Enhanced cathode integrity for zinc–manganese oxide fiber batteries by a durable protective layer

Abstract

Aqueous fiber batteries with high safety and flexibility have attracted extensive attention for their promising applications in next-generation wearable electronics. However, the further applications of aqueous fiber batteries are severely hindered by mechanical instability and insufficient electrochemical performance. Here, a durable protective layer with a compact structure and high conductivity is designed to endow the fiber cathode with improved integrity and reaction kinetics. The resulting Zn–MnO₂ fiber battery demonstrates high durability and stable energy output under varying deformations and delivers a long-term cycle life of up to 4000 cycles at 2 A g⁻¹. It also shows a high specific capacity of 332 mA h g⁻¹ and an improved rate capability of 163 mA h g⁻¹ at 5 A g⁻¹. The design of the durable protective layer provides a useful strategy for the construction of fiber batteries with high stability and performance.