(中南大學(xué) 冶金科學(xué)與工程學(xué)院，長沙410083)
摘 要: 研究了一種從鋰離子蓄電池正極片的邊角料中直接回收鈷酸鋰的新工藝。先用二甲基乙酰胺(DMAC)浸泡正極片，將LiCoO2從鋁箔上剝離，再在高溫下除去正極中的聚偏氟乙烯(PVDF)和碳粉等雜質(zhì)。然后添加不同的鋰鹽(Li2CO3、LiOH·H2O和 LiAc·2H2O)調(diào)節(jié)回收粉末中的Li與Co的量比為1.00，再在850 ℃下焙燒12 h得到最終產(chǎn)品。用掃描電子顯微鏡(SEM)和X射線衍射(XRD)分析技術(shù)對得到的樣品進(jìn)行微觀形貌與晶相結(jié)構(gòu)的研究。研究結(jié)果表明，添加Li2CO3合成的LiCoO2層狀結(jié)構(gòu)發(fā)育最為完善，其首次放電容量和循環(huán)性能也最好；在3.0~4.3 V進(jìn)行充放電，首次放電容量達(dá)到160 mA∙h/g，經(jīng)30次循環(huán)以后，仍有150 mA∙h/g。
關(guān)鍵字: LiCoO2；回收；合成；放電容量；循環(huán)性能
LiCoO2 recycled from incisors bound of Li-ion batteries
（School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China）
Abstract:A new LiCoO2 recovery technology from Li-ion battery was studied. LiCoO2 was peeled off the Al foil with dimethyl acetamide(DMAC), and then the polyvinylidene fluoride(PVDF) and carbon powders in the active material were eliminated by high temperature calcining. And then the Li2CO3, LiOH·H2O and LiAc·2H2O were added into the recycled powders to adjust the molar ratio of Li to Co to 1.00. The new LiCoO2 was obtained by calcining the mixture at 850 ℃ for 12 h in the air. Structure and morphology of the recycled powders and resulted sample were observed by XRD and SEM technique, respectively. The layered structure of the LiCoO2 synthesized by adding Li2CO3 is best with the characteristics as cathode material in terms of charge–discharge capacity and cycling performance. The first discharge capacity is 160 mA∙h/g from 3.0 V to 4.3 V. The discharge capacity after cycled 30 times is still 150 mA∙h/g.
Key words: LiCoO2; recycle; synthesis; discharge performance; cycling performance
