Atomic-scale inorganic carbon additive with rich surface polarity and low lattice mismatch for zinc to boost Zn metal anode reversibility

Abstract

The renaissance of aqueous zinc-ion batteries (ZIBs) is impeded by the disordered Zn deposition and notorious water attack at the Zn-electrolyte interface. Electrolyte additive engineering plays a vital role in tuning the electrode–electrolyte interface chemistry to stabilize Zn anode but its long-term performance at high plating/stripping rates and capacities remains a challenge. Herein, we demonstrate highly reversible Zn anodes by employing the atomic-scale inorganic carbon nanomaterials (ICN) as a multifunctional electrolyte additive into the common ZnSO4 solution to regulate the Zn deposition behaviors. The ICN with rich surface polar groups modulates the primary Zn2+ solvation structure to avoid the side reactions, and preferentially absorbs on the Zn anode surface to build a passivated-protect interface to suppress Zn corrosion and dendrite growth. More importantly, its low lattice mismatch with zinc navigates the preferred Zn (002) deposition to induce smooth and dense Zn plating morphology, fundamentally eradicating the Zn dendrite issues and further Zn corrosion. Consequently, the electrolyte containing ICN additive endows the symmetric Zn cells with fabulous cumulative capacity (3500 mAh cm−2), decent Coulombic efficiency (99.69 %) at 10 mA cm−2, and excellent stability of 800 cycles with only 0.022 % capacity decay per cycle in the Zn||VOX battery under practical conditions of limited Zn supply, high-loading cathode and lean electrolyte. This work presents an effective strategy to advance the practical applications of rechargeable aqueous zinc batteries.