CF_x-Ru复合阴极材料的制备及在锂一次电池中的应用（英文）

CF_x-Ru Composite Cathode for Lithium Primary Battery with Significantly Improved Electrochemical Performance

首次采用简单的原位化学改性方法合成了CFx-Ru复合阴极材料并应用于锂一次电池。与原始CFx材料相比,CFx-Ru在5C的放电倍率下放电容量、放电电压平台和最大功率密度可分别高达605 mAh·g^-1、2 V、8727 W·kg^-1。通过X射线衍射、X射线光电子能谱、扫描电子显微镜和透射电子显微镜对阴极材料结构、化学环境和形貌进行了研究。研究发现,在CFx-Ru复合材料中,nF/nC和C-F2键与C-F共价键的峰面积比都有所降低,这可能是由于RuO2与CFx材料表面或边缘的CF2惰性基团反应所致。这种原位化学反应消耗了非活性的CF2,产生了导电元素钌,并由于气相产物的演化而增加了比表面积。这些特性有助于改善阴极材料的电化学性能。电化学阻抗谱和N2吸附-脱附测试结果也进一步证实了改性材料拥有较大的比表面积和优异的电导率。

CFx-Ru cathode materials for lithium primary batteries were synthesized by a simple in-situ chemical modification for the first time.Compared with pristine commercial CFx,CFx-Ru exhibited an improved capacity of 605 mAh·g^-1 and a maximum power density of 8727 W·kg^-1 with a plateau of 2 V at 5C,which shows a promising application in the market.The structure,chemical environment and morphology were investigated by X-ray diffraction,X-ray photoelectron spectroscopy,scanning electron microscopy and transmission electron microscopy.It is found that the ratio of F to C(nF/nC)and the peak area ratio of the C-F2 bond to the C-F covalent bond in CFx-Ru were both lowered,which is supposed to come from the reaction of RuO2 with CF2 inert group of CFx materials in situ synthesis.This in-situ chemical reaction consumed inactive CF2,produced conductive elemental ruthenium,and increased specific surface area due to gas phase product evolution.These features contribute to the excellent electrochemical performance of the modified material.The improved conductivity and larger specific surface area were further comfirmed by the results of electrochemical impedance spectroscopy and N2 adorption-desorption measurements.