Improvement of elevated-temperature performance of LiL02Cr0. 1MnLg04 cathode material by silicious sur- face modification was studied. The Lil0Cr0. 1lMnl. 904 cathode material was treated by silanes coupling agent and then heated at 580℃ to remove organic material. The structures of the modified and unmodified Li1. 02Cr0. lMn1. g04 were characterized by SpectraPlus, SEM and XRD. The results show that the surface layer of Li1. 02Cr0. 1Mnl. 904 ma- terial is found to be rich in silicious compound. X-ray diffraction show that all the samples have perfect spinel structure. The electrochemical characterization of modified Li1. 02Cr0. 1Mnl904 cathode material was tested. The cycle stability of charge/discharge at 55℃ is improved. The results of the charge/discharge curves show that the modi- fied LiCralMnl. 904 has better performance than those unmodified according to the inhibition of decline of reversible capacity of spinel Li1. 02Cr0. 1Mnl. 904. Therefore, cycle performance is improved so obviously that 86. 03% of the initial capacity is preserved after 100 cycles.

Olivine-type LiFePO4/C composite cathode materials were synthesized by a solid-state reaction methodin an inert atmosphere. The glucose was added as conductive precursors before the formation of the crystallinephase. The effects of glucose content on the properties of as-synthesized cathode materials were investigated. Thecrystal structure and the electrochemical performance were characterized by X-ray diffraction (XRD), scanningelectron microscopy (SEM), laser particle-size distribution measurement and electrochemical performance testing. The material has a single crystal olivine structure with grain-sizes ca. 100-200rim. SEM micrographs and thecorresponding energy dispersive spectrometer (EDS) data confirm that the carbon particulates produced by glucosepyrogenation are uniformly dispersed among the LiFePO4 grains, ensuring a good electronic contact. Impedancespectroscopy was used to investigate the ohmic and kinetic contributions to the cell performance. It is found thatincreasing the carbon content leads to a reduction of the cell impedance due to the reduction of the charge transferresistance. The galvanostaticaUy charge and discharge tests show that the material obtained by adding 10% C (bymass) gives a maximum discharge capacity of 140.8mA. h. g, 1 at the same rate (C/10). The material also displaysa more stable cycle-life than the others.

采用固相反应法在惰性气氛中合成了橄榄石型LiFePO/C复合正极材料，考察了焙烧温度对目标材料性能的影响，采用XRD、SEM、TG-DSC、激光粒度分布以及电化学测试等手段对该材料进行了结构表征和性能测试。结果表明，完美的结晶、较小的粒径以及与导电剂的良好接触是产物具有优良电化学性能的保证。于750℃下制得产物的结构完整，表面形貌较好，粒经分布均匀，具有良好的电化学性能。在室温及0.05C充放电倍率下，该材料的首次放电容量为142.5mA•h/g，循环50次后，未见明显衰减。

从LaNiO的B位掺杂出发，采用溶胶-凝胶法制备了一系列掺杂co和Fe离子的高催化活性的LaNj-Co（Fe）vC，型钙钛矿电催化剂。并进一步研究了催化剂对于氧还原反应和氧析出反应的电催化性能。筛选出最佳催化活性的催化剂一将LaNiOxFe03和LaNio催化剂制备的双功能氧电极初步应用于MH-空气蓄电池：结果表明：使用较高催化活性的LaNi0为氧电极催化剂的电池性能比使用LaNi08Fe203为催化剂的电池高，但是电池放电容量的衰减比LaNiFe203为催化剂的电池大。这是由于钙钛矿催化剂晶格内的co离子不如Fe离子稳定造成的，两种催化剂制备的双功能氧电极都在152 h的充放电循环时间内保持了比较好的工作状态。

Treated FeS2 samples were prepared by natural FeS2 samples which were ground first, heated in nitrogen and then washed in acid. The levels of impurity elements, primarily present asmetallic oxides and sulfides, are higher in the natural FeS than those in the treated sample. Scan-ning electron microscopy shows that the grain sizes of treated FeS:, particles are smaller than thoseof natural FeS2 particles. The electrochemical performance of Li/treated FeS2 cells is attributed tothe smaller grain sizes and higher purity of treated FeS particles in comparison to the natural FeSsample.