Recycling of lithium-ion batteries (LIBs) is essential not only to protect the environment but also to recover valuable metals, such as lithium and cobalt. The effect of ferrous (Fe²⁺) has been explored on LIBs leaching, as a reducing agent. The influence of four different parameters including agitation rate, pH, ferrous concentration and temperature has been investigated on LIBs leaching to optimize the leaching process and kinetics modelling. While ferrous ions did not have significant effect on lithium recovery, the cobalt recovery was increased from 33.6% to 88.7% when ferrous concentration were increased from 0 g/L to 6 g/L. The results indicated that the highest lithium and cobalt recoveries achieved at agitation rate = 500 rpm, pH = 0.5 (∼0.57 mol/L H₂SO₄), ferrous concentration = 6 g/L, and temperature = 75 °C. The kinetics modelling indicated that adding ferrous ions to leaching environment decreases the ash layer formation by reducing the metals in particles surface and transfer them in liquid medium. The activation energies for cobalt and lithium dissolution were 58.71 kJ/mol and 37.45 kJ/mol, respectively. After process optimization, the chemical ferrous ions were replaced by iron scraps were obtained from 18650 LIBs shells. The results showed that 92.67% of lithium and 98.91% of cobalt are recovered by adding 6 g/L iron scrap to the leaching environment. Therefore, the iron scrap can be used as an efficient, economic and sustainable reducing agent for LIBs leaching, at low concentrations of sulfuric acid.

回收锂离子电池（LIB）不仅对保护环境至关重要，而且对于回收有价值的金属（例如锂和钴）也至关重要。已经研究了亚铁（Fe ²⁺）作为还原剂对LIB浸出的影响。研究了搅拌速率，pH，亚铁浓度和温度这四个不同参数对LIBs浸出的影响，以优化浸出过程和动力学建模。尽管亚铁离子对锂的回收率没有显着影响，但是当铁含量从0 g / L增加到6 g / L时，钴的回收率从33.6％增加到88.7％。结果表明，在搅拌速度= 500 rpm，pH = 0.5（〜0.57 mol / LH ₂ SO ₄时，锂和钴的回收率最高），亚铁浓度= 6 g / L，温度= 75°C。动力学模型表明，向浸出环境添加亚铁离子可通过减少颗粒表面的金属并将其转移到液体介质中来减少灰分层的形成。钴和锂溶解的活化能分别为58.71 kJ / mol和37.45 kJ / mol。经过工艺优化后，从18650个LIB壳中获得的铁屑代替了化学亚铁离子。结果表明，通过向浸出环境中添加6 g / L铁屑，可以回收92.67％的锂和98.91％的钴。因此，铁废料可以用作低浓度硫酸时LIB浸出的高效，经济和可持续的还原剂。