A Nitro-Rich Small-Molecule-Based Organic Cathode Material for Effective Rechargeable Lithium Batteries

Organic cathode materials have attracted extensive research interest for rechargeable lithium-ion batteries (LIBs) because of their diverse structures and tunable properties. However, the preparation of organic cathode materials with high capacities, long cycling life, and high energy densities still remains a big challenge. To address these issues, we designed and synthesized a novel multinitro-decorated organic small molecule, N⁴,N^4''-bis(2,4-dinitrophenyl)-5'-(4-((2,4-dinitrophenyl)amino)phenyl)-[1,1':3',1''-terphenyl]-4,4''-diamine (TAPB-6NO₂), where the unique electronic character of nitro group should enable TAPB-6NO₂ to be a promising cathode candidate for LIBs. We found that the introduction of multiple nitro groups could efficiently reduce the solubility of TAPB-6NO₂ in organic electrolytes, resulting in a high specific capacity of around 180 mAh g^-1 and stable cycling with a capacity retention of 91% after 1100 cycles at 1000 mA g^-1. This work suggests that attaching multiple nitro groups on a small molecule is an effective approach to construct high-performance organic cathode materials for stable and sustainable rechargeable LIBs.