Organic Cathode Materials in Lithium Primary Batteries: Multi‐Electron Reduction Mechanism and Challenges

Primary batteries are crucial for aerospace and medical implants; however, traditional inorganic systems (like Li‐MnO 2 and Li‐CF x ) face strict energy limits and high costs. Tunable, eco‐friendly organic cathodes offer a promising alternative. In this review, we categorize organic primary batteries into two main groups: carbonyl‐ and nitro‐based systems. Their massive energy density is unlocked when fluoroethylene carbonate (FEC) is added to the electrolyte. FEC triggers an irreversible four‐electron reduction for carbonyls and a six‐electron reduction for nitro groups. Despite better than inorganic systems in capacity and safety, organics still struggle with low discharge voltages, spontaneous dissolution during storage, capacity drops at high FEC levels, and difficulties in making high‐loading electrodes. To overcome these hurdles, future work could focus on targeted molecular redesign, modification of electrolytes and separators, and improvement of electrode processing techniques. Currently, organic primary batteries are still in early‐stage research but have already demonstrated comprehensive advantages, offering a new pathway toward safe, high‐energy, and green primary batteries.