短程高效回收废锂离子电池中铜金属的技术及机理研究

Short-cut and high-efficiency process to recycle copper from spent lithium-ion battery

信息通讯技术和电动汽车产业的快速发展产生了大量的废锂离子电池,其资源化回收成为资源可持续利用及环境保护的重要手段.但传统的回收过程工艺繁琐,资源化效率较低阻碍了产业的良性发展.为了缩短废锂离子电池的资源化工艺,选择离子液体作为加热介质,通过熔化黏结剂,分离铜箔和负极材料实现对废锂离子电池中铜金属的回收.回收过程发生急剧的热对流和热传导过程,利用搅拌机快速运转强化了热对流的过程和机械力分离正极材料,基于传热理论傅里叶定律建立了热传递过程数学模型.通过详细实验研究发现,当加热温度180℃、搅拌速度350 r/min、停留时间30 min,可以实现铜金属的短程高效回收.本技术的研发大大促进了铜铝金属的高效回收,打通了废锂离子电池的闭环供应链.

The booming flourish of information communication technology and electric vehicle industry has resulted in plenty of spent lithiumion battery（Li B）. Its recycling is recognized as the vital approach for resource sustainability and environmental improvement.However, the conventional recycling process was much complicated with a low recycling efficiency. We chose ionic liquid as heat medium to melt the binder and separate copper foil and anode material. Theoretical analysis based on Fourier＇s law was adopted to determine the heat transfer mechanism of cathode material and to examine the relationship between heating temperature and retention time. All the experimental and theoretic results show that peel-off rate of copper foil from anode materials could reach 95% when major process parameters were controlled at 180°C heating temperature, 350 r/min agitator rotation, and 30 min retention time. The obtained results further imply that the application of ionic liquid for recycling copper and anode materials from spent Li Bs is short cut and highly efficient, regardless of the application source of the Li Bs or the types of anode material. The proposed process will smooth the high recycling rate for copper and aluminum, and enable the closed-loop supply chain for spent lithium-ion battery.