Pt基催化剂对金属氧化物助催化作用

介绍金属氧化物修饰Pt基催化剂作为直接甲醇燃料电池用阳极催化剂的研究工作,重点阐述了催化剂的结构和组成对反应机理的影响,探讨了存在的主要问题和发展前景.     

高利用率多壁碳纳米管负载金铂合金纳米粒子催化剂在碱性溶液中的甲醇电催化氧化性能研究

使用乙二醇还原法合成了一系列高利用率多壁碳纳米管负载的金铂双金属纳米粒子电催化剂,在碱性溶液中由循环伏安和计时电流法测试该AuPt催化剂对于甲醇氧化反应的电催化活性.透射电子显微镜、X射线衍射与X射线能谱观测催化剂形貌,表征催化剂结构.结果表明,金铂双金属纳米粒子均匀分散在碳纳米管上,催化剂具有良好甲醇电氧化性能.实验表明Au/Pt/MWCNTs比为10∶8∶32(bymass)时,该催化剂具有最高甲醇电氧化峰电流密度与最负起始氧化电位.     

锂离子电池用具有分级三维离子电子混合导电网络结构的纳微复合电极材料

文章评述了分级三维离子电子混合导电网络结构和具有该结构的纳微复合电极材料在锂离子电池中的应用等方面的最新研究工作进展.首先介绍了纳微复合电极结构相关概念及其优缺点,然后列举了一些运用此概念设计并构筑出的电极材料实例.研究证明,此新型电极结构能够大幅提高锂离子电池电极材料的储锂性能,并且该结构设计还可推广到其他电化学储能...     

A High-Temperature β-Phase NaMnO_2 Stabilized by Cu Doping and Its Na Storage Properties

The high-temperature β-phase NaMnO_2 is a promising material for Na-ion batteries(NIBs) due to its high capacity and abundant resources. However, the synthesis of phase-pure -NaMnO_2 is burdensome and costineffective because it needs to be sintered under oxygen atmosphere at high temperature and followed by a quenching procedure. Here we first report that the pure β phase can be stabilized by Cu-doping and easily synthesized by replacing a proportion of Mn with Cu via a simplified process including sintering in air and cooling to room temperature naturally. Based on the first-principle calculations, the band gap decreases from 0.7 eV to 0.3 eV, which indicates that the electronic conductivity can be improved by Cu-doping. The designed -NaCu_(0.1)Mn_(0.9)O_2 is applied as cathode in NIBs, exhibiting an energy density of 419 Wh/kg and better performance in terms of rate capability and cycling stability than those in the undoped case.     

Computational screening of doping schemes for LiTi2(PO4)3 as cathode coating materials

In all-solid-state lithium batteries,the impedance at the cathode/electrolyte interface shows close relationship with the cycle performance.Cathode coatings are helpful to reduce the impedance and increase the stability at the interface effectively.LiTi2(PO4)3(LTP),a fast ion conductor with high ionic conductivity approaching 10^-3S·cm^-1,is adopted as the coating materials in this study.The crystal and electronic structures,as well as the Li^+ion migration properties are evaluated for LTP and its doped derivatives based on density functional theory(DFT)and bond valence(BV)method.Substituting part of Ti sites with element Mn,Fe,or Mg in LTP can improve the electronic conductivity of LTP while does not decrease its high ionic conductivity.In this way,the coating materials with both high ionic conductivities and electronic conductivities can be prepared for all-solid-state lithium batteries to improve the ion and electron transport properties at the interface.     

Moessbauer study and magnetic properties of electrochemical material LiFePO4

Magnetic properties and crystal symmetry of electrochemical material LiFePO4 have been investigated by Moessbauer spectroscopy and magnetization measurement. Magnetization reveals the antiferromagnetic nature of LiFePO4. Temperature dependence of inverse susceptibility and that of hyperfine field confirm that there is an antiferromagnetic-paraxaagnetic transition at about 50K.     

纳米储锂材料和锂离子电池

简单综述了锂离子电池的基本原理和发展现状，对中国科学院物理研究所固体离子学课题组在纳米储锂材料方面的研究进展做了介绍。用HRTEM等手段研究了纳米SnO、纳米Si以及纳米SnSb合金在Li入脱嵌过程中结构的变化。着重介绍了一种具有纳米微孔的球形硬碳材料和纳米SnSb合金钉扎的复合负极材料，在高功率密度和高能量密度锂离子电池方面具有广阔应用前景。     

分散第二相γ-Al2O3对β-Li2SO4离子导电性的影响

本文研究了分散第二相γ-Al₂O₃对β-Li₂SO₄离子导电性的影响。β-Li₂SO₄(γ-Al₂O₃)的电导率随γ-Al₂O₃含量的增加而提高,到γ-Al₂O₃为50mol％时达到极大。当温度为253℃时,β-Li₂SO< 关键词：