(1. 昆明理工大学省部共建复杂有色金属资源清洁利用国家重点实验室，昆明 650093；
2. 昆明理工大学冶金与能源工程学院，昆明650093；
3. 昆明理工大学真空冶金国家工程实验室，昆明 650093)
摘 要: 采用低温固相法合成LiNi0.5Mn1.5O4正极材料，考察升温速率对LiNi0.5Mn1.5O4正极材料结构、晶粒尺寸和形貌以及电化学性能的影响。结果表明：升温速率对LiNi0.5Mn1.5O4正极材料的晶粒形貌和电化学性能有重要的影响。当升温速率为10 ℃/min时，LiNi0.5Mn1.5O4的晶粒尺寸较小，形貌不规则，电化学性能不理想；当提高升温速率到20 ℃/min时，LiNi0.5Mn1.5O4的晶粒尺寸变大，同时大部分的晶粒形貌变成规则的八面体状，样品不仅容量高而且具有非常优异的倍率性能；当继续提高升温速率到30 ℃/min时，样品的晶粒尺寸基本不变，但表面出现破碎，破坏了晶粒八面体的完整性，样品的容量和倍率性能降低。因此，在低温固相合成时，升温速率控制是一种调控LiNi0.5Mn1.5O4正极材料晶粒形貌和电化学性能非常简单而有效的方法。
关键字: 锂离子电池；正极材料；LiNi0.5Mn1.5O4；升温速率
（1. State Key Laboratory of Complex Nonferrous Metal Resources Clear Utilization,
Kunming University of Science and Technology, Kunming 650093, China;
2. Faculty of Metallurgy and Energy Engineering,
Kunming University of Science and Technology, Kunming 650093, China;
3. National Engineering Laboratory for Vacuum Metallurgy,
Kunming University of Science and Technology, Kunming 650093, China）
Abstract:LiNi0.5Mn1.5O4cathode material was prepared by low temperature solid-state method, and the effects of heating rate on its structure, crystal size and morphology, and electrochemical performance were studied. The results show that the crystal morphology and electrochemical performance of the prepared LiNi0.5Mn1.5O4 are highly influenced by the heating rate. The sample obtained at the heating rate of 10 ℃/min has smaller crystal size, irregular morphology and unsatisfactory electrochemical performance. When the heating rate increases to 20 ℃/min, the obtained sample shows bigger crystal size with octahedral shape and excellent electrochemical performance. Further increasing heating rate to 30 ℃/min leads to some surface cracking of crystal and obvious degradation of electrochemical performance. Therefore, when LiNi0.5Mn1.5O4 is synthesized by low temperature solid-state method, heating rate control is a simple and effective way to tailor its crystal morphology and electrochemical performance.
Key words: lithium ion battery; cathode material; LiNi0.5Mn1.5O4; heating rate
