Zn@cellulose nanofibrils composite three-dimensional carbon framework for long-life Zn anode

Construction of composite Zn anode with highly conductive frame can effectively homogenize the interfacial electric field and charge distribution, thereby effectively inhibiting the formation of dendrites of aqueous Zn-ion batteries. Herein, highly conductive nanocellulose-based carbon aerogels with honeycomb porous structure and high specific surface area were synthesized by bidirectional freezing and carbonization. Dendrite-free Zn@Carbon Aerogel (Zn@CA) composites were prepared by facile electrodeposition. Benefiting from the ordered porous structure of nanocellulose-based carbon aerogels, Zn was uniformly dispersed on carbon aerogels. The carbon aerogels with connected conductive network can adjust the nucleation sites of Zn, thus inhibiting the formation of dendrites. Zn@CA composite electrode material exhibits high specific surface area and hydrophilicity (water contact angle of 37.8°), and owns rapid electron transfer channels. The assembled symmetrical cells with Zn@CA electrodes exhibit lower polarization voltage, excellent cycling performance, and almost 100% Coulombic efficiency as well as fast electrochemical kinetics during repeated Zn plating/stripping processes for 13,000 cycles.