Flexible, solid electrolyte-based lithium battery composed of LiFePO4 cathode and Li4Ti5O10 anode for applications in smart textiles

摘要

Here we report fabrication of flexible and stretchable battery composed ofstrain free LiFePO4 cathode, Li4Ti5O10 anode and a solid poly ethylene oxide(PEO) electrolyte as a separator layer. The battery is developed in a view ofsmart textile applications. Featuring solid thermoplastic electrolyte as a keyenabling element this battery is potentially extrudable or drawable into fibersor thin stripes which are directly compatible with the weaving process used insmart textile fabrication. The paper first details the choice of materials,fabrication and characterisation of electrodes and a separator layer. Then thebattery is assembled and characterised, and finally, a large battery samplemade of several long strips is woven into a textile, connectorized withconductive threads, and characterised. Within this paper, there are twopractical aspects of battery design that we have investigated in details: firstis making composites of cathode/anode material with optimized ratio ofconducting carbon and polymer binder material, and second is batteryperformance including cycling, reversibility, and compatibility of thecathode/anode materials. Finally, when casting electrodes and separator layerwe mostly focused on using aqueous solutions instead of organic solvents inorder to make the fabrication process environmentally friendly.