An extremely safe and flexible zinc-ion hybrid supercapacitor based on a scalable, thin and high-performance hierarchical structured gel electrolyte

High performance and low cost energy storage electronic equipments, together with flexibility and safety, is a major progress in portable and wearable electronics. Unfortunately, flexible batteries are greatly limited due to their inherent cost and safety drawbacks. Herein, we build an extremely safe and flexible quasi-solid-state zinc-ion hybrid supercapacitor (ZHSC) by a scalable, thin, and high-performance hierarchical gel electrolyte including the electrospun polyacrylonitrile (PAN) matrix, polyacrylamide (PAM) and zinc salt. Benefiting from the unique interface and superior electrochemical performance of the well-designed electrolyte, the flexible ZHSC achieves a high energy density and power density (132.5 Wh kg −1 and 1244.4 W kg −1 , respectively), high specific capacity (106.0 mAh/g at 1.0 A/g) and prominent cycling stability (100% capacity retention after 15 000 cycles at 10.0 A/g). More importantly, the quasi-solid-state ZHSC exhibits an extreme safety and a high wearability outperforming traditional flexible batteries and can continuously work in various extreme conditions, such as hammering, burning, washing, cutting, bending and piercing. It is believed that this hierarchical structured gel electrolyte provides a new platform and pave the way for flexible and wearable electronics with high performance and safety.