Green low-melting mixture solvents/ionic liquids-based carbon materials and lithium-ion batteries recycling leachate unexpectedly cause water pollution from dissolved organic matter

Low-melting mixture solvents (LoMMSs) and ionic liquids (ILs) are regarded as green solvents for the recovery of lithium-ion batteries (LIBs) cathode with high sustainability. Unexpectedly, we find for the first time that the release of LoMMSs- or ILs-based carbon materials and LIBs recycling leachate into water can lead to significant pollution from dissolved organic matter (DOM). Moreover, COD, NH₄–N and total P concentration in river from Jingjinji Region is relatively high due to the high concentration of DOM. This work would provide us a hint that the application of so-called green LoMMSs and ILs in materials preparation and LIBs recovery should be treated with high caution in order to minimize DOM pollution for the rivers in Jingjinji Region.