核/壳结构的二维异质石墨烯/氧化钛复合材料的可控制备及其电化学性能研究

项目名称： 核/壳结构的二维异质石墨烯/氧化钛复合材料的可控制备及其电化学性能研究

项目编号： No.51502177

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 一般工业技术

项目作者： 李永亮

作者单位： 深圳大学

项目金额： 21万元

中文摘要： 充电过电位过高严重地影响了锂空气电池的能量效率和循环性能，限制了其在大型能源器件中的应用。本项目拟采用微波辐照加热法一步合成氮元素掺杂的石墨烯材料，在其表面通过原子层沉积技术共形涂覆具有钛空位掺杂的氧化钛薄膜，合成新型的核/壳结构的二维异质石墨烯/氧化钛复合电催化剂材料，利用氮元素掺杂进石墨烯能够减小其功函数，以及钛空位掺杂进氧化钛可以降低其费米能级的特性，以期通过调控复合材料的内部能带结构来加快过氧化锂中电子从其内部向复合材料电极的传输，从而降低锂空气电池充电过电位，提高其能量效率与循环性能。同时，结合TEM、XRD、XPS等手段，进一步开展微时空尺度内物质传递与电化学反应过程的研究，探索异质结与界面性质、能带结构之间的联系以及其在电极反应中的作用机理，为构建高活性及高稳定性的复合电催化剂材料提供理论依据和技术支持。

中文关键词： 纳米复合材料；可控制备；锂空气电池；石墨烯；二维异质结构

英文摘要： The efficiency and cycleablility of non-aqueous lithium-air batteries are significantly restricted by the high polarization of electrode during charge process which hinders their application in large energy devices. In this project, nitrogen-doped graphene will be synthesized by a microwave heating method and applied as substrate for titanium-defected tatania which is fabricated by atomic layer deposition. The Fermi levels of two materials will be controlled by nitrogen-doping into graphene and introduction of titanium defects into titania, respectively. The two-dimensional core/shell heterostructured graphene/titania composite materials will be employed as electrocatalysts for the cathode reactions for lithium-air batteries. It is expected to decrease the charging voltage by tuning the electronic structures of the composites, therefore, increase the electrochemical performance and life time of the batteries. Moreover, it will give a rational direction for developing electrocatalysts for non-aqueous lithium-air batteries on the study of the relationships between the interface, band structures and the mechanisms for electrode reactions by using TEM, XRD, XPS, etc.

英文关键词： nano-composite materials;controllable synthesis;Li-air battery;graphene;two-dimensional heterostructure