炭胶囊化中空过渡金属氧化物/石墨烯纳米复合材料的制备及其电化学储能性能研究

In this work, we designed various novel nanocarbon carbon/metal oxide composites with suitable nanostructures for storage and rapid insertion/desertion of lithium ions by utilizing nanoscale Kirkendall effect, confinement effect, and interfacial interaction between metal/metal oxide and nanocarbons. First，carbon-encapsulated metal nanoparticles were prepared by co-pyrolysis of carbon sources and metal compounds. Then, the as-prepared carbon/metal composites were converted to hollow metal oxide/carbon composites with various morphologies and structures via the outward diffusion of metal atoms in the carbon-confined space induced by the nanoscale Kirkendall effect. At last, the electrochemical performances of these hollow metal oxide/carbon composites were investigated in detail. In further, we explore in-depth the interfacial interaction between metal oxide nanoparticles and graphene nanosheets as well as its impact on the electrochemical performance of metal oxides/graphene anode materials for lithium-ion batteries. In a word, the diffusion of metal atoms in graphene-based metal spheres and a nanospace confined by carbon shells is a great extension to the nanoscale Kirkendall effect, which not only can synthesize various novel nanostructures, but also is helpful to advance in basic and scientific studies on the interaction between metal oxides and graphene.

本项目旨在为满足高性能锂离子电池的需求，基于金属/氧化物与纳米碳之间的交互作用原理合成系列具有新型结构的、适于锂离子存储的碳/氧化物纳米负极材料。首先采用溶剂热解法制备碳包覆金属纳米颗粒，利用Kirkendall效应引发的金属在限域空间内的扩散行为制备具有不同形貌和结构的碳/金属氧化物空心复合材料，详细考察氧化过程中金属原子的扩散机制；研究碳胶囊化氧化物空心纳米结构结构与石墨烯复合用作锂离子电池负极材料的电化学性能，考察纳米金属氧化物与碳界面的交互作用对电池高倍率、长周期循环性能的影响，揭示形貌、结构以及炭材料种类对电化学性能的影响规律。上述对于金属原子在纳米碳限域空间内的扩散的研究，不仅有助于设计各种特殊形貌和组成的碳/石墨烯包覆金属氧化物空心结构，而且对于金属氧化物与石墨烯之间的交互作用等基础科学问题的研究具有重要意义。

本项目旨在为满足高性能锂离子电池的需求，基于金属/氧化物与纳米碳之间的交互作用原理合成系列具有新型结构的、适于锂离子存储的碳/氧化物纳米负极材料。首先采用溶剂热解法制备碳包覆金属纳米颗粒，利用Kirkendall效应引发的金属在限域空间内的扩散行为制备具有不同形貌和结构的碳/金属氧化物空心复合材料，详细考察氧化过程中金属原子的扩散机制；研究碳胶囊化氧化物空心纳米结构结构与石墨烯复合用作锂离子电池负极材料的电化学性能，考察纳米金属氧化物与碳界面的交互作用对电池高倍率、长周期循环性能的影响，揭示形貌、结构以及炭材料种类对电化学性能的影响规律。上述对于金属原子在纳米碳限域空间内的扩散的研究，不仅有助于设计各种特殊形貌和组成的碳/石墨烯包覆金属氧化物空心结构，而且对于金属氧化物与石墨烯之间的交互作用等基础科学问题的研究具有重要意义。