(1. 昆明理工大學(xué)省部共建復(fù)雜有色金屬資源清潔利用國(guó)家重點(diǎn)實(shí)驗(yàn)室，昆明 650093；
2. 昆明理工大學(xué)冶金與能源工程學(xué)院，昆明650093；
3. 昆明理工大學(xué)真空冶金國(guó)家工程實(shí)驗(yàn)室，昆明 650093)
摘 要: 采用低溫固相法合成LiNi0.5Mn1.5O4正極材料，考察升溫速率對(duì)LiNi0.5Mn1.5O4正極材料結(jié)構(gòu)、晶粒尺寸和形貌以及電化學(xué)性能的影響。結(jié)果表明：升溫速率對(duì)LiNi0.5Mn1.5O4正極材料的晶粒形貌和電化學(xué)性能有重要的影響。當(dāng)升溫速率為10 ℃/min時(shí)，LiNi0.5Mn1.5O4的晶粒尺寸較小，形貌不規(guī)則，電化學(xué)性能不理想；當(dāng)提高升溫速率到20 ℃/min時(shí)，LiNi0.5Mn1.5O4的晶粒尺寸變大，同時(shí)大部分的晶粒形貌變成規(guī)則的八面體狀，樣品不僅容量高而且具有非常優(yōu)異的倍率性能；當(dāng)繼續(xù)提高升溫速率到30 ℃/min時(shí)，樣品的晶粒尺寸基本不變，但表面出現(xiàn)破碎，破壞了晶粒八面體的完整性，樣品的容量和倍率性能降低。因此，在低溫固相合成時(shí)，升溫速率控制是一種調(diào)控LiNi0.5Mn1.5O4正極材料晶粒形貌和電化學(xué)性能非常簡(jiǎn)單而有效的方法。
關(guān)鍵字: 鋰離子電池；正極材料；LiNi0.5Mn1.5O4；升溫速率
（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
