论文部分内容阅读
针对高性能锌离子电池的制备,在AOT/异辛烷反相微乳液体系中,以KMnO4为氧化剂,琥珀酸二(2-乙基己酯)磺酸钠(AOT)同时作为表面活性剂和还原剂制备了纳米α-MnO2。借助X射线衍射(XRD)、透射电子显微镜(TEM)和恒流充放电测试等手段研究了反应温度对粉体晶型和结构形貌及其在模拟锌离子电池中的放电容量和循环性能的影响。结果表明:所制备的粉体为高纯度弱结晶性纳米α-MnO2,且随着反应温度的提高,粉体由无定形态逐渐向三维刺球状颗粒转变,但粉体团聚加重。反应温度为40℃时制备的样品在30mg/cm2高活性物质载量、100mA/g和1000mA/g放电速率下电极比容量分别为212.6mAh/g和98mAh/g,相对于普通低温固相反应法制备的MnO2,放电比容量、高倍率放电性能和循环性能均明显提高。
For the preparation of high performance zinc ion batteries, KMnO4 was used as oxidant and AOT was used as surfactant in the AOT / isooctane reverse microemulsion system Reducing agent prepared nano α-MnO2. The effects of reaction temperature on the crystal structure and morphology of the powder and its discharge capacity and cycling performance in a simulated zinc-ion battery were studied by means of X-ray diffraction (XRD), transmission electron microscopy (TEM) and constant current charge- influences. The results show that the prepared powders are α-MnO2 with high purity and weak crystallinity. With the increase of reaction temperature, the powder gradually changes from amorphous state to spheroidal particles, but the agglomeration increases. The samples prepared at the reaction temperature of 40 ℃ had the highest specific capacity of 212.6mAh / g and 98mAh / g at the high active material loading of 30mg / cm2 and the discharge rates of 100mA / g and 1000mA / g, respectively. MnO2 prepared by the method, the specific discharge capacity, high rate discharge performance and cycle performance were significantly improved.