比較不同前處理方式對鋰電池金屬回收之效果

Abstract

隨著技術進步與對環境永續發展，鋰電池的應用日益廣泛，特別是在電動車和便攜式電子設備中。然而，鋰電池中含有大量貴重金屬，如鎳、鈷和錳，這些金屬開採及隨意棄置往往對環境造成重大影響。因此，研究有效的回收技術，從廢棄鋰電池中回收金屬，不僅對環境永續有重要意義，同時也具有循環經濟價值。 本研究主要探討不同前處理方法對於從18650 NMC型鋰電池中回收鎳、鈷和錳等金屬的效率影響。研究中比較三種不同的前處理技術：高溫熱裂解法、有機溶劑溶解法和氫氧化鈉溶解法，並且將三種前處理方法兩兩結合，進行兩階段前處理並分析。每種前處理的效果都通過後續的濕式冶金法來評估，以確定其對金屬萃取率的實際影響。 實驗結果顯示，高溫熱裂解法在所有前處理方法中對於鎳、鈷和錳的萃取效果最佳，鈷萃取率為69.43%；錳萃取率為98.27%；鎳萃取率為97.06%；鈀萃取率為97.45%。主要為高溫熱裂解法能夠有效去除電池中PVDF黏著劑及碳黑等雜質，從而使金屬顆粒暴露並易於後續處理。相比之下，有機溶劑溶解法在去除PDVF黏著劑，以及氫氧化鈉溶解法雖然在去除鋁箔方面表現良好，但對於金屬的萃取率較低。而兩階段前處理效果同樣不及高溫熱裂解法。 化學沉澱法對錳金屬形成氫氧化物沉澱有良好的效果，受到鈷、鎳共沉澱作用影響，無法有效將兩者完全分離。鈀金屬則無法使用化學沉澱法沉澱分離。

With technological advancements and the increasing emphasis on sustainable development, the application of lithium batteries had become increasingly widespread, especially in electric vehicles and portable electronic devices. However, lithium batteries contained a significant amount of valuable metals such as nickel, cobalt, and manganese, whose extraction and improper disposal often caused substantial environmental impact. Therefore, researching effective recycling technologies to recover metals from discarded lithium batteries was not only crucial for environmental sustainability but also had significant value for the circular economy. This study primarily explored the efficiency of different pretreatment methods in recovering nickel, cobalt, and manganese from 18650 NMC-type lithium batteries. The research compared three different pretreatment techniques: traditional high-temperature pyrolysis, organic solvent dissolution, and sodium hydroxide dissolution, and combined these three pretreatment methods in pairs to perform two-stage pretreatment and analysis. The effectiveness of each pretreatment method was evaluated through subsequent hydrometallurgical processes to determine their actual impact on metal extraction rates. The experimental results showed that the traditional high-temperature pyrolysis method had the best recovery efficiency for nickel, cobalt, and manganese among all pretreatment methods, with cobalt recovery rate at 69.43%; manganese recovery rate at 98.27%; nickel recovery rate at 97.06%; and palladium recovery rate at 97.45%. This was mainly because the high-temperature pyrolysis method effectively removed PVDF binder and carbon black impurities in the battery, thereby exposing the metal particles and making them easier for subsequent processing. In contrast, although the organic solvent dissolution method effectively removed the PVDF binder, and the sodium hydroxide dissolution method performed well in removing aluminum foil, their metal extraction rates were relatively low. The two-stage pretreatment effects were also not as good as the traditional high-temperature pyrolysis method. The chemical precipitation method had a good effect on forming manganese hydroxide precipitate but was unable to effectively separate cobalt and nickel due to co-precipitation. Palladium could not be separated using the chemical precipitation method.