Lang Jialiang,Jin Yang,Liu Kai,Long Yuanzheng,Zhang Haitian,Qi Longhao,Wu Hui,Cui Yi
Lithium (Li) is an important resource for the sustainability of socioeconomic systems given its wide use in various industrial applications. The industrial production of Li metals relies on the electrolysis of a mixture consisting of high-purity lithium chloride (LiCl) and potassium chloride. However, the purification of LiCl is expensive and unsustainable, requiring a substantial amount of energy and the use of noxious chemical reagents, so that producing high-purity Li efficiently and sustainably is a challenge. Herein we report a new method of producing high-purity electrolytic Li from low-purity LiCl using solid-state electrolyte. Taking advantage of the high Li-ion selectivity of the solid electrolyte, we directly obtained high-purity metallic Li through the electrolysis of low-purity LiCl. Our new method provides two important advantages over conventional methods: (1) the cost of producing high-purity Li is reduced by using low-purity LiCl from low-grade brine, and the simpler purification process reduces the use of energy and chemical reagents; and (2) the operating temperature of the electrolytic process decreases from 400 °C to 240 °C, leading to an additional reduction in energy use.
The recycling of spent ternary lithium batteries (T-LIBs) promises scarce strategic resource recovery, however, efficient and selective recovery of Li + from T-LIBs leaching solution with complex components is still a considerable challenge. Herein, we present a polyamide nanofiltration membrane based on the positively charged nanoscale dispersion interlayer for the first application in recycling lithium from the leaching solution of spent T-LIBs. The electronegativity is weakened by positive charge within the interlayer, which enhance the effect of Donnan exclusion. The pos-TFNi membrane can effectively permeate Li + while the interfering divalent ions are almost completely separated, achieving the high purity (separation factor ≥ 93.5) and high recovery rate (79.2%) of Li + from leaching solution simultaneously, with a 6.2-fold improvement in the separation factor over the pristine TFC membrane, and outperformed the majority of the NF membranes. This work represents a reference for the recycling of the massive accumulation of spent T-LIBs worldwide.
Yutao Yang,Rongzheng Tian,Hongzhou Zhang,Zhenyu Wang,Lianqi Zhang,Yongan Yang,Dawei Song
Lithium sulfide (Li2S) is the critical raw material used for the synthesis of sulfide solid-state electrolytes, but its high cost and pollution restrict the commercialization of sulfide solid-state electrolytes and sulfide-based all-solid-state batteries. A new green and cost-effective method for the synthesis of high-quality Li2S is designed and proposed in this work. The method of reducing Li2SO4 with H2 circumvents the disadvantages of many side reactions, complicated purification processes, impure products and emission of greenhouse gases (CO and CO2) associated with traditional carbothermal reduction methods, and high-purity Li2S (H-Li2S) is obtained. Subsequently, H-Li5.6PS4.6Cl1.4 solid electrolyte was synthesized and compared with the C-Li5.6PS4.6Cl1.4 electrolyte synthesized from commercial Li2S (C-Li2S). The ionic conductivity (8.06 mS cm−1) and chemical/electrochemical stability as cathode/anode material were better than those of C-Li5.6PS4.6Cl1.4. Besides, the rate performance and long cycling stability of an all-solid-state lithium battery NCM//Li5.6PS4.6Cl1.4//Li–In assembled with H-Li5.6PS4.6Cl1.4 are better than those of batteries assembled with C-Li5.6PS4.6Cl1.4. It can maintain a discharge capacity of 133.23 mA h g−1 after 300 cycles at 1C (95% of the initial discharge capacity), and has a high discharge capacity of 127.9 mA h g−1 at 3C. The high electrochemical performance of the all-solid-state battery confirms the superiority of high-purity H-Li2S and the advantages of the hydrogen reduction method.