Dynamic Interfacial Adsorption via a Thermoresponsive Biomass Interphase Enables Temperature‐Adaptive Zinc Anodes

ABSTRACT Aqueous zinc batteries face temperature‐dependent interfacial challenges, whereas conventional artificial interphases rely on static passivation and therefore lose effectiveness under thermal perturbation. Here we report a thermoresponsive biomass interphase that enables temperature‐adaptive zinc anodes through dynamic interfacial adsorption. Constructed from gelatin and sulfonated cellulose nanocrystals, the interphase undergoes reversible gel‐quasi‐liquid transitions within the operating temperature window of aqueous zinc batteries. At room temperature, the hydrogen‐bonded network homogenizes Zn 2+ flux and spatially confines deposition, thereby suppressing dendrite growth and corrosion. At elevated temperature, the interphase switches to a dynamic adsorption mode, in which reconfigured polymer chains expose zincophilic groups that promote Zn(002)‐preferred deposition and inhibit hydrogen evolution and by‐product formation. This thermally triggered switching mechanism enables symmetric cells to achieve stable cycling over 2000 h at 30°C and 730 h at 60°C. At 30°C, full cells with a V 2 O 4 cathode retain 90.53% of their initial capacity after 2000 cycles at 10C. At 60°C, the I 2 ‐based full cell achieves 91.1% after 2500 cycles at 4C, and can even sustain 9600 cycles at 15C. Life‐cycle assessment further reveals reduced environmental impacts relative to conventional protective films. This work establishes a new interphase design paradigm offering a sustainable route toward high‐temperature‐stable batteries.