Sustainable strawberry DNA-based biomimetic interphase with synergistic buffering and directional transport for dendrite-free lithium metal batteries

Abstract

Circumventing the environmental toxicity and high costs inherent in traditional animal-derived DNA extraction, this study pioneers a green farm to battery strategy utilizing high-yield biomass DNA obtained from octoploid strawberries via a non-toxic process. Based on this approach, we construct a biomimetic Cu@DNA interface that operates through a dual mechanism of molecular buffering and directional transport. Mechanistically, theoretical calculations reveal that the negatively charged phosphate backbone possesses a high binding energy of −7.13 eV, functioning as an electrostatic potential well to homogenize Li⁺ flux and serving as a molecular buffer to effectively suppress dendrite growth. Simultaneously, the guanine/adenine base pairs, characterized by moderate binding energies (−2.77 eV and −1.61 eV), act as “stepping stones” to facilitate rapid Li⁺ desolvation through transient nitrogen coordination, which directs ion transport and significantly enhances reaction kinetics. As a result, this synergistic effect lowers the nucleation overpotential by 51.4%, dropping from 0.1611 V to 0.0828 V, and enables ultra-stable symmetric cell cycling for 700 hours with a low hysteresis of 22 mV. Furthermore, the full cell exhibits superior rate capability with a discharge capacity of 130 mAh g⁻¹ at 3C, maintaining 92.7% capacity retention after 300 cycles. Validating practical viability, pouch cells with a high cathode loading of 5 mg cm⁻² achieve 500 stable cycles with a coulombic efficiency near 100%. Beyond elucidating the synergistic mechanism of DNA-Li⁺ interactions, this work highlights the immense potential of agricultural biomass in sustainable high-energy batteries.