Organic tailored batteries materials using stable open-shell molecules with degenerate frontier orbitals

Secondary batteries using organic electrode-active materials promise to surpass present Li-ion batteries in terms of safety and resource price(1,2). The use of organic polymers for cathode-active materials has already achieved a high voltage and cycle performance comparable to those of Li-ion batteries(3-6). It is therefore timely to develop approaches for high-capacity organic materials-based battery applications. Here we demonstrate organic tailored batteries with high capacity by using organic molecules with degenerate molecular orbitals (MOs) as electrode-active materials. Trioxotriangulene (TOT), an organic open-shell molecule, with a singly occupied MO (SOMO) and two degenerate lowest-unoccupied MOs (LUMOs) was investigated. A tri-tert-butylated derivative ((t-Bu)(3)TOT) exhibited a high discharge capacity of more than 300 Ah kg(-1), exceeding those delivered by Li-ion batteries. A tribrominated derivative (Br3TOT) was also shown to increase the output voltage and cycle performance up to 85% after 100 cycles of the charge-discharge processes.