WS2正极的制备及其在铝二次电池中的应用

Synthesis of WS 2 Cathode and Its Application in Aluminium Secondary Batteries

以硫脲为硫源、偏钨酸铵为钨源、氯化钠为模板剂,通过低温处理和化学气相沉积制备层片状二硫化钨(WS2).研究了反应物配比、煅烧温度和保温时间对WS2电化学性能的影响,并通过X射线衍射、扫描电子显微镜、透射电子显微镜、X射线光电子能谱、能量色散光谱等方法对产物的物相组成和微观形貌进行表征.研究结果表明:以反应物n(W):n(S)=1:2.2、煅烧温度为800℃、保温时间为3 h的条件下得到的产物作为铝二次电池正极材料时表现出最佳的电化学性能,放电比容量达105 mAh·g-1,经过160圈循环后容量保持率仍高于90%;AlCl-4的嵌入/脱出是充放电反应的关键;W—Cl键的形成则与电池失效有关.

In this paper,layered WS 2 nanosheets were synthesized by low temperature treatment and chemical vapor deposition,in which thiourea and ammonium metatungstate was used as the source of S and W while sodium chloride used as template.We studied the key factors which may influence on electrochemical properties of WS 2,including the ratios of raw materials,calcining temperature and holding time.Its ingredient and microstructure were analyzed by X-ray diffraction,scanning electron microscope,transmission electron microscope,X-ray photoelectron spectroscopy,X-ray energy dispersive spectrum.According to experiments,the optimized conditions of synthesis were n(W)∶n(S)=1∶2.2,calcining temperature of 800℃and holding time of 3 h.In these conditions,the aluminium batteries had the best electrochemical properties.Its specific capacity was up to 105 mAh·g-1 and retention ratio was above 90%after 160 cycles.Intercalation/de-intercalation of AlCl-4 played an important role in reactions of charge and discharge.Formation of W—Cl bond was related to failure of the batteries.