Recent Advances and Future Perspectives in Ni–Fe Batteries: Overcoming Challenges and Exploring New Opportunities

In recent years, alkaline rechargeable nickel–iron (Ni–Fe) batteries have advanced significantly primarily due to their distinct advantages, such as a stable discharge platform, low cost, and high safety performance. These attributes make Ni–Fe batteries suitable for a wide range of applications, including large-scale power grid energy storage, electric vehicles, hybrid vehicles, and wearable and portable energy devices. While several reviews have addressed specific aspects of Ni–Fe batteries, a comprehensive review focusing on iron-based anode materials for alkaline rechargeable Ni–Fe batteries is scarce, making this review both timely and valuable. This review systematically analyses recent advancements in Ni–Fe batteries, with a particular focus on design strategies for cathode and anode materials as well as electrolytes. For electrode materials, the application of nanostructure design and interface engineering has been shown to significantly enhance battery performance. Additionally, incorporating ion doping and gel electrolytes offers new approaches to enhance energy storage efficiency and extend the cycle life of batteries. The review also explores the potential of Ni–Fe batteries in emerging areas, such as flexible batteries. Finally, the review outlines the challenges and potential solutions in this area, aiming to provide guidance for future research and encourage further breakthroughs in this rapidly evolving field.