Thousands-fold Conductivity Increase in Organic Battery Material during the Initial Current Flow

S Uchida and M Yao and Y Maeda and Z Siroma and K Tada and K Kiyohara and S Miyakawa and T Saito and T Kiyobayashi, CHEMISTRY OF MATERIALS, 37, 6534-6542 (2025).

DOI: 10.1021/acs.chemmater.5c00900

Redox active organic compounds can be harnessed as precious-element-free electrode materials for rechargeable lithium batteries. Although previous studies of organic batteries abound, it remains a mystery why they can function as electrodes despite their apparent poor conductive characteristics compared to those of the current inorganic counterparts. In this study, using a lithium salt of a naphthazarin dimer, DNP-Li4, as a model organic compound, we discovered that, if the electronic conduction path is properly provided, the conductivity of the compound significantly increases to the level of conventional inorganic electrode materials with slight Li-doping or dedoping. By optimizing the electrode structure, we succeeded in increasing the organic battery material content to 94% without compromising the discharge capacity. The observed phenomenon is explained by the electronic band formation of the aggregates and the carrier-transfer in the band, as indicated by theoretical calculations.

Return to Publications page