Multifunctional Role of Nitrogen in Organic Cathodes for Rechargeable Batteries

ConspectusThe global transition toward carbon neutrality is accelerating the integration of intermittent renewable energy sources, including solar and wind power, and creating a pressing demand for large-scale energy storage systems. Among available technologies, rechargeable metal batteries have emerged as promising candidates for high-energy storage systems (e.g., lithium metal batteries) or grid-scale energy storage (e.g., zinc metal batteries) due to their high energy density, environmental compatibility, and cost efficiency. However, their commercialization remains hindered by limited energy density in cathodes. While notable progress has been achieved in anode stabilization, the development of cathode materials continues to lag, significantly restricting the overall energy output of full cells. Conventional cathode materials, whether inorganic or organic, consistently face a trade-off between high capacity and cycling stability. Although organic electrodes offer advantages such as molecular tunability and sustainability, their performance is often undermined by low electronic conductivity and dissolution of reactive intermediates, resulting in unsatisfactory capacity and cycling durability for practical applications.In this Account, we integrate our research progress with relevant insights from the field to propose that using nitrogen (N) as a multifunctional species represents a powerful approach to addressing these limitations. We systematically analyze how three inherent properties of N, i.e., variable valence states, high electronegativity, and lone-pair electrons, can be strategically utilized to increase operating voltage and reaction kinetics, construct stable electrode-electrolyte interfaces, and enable efficient multi-electron transfer processes. By presenting tailored molecular systems from our studies, e.g., N-doped organic sulfur cathodes, bipyridine-based interfacial anchoring systems, and cooperative halogen fixation platforms, we clarify the essential structure-property-performance relationships and derive general design principles for N-enhanced organic cathodes.This Account seeks to reveal the role of nitrogen in electrochemical materials, transforming its perception from a passive constituent into an active design species that decisively influences electrochemical behavior. We expect the conceptual and practical framework outlined here to offer actionable guidance for the rational development of next-generation high-performance and sustainable energy storage systems.