多元异质纳米结构过渡金属氧化物与蚕丝蛋白衍生碳复合材料的设计合成及其储锂特性研究

In order to obtain high performance energy conversion and storage devices, numerous efforts have been devoted to the design, fabrication and manipulation of various environmentally friendly anode materials for lithium-ion batteries with high reversible capacity and long cycle life. The carbon/non-carbon composite materials could largely improve the capacity and cycle life of lithium-ion batteries. Silk fibroin, a protein derived from the domestic silkworm (Bombxy mori), is regarded as one of the carbon-based materials. Taking advantage of the silk fibroin unique recognition site (amino acid residue) and self-assembly performance, it is expected to expand the silk fibroin, which served as a biotemplate, to synthesis novel transition metal oxide nanomaterials with various morphology. Multiple hetero-nanostructure transition metal oxide and silk fibroin-derived carbon composite will be synthesized and their electrochemical properties will be studied. The effects of various reaction conditions on the composite will also be explored, as well as the different components, structures and morphologies of the composites. We will do further investigation on the formation mechanism of transition metal oxides and the behavior of the interfacial interaction between transition metal oxide and silk fibroin by controlling the surface chemistry. Furthermore, this project will analyze the mechanism of lithium ion diffusion, extraction, insertion, and storage in the composite materials, providing the scientific basis and technical support for its application in the lithium batteries field.

为了获得高性能的能量转换和存储设备，设计合成环境友好、具有高容量和长循环寿命的锂离子电池负极材料是目前国内外研究的热点。碳材料与非碳材料的复合有利于锂离子电池容量与循环性能的提高。本项目以蚕丝蛋白为生物模板，利用其独特的识别位点（氨基酸残基）和自组装性能，调控生成具有不同形貌的过渡金属氧化物，构筑三维多元异质纳米结构过渡金属氧化物与蚕丝蛋白衍生碳的复合材料；考察不同实验条件对复合材料的影响，揭示复合材料不同的组分、结构、形貌对其电化学性能的影响规律；深入研究蚕丝蛋白调控生成不同形貌的过渡金属氧化物的机理，以及过渡金属氧化物与蚕丝蛋白之间的界面行为；阐明复合材料的储锂机理，为获得高性能锂离子电池负极材料及其在动力电池领域中的应用提供科学依据和技术支撑。

为了获得高性能的能量转换和存储设备，设计合成环境友好、具有高容量和长循环寿命的锂离子电池负极材料是目前国内外研究的热点。碳材料与非碳材料的复合有利于锂离子电池容量与循环性能的提高。本项目以桑蚕丝蛋白为生物模板，以醋酸铜或硝酸铜为铜源，以硝酸铁为铁源，利用蚕丝蛋白独特的识别位点（氨基酸残基）和自组装性能，通过一步水热法，调控制备单元、二元或多元的异质结构纳米复合材料，例如：CuO、Fe2O3、CuO-Cu2O、Fe2O3-CuO、CuO-Cu2O-Cu、Fe2O3-CuO-Cu2O等等。通过X-射线粉末衍射仪、扫描电子显微镜、透射电子显微镜、热重分析仪对材料的物质组成、结构及形貌进行表征，并进行循环性能、阻抗大小等基本电化学性能测试。考察不同反应条件，如丝蛋白水溶液浓度、水热温度和水热时间等因素，对异质结构纳米复合材料的成分及电化学性能的影响。研究结果表明，丝蛋白参与了异质结构纳米复合材料的形成，并能有效调控复合材料的成分。在丝蛋白水溶液浓度为0.1 wt%，水热温度为180 oC，水热时间为360 min的条件下，制得的三元CuO-Cu2O-Cu异质结构纳米复合材料的综合电化学性能最佳。这为获得高性能锂离子电池负极材料及其在动力电池领域中的应用提供科学依据和技术支撑。