高性能的纤维状水系锂离子电池

Conventional bulk lithium ion batteries suffering from flammable and toxic organic electrolytes, rigidity configuration and low energy storage ability can hardly meet the miniature and lightweight requirements of modern electronics. This proposal develops a new family of high-performance fiber-shaped aqueous lithium ion batteries by applying the polyimide/multi-walled carbon nanotube (MWCNT) hybrid fiber and LiMn2O4/MWCNT hybrid fiber as the anode and cathode electrodes, respectively, and an aqueous solution containing lithium sulfate serves as the electrolyte. The anode hybrid fiber is obtained through the in-situ growth of polyimide sheets on the surfaces of aligned MWCNTs, and the synergistic effect of these two components will efficiently enhance the electrochemical storage performance of the electrodes. Moreover, the dependences of the battery performances on several key parameters including the constituent, structure and morphology of the electrodes have been also systemically investigated to develop a series of high performance fiber-shaped batteries. The one-dimensional configuration also contributes to a high flexibility that can be bended and twisted in any direction, which promises large potentials in portable and wearable applications. To the best of our knowledge, it represents the first work on flexible aqueous lithium ion batteries.

传统的块状锂离子电池因为易燃的有机电解液带来的安全隐患，低于市场期望的储能性，及刚性结构造成的适应性不足等问题，无法满足现代电子器件微型化、轻量化的迫切发展需要。本项目提出并发展了一类新型纤维状的水系锂离子电池：重点以取向碳纳米管/聚酰亚胺复合纤维为负极，取向碳纳米管/锰酸锂复合纤维为正极，组装为纤维状电池再注入水系电解质制得。水系电解质替代易燃、有毒的有机电解液后，将显著降低锂离子电池制备工艺的难度，消除由有机电解液引发的制备和使用过程中的安全隐患。通过设计电极结构，在取向碳纳米管表面原位生长聚酰亚胺片状聚集体，通过二者协同作用制备高储能性能的电极。同时系统研究并揭示复合纤维组成、结构和聚集体形貌等参数对电极性能的影响规律，最终发展出一类新型高性能的柔性纤维状锂离子电池。纤维状结构更赋予电池任意方向弯曲变形的柔性及可编织性。据我们所知，迄今为止国际上尚未有柔性水系锂离子电池的报道。

本项目在取向碳纳米管表面原位生长活性材料，制备了以取向碳纳米管/聚酰亚胺复合纤维为负极，取向碳纳米管/锰酸锂复合纤维为正极，硫酸锂水溶液作为电解液的高性能的柔性水系锂离子电池，从而解决传统平板状锂离子电池存在的一些问题，如需要用到易燃的有机电解液、相对较低的储能性能和刚性的结构等。除此之外，本项目以取向碳纳米管纤维为基底，设计合成具有三维网络结构的多组分活性材料，制备得到同时具有高倍率性能和高能量密度的纤维电池。通过进一步的系统研究，揭示了纤维组成、结构等参数对电极性能的影响规律，最终发展出一类新型高性能的柔性纤维状电池，并且纤维状结构更赋予电池任意方向弯曲变形的柔性及可编织性。在项目执行期间，项目负责人以通讯作者发表论文11篇（含接收），包括2篇Angew. Chem. Int. Ed.、1篇Adv. Mater、1篇Adv. Funct. Mater.、2篇Small等。申请中国发明专利9项，授权4项。