5,7,12,14-Pentacenetetrone as a High-Capacity Organic Positive-Electrode Material for Use in Rechargeable Lithium Batteries

The performance of 5,7,12,14-pentacenetetrone (PT) as an organic active material for rechargeable lithium batteries was investigated. A positive-electrode incorporating PT showed an initial discharge capacity of more than 300 mAh/g(PT) with an average voltage of 2.1 V vs. Li+/Li. The obtained discharge capacity corresponded to a four-electron redox behavior and is more than twice that of a conventional positive-electrode material, lithium cobalt oxide (LiCoO2). A quantum calculation based on the density functional theory (DFT) was also performed to clarify the mechanism of the electron-transfer in the PT crystal.