Selective Recovery of Lithium from Spent Lithium-ion Batteries Synergized by Carbon and Sulfur Elements

Abstract

Recycling of spent lithium-ion batteries (LIBs) has attracted ever-growing attention globally owing to the scarcity of critical metals and potential environmental risk. To solve the bottlenecks including poor selectivity and prominent environmental risks during the recovery of valuable metals from spent LIBs, the work proposed a novel process for selectively recovery of lithium synergized by carbon and sulfur elements. Firstly, H2SO4 was determined as the optimal roasting reagent by systematically investigating the effects of various roasting reagents including NaHSO4, (NH4)2SO4, NH4HSO4 and H2SO4 on the leaching selectivity of lithium from the LiNi1/3Co1/3Mn1/3O2 active material in spent LIBs, environmental impact and cost of reagents. Then, the effect of graphite dosage on the selectivity of lithium from LiNi1/3Co1/3Mn1/3O2 is investigated. Finally, the conversion path and mechanism under the synergistic effect of C and S elements for enhancing the selectivity of lithium is revealed. It is found that the leaching efficiency can achieve 93% under the following optimal conditions: the molar ratio of LiNi1/3Co1/3Mn1/3O2 to H2SO4 of 2∶1, graphite dosage of 20% (w), roasting temperature of 600 ℃, and roasting time of 120 min. The purity of the precipitated Li2CO3 from the obtained leachate is higher than that of battery grade Li2CO3. Ni, Co and Mn from LiNi1/3Co1/3Mn1/3O2 almost remains in the leaching residue which can be employed as the precursor materials for synthesizing cathode materials after separation and purification treatment. In addition, the separated graphite can be reused as roasting additive during the sulfation roasting of LiNi1/3Co1/3Mn1/3O2. By analyzing

Electron/ion Conductor Double-coated LiNi0.8Co0.1Mn0.1O2 Li-ion Battery Cathode Material and Its Electrochemical Performance

“…然而, 以较低的成本追求更高的能量密度给 NCM 材料带来了新的挑战. 先前研究表明, 更高镍含量的层 状 NCM 材料在结构上不稳定, 尤其是在高电压充电的 条件下, 过度 Li ＋ 脱出会导致 NCM 结构的破坏, 由此引 起容量的衰减 [4][5] . 随着锂离子的脱出, 材料会生成活性 较高的 Ni 4＋ , 导致材料的放热反应加剧.…”

Recycling of Valuable Metals from the Priority Lithium Extraction Residue Obtained through Hydrogen Reduction of Spent Lithium Batteries

“…However, the roasting process used in the treatment of spent lithium batteries generates NO, CO, CO 2 , NO 2 , SO 2 and other pollutants. In addition, the roasting kinetics are relatively slow, and the lithium in the cathode can only be completely converted into nitrate, sulfate or carbonate salt when the roasting time is more than 2 h [22,23]. Therefore, in response to the many deficiencies of the combined method described above, a green and environmentally friendly hydrogen reduction process was developed by our research group [24].…”