High-Performance Neutral Zinc-Air Batteries Based on Hybrid Zinc/Carbon Nanotube Fiber Anodes

Neutral zinc-air batteries are considered potential wearable energy storage devices due to their high theoretical energy density, superior safety, and low cost. However, the current performance of neutral zinc-air batteries is severely influenced by the zinc anodes. The pure zinc anode can be comminuted during charge and discharge cycles due to its unstable electrode structure, resulting in the failure of electrical contact. As a result, the battery exhibits low capacity and short cycle life. In addition, the pure zinc anodes show slow reaction kinetics in neutral electrolytes, which causes the battery to perform low power density and poor energy efficiency. Besides, pure zinc anodes own high bending stiffness, which cannot meet the demands for powering flexible electronics. Herein, a new kind of hybrid zinc/carbon nanotube fiber anode with a stable electrode structure, high reaction activity, as well as high flexibility is proposed to produce high-performance neutral zinc-air batteries. The fabricated fiber battery showed a high specific capacity and maximum power density of 645.3 mAh g-1 and 615.8 mW g-1, respectively. Furthermore, a high energy efficiency of 71% is achieved, the highest among the reported neutral zinc-air batteries. The entire fiber battery is highly flexible, highlighting its potential for wearable energy storage applications. A novel zinc/carbon nanotube hybrid fiber anode is designed to improve the structural stability and reaction activity of anodes in neutral electrolytes. The zinc-air batteries based on the designed hybrid fiber anodes show a specific capacity of 645.3 mAh g-1, a maximal power density of 615.8 mW g-1, a highest round-trip efficiency of 71%, and mechanical flexibility. image