“…If we could use a redox system that includes 1,4-benzoquinone, which is the simplest quinine derivative, as a positive-electrode material, a large capacity of up to about 500 mAh g −1 should be expected, although the use of 1,4-benzoquinone itself is practically difficult because of its high capacity for sublimation. Several pioneering works have tried to apply this redox reaction to battery systems through the synthesis of various polymers [3,[10][11][12]. However, the two-electron redox reaction in battery materials has not been realized in most cases due to various problems, such as the dissolution of these organic compounds into the electrolytes, the instability of intermediate radical species, and low electrical conductivity.…”