Study On Pretreatment And Elecrochemical Properties Of Pyrite

The pyrite as Li/FeS2 battery cathode materials have been studied hotly for long time. Li/FeS2 as a new-style lithium battery has been drawn close attention because of their many excellent characteristics including:high specific energy working voltage, low spontaneous discharge rate, good leaking resistance, wide working temperature range, safe and has no pollution and so on. Studies were done in this paper on pyrite physicochemical and structural after being thermally treated and relation of those changes with battery performances.The pyrite was heated at 100℃～550℃respectively. To those samples, the test of content as follows:the change of stability in pyrite powder during heating was studied by TG and DTA methods, the stack of density,electrolyte absorbing quantity and FeS2 content; the XRD was used to study crystal structure; the SEM was used to study changes of particle appearance; and the influence of discharge capacity. After heat-treatment at 400℃,the electrochemical performance test showed that the discharge capacity was 450.7,500.5and670.9 mAh·g-1 under current density of 3,0.5and0.2 mA·cm-2,respectively.In this work, effects of the positive electrode, The emphases of research were the influence of conduct electricity, binder and the electrolyte on Li/FeS2 battery safety and discharge performance. We used orthogonal tests to seek the optimized synthesis technology. Discharge performances of batteries were tested, AA type of Li/FeS2 primary battery discharged to 1.1Vwith 1000mAh,and it was 6.5-7 times higher than alkaline Zn/MnO2 battery. The Li/FeS2 primary battery discharged to 0.8Vwith 10 Q, and it was 2～2.5 times higher than alkaline Zn/MnO2 battery.The electrode-preparing technology on characteristics of the electrode had been investigated detail. The electrodes were prepared by two methods:pressing-film and coating method. The pressing-film technology was adopted. The powder size of the positive materials must be controlled to smaller, the surface of electrodes would be smooth and well-proportioned. And then we can get an electrode with better performances. The pressing-film could be enhanced by 5% at high discharge rate.