(1. 湘潭大學(xué) 化學(xué)學(xué)院 電化學(xué)能源儲存與轉(zhuǎn)換湖南省重點(diǎn)實(shí)驗(yàn)室，湘潭 411105
2. 湘潭大學(xué) 化學(xué)學(xué)院 新能源裝備及儲能材料與器件國家國際科技合作基地，湘潭 411105)
摘 要: 根據(jù)廢舊LiFePO4正極片中各元素物理化學(xué)性質(zhì)差異，通過高溫焙燒、酸浸并選擇不同沉淀劑分離等手段，回收廢舊LiFePO4電池極片中Li、Fe元素和集流體-Al箔。Li首先以Li3PO4的形式回收，F(xiàn)e以FePO4形式回收。結(jié)果表明：廢舊LiFePO4電池極片經(jīng)過600 ℃高溫煅燒后，當(dāng)溶解混合物的HCl濃度為5 mol/L時，在60 ℃加熱攪拌4 h，混合粉料的溶解率達(dá)到了98%，未溶解的是殘留的少量導(dǎo)電碳和PVDF。向?yàn)V液中加入3% SDS，調(diào)節(jié)濾液pH值至2，在80 ℃得到無定形FePO4可作為新制備LiFePO4的前驅(qū)體。繼續(xù)向?yàn)V液中加入Na3PO4至飽和，可以最大程度地回收鋰元素，Li以梭形形貌的Li3PO4形式沉淀。Fe的回收率為97%，Li的回收率可以達(dá)到96%。
關(guān)鍵字: 廢舊LiFePO4電池；元素回收；原子經(jīng)濟(jì)；磷酸鋰；磷酸鐵
（1. Hunan Province Key Laboratory of Electrochemical Energy Storage and Conversion, School of Chemistry, Xiangtan University, Xiangtan 411105, China;
2. National Base for International Science and Technology Cooperation, School of Chemistry, Xiangtan University, Xiangtan 411105, China）
Abstract:According to the differences of the physical and chemical properties for each element in the spent LiFePO4 battery, Li, Fe and current collector-Al foil were atomic-economically recovered by high temperature sintering, acid leaching and adding different precipitating reagents. Lithium was first recovered in the form of Li3PO4, and iron was recovered in the form of FePO4. The results show that when the concentration of HCl is 5 mol/L, the dissolution rate of the mixed material reaches 98% when being heated at 60 ℃ for 4 h. The pH of the filtrate is adjusted to 2 after adding SDS to recover FePO4. Followed by adding of Na3PO4, when the concentration of Na3PO4 is close to saturation, lithium precipitates in the form of Li3PO4. The precipitation rate of iron can reach 97%, the precipitation rate of lithium can reach 96%.
Key words: spent LiFePO4 battery; element recycling; atomic economy; Li3PO4; FePO4
