  Aqueous batteries, particularly those integrating organic active materials
functioning in a neutral pH environment, stand out as highly promising
contenders in the stationary electrochemical storage domain, owing to their
unparalleled safety, sustainability and low-cost materials. Herein, a novel
di-block oligomer (DNVBr), serving as the negative electrode of an all-organic
aqueous battery, is shown to offer exceptional output capabilities. The
battery's performance is further enhanced by a unique intermixed p/n-type
storage mechanism, which is able to simultaneously exchange light and naturally
abundant Na+, Mg2+ and Cl-. Reaching up to 105 mAh/g, this system shows
remarkable capacity retention for several thousand cycles (6500 cycles, ~40
days) in various neutral electrolytes, including raw ocean water (~3000 cycles,
~75 days). The surprisingly fast kinetics of this di-block oligomer allow to
attain an unmatched specific capacity of near to 60mAh/g electrode while
entirely devoid of conducting additives, and more than 80mAh/g electrode with
10% carbon additive, as well as displaying an areal capacity as high as
3.4mAh/cm2 at C rate. Full cell validation was demonstrated over 1600 cycles by
virtue of a commercial TEMPO molecule, which permitted an energy density of
close to 40Wh/kgmaterials at C rate in a self-pH-buffered and inexpensive
aqueous electrolyte.
