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991.
G.?Perentzis E.?Horopanitis I.?Samaras S.?Kokkou L.?PapadimitriouEmail author 《Journal of Solid State Electrochemistry》2003,8(1):51-54
Cathode powders of the Li–Mn–Ni–O system have been prepared at a Mn/(Mn+Ni) ratio varying from 0 to 1. The solid state reaction method was used to obtain the cathode materials by mixing MnO2, LiCO3 and NiO. A 20% excess of lithium was used in the precursors. The materials produced were examined by X-rays to identify their structure. Batteries were assembled by using these materials as cathode with a liquid electrolyte consisting of EC/DC 1:1, 1 LiPF6 and Li anode. Their capacity, cycle fading and charge-discharge conditions were evaluated.Presented at the 3rd International Meeting "Advanced Batteries and Accumulators", June 16th–June 20th 2002, Brno, Czech Republic 相似文献
992.
The glass-forming composition regions of aqueous tetraalkylammonium nitrate solutions (alkyl = ethyl and n-propyl) were determined by a simple DTA method with a cooling rate of about 600 K-min–1. The glass transition temperatures Tg of these solutions vary in a different manner from those for simple inorganic salt solutions such as aqueous LiCl, MgCl2,and AlCl3 solutions. Liquid-liquid immiscibilities are observed in these solutions at low temperatures. 相似文献
993.
The X-ray absorption spectra (XAS) of LiCoO2, LiCo1/2Ni1/2O2 and LiNiO2 were examined together with X-ray diffraction (XRD). Co and Ni K-edge XANES spectra of LiCo1/2Ni1/2O2 are quite similar to that of LiCoO2 or LiNiO2, suggesting that electronic states of Co and Ni in LiCo1/2Ni1/2O2 are Co3+ and Ni3+. Analytical results of Co and Ni K-edge EXAFS oscillations on the first coordination shell of nickel and cobalt ions in LiCo1/2Ni1/2O2 indicate that the local environment around the targeted species is the same as that in LiCoO2 or LiNiO2. Since there is no doubt about the crystal and electronic structures of LiCoO2 and LiNiO2, the results indicate that LiCo1/2Ni1/2O2 consists of low-spin states of Co3+ and Ni3+ distributed at equivalent positions in triangular lattice of sites forming homogeneous transition metal oxide layers. Thus,
XAS complements XRD in describing solid solution LiCo1/2Ni1/2O2 of LiCoO2 and LiNiO2. The electrochemical behaviors of LiCoO2, LiCo1/2Ni1/2O2 and LiNiO2 are also restated and the effects of the formation of solid solution on the change in lattice dimension during topotactic
electrochemical reactions are discussed. 相似文献
994.
新型正极材料三硫代环磷氮烯无机聚合物的合成 总被引:1,自引:0,他引:1
采用缩合聚合方法合成了新型三硫代环磷氮烯无机聚合物[(NPS3)3]n,利用红外光谱测试与元素含量分析技术证明了[(NPS3)3]n的分子结构与组成,并对聚合物材料的粒度、比表面积及微观形貌进行了考察。TG/DTA 实验证明材料在200 ℃ 以下具有良好的热稳定性。循环伏安测试表明[(NPS3)3]n正极材料在锂电池体系具有2.15 V的电化学还原电位和2.45 V的电化学氧化电位,经充放电循环实验观察,材料的首次放电容量达到749.0 mAh·g-1,与理论容量(759.0 mAh·g-1)十分接近;经过50次充放电循环后,放电容量保持在674.8 mAh·g-1,具有很高的使用容量和优秀的循环性能。 相似文献
995.
Pedro Bernal Sherril D. Christian Edwin E. Tucker 《Journal of solution chemistry》1986,15(11):947-956
An automated vapor pressure apparatus has been used to obtain measurements of the vapor pressure of aqueous solutions of fluorobenzene at temperatures of 15, 25, 35, and 45°C, and in the concentration range 0 to 0.011M. The results have been interpreted to infer the dimerization constant of fluorobenzene in very dilute aqueous solutions, equivalent to the second virial coefficient of interaction between fluorobenzene molecules. The hydrophobic association of fluorobenzene molecules is thermodynamically quite similar to that of benzene at comparable temperatures and concentrations. A dimerization constant of fluorobenzene of 0.56 M–1 at 30°C and an endothermic enthalpy of association equal to 3.9 kcal-mol–1 are calculated from the measurements. 相似文献
996.
