,由于其含有一定数量的共价键且在分子水平上具有稳定的结构,使得储钾系统能够实现优异的电化学性能.FeNCN阳极具有高导电性,带隙接近0 eV,并且由于其共价键结构具有良好的结构稳定性.此外,无定形反应产物也为离子扩散提供了多种途径.因此,FeNCN阳极表现出高可逆比容量(在50 mA g^(-1)电流密度下具有600 mA h g^(-1)比容量),显著的倍率性能和长寿命循环(电流密度为500 mA g^(-1)时拥有400 mA h g^(-1)比容量且超过300次循环).通过理论模拟、X射线原位衍射分析和X射线光电子能谱分析揭示了Fe^(2+)和K^(+)之间的转化反应机理.此外,将FeNCN负极与苝-3,4,9,10-四羧酸二酐正极材料匹配,组装成的全电池在198.6 Wkg^(-1)的功率密度下实现了184.7 W h kg^(-1)的超高能量密度,明显高于以往所有铁基负极的PIBs或钾离子混合电容器.
基金supported by the National High Technology Research and Development Program of China(2012AA053305 and 2014AA052501)the National Natural Science Foundation of China(21506224)
文摘The coupling between electrochemically active material and conductive matrix is vitally important for high efficiency lithium ion batteries （LIBs）. By introducing oxygen groups into the nanoporous carbon framework, we accom- plish sustainably enhanced electrochemical performance for a SnO2/carbon LIB. 2-5 nm SnO2 nanoparticles are hydro- thermally grown in different nanoporous carbon frameworks, which are pristine, nitrogen- or oxygen-doped carbons. Compared with pristine and nitrogen-doped carbon hosts, the SnO2/oxygen-doped activated carbon （OAC） composite ex- hibits a higher discharge capacity of 1,122mAhg^-1 at 500 mA g^-1 after 320 cycles operation and a larger lithium storage capacity up to 680 mAhg-I at a high rate of 2,000 mA g^-1. The exceptional electrochemical performance originated from the oxygen groups, which could act as Lewis acid sites to attract electrons effectively from Sn during the charge process, thus accelerating reversible conversion of Sn to SnO2. Meanwhile, SnO2 nanoparticles are effectively bonded with carbon through such oxygen groups, thus preventing the electrochemical sintering and maintaining the cycling stability of the SnO2/OAC composite anode. The high electrochemical performance, low biomass cost, and facile preparation renders the SnO2/OAC composites a promising candidate for anode materials.
