Corrosion behavior and corrosion inhibition performance of spent lithium-ion battery during discharge

• Corrosion of batteries discharged in different solutions was studied in detail. • Developed a more effective and cleaner discharge system. • No corrosion of Fe shim in NaOH + Na 2 SiO 3 system. • Corrosion of Al was reduced by more than 30 times in NaOH + Na 2 SiO 3 system. • The corrosion inhibition system has good applicability to different batteries. Discharge is an important pretreatment step to avoid thermal runaway of spent lithium-ion battery (LIB) during recycling. At present, chemical discharge is the most researched method to release residual energy of spent LIB. However, the corrosion of battery in the process of chemical discharge has been neglected. In this study, the corrosion of spent LIBs in different electrolyte solutions was studied in detail. The corrosion of battery in traditional electrolyte solution (NaCl, Na 2 SO 4 , NaOH, H 2 SO 4 ) and the changes of ion content in electrolyte solution during discharge were summarized. In addition, a cleaner discharge method was proposed to solve the problem of battery corrosion during discharge. In the NaOH + Na 2 SiO 3 system, the aluminosilicate cementitious formed by aluminum ions and silicates covered the aluminum flake to prevent further corrosion of the aluminum flake, so as to achieve the purpose of corrosion inhibition. The experimental results show that there was no corrosion to Fe shim in the NaOH + Na 2 SiO 3 system, and the content of aluminum ions can be reduced to less than 30 ppm, which perfectly solved the corrosion problem of the battery during discharge. Furthermore, using this method to discharge the soft-pack spent LIB and the square aluminum shell spent LIB also greatly reduced the corrosion of the battery and achieved an excellent discharge effect. Therefore, a clean and green discharge system was developed in this paper, which was of great significance for the safe and clean recycling of spent LIB.