基于功能碳纤维的柔性纤维状锂离子电池制备及性能研究

Flexible/wearable electronics have attracted great attention in the international frontier research, and the development of compatible and high-efficiency portable power devices is crucial. As an emerging flexible energy storage technology, novel wire-shaped lithium-ion batteries possess prominent weavability and unique wearable feature, which show promising potential in applications for portable electronics and smart fabrics (textiles). Currently, the electrode materials for the preparation of high performance wire-shaped lithium-ion batteries urgently need to be further developed. In virtue of the excellent mechanical properties and electrical conductivity of carbon fiber materials, functionalized carbon fibers are adopted as free-standing active electrodes for wire-shaped lithium-ion batteries. In this regard, to explore the key fabrication techniques of carbon fiber-based flexible wire-shaped lithium-ion batteries, it aims to rationally design the micro/nano structure and the interfaces of the wire electrodes, with combinative investigation of the material composition, thin film preparation and device architecture/assembly. In addition, the battery electrochemical performance and cycling stability will be systematically characterized as well. With better elucidation of the operation mechanism of the functionalized carbon fiber and the fundamental properties of corresponding wire-shaped lithium-ion batteries, flexible carbon fiber-based wire lithium-ion batteries with considerable specific capacity (250 mAh/g) and durable performance (stable cycling of over 200 cycles ) are expected. Our study will further enrich the structural design and available electrode materials of wire-shaped lithium-ion batteries, which could innovate an alternative strategy and offer some useful basis for advancing miniaturized, lightweight and inexpensive flexible/wearable lithium-ion batteries.

柔性可穿戴电子器件在国际前沿研究领域受到极大关注，发展兼容匹配的高效便携电源至关重要。新型的纤维锂离子电池具有突出的可编织与可穿戴特性，在便携电子设备与智能织物等领域具有重要的应用潜力。目前，用于制备高性能纤维锂离子电池的电极材料体系亟待发展。鉴于碳纤维材料优良的力学性能与导电性，本项目以功能碳纤维作为纤维锂离子电池的自支撑活性电极，拟通过设计合理的电极微/纳结构与界面，研究材料组成、薄膜制备以及电池结构等探索基于碳纤维的柔性纤维状锂离子电池的关键制备技术，并系统表征电池的电化学性能与稳定性。通过深入理解功能碳纤维的作用机制及其纤维锂离子电池的基本特性，实现比容量可观（达到250 mAh/g）、性能稳定（循环寿命>200次）的碳纤维基纤维状锂离子电池，进一步丰富纤维锂离子电池的结构设计和电极材料体系，为发展微型、轻质、低成本的柔性可穿戴锂离子电池提供新的思路与有用的依据。

柔性可穿戴电子器件在国际前沿研究领域受到极大关注，发展兼容匹配的高效便携电源至关重要。柔性锂离子电池和纤维状锂离子电池具有突出的可弯曲、可穿戴特性，在便携电子设备与智能织物等领域具有重要的应用潜力。目前，用于制备高性能柔性/纤维锂离子电池的电极材料体系亟待发展。立足功能碳纤维及其柔性锂离子电池的总体研究目标，围绕微/纳结构活性负极材料设计、功能薄膜电极制备及其锂离子电池组装与储锂机制，项目重点开发并制备了多种适用于碳纤维的高活性负极储锂材料，包括一系列新型的硅-碳复合负极材料以及碳修饰的金属化合物复合负极材料，系统研究了相关锂离子电池的电化学性能，拓展了纤维锂离子电池的电极材料体系，特别是阐明了硅-碳复合负极材料对其锂离子电池性能的影响机制。同时，结合溶液法与静电纺丝技术等开发了新型无粘结剂（binder-free）的柔性自支撑薄膜电极材料，实现了具有可观充放电比容量（680 mA h g-1）与长循环寿命（> 200次）的柔性可弯曲锂离子电池。针对纤维锂离子电池的性能要求，设计制备了碳包覆纳米硅/碳纳米纤维薄膜负极材料，并对其柔性储锂性能进行了研究。在柔性锂离子电池研究的基础上，我们将研究工作进一步拓展到柔性纤维状可充锌-空电池新领域，探索了使用无定形三金属氢氧化物壳层包覆的钴酸镍纳米阵列作为双功能氧催化电极，组装实现了高比能量密度（38.1 mW h cm-3）与高柔性的纤维状可充锌-空电池，进一步丰富了柔性微/纳电子器件的研究内容，为发展低成本、高性能的柔性可穿戴便携电池提供了新的依据与途径。