Development of a Hydrophobic Ni0.5mn0.5co2o4-Based Gel Matrix for Mitigating Moisture-Induced Degradation in Li-Air Batteries

Abstract

Li-air batteries are a promising candidate for next-generation energy storage technology. However, their practical development is limited by cathode channel clogging and moisture induced degradation. In this work, a Ni0.5Mn0.5Co2O4-loaded three-dimensional sodium alginate gel was synthesized as an efficient catalyst for Li-air batteries. To further enhance its performance, a hydrophobic treatment was applied to the catalyst, which significantly reduced the formation of by-products and the lifespan of the Li-air battery in humid atmospheres was extended. At a current density of 500 mA g-1, the modified Li-air batteries demonstrated remarkable cycle stability, achieving 142 cycles in pure oxygen, 91 cycles in ambient air (~40% relative humidity, RH), and 58 cycles in humid oxygen (~55% RH, threefold increase compared to unmodified cells). Additionally, the discharge cut-off capacities were significantly enhanced, reaching 19876.5 mAh g-1 and 16465.6 mAh g-1 at a current density of 200 mA g-1 in ambient air and humid oxygen, respectively.

Keywords: Sodium alginate gel, Li-air battery, Catalyst, Anodic corrosion