Manipulating Interfacial Stability Via Absorption-Competition Mechanism for Long-Lifespan Zn Anode

Abstract

Abstract The stability of Zn anode in various Zn-based energy storage devices is the key problem to be solved. Herein, aromatic aldehyde additives are selected to modulate the interface reactions between the Zn anode and electrolyte. Through comprehensively considering electrochemical measurements, DFT calculations and FEA simulations, novel mechanisms of one kind of aromatic aldehyde, veratraldehyde in inhibiting Zn dendrite/by-products can be obtained. This additive prefers to absorb on the Zn surface than H2O molecules and Zn2+, while competes with hydrogen evolution reaction and Zn plating/stripping process via redox reactions, thus preventing the decomposition of active H2O near the interface and uncontrollable Zn dendrite growth via a synactic absorption-competition mechanism. As a result, Zn–Zn symmetric cells with the veratraldehyde additive realize an excellent cycling life of 3200 h under 1 mA cm−2/1 mAh cm−2 and over 800 h even under 5 mA cm−2/5 mAh cm−2. Moreover, Zn–Ti and Zn–MnO2 cells with the veratraldehyde additive both obtain elevated performance than that with pure ZnSO4 electrolyte. Finally, two more aromatic aldehyde additives are chosen to prove their universality in stabilizing Zn anodes.

Keywords

• Aromatic aldehyde
• Absorption-competition mechanism
• Zn anode
• Interfacial stability