掺杂尖晶石结构硫化物纳米材料的可控制备及其电化学性能研究

As compared to secondary batteries, supercapacitors have the advantages of fast charge rate, high power density, wide operating temperature range and long cycle life, which make them widely been concerned in the field of power storage. However, the energy density of supercapacitors is quite low, which is a major hurdle for their implementation in practical applications. Therefore, it is necessary to develop new types of electrode materials with high capacity based on pseudocapacitor energy storage mechanism. Spinel sulfide NiCo2S4 is an excellent pseudocapacitor electrode material; it has attracted extensive attentions due to its high specific capacitance and good conductivity. In this project, we are going to improve the electrochemical performances of NiCo2S4 electrode material through ion doping. By incorporation of divalent cations (e.g. Mn2+, Fe2+，Zn2+, etc.), trivalent cations (e.g. Al3+, Fe3+, Ga3+, etc.) or anions (e.g. Se2-), doped spinel sulfide nanomaterials can be obtained. Through systematic studying on the effect of doping on the electrochemical performances, along with the control of size and morphology of the products, high performance pseudocapacitor electrode materials can be obtained. The products will be assembled into asymmetric supercapacitor devices, and the electrochemical performances of the devices such as specific capacity, energy density, power density and cycle stability will be tested.

跟二次电池相比，超级电容器具有充电速率快，功率密度大，工作温度范围宽和循环寿命长等优点，因而近年来在电能存储领域获得了广泛的关注。但是，超级电容器的能量密度较低，距离实际应用的需求还有较大的差距。因此，有必要研发新型的基于赝电容储能机制的高容量电极材料。尖晶石结构硫化物NiCo2S4是一种优秀的赝电容电极材料，具有容量高，导电性好等优点，受到了广泛的关注。本项目拟采用离子掺杂的方式进一步提高NiCo2S4电极材料的电化学性能。通过掺入二价阳离子（如Mn2+，Fe2+，Zn2+等）、三价阳离子（如Al3+，Fe3+，Ga3+等）或阴离子（如Se2-离子），获得掺杂的尖晶石结构硫化物纳米材料。系统研究掺杂对产物电化学性能的影响，结合对产物的形貌和尺寸的控制，获得高性能的赝电容电极材料。将产物组装成非对称型超级电容器，测试器件的电化学性能如电容量、能量密度、功率密度以及循环稳定性等。

超级电容器作为一种介于传统电容器和二次电池之间的新型储能器件，具有充电速率快，功率密度大，工作温度范围宽和循环寿命长等优点，但是也具有能量密度较低的缺点。本项目以提高超级电容器电极材料的能量密度为目标，以尖晶石结构过渡金属硫化物为主要研究对象，制备了多种尖晶石结构过渡金属硫化物纳米材料和纳米复合材料作为超级电容器的电极材料，例如NiCo2S4纳米片阵列，核壳结构NiCo2O4@NiCo2S4纳米复合材料，NiCo2S4/镍钴双氢氧化物纳米复合材料，以及一些其他的过渡金属硫化物和氧化物电极材料，例如分级结构Co9S8纳米材料，Ni2+离子掺杂的ZnS纳米片，分级结构硫化钴/钴碱式盐纳米复合材料，MnCo2O4@NiMoO4核壳结构纳米复合材料，研究了形貌、掺杂和材料复合对电化学性能的影响。将部分产物组装成非对称型超级电容器，测试了器件的电化学性能如比电容量、能量密度、功率密度以及循环稳定性等。在本项目的资助下，我们还进行了一些探索性的研究，例如用于甲醇氧化反应的电催化剂的合成与性能等。