LiCoO_2在酸性焙烧过程中Co元素赋存状态的演变研究

Co Element Occurrence Evolution in Sulphating Roasting Process of LiCoO_2

本文以Li Co O2在酸性焙烧环境中元素的化学演变特点为研究对象,采用TG-DSC、XRD、SEM等对Li Co O2在酸性焙烧过程中的重量变化、热量变化、物相组成变化、形貌变化等进行了研究。TG-DSC研究结果表明：Li Co O2与Na HSO4·H2O在300℃~460℃温度范围内将发生化学反应,温度范围内的元素的存在形式是研究的终点。XRD的研究结果表明：当温度在300℃时,Co元素以Co SO4·H2O的形式存在;当温度升到400℃时,钴元素以Na2Co（SO4）2形式存在,随温度进一步升高,450℃和500℃时,钴的赋存形式不变。SEM的研究结果表明：随着焙烧温度的升高,Li Co O2与Na HSO4·H2O焙烧后产物的形貌没有明显发生变化,但其表面的块状物慢慢消失,最后全部转化为熔融态。

In this paper, regarding chemical element evolution characteristics of Li Co O2 roasting in the acidic environment as the research object, the weight, heat changes, phase composition and morphology changes were studied by TG, DSC, XRD, SEM, etc in process of acid roasting of the Li Co O2. TG-DSC results indicate that： chemical reaction of Li Co O2 with Na HSO4·H2O mixture will occur in 300℃~460℃ temperature range and the temperature range of phase evolution should be the end of the study. XRD results indicate that： when the temperature rises to 350℃, the cobalt element exists in the form of Na2Co（SO4）2. With the temperature rise further, 400℃ and 450℃, the occurrence of cobalt form remains the same. SEM results indicate that： As the calcination temperature, Li Co O2 with Na HSO4·H2O morphology of the-calcined product is not significantly changed, but the surface of the lumps disappear slowly, and finally completely converted to a molten state.