LiNi_0.5Mn_1.5O₄ synthesized through ammonia-mediated carbonate precipitation

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• 作者：Yi-Jie Gu^a ; ^{guyijie@sdust.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; Yu Li^a ; Yang Fu^a ; Qing-Feng Zang^a ; Hong-Quan Liu^a ; Jian-Xu Ding^a ; Yan-Ming Wang^a ; Hai-Feng Wang^b ; Jiangfeng Ni^c ; ^{jeffni@suda.edu.cn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：LiNi0.5Mn1.5O4 ; Antisite defect ; Ammonia concentration ; Co-precipitation
• 刊名：Electrochimica Acta
• 出版年：2015
• 出版时间：10 September 2015
• 年：2015
• 卷：176
• 期：Complete
• 页码：1029-1035
• 全文大小：2799 K

文摘

We synthesized LiNi_0.5Mn_1.5O₄ cathode materials by using ammonia-mediated carbonate precipitation, and we studied how the ammonia concentration during synthesis (0.1–0.5 mol/L) affected the structural, physicochemical, and electrochemical characteristics of the prepared materials. X-ray diffraction and Rietveld refinement reveal that the amount of Li/Ni antisite defects in the LiNi_0.5Mn_1.5O₄ depend much on the ammonia concentration. The LiNi_0.5Mn_1.5O₄ prepared at 0.3 mol/L has the fewest Li/Ni antisite defects. This sample also delivers the best electrochemical performance, retaining a capacity of 133.5 mAh g⁻¹ after 20 cycles at 0.1 C. Electrochemical impedance spectroscopy confirms that the LiNi_0.5Mn_1.5O₄ prepared at 0.3 mol/L has lower charge transfer resistance, correlating with its better ion diffusion kinetics than the other materials.