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Redox‐active azo compounds are emerging as promising cathode materials due to their multi‐electron redox capacity and fast redox response. However, their practical application is often limited by low output voltage and poor thermal stability. Herein, we use a heteroatomic substitution strategy to develop 4,4′‐azopyridine. This modification results in a 350 mV increase in reduction potential compared to traditional azobenzene, increasing the energy density at the material level from 187 to 291 Wh kg−1. The introduced heteroatoms not only raise the melting point of azo compounds from 68 °C to 112 °C by forming an intermolecular hydrogen‐bond network but also improves electrode kinetics by reducing energy band gaps. Moreover, 4,4′‐azopyridine forms metal‐ligand complexes with Zn2+ ions, which further self‐assemble into a robust superstructure, acting as a molecular conductor to facilitate charge transfer. Consequently, the batteries display a good rate performance (192 mAh g−1 at 20 C) and an ultra‐long lifespan of 60,000 cycles. Notably, we disclose that the depleted batteries spontaneously self‐charge when exposed to air, marking a significant advancement in the development of self‐powered aqueous systems. [ABSTRACT FROM AUTHOR]

A series of polyimide (PI)/V2CTx MXene composites was synthesized via polyamide acids (PAA) and two‐dimensional (2D) V2CTx MXene obtained by etching precursor V2AlC. PI/V2CTx MXene composites with different mass ratios were obtained by blending and heating with PAA. The results showed that V2CTx MXene has excellent dispersion in PI. In particular, V2CTx MXene exhibited excellent friction reduction and anti‐wear properties as a solid lubricant additive, and the wear rate (WR) was reduced by 43.2% by incorporating only 0.8 wt% of V2CTx MXene in the pristine PI and 71.9% by incorporating 1.2 wt%. Scanning electron microscopy (SEM) and x‐ray photoelectron spectroscopy (XPS) analyses showed that the continuous transfer film consisting of a high proportion of tribo‐chemical products formed on the contact surface is significant to improve the lubrication performances of the PI composites. This work broadens the application of MXene in the field of tribology and contributes to energy conservation and sustainable development of human society. Highlights: The tribological properties could be tuned by changing the ratio of PI to V2CTx MXene.The WR of PI composites was reduced by 71.9% with incorporating 1.2 wt% of V2CTx MXene.The formation of transfer films on the contact surface is significant for improving anti‐wear of PI. [ABSTRACT FROM AUTHOR]