Flexible and Tailorable Na−CO2 Batteries Based on an All‐Solid‐State Polymer Electrolyte

Abstract

AbstractRechargeable Na< C‐>CO2 batteries coupling Na anodes with the greenhouse gas CO2 cathode are promising energy‐storage devices due to the high energy density, environmental friendliness and cost‐effectiveness. However, major challenges impeding the application of Na−CO2 batteries are safety concern regarding the leakage of flammable liquid electrolytes and the instability of the Na anodes. Herein, we construct all‐solid‐state flexible Na−CO2 batteries by designing an integrated structure built of a Na anode, poly(ethylene oxide)/NaClO4/SiO2 electrolyte and multiwall carbon nanotubes cathode. The batteries exhibit much improved safety and good cyclability (240 cycles with an overpotential increase of ∼0.4 V). Remarkably, we fabricated lab scale‐up integrated batteries (8×16 cm2), which display large capacity (450 mAh) and high energy density (173 Wh kg−1). Moreover, the integrated batteries show excellent bendability (≥1,000 times), foldability in individual shapes, as well as stable operation time (80 h) at bending states of 0° to 360°. Our work demonstrates a way to exploit flexible and safe solid‐state Na−CO2 batteries.