Liquid–metal-bridge∼island design: seamless integration of intrinsically stretchable liquid metal circuits and mechanically deformable structures for ultra-stretchable all-solid-state rechargeable Zn–air battery arrays

Abstract

Flexible/stretchable Zn–air batteries (ZABs) are a promising compatible power solution for wearable electronics. However, there still remains a great challenge to simultaneously achieve the goals of high energy efficiency, large elongation, and excellent output stability. Herein, a nitrogen-doped dodecahedral carbon framework of ordered interconnected macropores loaded with monodisperse cobalt nanoparticles (NdDCF-OIM/Co) is first designed and synthesized to serve as the air-cathode bifunctional electrocatalyst to fabricate all-solid-state micro-Zn–air batteries (mZABs). Then, a novel “liquid–metal-bridge∼island (LMBI)” architecture is demonstrated to seamlessly integrate the intrinsically stretchable liquid metal bridge of a mechanically deformable structure with the obtained mZAB islands toward an ultra-stretchable mZAB array (mZABA). Benefiting from the excellent bifunctional catalytic activity and durability of the NdDCF-OIM/Co, the as-obtained mZAB exhibits a high energy efficiency in terms of a high power density of 84 mW cm⁻², a large specific capacity of 749 mA h g⁻¹, and an excellent cycling stability of 165 cycles (55 h). More notably, the high effectiveness and reliability of the developed LMBI architecture design endow the further obtained mZABA with excellent electrochemical stability under an elongation of up to 400%, and integration capability, enabling the exceptional adjustability of the open circuit voltage/peak power of the mZABA (1.346–5.24 V/38–145 mW) via the arbitrary series/parallel connections of the mZABs based on the stretchable liquid metal bridges. By virtue of their stable/controllable electrochemical output and excellent stretchability, combined with their superb integration capability, the mZABA developed in this work represents a promising solution for a compatible micropower source in wearable microelectronics.