(合肥工業(yè)大學(xué) 材料科學(xué)與工程學(xué)院,合肥 230009)
摘 要: 采用固相反應(yīng)法制備Mg2+摻雜的鋰離子電池正極材料LiNil/3Col/3Mnl/3O2,并將Mg2+最佳摻雜量為0.03(摩爾分?jǐn)?shù))的樣品進(jìn)行CuO復(fù)合。通過X射線衍射(XRD)、掃描電鏡(SEM)和電池測試系統(tǒng)等手段對制備的LiNil/3Col/3Mnl/3O2樣品的結(jié)構(gòu)、形貌及電化學(xué)性能進(jìn)行表征。結(jié)果表明:Mg2+摻雜沒有改變LiNil/3Col/3Mnl/3O2的層狀結(jié)構(gòu),Mg2+摻雜量為0.03的LiNil/3Col/3Mnl/3-0.03Mg0.03O2材料具有最好的電化學(xué)性能和循環(huán)性能,在0.2C倍率下,首次放電比容量達(dá)158.5 mA?h/g,10次循環(huán)后容量保持率為91.2%。添加CuO的LiNil/3Col/3Mnl/3-0.03Mg0.03O2的首次放電容量為167.4 mA?h/g,高電壓下達(dá)到181.0 mA?h/g;循環(huán)10次后,放電比容量為159.4 mA?h/g,容量保持率為95.3%,改性后的放電比容量、循環(huán)性能及在高倍率和高電壓下的性能均得到改善。
關(guān)鍵字: LiNil/3Col/3Mnl/3O2;正極材料;Mg2+摻雜;電化學(xué)性能;合成
(School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009, China)
Abstract:The electrode materials LiNi1/3Col/3Mnl/3O2 doped Mg2+ were synthesized by solid state reaction, the optimum sample LiNil/3Col/3Mnl/3-0.03Mg0.03O2 was mixed with CuO. The structure, morphology and electrochemical properties of the as-prepared materials were characterized by XRD, SEM and battery testing system. The results show that Mg2+ doping does not change the material layer structure, and the optimum sample is LiNil/3Col/3Mnl/3-0.03Mg0.03O2, which has the best electrochemical properties and cycle performance. The first discharge specific capacity of LiNil/3Col/3Mnl/3-0.03- Mg0.03O2 is 158.5 mA?h/g at 0.2C, and the conservation ratio of capacity is about 91.2% after 10 cycles. The first discharge capacity and cycle performance of the sample mixed with CuO improve obviously, which are 167.4 mA?h/g at 0.2C and maintain 95.3% after 10 cycles. The materials have good performances at high rate and high voltage.
Key words: LiNi1/3Co1/3Mn1/3O2; cathode material; Mg2+ doping; electrochemical properties; synthesis


