Safe and effective recycling of lithium-ion batteries (LIBs) is decisive, as their application in daily life is growing exponentially. This surge is creating serious challenges for the recycling industry, particularly due to the limited availability of critical materials like lithium and cobalt, as well as the environmental risks associated with improper disposal. The main issue with recycling LIBs is residual energy, which can cause thermal runaway if left unchecked. Electrochemical discharge using aqueous inorganic salt solutions like NaCl is a cost-effective and scalable method for ensuring safety. However, the existing approach has faced issues related to low discharge rates, extensive corrosion, or toxic gas emissions. In this study, we introduce a different electrochemical discharge method based on a Fe(II)–Fe(III) redox couple electrolyte that enables the deep discharge of LIBs to a safe voltage below 1V without substantial casing corrosion. We demonstrate that 5 wt% potassium hexacyanoferrate/ferrite electrolyte provides efficient discharge with low voltage rebound and reduced gas evolution. To improve the industrial viability of this approach, our results indicate the importance of material selection, and battery casing composition with Ni content improving the stainless-steel composition as critical factors. While future research is needed to avoid potential HCN formation, the results introduce a possibility of scale-up, non-corrosive, and efficient pre-treatment of LIB recycling.