High-capacity organic positive-electrode material based on a benzoquinone derivative for use in rechargeable lithium batteries

The performance of 2,5-dimethoxy-1,4-benzoquinone (DMBQ) as an active material for rechargeable lithium batteries was investigated. A positive-electrode that incorporated DMBQ showed an initial discharge capacity of 312 mAh g−1 with an average voltage of 2.6 V vs. Li+/Li. This discharge capacity corresponds to a benzoquinone-based two-electron redox behavior, and is more than twice that of the conventional positive-electrode material lithium cobalt oxide (LiCoO2). Furthermore, the positive-electrode with DMBQ showed fair cycle-life performance. Theoretical quantum calculations based on the density functional theory (DFT) were also performed to clarify the mechanism of the electrochemical properties of the solid state of DMBQ.