Development of Secondary Batteries by suing Graphite Intercalation Compounds

本课题的研究目的是通过将电化学活性物质保持在石墨结构廊内，同时具有高导电性，从而了解石墨插层化合物（GICs）上的基本电化学反应。受体型集成电路二次电池的研制。以相应的金属氯化物- gics为原料，在KOH水溶液中电解制备了Ni (OH) _2-Fe (OH) _3和Ni (OH) _2-Cu (OH) _2-GICs三元化合物。以Ni (OH) _2-GICs为正极的二次电池具有良好的充放电性能。实验结果表明，该电极的放电活化能约为2 kcal/mol，约为Ni (OH) _2和石墨粉混合电极放电活化能的一半。这种低活化能使大电流密度放电成为可能。在KBr水溶液中，通过对基体石墨进行阳极氧化，发现了溴- gics的形成。在还原过程中，观察到两个潜在的平台，这似乎对应于脱插过程中的阶段转变过程。这为开发结构简单的二次电池提供了新的可能性。供体型GICs二次电池研制的基础研究。用循环伏安法研究了碱金属离子（Li^+、Na^+、K^+和Rb^+）的电化学插入和脱插。检测了明确的插层和脱层过程，并通过电化学插层得到了含碱金属离子的第2阶段GICs。从电极电位随时间的变化来看，K-GIC的自放电程度较低。钾- gic可以吸收大量的气体，如氢、氨、四氢呋喃、苯等。研究了K-GICs的电导率、磁阻和霍尔系数随气体吸收的变化。通过对氨的吸收，观察到导电电子从石墨向中间层的反向捐赠。少

The purpose of the present research project is to understand the basic electrochemical reactions on graphite intercalation compounds (GICs) which have high activity by keeping electrochemicall active materials in the gallery of graphite structure and also have high electrical conductivity.1. Development of secondary batteries with acceptor-type GICs.Ternary Ni (OH) _2-Fe (OH) _3 and Ni (OH) _2-Cu (OH) _2-GICs were prepared from corresponding metal chlorides-GICs by electrolysis in KOH aqueous solution. A secondary battery by using Ni (OH) _2-GICs as cathode showed excellent performance of charging and discharging processes. The activation energy for the discharging process in these ternary GICs was determined to be about 2 kcal/mol, which was roughly half of that in a conventional electrode of a mixture of Ni (OH) _2 and graphite powders. This low value of activation energy was supposed to make the discharge with large current density possible.The formation of bromine-GICs was found by … More anodic oxidation of host graphite in KBr aqueous solution. On the process of reduction, two potential plateaux were observed, which seemed to correspond to stage transformation processes during de-intercalation. This suggests a new possibility to develop a secondary battery with simple construction.2. Fundamental studies on the development of secondary batteries with donor-type GICs.Electrochemical intercalation and de-intercalation of alkali metal ions (Li^+, Na^+, K^+ and Rb^+) were studied by cyclic voltammetry. Well-defined intercalation and de-intercalation processes were detected and the stage-2 GICs with respective alkali metal ions were obtained by electrochemical intercalation. From the changes of electrode potential with time, K-GIC was suggested to have low degree of self discharging.Potassium-GICs could absorb large amount of gases, such as hydrogen, ammonia, tetrahydrofuran, benzene, etc. The changes of electrical conductivity, magnetoresistance and Hall coefficient of the K-GICs with the absorption of these gases were studied in-situ. A back-donnation of conduction electrons from graphite to intercalate layers were observed by the absorption of ammonia. Less