A green and sustainable strategy toward lithium resources recycling from spent batteries.

Recycling lithium from spent batteries is challenging because of problems with poor purity and contamination. Here, we propose a green and sustainable lithium recovery strategy for spent batteries containing LiFePO, LiCoO, and LiNiCoMnO electrodes. Our proposed configuration of "lithium-rich electrode || LLZTO@LiTFSI+P3HT || LiOH" system achieves double-side and roll-to-roll recycling of lithium-containing electrode without destroying its integrity. The LiTFSI+P3HT-modified LLZTO membrane also solves the H/Li exchange problem and realizes a waterproof protection of bare LLZTO in the aqueous working environment. On the basis of these advantages, our system shows high Li selectivity (97%) and excellent Faradaic efficiency (≥97%), achieving high-purity (99%) LiOH along with the production of H. The Li extraction processes for spent LiFePO, LiNiCoMnO, and LiCoO batteries is shown to be economically feasible. Therefore, this study provides a previously unexplored technology with low energy consumption as well as high economic and environmental benefits to realize sustainable lithium recycling from spent batteries.