Zinc-ion batteries at elevated temperatures: linking material design to wearable/biocompatible applications

Aqueous zinc-ion batteries (AZIBs) have gained recognition as safe, sustainable, and cost-effective alternatives to lithium-ion batteries (LIBs). Despite considerable progress in enhancing performance at room and low temperatures for large-scale applications, maintaining functionality at high temperatures remains a major challenge, restricting the use of safe, biocompatible, and body-adaptive AZIBs in small-scale wearable and implantable technologies. Exploring advanced materials to enhance high-temperature performance and ensure a long lifespan with a stable power supply is essential for enabling the practical use of wearable and biocompatible devices across diverse scenarios. This review begins with an overview of the failure mechanisms of AZIBs at elevated temperatures, followed by an exploration of material design strategies to address these challenges, focusing on electrode development, electrolyte optimization, and electrolyte optimization to date. Emphasis is placed on aligning material innovations with practical performance requirements in compact applications, particularly for wearable electronics and biocompatible batteries in medical devices, where elevated temperatures are often unavoidable and safety is paramount. Future research directions for small-scale wearable, biocompatible, and implantable AZIBs include precise device-level design and packaging, development of pilot-scale low-cost continuous material production protocols, and implementation of in situ visualization and analysis techniques to monitor battery and material failure to prevent side reactions and ensure battery long-term stability and practicability.