废旧锂离子电池负极片的硫酸浸出回收研究

Recycling of negative electrode sheets of spent lithium ion batteries by sulfuric acid leaching

废旧锂离子电池负极片中含有铜、锂和石墨,对其回收具有一定的经济价值。采用硫酸溶液作为浸出剂,研究了硫酸浓度、浸出时间、浸出温度对负极片中锂的浸出以及石墨与铜箔分离的影响。结果表明,在浸出时间为5 min、硫酸浓度为0.9 mol/L时,铜箔与负极石墨可以完全分离,铜箔以金属的形式回收;在浸出温度为40℃、硫酸浓度为1.8moL/L、浸出时间为50 min、固液比60 g/L时,石墨中的锂几乎全部浸出进入溶液中,可实现锂与石墨的完全分离。

The negative electrode sheet of spent lithium ion battery contains copper,lithium and graphite,which has an economic value if being recycled.In this paper,the sulfuric acid solution was used as the leaching agent to recycle copper,lithium and graphite simultaneously.The effects of concentration of sulfuric acid solution,leaching time and temperature on the leaching of lithium,and the recovery of graphite and copper foil were investigated.The results show that,when the leaching time is 5 min and the concentration of sulfuric acid solution is 0.9 mol/L,the copper foil and the anode graphite can be completely separated,and the copper foil is recovered in the form of metal.When the leaching temperature is 40℃,the concentration of sulfuric acid is 1.8 mol/L,the leaching time is 50 min and the solid-liquid ratio is 60 g/L,almost all of the lithium in the graphite is leached into the solution,and the complete separation of lithium and graphite can be achieved.