Flexible Zinc-Ion Battery-Powered Wearable Devices for Vital Sign Monitoring

ABSTRACT: Wearable devices play a crucial role in real-time health monitoring by continuously tracking important physiological indicators such as heart rate, blood oxygen saturation, and body temperature. This not only helps achieve personalized health management but also enables early disease warning. However, traditional rigid power sources (such as lithium-ion batteries) are difficult to adapt to the dynamic deformations of wearable devices in use, such as bending and stretching, and also pose certain safety risks. Therefore, developing flexible energy storage systems that combine high safety, good mechanical flexibility, and high energy density has become an important research direction. Flexible zinc-ion batteries are regarded as a promising solution due to their use of non-flammable aqueous electrolytes, abundant resources, low cost, and good mechanical adaptability. This article systematically reviews the latest progress of flexible zinc-ion batteries, covering key components (electrodes, electrolytes, packaging), device structure design, integration solutions with wearable sensors, and their applications in scenarios such as electrocardiogram monitoring, body temperature tracking, and motion monitoring. The article also explores the current challenges that still exist in terms of energy density, cycle life, mechanical-electrochemical stability, and biocompatibility. Finally, the development directions of future practical applications were prospected, with a focus on innovative material design, structural optimization, intelligent system integration, and the promotion of related standardization.