Corrosion inhibition of aluminum current collector by a newly synthesized 5-formyl-8-hydroxyquinoline for aqueous-based battery

Aluminum foil is frequently used as a cathodic current collector for batteries because of its high electrical conductivity, low cost, robust electrochemical properties, and low density. However, as next-generation batteries are created, severe corrosion poses new challenges to aluminum current collectors, especially with no effective additive in an aqueous electrolyte so far. 5-formyl-8-hydroxyquinoline (FHQ) is designed and synthesized as an effective corrosion inhibitor for aluminum foil. Its corrosion inhibition efficacy and the passivation film are assessed by electrochemical methods and spectroscopy techniques. The corrosion rate in millimeters per year (mmpy) measured in the aqueous electrolyte of 21 m LiTFSI with the FHQ additive 1.37 x 10-3 mmpy is much lower than 2.29 x 10-2 mmpy in the unmodified electrolyte. Meanwhile, the Zn//LVPF configuration is developed as an efficient protocol to evaluate the corrosion prevention efficiency of inhibitors in an aqueous-based battery for the first time. The Zn//LVPF cell in the aqueous electrolyte with the FHQ additive provides much higher capacity retention and average Coulombic efficiency. Interestingly, the Al corrosion prevention efficiency of the developed additive is also testified in an organic electrolyte-based battery. This work paves a new pathway to develop effective Al corrosion inhibitors for lithium-ion batteries, especially in aqueous electrolytes.

Automated summary

Aluminum foil is commonly used as a cathodic current collector in batteries due to its favorable properties. However, the emergence of next-generation batteries has brought new challenges in terms of corrosion. In this study, a new corrosion inhibitor, 5-formyl-8-hydroxyquinoline (FHQ), was designed and synthesized for aluminum foils. The efficacy of FHQ in inhibiting corrosion and promoting the formation of a passivation film was evaluated through various tests. The results showed that FHQ significantly reduced the corrosion rate of aluminum foils in aqueous electrolytes and demonstrated promising potential in improving the performance of lithium-ion batteries.