热电池铁粉加热药燃烧产物特性

SEM(scanning electron microscope)、TEM(transmission electron microscope)形貌观察及XRD(x-raydiffraction)物相、EDX(energy dispersive X-ray detector)能谱分析表明,热电池用铁粉加热药经燃烧后其物相主要成分为Fe、FeO和KCl,并形成一层200 nm厚FeO壳层,该壳层包覆着未反应的Fe核.经导电类型鉴别确定室温下该材料具有以空穴导电为主的P型半导体导电特性.电导率103S.cm-1,比800 K时Fe的电导率低5个数量级.该材料虽具半导体导电特性,但并不增加热电池内阻.

Combustion Product Characterization of the Iron-Heated Powders in Thermal Batteries

The combustion products of thermal battery used iron-heated powders have been studied.It is identified by X-ray diffraction(XRD) analysis that the main compositions of the combustion products are Fe、FeO and KCl.The transmission electron microscopy(TEM) shows a typical core-shell structure with un-reacted Fe particle core coated by FeO shell with a shell thickness of around 200 nm.The combusted iron-heated powders exhibit no metal property,which is contrast to previous assumption.Further measurement indicates that at the ambient temperature the combustion products show semiconductor property of the p-type with conductivity in the order of 103 S·cm-1,which is five order lower than that of the iron at 800 K.Since the FeO layer formed during the iron-heated powders combustion is thin,its contribution to the internal resistance of the thermal batteries is negligible.