Boosting Energy Density: The Voltage-Capacity Synergy in Organic Cathodes

Organic cathode materials (OCMs), with their inherent structural diversity, elemental sustainability, and environmental compatibility, present a promising pathway to overcome the energy density and resource limitations of conventional inorganic cathodes. As such, they are regarded as highly promising candidates for next-generation rechargeable batteries. Nevertheless, the simultaneous achievement of high-energy density and robust stability in OCMs remains a significant challenge. High energy density depends on the high capacity and high voltage of the material, while robust stability relies on the low solubility of the material. In this review, we begin by systematically examining the fundamental causes of the low capacity, low voltage, and strong solubility in OCMs. On this basis, we summarize recent advances in enhancing the energy density of OCMs, including molecular-level material design, electrode-level engineering, and electrolyte-level optimization. Meanwhile, we offer forward-looking perspectives on the future development of organic electrodes for next-generation battery technologies.