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

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 Zn2+ 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 V2O4 cathode retain 90.53% of their initial capacity after 2000 cycles at 10C. At 60°C, the I2-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.