Fabrication of Flexible Ionic-Liquid Thin Film Battery Matrix on FlexTrate™ for Powering Wearable Devices

To improve the flexibility of Li-ion batteries for powering wearables, we develop a simple battery interconnection method on FlexTrate™ to fabricate a thin-film flexible Li-ion battery matrix by using ionic liquid electrolyte, commercial lithium iron phosphate (LFP) cathode, and Li-metal anode. The mechanical fatigue process of the Li-ion cathode materials during is analyzed. The thin-film battery achieves 1.33 mAh/cm
²
energy density at C/10 charging/discharging rate after 1000 times bending cycles at 5 mm bending radius.