High-energy fiber-shaped calcium-ion batteries enable integrated wearable electronics for human body monitoring

Abstract

Electronic textiles hold the merits of high conformability with the human body and natural surrounding, possessing large market demand and wide application foreground in smart wearable and portable devices. However, their further application is largely hindered by the shortage of flexible and stable power sources with multifunctional designability. Herein, a free-standing ZnHCF@CF electrode (ZnHCF grown on carbon nanotube fiber) with good mechanical deformability and high electrochemical performance for aqueous fiber-shaped calcium ion battery (FCIB) is reported. Benefiting from the unique Ca2+/H+ co-insertion mechanism, the ZnHCF@CF cathode can exhibit great ion storage capability within a broadened voltage window. By pairing with a polyaniline (PANI)@CF anode, a ZnHCF@CF//PANI@CF FCIB is successfully fabricated, which exhibits a desirable volumetric energy density of 43.2 mWh cm−3 and maintains superior electrochemical properties under different deformations. Moreover, the high-energy FCIB can be harmoniously integrated with a fiber-shaped strain sensor (FSS) to achieve real-time physiological monitoring on knees during long-running, exhibiting great promise for the practical application of electronic textiles.