Super‐Stretchable Zinc–Air Batteries Based on an Alkaline‐Tolerant Dual‐Network Hydrogel Electrolyte

• Published in: Advanced energy materials 2019-03, Vol.9 (12), p.n/a
• Main Authors: Ma, Longtao, Chen, Shengmei, Wang, Donghong, Yang, Qi, Mo, Funian, Liang, Guojin, Li, Na, Zhang, Haiyan, Zapien, Juan Antonio, Zhi, Chunyi
• Format: Article
• Language: English
• Subjects: alkaline‐tolerant; Batteries; Deformation; Display devices; Domains; dual‐network; Electrolytes; Electronic devices; Energy storage; Flexible components; hydrogel electrolyte; Hydrogels; Metal air batteries; Potassium hydroxides; Stretchability; super‐stretchable; Zinc; Zinc-oxygen batteries; zinc–air batteries
• ISSN: 1614-6832; 1614-6840
• DOI: 10.1002/aenm.201803046

Stretchable devices need elastic hydrogel electrolyte as an essential component, while most hydrogels will lose their stretchability after being incorporated with strong alkaline solution. This is why highly stretchable zinc–air batteries have never been reported so far. Herein, super‐stretchable, flat‐ (800% stretchable) and fiber‐shaped (500% stretchable) zinc–air batteries are first developed by designing an alkaline‐tolerant dual‐network hydrogel electrolyte. In the dual‐network hydrogel electrolyte, sodium polyacrylate (PANa) chains contribute to the formation of soft domains and the carboxyl groups neutralized by hydroxyls as well as cellulose as potassium hydroxide stabilizer are responsible for vastly enhanced alkaline tolerance. The obtained super‐stretchable, flat zinc–air battery exhibits a high power density of 108.6 mW⋅cm−2, increasing to 210.5 mW⋅cm−2 upon being 800% stretched. Similar phenomena are observed for the 500% stretchable fiber‐shaped batteries. The devices can maintain stable power output even after being heavily deformed benefiting from the highly soft, alkaline‐tolerant hydrogel electrolyte developed. A bendable battery‐display system and water proof weavable fiber zinc–air battery are also demonstrated. This work will facilitate the progress of using zinc–air battery powering flexible electronics and smart clothes. Moreover, the developed alkaline‐tolerant super‐stretchable electrolyte can also be applied for many other alkaline electrolyte‐based energy storage/conversion devices. An alkaline‐tolerant, dual‐network hydrogel electrolyte‐based sodium polyacrylate and cellulose is developed. The hydrogel infiltrated by 6 m KOH solution as electrolyte still shows over 1000% stretchability, together with a 0.28 S∙cm−1 ion conductivity. Super‐stretchable, flat‐ (800% stretchable) and fiber‐shaped (500% stretchable) zinc–air batteries with high electrochemical performance and mechanical flexibility are developed based on the hydrogel electrolyte.