The use of lithium-ion batteries (LIBs) has increased in recent years. Thus, efficient recycling is important. In this study, the Taguchi method was used to find the optimal selective lithium leaching parameters for spent LIB recycling. Orthogonal array, signal-to-noise ratio, and analysis of variance were employed to investigate the optimization of selective lithium leaching. The experimental parameters were heat treatment and leaching conditions. The lithium leaching ratio was analyzed by inductively coupled plasma (ICP). The reaction temperature was analyzed by thermogravimetry differential scanning calorimetry (TG-DSC) using lithium cobalt oxide (LCO) and carbon powder, and X-ray diffraction (XRD) was performed after heat treatment at different temperatures. From the XRD analysis, a Li₂CO₃ peak was observed at 700 °C. After heat treatment at 850 °C, a peak of Li₂O was confirmed as Li₂CO₃ decomposed into Li₂O and CO₂ over 723 °C. The Li₂O reacts with Co₃O₄ at a high temperature to form LCO. The phase of lithium in the LIB changes according to the conditional heat treatment, affecting the lithium leaching rates. As heat treatment conditions, N₂ atmosphere combined with 700 °C heat treatment is suitable, and the solid–liquid ratio is important as a leaching factor for selective lithium leaching.

中文翻译：

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基于Taguchi方法的废锂离子电池正极活性物质选择性浸出锂的设计优化

近年来，锂离子电池（LIB）的使用有所增加。因此，有效的回收很重要。在这项研究中，使用Taguchi方法找到用于废LIB回收的最佳选择性锂浸出参数。采用正交阵列，信噪比和方差分析来研究选择性锂浸出的优化。实验参数是热处理和浸出条件。通过电感耦合等离子体（ICP）分析锂的浸出率。使用氧化钴锂（LCO）和碳粉通过热重差示扫描量热法（TG-DSC）分析反应温度，并且在不同温度下热处理后进行X射线衍射（XRD）。根据XRD分析，Li ₂ CO ₃在700°C观察到峰值。在850℃下进行热处理后，证实了Li ₂ O的峰，因为在723℃下Li ₂ CO ₃分解为Li ₂ O和CO ₂。Li ₂ O在高温下与Co ₃ O ₄反应形成LCO。LIB中锂的相随条件热处理而变化，从而影响锂的浸出率。作为热处理条件，N ₂气氛与700°C热处理相结合是合适的，并且固液比作为选择性锂浸出的浸出因子非常重要。