Evolution‐Driven Bio‐Composite Aerogels for Self‐Adaptive Thermal Regulation and Energy Storage

Abstract

ABSTRACT Nature achieves remarkable multifunctionality by integrating chemically dissimilar phases into hierarchically organized architectures. Inspired by this principle, we develop a simple and universal strategy to construct bio‐composite aerogels by incorporating trivalent metal chlorides (MCl 3 ) into biopolymer chitosan (CTS) matrices. Coordination‐driven assembly in aqueous media enables the direct formation of metal ion‐coordinated chitosan (CTS–M) aerogels without external acids or additional crosslinkers. These aerogels exhibit reversible brittle‐to‐flexible transitions under humidity stimuli, together with exceptional mechanical resilience, enabling self‐adaptive thermal insulation under temperature extremes. Upon pyrolysis, the same precursor is converted into conductive carbon–metal oxide (C–M 2 O 3 ) aerogels, where metal oxide nanocrystals are embedded within an interconnected carbon framework. This structural integration couples a continuous electron‐transport network with redox‐active domains, thereby promoting charge‐transfer and increasing accessible storage sites. As a representative example, the C–V 2 O 3 cathode for aqueous zinc‐ion batteries (ZIBs) delivers excellent energy–power performance (656 Wh kg −1 at 200 W kg −1 , 178 Wh kg −1 at ∼20 000 W kg −1 ) with 85% capacity retention after 10 000 cycles, outperforming previously reported carbon–metal oxide systems. By linking adaptive thermal regulation and electrochemical energy storage through a single precursor‐to‐function pathway, this work establishes an evolution‐driven aerogel design paradigm for next‐generation multifunctional materials.