George A. Vidulich Francis X. Gleason James F. Lynch William C. Mattern Robert McCabe 《Journal of solution chemistry》1972,1(3):263-267
Determination of potassium ion conductances directly from measurements of boundary velocities and solution potential gradients are reported for water, urea-water, methanol, and urea-methanol solutions. The results are interpreted in terms of the structure-breaking role generally assigned to urea in aqueous solutions. 相似文献
997.
在金属氢化物一镍电池(MH/Ni)负极材料中,ABS型贮氢合金是非常具有吸引力的一种,以AB。型贮氢合金作为负极材料的MH/Ni电池目前已大批量进入市场.其中A代表混合稀土RE(主要成分为La,Ce,Pr,Nd);B代表Ni和Co,Mll,AI等取代元素.B侧取代元素已被广泛研究D,习,A侧混合稀土的成分也已引起人们的广泛重视*‘,’],*血1c等【阿针对儿一N13。5C00.75Mll。。A10.3,详细研究了L31。CI。BS系列合金,得出在。=0.2处合金具有较好的综合性能.本文针对B侧Ni。。。Coo,。Mno、。Alo二。(记为民)成分,在研… 相似文献
998.
Akitoshi Hayashi Takanori Konishi Kiyoharu Tadanaga Tsutomu Minami Masahiro Tatsumisago 《Research on Chemical Intermediates》2006,32(5):497-506
SnS-P2S5 and SnO-P2O5 amorphous materials were prepared by a mechanical milling technique. The SnO-P2O5 milled materials worked as a reversible electrode with higher capacity than SnO crystal in rechargeable lithium cells with
conventional liquid electrolytes. All-solid-state cells with a SnX-P2X5 (X = S and O) amorphous electrode and the Li2S-P2S5 glass-ceramic electrolyte were charged and discharged at room temperature. The sulfide electrodes exhibited better charge-discharge
performance than the oxide electrodes, suggesting that SnS-P2S5 electrodes are more compatible with Li2S-P2S5 sulfide solid electrolytes. All-solid state batteries 80SnS·20P2S5/LiCoO2 showed a charge-discharge plateau of about 3.4 V and high reversible capacity of over 400 mAh/g, even after 50 cycles. The
SnX (X = S and O)-based amorphous materials are promising negative electrode materials with high capacity for rechargeable
lithium batteries using not only liquid electrolytes but solid electrolytes. 相似文献
999.
Takashi Hayashita Norio Teramae Toshiharu Kuboyama Shigeo Nakamura Hiromasa Yamamoto Hiroshi Nakamura 《Journal of inclusion phenomena and macrocyclic chemistry》1998,32(2-3):251-265
Recent progress in chromoionophores based on (1) spherand and hemispherand, (2) cryptand, and (3) dibenzo-16-crown-5 and calix[4]crown which selectively respond to alkali metal ions in aqueous media is reviewed in relation to their molecular structure and photometric function. The design concept of the chromoionophores for colorimetry in aqueous media is discussed in the light of their acid dissociation and metal complex formation equilibria. 相似文献
1000.
离子交换法制备层状LixNi0.3Mn0.7O2正极材料及其离子交换规律的研究 总被引:5,自引:0,他引:5
通过共沉淀法高温固相反应在空气气氛中合成出具有P2型结构特征的碱青铜前驱体Na0.66Ni0.3Mn0.7O2,研究了在4种不同离子交换条件下进行离子交换反应得到目标正极材料LixNi0.3Mn0.7O2的离子交换规律,并用XRD、SEM、粒度分析和电性能测试考察了目标正极材料及其前驱体的结构、形貌和电化学性能。结果表明,以熔融LiNO3为介质于300 ℃离子交换4h反应进行得最为完全,离子交换率达98 %,且目标正极材料具有较完善的O2型层状结构,在2.6~2.9 V存在唯一的充放电平台,循环过程中未发现向尖晶石相转变;而离子交换时间过长,目标正极材料将出现尖晶石相而影响其放电容量和循环稳定性。 相似文献