電化學(xué)性能的影響
(深圳大學(xué) 化學(xué)與化工學(xué)院，深圳 518060)
摘 要: 以Li2CO3、NiO、Co2O3、MnO2、LiF和SiO2為原料，采用機(jī)械力活化固相法制備了Si4+和F－摻雜的鋰離子電池正極材料LiNi1/3Co1/3Mn1/3O2。通過X射線衍射(XRD)、掃描電鏡(SEM)和電化學(xué)性能測(cè)試等技術(shù)研究了LiNi1/3Co1/3Mn1/3O2的結(jié)構(gòu)特征、形貌及電化學(xué)性能等。結(jié)果表明：摻雜離子的引入沒有改變材料的晶型結(jié)構(gòu)，通過機(jī)械力活化后的材料分散更均勻，顆粒也較小，其中Li(Ni1/3Co1/3Mn1/3)0.98Si0.02O1.96F0.04的電化學(xué)性能最佳，首次放電比容量達(dá)157.5 mA·h/g，充放電循環(huán)過程中最高放電比容量為173.3 mA·h/g，循環(huán)50次后，容量保持率達(dá)96.19%，循環(huán)穩(wěn)定性好。
關(guān)鍵字: LiNi1/3Co1/3Mn1/3O2；機(jī)械力活化；摻雜；電化學(xué)性能
electrochemical properties of LiNi1/3Co1/3Mn1/3O2
（School of Chemistry and Chemical Engineering, Shenzhen University, Shenzhen 518060, China）
Abstract:The layered LiNi1/3Co1/3Mn1/3O2 cathode materials doped by Si4+ and F− were synthesized by solid state of mechanical activation method using Li2CO3, NiO, Co2O3, MnO2, LiF and SiO2 as the raw materials. The bare sample and doping composites were characterized by X-ray diffraction(XRD), scanning electron microscopy (SEM) and charge-discharge test. The results show that doping does not change the crystal of materials, the doped samples have a smaller grain sizes and uniform distributions, furthermore, the composite Li(Ni1/3Co1/3Mn1/3)0.98Si0.02O1.96F0.04 has a good electrochemical performance, which exhibits initial capacity of 157.5 mA·h/g, and the capacity retains 96.19% after 50 cycles. Through the process of the cycles, the highest discharge specific capacity arrives at 173.3 mA·h/g.
Key words: LiNi1/3Co1/3Mn1/3O2; mechanical activation; doping; electrochemical property
