Controlling Reversible Expansion of Li2O2 Formation and Decomposition by Modifying Electrolyte in Li-O2 Batteries

锂空电池分别使用空气中的氧气和金属锂作为正负极活性材料，具有极高的能量密度。但是，这一体系尚不能实现商业化的应用，其中一些关键问题未能解决。由于其正极活性材料是气体，使得电化学反应涉及气-液-固三相界面，电极过程十分复杂。与其它二次电池相比，空气电极需要考虑结构因素和催化因素。不仅要改善氧气电化学反应的动力学迟缓问题，还要考虑放电产物的驻留空间问题。董全峰教授课题组在前期开展了基于空气电极固相表面电催化研究，并结合电极结构方面的问题，构筑了有利于氧气发生反应的仿生开放式结构电极。 该研究工作主要由化学化工学院2015级iChEM直博生林晓东（第一作者）在董全峰教授、郑明森副教授和龚磊副教授的共同指导下完成，理论计算由袁汝明助理教授（共同第一作者）完成，曹勇、丁晓兵、蔡森荣、韩博闻等学生参与了部分工作。周志有教授和洪宇浩博士生在电化学微分质谱方面给予大力的帮助与支持。【Abstract】The aprotic lithium-oxygen (Li-O2) battery has attracted worldwide attention because of its ultrahigh theoretical energy density. However, its practical application is critically hindered by cathode passivation, large polarization, and severe parasitic reactions. Here, we demonstrate an originally designed Ru(Ⅱ) polypyridyl complex (RuPC) though which the reversible expansion of Li2O2 formation and decomposition can be achieved in Li-O2 batteries. Experimental and theoretical results revealed that the RuPC can not only expand the formation of Li2O2 in electrolyte but also suppress the reactivity of LiO2 intermediate during discharge, thus alleviating the cathode passivation and parasitic reactions significantly. In addition, an initial delithiation pathway can be achieved when charging in turn; thus, the Li2O2 products can be decomposed reversibly with a low overpotential. Consequently, the RuPC-catalyzed Li-O2 batteries exhibited a high discharge capacity, a low charge overpotential, and an ultralong cycle life. This work provides an alternative way of designing the soluble organic catalysts for metal-O2 batteries.This work was supported by the National 973 Program (2015CB251102), the Key Project of National Natural Science Foundation of China (21673196, 21621091, 21703186, 21773192),and the Fundamental Research Funds for the Central Universities (20720150042,20720150043). The authors thank Prof. Eric Meggers at Philipps-Univeristaet Marburg for his discussion about the synthesis of RuPC complex; Prof. Gang Fu at Xiamen University for his instructive discussions in DFT calculations; Lajia Yu and Dandan Tao at Xiamen University for their assistance in EPR experiments and UV-Vis spectroscopy experiments, respectively; and Yu Gu and Tao Wang at Xiamen University for their discussions in XPS results and CV data,respectively. 该工作得到科技部重大基础研究计划（项目批准号：2015CB251102）、国家自然科学基金（项目批准号：21673196、21621091、21703186、21773192）和中央高校基本科研业务费专项资金（项目批准号：20720150042、20720150043）的资助。 此外，感谢傅钢教授在理论计算方面的讨论和建议，Eric Meggers教授在配合物合成上的讨论，泉州师范学院吴启辉教授和化学化工学院谷宇博士生在X射线光电子能谱方面的帮助，于腊佳老师在电子顺磁共振实验上的帮助，陶丹丹博士生在紫外可见光谱测试上的帮助以及王韬博士生在循环伏安方面的讨论

N Alkylation of 1,2,3 Benzotriazole Catalyzed by KF Alumina

研究了用固体碱kf/Al2O3为缚酸剂，dMf为溶剂，以卤代烃为烷基化剂实现1，2，3-苯并三唑n-烷基化反应.不同的卤代烃，得到不同比例n1及n2烷基化产物，烷基化产率在57%~95%之间.N Alkylation of 1,2,3 benzotriazole catalyzed by KF/Al 2O 3 was studied.Be nzotriazole reacted with alkyl halides on KF/Al 2O 3 in DMF at 30 ℃ for 1 h, giving N 1 and N 2 substituted benzotriazoles in yield of 57%～95%

Microwave Irradiated N Alkylation of 1,2,3 Benzotriazole in Absence of Solvent

报道了无溶剂存在下微波照射的1，2，3-苯并三唑n-烷基化反应，将1，2，3-苯并三唑和烷基化剂（卤代烷）吸附在固体kf/Al2O3上，用强度适当的微波照射2~3MIn，得到相应的n-烷基化产物.N Alkylation of 1,2,3 benzotriazole by microwave irradiation in absence of solvent was studied.1,2,3 Benzotriazole and alkyl halides were absorbed on solid base KF/Al 2O 3,then the mixtures without solvent was irradiated with microwave for 2￣3 minutes, giving N 1 and N 2 substituted 1,2,3 benzotriazoles

玛湖凹陷砾岩裂缝扩展数值模拟

玛湖凹陷砾岩裂缝扩展规律不清晰，其影响因素也不明确。构建多相混合介质砾岩数值模拟模型，对不同加载方式、不同特征砾岩的裂缝扩展规律进行研究。结果表明，砾石含量越高，胶结强度越低，砾石和基质的相对强度越大，则砾岩形成的裂缝越复杂；拉伸载荷和剪切载荷共同作用下砾岩裂缝最为复杂；砾石对砾岩裂缝的吸引作用和屏蔽作用促进砾岩形成复杂缝网

用于太阳能转换的TiO_2与二维碳材料的复合物

石墨烯(GR)具有优异的导电和导热性质,以及大的比表面积,该材料已经被广泛应用于催化和光伏等领域。石墨炔(GD)这种新型的二维碳材料则具有半导体的性质,Malko预测石墨炔的同素异性体可能拥有优于石墨烯的电学性质。我们的研究结果表明TiO2-GD的复合物表现出优于TiO2和其它二维碳材料的复合物光催化性质,包括TiO2-GR复合物。因此我们可以推测,在光催化和光伏等领域,石墨炔将成为包括石墨烯的其它所有不同类型二维碳材料的强劲对手

日本におけるITER超伝導機器の製作

Plasma Conference 2017に参加し、日本が担当するITER用超伝導機器の製作の成果を報告する。Plasma Conference 201

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel