Synthesis and electrochemical properties of LiNi_0.8Co_xMn_0.2-xO₂ positive-electrode material for lithium-ion batteries

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• 作者：Shengwen Zhong^a ; ^{zhongsw@126.com" class="auth_mail" title="E-mail the corresponding author} ; Meizhen Lai^a ; Wenli Yao^a ; ^{wenliyao@126.com" class="auth_mail" title="E-mail the corresponding author} ; ^{523377376@qq.com" class="auth_mail" title="E-mail the corresponding author} ; Zhicheng Li^a ; ^b
• 关键词：LiNi0.8CoxMn0.2-xO2 ; Nickel rich ; Positive-electrode materials ; Cobalt content ; Lithium-ion batteries
• 刊名：Electrochimica Acta
• 出版年：2016
• 出版时间：10 September 2016
• 年：2016
• 卷：212
• 期：Complete
• 页码：343-351
• 全文大小：3348 K

文摘

Spherical Ni-rich LiNi_0.8Co_xMn_0.2-xO₂ (x = 0, 0.05, 0.1, 0.15) positive-electrode materials were synthesized by calcining the mixtures of LiOH·H₂O and Ni_0.8Co_xMn_0.2-x(OH)₂ precursor formed from a simple continuous co-precipitation method. The influences of Co content on the microstructures and electrochemical properties of LiNi_0.8Co_xMn_0.2-xO₂ positive-electrode materials were investigated through X-Ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscope, transmission electron microscope and electrochemical tests. The results showed that the intensity ratio of I₍₀₀₃₎/I₍₁₀₄₎ for positive-electrode material became higher with increasing Co content, implying the layered structure became better. The electrochemical tests confirmed LiNi_0.8Co_0.15Mn_0.05O₂ (x = 0.15) exhibited the best discharge capacity of 180.8 mAh g⁻¹ after 100 cycles between 2.75 and 4.3 V at 0.2C, with an excellent capacity retention of 97.31% and an high capacity of 165.2 mAh g⁻¹ at 5C. Importantly no obvious structure and morphology change was observed for LiNi_0.8Mn_0.05Co_0.15O₂ before and after cycling processes. The improved cycling stability and rate capability maybe resulted from low Li/Ni cation mixing, high electric conductivity and good structure stability.