(1. 中南大學(xué) 化學(xué)化工學(xué)院，長(zhǎng)沙 410083；
2. 中南大學(xué) 有色金屬資源化學(xué)教育部重點(diǎn)實(shí)驗(yàn)室，長(zhǎng)沙 410083)
摘 要: 以廢舊鋰電池正極條為陰極，以鉛板作陽(yáng)極，在稀硫酸溶液中，電解浸出正極材料中的鈷，從熱力學(xué)和動(dòng)力學(xué)兩方面對(duì)鈷的電解浸出過(guò)程進(jìn)行研究。實(shí)驗(yàn)及熱力學(xué)數(shù)據(jù)分析表明：LiCoO2主要通過(guò)Co(OH)3還原浸出得到Co2+，考查浸出溫度和時(shí)間表明在電解前期5~30 min電解浸出由縮核模型的化學(xué)反應(yīng)過(guò)程控制，浸出率α與時(shí)間t滿(mǎn)足未反應(yīng)核收縮模型1-(1-α)1/3=Kt，其表觀活化能為7.32 kJ/mol；中期是混合控制；后期75~180 min符合內(nèi)擴(kuò)散控制模型1-2α/3-(1-α)2/3=Kt，表觀活化能17.05 kJ/mol。浸出液中的鋁主要是鋁箔表面氧化鋁層不受陰極保護(hù)而溶于硫酸溶液，正極材料從鋁箔上剝離與氧化鋁層的溶解有關(guān)，剝離時(shí)間影響鈷的浸出率。
關(guān)鍵字: 廢舊鋰電池；電解浸出；熱力學(xué)；動(dòng)力學(xué)
（1. College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Nonferrous Metal Resource Chemistry, Ministry of Education Hunan,
Central South University, Changsha 410083, China）
Abstract:Cobalt in spent lithium-ion battery was leached out in sulfuric acid using the cathode bar as cathode and lead plate as anode. And the process was studied in thermodynamics and dynamics two aspects. The results show that LiCoO2 is reductive leached Co2+ by Co(OH)3 through compared experiments and thermodynamic data. Through theoretical analysis and experimental research, the process is controlled by chemical reaction process of shrinking core model in the early 5-30 min, leaching rate α and time t satisfy inner diffusion the unreacted core shrinking model equation 1-(1-α)1/3=Kt, apparent activation energy is 7.32 kJ/mol. The middle stage is hybrid control. And the last conforms with the internal diffusion model, where α and t suit to 1-2α/3-(1-α)2/3=Kt, and the apparent activation energy is 17.05 kJ/mol. Al3+ in leach solutions comes from aluminium oxide dissolved in liquid without protection. The cathode material peeled from aluminum foil is related to the dissolution of aluminium oxide, which affects the leaching rate of cobalt.
Key words: spent lithium-ion battery; electrolytic leaching; thermodynamics; kinetics
