Rapid Fabrication of Antifreezing Piezoionic Hydrogels for Fast Charging and Enhanced Energy Harvesting Frequency via Ion‐Regulating Nanoparticles

Abstract Piezoionic hydrogel generators have attracted significant attention as highly promising energy conversion devices. However, their practical applications are constrained by insufficient output performance, particularly the limitation of operating frequency at ≤0.1 Hz and low charging rate. This study presents a rapidly preparable piezoionic hydrogel generator designed for fast charging in various dynamic scenarios. Surface‐functionalized Super P carbon black nanoparticles strengthen electrostatic interactions and introduce active sites, achieving gelation within tens of seconds without external energy input. The synergistic effect of nanoparticles and lithium salts effectively inhibits ice crystal formation and ensures mechanical flexibility at −90 °C. Mechanistically, the positively charged nanoparticles act as “ion regulation switches,” amplifying differences in ion mobility through selective adsorption of anions, inducing local enrichment of anions, and generating an exceptionally high output of 827.90 mV and 3.2 A m −2 . This hydrogel also achieves two orders of magnitude improvement over conventional piezoionic generators. Its compatibility is demonstrated with both human movements (1 to 4 Hz) and low‐frequency mechanical vibrations (10 Hz), capable of delivering an ultra‐high charging rate of 146 mV s −1 for a 1 mF capacitor. This work paves the way for multi‐scenario energy harvesting and portable power sources applications.