An Ultrafast and Ultralow‐Temperature 3D‐Printed All‐Organic Proton Pseudocapacitor

Abstract A critical challenge for pseudocapacitors applications is the rapid capacitance fading under extreme environments, which originates from sluggish diffusion kinetics of inorganic materials and tortuous ionic channels in conventional bulk electrodes. Herein, a novel 3D‐printed all‐organic proton pseudocapacitor (composed of 2,6‐diaminoanthraquinone (DQ)‐based anode and polyaniline‐based cathode) with chemical and structural stability is developed, which exhibits an extraordinary rate performance and cycle stability under ultralow temperature. The DQ molecules are anchored on reduced graphene oxide, which enhances the electronic conductivity and structural stability. Theoretical calculation and spectroscopic characterization reveal that the two‐electron transfer process involves quinone/hydroquinone transition. Exploiting the synergy of fast reaction kinetics of organic and the efficient ion diffusion paths of the 3D architecture, the 3D‐printed anode achieves an impressive areal capacitance of 10.14 F cm −2 at high mass loading (28.73 mg cm −2 ). The 3D‐printed all‐organic proton pseudocapacitor shows stable cycling performance at −80 °C and releases a high energy density of 0.76 mWh cm −2 at −60 °C. This work is instructive for the development of competitive ultra‐low temperature energy storage devices via integrating organic materials and 3D architectural electrode designs.