Recycling of spent lithium-ion batteries was an important step for the utilization of waste electric and electronic equipment. Commonly studies mainly focused on metal extraction while bringing the waste of chemical reagents, secondary pollution, and energy consumption. The reasons for the failure of lithium-ion batteries were the pore blocking by organics and the structural collapse in LiCoO₂ crystal. Ultrasonic hydrothermal renovation was a promising method to directly renovate spent LiCoO₂ crystal structure and remove the organics. It combined the advantages of ultrasonic and hydrothermal technologies which were high-efficiency and clean production. Ultrasonic cavitation generated by high-powered ultrasonic in liquid phase was a process with bubble formation and implosion. Under the effect of ultrasonic cavitation and advanced oxidation synergistically, the blocked channels and layer structure were effectively rebuilt, the organics were removed and the crystal structure of LiCoO₂ was renovated. This experimental result showed that the optimal renovation condition was at the ultrasonic power of 1050 W, the reaction temperature of 90 ℃, the reaction time of 6 h, 1 mL of H₂O₂, and 0.5 MPa of Ar gas content. The renovated LiCoO₂ exhibited good electrochemical properties, the first charge and discharge capacity of 132.1mAh•g ^− 1 and 131.0mAh•g ^− 1, and the first cycle efficiency arrived at 99.16%. Additionally, an environmentally friendly and efficient route for the recycling of spent lithium-ion batteries was developed.

回收废旧锂离子电池是利用废弃电子电气设备的重要一步。通常，研究主要集中在金属提取上，同时带来化学试剂的浪费，二次污染和能源消耗。锂离子电池失效的原因是有机物堵塞了孔，LiCoO ₂晶体结构崩溃。超声波水热翻新是直接翻新废LiCoO _2的一种有前途的方法晶体结构并去除有机物。它结合了超声波和水热技术的优势，即高效和清洁生产。高功率超声在液相中产生的超声空化是一个气泡形成和内爆的过程。在超声空化和先进氧化的协同作用下，有效地重建了堵塞的通道和层结构，去除了有机物，并修复了LiCoO ₂的晶体结构。实验结果表明，最佳的修复条件为：超声功率1050 W，反应温度90℃，反应时间6 h，H ₂ O ₂ 1 mL ，氩气含量0.5 MPa。翻新的LiCoO ₂表现出良好的电化学性质，132.1mAh•的第一充电和放电容量克 ^{-  1}和131.0mAh•克 ^{-  1}，并且所述第一循环效率到达99.16％。此外，还开发了一种环保，高效的回收废旧锂离子电池的途径。