Elastic and Wearable Wire‐Shaped Lithium‐Ion Battery with High Electrochemical Performance

TLDR

A stretchable wire‑shaped lithium‑ion battery is fabricated from two aligned multi‑walled carbon nanotube/lithium oxide composite yarns as anode and cathode, eliminating extra current collectors and binders. The resulting wire‑shaped batteries deliver energy densities of 27 Wh kg⁻¹ (17.7 mWh cm⁻³) and power densities of 880 W kg⁻¹ (0.56 W cm⁻³), retain 97 % of capacity after 1000 bending cycles and 84 % after 200 stretching cycles at 100 % strain, and can be woven into lightweight, flexible, stretchable textiles for large‑scale applications.

Abstract

A stretchable wire-shaped lithium-ion battery is produced from two aligned multi-walled carbon nanotube/lithium oxide composite yarns as the anode and cathode without extra current collectors and binders. The two composite yarns can be well paired to obtain a safe battery with superior electrochemical properties, such as energy densities of 27 Wh kg(-1) or 17.7 mWh cm(-3) and power densities of 880 W kg(-1) or 0.56 W cm(-3), which are an order of magnitude higher than the densities reported for lithium thin-film batteries. These wire-shaped batteries are flexible and light, and 97 % of their capacity was maintained after 1000 bending cycles. They are also very elastic as they are based on a modified spring structure, and 84 % of the capacity was maintained after stretching for 200 cycles at a strain of 100 %. Furthermore, these novel wire-shaped batteries have been woven into lightweight, flexible, and stretchable battery textiles, which reveals possible large-scale applications.