柔性自支撑锂离子电池电极用高性能纳米碳纤维布的制备与性能研究

Enhancing the mechanical strength of carbon-based platform is key challenge for building flexible and free-standing lithium-ion battery electrodes. Carbon nanofibers mat (CFM) is an ideal candidate for high-performance electrode platform based on its unique 3D intertwining and conductive nano-fibrous structure. Meanwhile, CFM has potentially superior mechanical strength. In this project, we will study the structural transition of polyacrylonitrile (PAN) nanofibers during the preparation process and explore its effect on the mechanical strength of resulting carbon nanofibers. We will focus on studying the mechanism of radial oxidation reaction during the oxidative stabilization process and its effect on the structure and properties of carbon nanofibers; acquiring the thermal chemical reaction law of nanoscale PAN fibers via exploring the characteristics of oxidation and cyclization reactions; attaining the control of nanofibers’ aggregation structures; and subsequently preparing CFM with superior mechanical properties. We will build flexible and free-standing lithium-ion battery electrodes based on CFM to verify its electrode platform performance, and further improve CFM based on the battery characterization feedback. This project can provide theoretical guidance and technical support for developing next generation high-performance CFMs.

提高碳基载体的力学性能对构建柔性自支撑锂电池电极具有重要意义。纳米碳纤维布（carbon nanofibers mat，CFM）以其独特的三维导电纤维网络结构可成为良好的碳基载体，且具有进一步提升力学性能的空间。本项目拟采用结构表征与性能研究相结合的方法，研究CFM制备过程中的聚丙烯腈纤维结构演变对纳米碳纤维力学性能影响的机制，重点研究预氧化阶段纳米纤维径向氧化反应的作用机制及其对碳纤维结构、性能的影响；通过探索尺寸效应下聚丙烯腈大分子的氧化、环化等气固相反应特征，掌握纳米纤维的热化学反应规律，获得调控纤维聚集态结构的途径，制备出更高性能的CFM。通过柔性自支撑电极材料的构建与表征，验证CFM的载体性能，并根据电池性能反馈进一步完善CFM。该项目可以为开发更高性能纳米碳纤维布的攻关探索有效途径，提供理论与技术支持。

为了解决纳米碳纤维布力学性能不足的瓶颈问题，本项目采用结构表征与性能研究相结合的方法，研究了纳米碳纤维布制备过程中的聚丙烯腈纤维结构演变对纳米碳纤维力学性能影响的机制，并重点研究了预氧化阶段纳米纤维径向氧化反应的作用机制及其对碳纤维结构、性能的影响；通过探索尺寸效应下聚丙烯腈大分子的氧化、环化等气固相反应特征，掌握了纳米纤维的热化学反应规律，获得了调控纤维聚集态结构的途径，提出了静电纺纳米碳纤维快速预氧化控制方法，并将预氧化时间压缩到40分钟以下，制备出拉伸强度达到200MPa且具有优良柔性的纳米碳纤维布。通过柔性自支撑电极材料的构建与表征，验证了纳米碳纤维布的载体性能，获得了纳米碳纤维布结构特征对电极材料电化学及力学性能的影响关系。本项目所提供的快速预氧化方法、预氧化时间及力学性能指标处于本领域先进水平。本项目可以为开发更高性能的纳米碳纤维布的攻关探索有效途径，提供理论与技术支持。项目执行过程中一共发表SCI收录论文6篇，申请专利2项。毕业研究生2名。