High strength bacterial cellulose/PANa-based hydrogel polyelectrolyte for flexible zinc-air batteries

As flexible electronics continue to develop, the demand for low-cost, high-security, and long-lasting deformable energy sources is imperative. Gel-based zinc-air batteries have received much attention as promising candidates due to the flexibility, while most hydrogel electrolytes will lose their deformability after absorbing alkaline electrolyte. Thus, PANa-BC (Bacterial Cellulose) gel electrolytes, with internal physical entanglement of PANa and BC fibers and hydrogen bonding interactions, are prepared by solution copolymerization and swelling. The hydrogel exhibits superior mechanical strength and toughness, as well as convincing ionic conductivity. After optimizing the battery structure and catalyst ratios, the hydrogel-based bendable zinc-air battery delivers the power density of 49 mWcm- 2, high specific capacity (726.6 mAhg- 1) and stable cycle performance. As expected, the battery shows stable electrochemical properties over a wide range of bending angles, suggesting their high desirability as wearable power sources.