Long-battery-life flexible zinc–air battery with near-neutral polymer electrolyte and nanoporous integrated air electrode†
The rapid advancement of flexible and wearable electronic devices drives the need for flexible batteries, and zinc–air batteries (ZABs) have attracted extensive interest due to their extremely high theoretical energy density, eco-friendliness and low cost. However, the use of conventional alkaline ZABs is significantly restricted by corrosion and dendrite growth at the Zn anode and fast carbonate formation of the electrolyte. Herein, we report an emerging type of ZAB that uses a near-neutral gel polymer electrolyte (neutral GPE) with good water retention and high ionic conductivity; this ZAB system is more environmentally friendly and less corrosive than alkaline electrolytes, thus potentially avoiding carbonation problems and mitigating corrosion issues. Furthermore, an integrated nanoporous air cathode with an enlarged interfacial contact area and catalytic sites is utilized, and it demonstrates excellent flexibility and high strength. Due to these advantages, the assembled neutral GPE-based flexible ZABs exhibit a prolonged cycle life of 70 h in the fresh state and after being packaged for 10 days, indicating a remarkable battery life performance. Furthermore, the ZABs can be fabricated in customized shapes and sizes to satisfy the space and energy demands of a variety of applications, and they can operate without degraded battery performance under bending conditions and even during the tailoring process.