DESIGN,PREPARATION,PROPERTIES AND MANIFESTATION OF FUNCTIONALITY OF FLUORIDE-GRAPHITE INTERCALATION COMPOUNDS.

1.金属氟化物在AHF溶液中的插层机理。在有氟存在的液体AHF中，四氟化锡与石墨反应生成了2级石墨插层化合物，其同位周期为I_C=11.53 a，而无氟则不发生插层反应。然而，对于四氟化铅，反应继续进行，没有氟产生二级化合物。结果表明，该体系在无氟条件下进行反应，并提出了以下反应机理：xC+PbF_4+2HF*Cx (HF_2) _2+PbF_2PbF_4+4HF <双半箭头> PbF_6^<2->+2H_2F^+Cx (HF_2) _2+PbF_6^<2-> <双半箭头> xpf_6 +2HF_2^-在该体系中，部分PbF_4作为氧化剂生成了GIC.2。氟插层CxF的氟离子传导。离子或半离子C-F成键的CxF阻抗分析表明，石墨廊中的氟离子具有一定的迁移性，表明CxF是氟离子导电的固态电解质。氟嵌入反应及C-F键的性质。石墨在液态HF中被单质氟氧化较长时间（约8小时）通常得到富氟的CxF （x<4）和半离子型C-F键，而单质氟与石墨在室温下直接相互作用产生具有离子型C-F键的CxF （6<x）。通过控制插层反应来控制其化学组成、物理性质和C-F键性质已成为可能。CxF的电化学特性。锂电池的半离子CxF阴极放电反应为非均相放电反应，而离子CxF阴极放电反应为均相放电反应。这种差异导致半离子型CxF阴极的放电性能大大优于离子型CxF阴极。

1.The Intercalation Mechanism in AHF solution of Metal Fluorides.The reaction of tin tetrafluoride with graphite in liquid AHF in the presence of fluorine yields a stage-2 graphite intercalation compound with an identity period I_C=11.53 A,whereas no intercalation reaction occurs without fluorine. With lead tetrafluoride, however, the reaction proceeds without fluorine yielding a stage-2 compound. From the results, it is concluded that reaction in this system proceeds in the absence of fluorine and the following reaction mechanism can be proposed :xC+PbF_4+2HF*Cx (HF_2) _2+PbF_2PbF_4+4HF <double half arrows> PbF_6^<2->+2H_2F^+Cx (HF_2) _2+PbF_6^<2-> <double half arrows> CxPbF_6+2HF_2^-In this system part of PbF_4 acts as an oxidizing agent for the formation of a GIC.2.Fluoride Ion Conduction of Fluorine Intercalated CxF.Impedance analysis of CxF with ionic or semi-ionic C-F bonding has indicated that the fluoride ions in the graphite gallery have some mobility, and that CxF are fluoride ion conducting solid state electrolytes.3. Fluorine Intercalation Reaction and the Nature of C-F Bonding.The longer time (ca.8 hours) oxidation of graphite by elemental fluorine in liquid HF usually give fluorine rich CxF (x<4) with semi-ionic C-F bond, whereas direct interaction of elemental fluorine with graphite at room temperature yields CxF (6<x) with ionic C-F bond. It has become possible to control the chemical composition, physical properties and C-F bond character by controling the intercalation reaction.4.Electrochemical Characteristics of CxF.The discharge reaction of semi-ionic CxF cathode for a lithium cell is a heterogeneous electrodereaction, While that of ionic CxF Cathode is a homogeneous reaction. This difference leads to discharge performances of semi-ionic CxF cathode which is extremely superior to those of ionic CxF.