Method for improving metal leaching rate in waste lithium ion batteries by controlling oxidation-reduction potential

The invention discloses a method for improving the metal leaching rate in waste lithium ion batteries by controlling oxidation-reduction potential, which comprises the following steps of: (1) removing shells of the waste lithium ion batteries; (2) preparing a leaching medium from the following components in a weight/volume ratio: 3.0g/L of (NH4)2SO4, 0.1g/L of KCl, 0.5g/L of K2HPO4, 0.5g/L of MgSO4.7H2O, 0.01g/L of Ca(NO3)2, and 25g/L of FeSO4.7H2O, and ensuring the pH of the leaching medium is 2.0; and (3) inoculating acidithiobacillus ferrooxidans in an inoculums concentration of 10 percent. The invention has the advantages that: the consumption of nutrients of the mediums can be reduced, the leaching efficiency of lithium cobaltoxide is greatly improved, the consumption of FeSO4 in a 9K medium of 44.8g/L is reduced to 25g/L, the leaching rates of cobalt and lithium can be respectively improved to 97 percent and 80 percent, and a new technical method with low cost and high leaching efficiency is provide for recovering valuable metals in the waste lithium ion batteries, and is a treatment method with good application prospect.