Zhu Yimeng, Qian Ye, Zhou Feifei, Sun Lijuan, Jin Hongyang, Ye Zhaolian, Min Xin, Zhao Songjian
School of Resources and Environmental Engineering, Jiangsu University of Technology, Changzhou, Jiangsu 213001, PR China.
Everbright Environmental Protection Technology and Equipment (Changzhou) Limited, Changzhou, Jiangsu 213001, PR China.
Waste Manag. 2025 Aug;205:115037. doi: 10.1016/j.wasman.2025.115037. Epub 2025 Jul 31.
The increasing demand for lithium-ion batteries (LIBs) has introduced significant challenges related to efficient and environmentally sustainable lithium recycling. Recovering cathode materials from spent LIBs via sulfuric acid roasting and subsequent leaching requires a comprehensive understanding of reaction mechanisms and gas emission behaviors to facilitate industrial application. In this study, thermodynamic calculations were conducted using HSC 6.0 software, and real-time gas evolution was analyzed through thermogravimetric mass spectrometry (TG-MS). Gas products were further identified indirectly using ion chromatography (IC) after absorption in an alkaline solution. Material characterization was performed by employing X-ray diffraction (XRD), scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS), and X-ray photoelectron spectroscopy (XPS). The reaction mechanisms and gas release behaviors of graphite-containing Li(NiCoMn)O during sulfuric acid roasting were systematically investigated to optimize the roasting-leaching process.The results revealed a two-stage reaction mechanism: at low temperatures (approximately room temperature to 400 °C), the cathode material reacts with sulfuric acid to form lithium sulfate and transition metal sulfates; during the medium-to-high temperature stage (400-700 °C), lithium sulfate remains thermally stable, while transition metal sulfates decompose or are reduced to water-insoluble oxides or metallic phases, enabling selective lithium extraction. Elevated roasting temperatures also lead to substantially increased emissions of SO and CO. These findings establish a thermodynamically informed roasting-leaching process, facilitating selective lithium recovery while effectively mitigating gas emissions. Additionally, the study provides valuable mechanistic insights into sulfuric acid roasting, presenting a scalable and sustainable strategy for environmentally friendly recycling of spent LIBs.
对锂离子电池（LIBs）日益增长的需求给高效且环境可持续的锂回收带来了重大挑战。通过硫酸焙烧和后续浸出从废旧LIBs中回收阴极材料，需要全面了解反应机理和气体排放行为，以促进工业应用。在本研究中，使用HSC 6.0软件进行了热力学计算，并通过热重质谱（TG-MS）分析了实时气体逸出情况。气体产物在碱性溶液中吸收后，再通过离子色谱（IC）间接进行进一步鉴定。采用X射线衍射（XRD）、带能谱的扫描电子显微镜（SEM-EDS）和X射线光电子能谱（XPS）进行材料表征。系统研究了含石墨的Li（NiCoMn）O在硫酸焙烧过程中的反应机理和气体释放行为，以优化焙烧-浸出工艺。结果揭示了一个两阶段反应机理：在低温（约室温至400°C）下，阴极材料与硫酸反应形成硫酸锂和过渡金属硫酸盐；在中高温阶段（400 - 700°C），硫酸锂保持热稳定，而过渡金属硫酸盐分解或被还原为水不溶性氧化物或金属相，从而实现锂的选择性提取。焙烧温度升高还会导致SO和CO的排放量大幅增加。这些发现建立了一个基于热力学的焙烧-浸出工艺，有助于选择性锂回收，同时有效减少气体排放。此外，该研究为硫酸焙烧提供了有价值的机理见解，提出了一种可扩展且可持续的废旧LIBs环境友好回收策略。
