The triazol-3-ylamine and three different kinds of Schiff base compounds are self-assembled on bronze surface. Electrochemical impedance spectroscopy and potentiodynamic polarization measurements show that the triazol-3-ylamine and Schiff base self-assembled films can protect bronze from corrosion in 0.5 M HCl solution. The corrosion efficiency increases with the self-assembly time increasing and reaches a stable value after 8 h. The highest corrosion efficiency of the bronze electrode modified with self-assembled films reaches 95.81% after immersing in 0.005 M 2,4-Dibromo-6-[(4H-[1,2,4]Triazol-3-ylimino)-methyl]-phenol Schiff base solution for 10 h. X-ray photoelectron spectroscopy and scanning electrochemical microscope are used to characterize the inhibitive ability of the self-assembled films. Quantum chemical calculations and dynamic simulations indicate that the triazol-3-ylamine and Schiff bases molecules can absorb on the copper surface via chemisorption. The adsorption energy increases with the number of aromatic rings.
Gege Wang,Feifan Zhang,Caiyu Ma,Jianhua Yang,Xiaowei Chi,Yu Liu
Aqueous zinc metal batteries (AZMBs) as one of the next-generation energy storage technologies have attracted both academic and industrial attention due to their high safety, low cost, and high specific energy, yet are facing interfacial challenges at the electrolyte/anode interface, e.g. uneven physical diffusion of Zn2+ flux, severe chemical corrosion, and disordered electrochemical deposition behavior of the zinc metal anode. To address these issues, herein, we propose a facile and effective electrolyte modulating strategy to construct a physico-chemo-electrochemically coupled stable interface between the aqueous electrolyte and zinc anode. The aqueous electrolyte modified using a tiny amount of water-soluble ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF4) can form a positively charged organic EMIM+ adsorption layer and a protective inorganic Zn2+-conducting layer through the in situ decomposition of BF4− on the zinc anode surface, thus effectively homogenizing the Zn2+ diffusion flux and decreasing the chemical corrosion rate. Moreover, EMIM+ provides an electrostatic shielding layer, leading to the preferential and ordered electrodeposition of Zn2+ along the Zn (002). Benefiting from this physico-chemo-electrochemically multifunctional interfacial layer, the Zn//Zn symmetric cells achieve a considerably extended lifespan of up to 1200 h at 5 mA cm−2 and 5 mA h cm−2, and more than 450 h even at an ultrahigh current density and large deposition capacity (10 mA cm−2 and 10 mA h cm−2). Zn//Cu asymmetric cells also exhibit excellent reversibility with a high coulombic efficiency of 99.75%. Furthermore, the physically, chemically, and electrochemically stabilized interface enables the AZMB with a quinone-based cathode to offer high specific capacity (256.9 mA h g−1) and a decent capacity retention rate (83.9% after 300 cycles).
Mg-based alloy anodes suffer from severe corrosion in conventional electrolytes (KOH solution) and this substantially obstructs the cycle life, which is a great challenge for using them in the Ni-MH battery. Herein, a high concentration tetramethylammonium hydroxide (TMAH) aqueous electrolyte with a special hydrate structure is explored and enables excellent cycle stability and high capacity for Mg-based alloy anodes. In this electrolyte, the Mg 0.4 Ti 0.1 Ni 0.5 alloy anode delivers a maximum discharge capacity of 466 mAh g −1 , and maintains 210 mAh g −1 after 100 cycles owing to the reduced corrosion rate , which are much better than that in 6 M KOH electrolyte, being 425 mAh g −1 and 69 mAh g −1 , respectively. Furthermore, by in-situ forming Cu coating on the Mg 0.4 Ti 0.1 Ni 0.5 electrode surface during charging process with the adding 0.01 M of Cu(OH) 2 in TMAH electrolyte, the corrosion of the electrode is further suppressed and the reversible capacity can reach 313 mAh g −1 after 100 cycles. The high conducting Cu coating can also increase the rate capability of the electrode by promoting the charge transfer. Thus, using TMAH electrolytes provides a new approach to promote the electrochemical performances of Ni-MH batteries with Mg-based alloy anodes.