Grafted MXene Assisted Bifunctional Hydrogel for Stable and Highly Sensitive Self-Powered Fibrous System

Achieving highly efficient self-powered fibrous sensing systems is desirable for smart electronic textiles but remains a great challenge. Here, a bifunctional hydrogel is proposed by introducing of polyacrylic acid grafted MXene (MXene-g-PAA) into polyacrylamide/chitosan, achieving high-sensitivity sensor and a stable hydrogel electrolyte of battery. The MXene-g-PAA flakes act as ion transport "highway", significantly enhance ionic conductivity, thereby increasing the sensitivity of sensors and facilitating Zn2+ diffusion in Zn-ion battery (ZIB). The rich hydrogen bonding network in the hydrogel improves its mechanical properties and limits water molecule movement, thus reducing side reactions and prolonging the stability of ZIB. As a result, the fibrous sensor exhibits high strain sensitivity (gauge factor of 2.4) with a wide detection range (0-800%), and the fibrous Zn-ion battery exhibits high capacity (353 mAh cm-3) with long cycling stability (400 cycles). The hydrogel-based sensor and ZIB can be easily integrated into a flexible self-powered sensing system, which effectively detects human movement and 3D ball motion. The bifunctional hydrogel with the integrated fibrous system will shed light on the development of next-generation smart electronic textiles. A bifunctional hydrogel with high Zn2+ conductivity and rich hydrogen bonds is simultaneously used for both highly sensitive strain sensor and stable electrolyte of Zn-ion battery. The sensor and battery are further integrated into a self-powered fibrous sensing system, which shows stability and high sensitivity for human motion monitoring and ball motion detection. image