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