【摘要】 钴酸锂（LCO）电池凭借其高能量密度在锂离子电池市场占据中地位,然而废旧电池中大量存在的贵重金属元素对环境和经济都会造成巨大影响。因此,合理回收再利用对于资源可持续化有着重要意义。与现有的火法冶金和湿法冶金回收方法相比,直接再生法作为废旧钴酸锂最具潜力的回收策略。在这里,我们展示了一种直接再生工艺,不仅可以从废旧锂离子电池中回收LCO,还可以对其进行升级,强化结构稳定性,提升电化学性能。在回收过程中,基于废LCO与NiF₂和Li₂CO₃混合物之间的直接反应,在此过程中,F和Ni进入LCO体相内,形成双掺杂后的HV-LCO。升级后的HV-LCO在4.6 V高压下具有优异的倍率性能(1 C克容量为207.2 mA h·g^-1,10C克容量为137.54 mA h·g^-1)、良好的高倍率长循环性能(5C初始克容量为193.2mA h·g^-1,200次循环后保留其初始容量的89.8%)、高度可逆的晶体结构和高Li⁺扩散系数。通过扫描电子显微镜（SEM）和X射线衍射（XRD）证实了回收工艺的有效性,通过循环伏安曲线、阻抗测试证实了HV-LCO的充放电特征。更多还原

【Abstract】 With the surge in lithium-ion batteries（LIBs）,a substantial influx of used lithium-ion batteries permeated the market,exerting significant pressure on both the environment and the economy.Nevertheless,judicious recycling and repurposing are crucial for the sustainability of resources.In comparison to the prevailing pyrometallurgical and hydrometallurgical recovery techniques,direct regeneration emerged as the most promising recovery strategy for degraded lithium cobalt oxide（LCO）.Here,we demonstrated a direct regeneration process that not only recovers LCO from used lithium-ion batteries,but also upscales it to enhance structural stability and improve electrochemical performance.Throughout the recovery process,a direct reaction transpired between the degraded LCO and a mixture of NiF₂ and Li₂CO₃ facilitating the incorporation of F and Ni into the LCO bulk phase to produce a doubledoped HV-LCO.The upgraded HV-LCO exhibited remarkable rate performance at a high voltage of 4.6 V(207.2 mA h·g^-1 for 1C and 137.54 mA h·g^-1 for 10C),commendable high-rate long-cycle performance(193.2 mA h·g^-1 for 5C initial gram capacity,89.8%of its initial capacity after 200 cycles),highly reversible crystal structure and high Li+diffusion coefficient.The efficacy of the recovery process was corroborated through scanning electron microscopy（SEM） and X-ray diffraction（XRD） analyses,while the charge-discharge characteristics of HV-LCO were substantiated by cyclic voltammetry curves and impedance measurements.更多还原