纳米级 LiMn2O4尖晶石合成及电化学性能研究

以Ｌｉ２ＣＯ３和Ｍｎ（ＮＯ３）２为原料，以聚丙烯酰胺为高分子网络剂制得前驱体后，用微波加热技术合成了纳米晶尖晶石ＬｉＭｎ２Ｏ４粉体，通过循环伏安及充放电技术对其进行电化学性能测试表明，该材料的电化学比容量为 １２０ｍＡｈ／ｇ；循环 ５０次后衰减率为 ４．７％；通过 ＳＥＭ及ＸＲＤ分析其微观形貌表明，该材料不仅相纯度高，而且颗粒粒度近于纳米级，有利于Ｌｉ＋的嵌入／脱嵌．本文所提供的微波一高分子网络技术不仅为合成具有优良性能的锂锰尖晶石氧化物材料提供了一个新方法，而且为合成其他类型高性能氧化物陶瓷材料提供了一条新思路．

Electrochemical Characterization of Superfine Spinel LiMn2O4 Synthesized By Microwave-Polymer Network Method

Superfine spinel LiMn2O4 powders were synthesized with a gelation precursor by microwave--polymer network process. The gelation precursor was obtained by mixing Li2CO3, Mn(NO3) and polyacrylamide. Electrochemical tests show that the initial specific capacity is 120mAh/g, and the degradation rate of specific capacity is only 4.7% after 50 cycles. SEM and XRD results prove that the microwave-polymer network process can increase the purity of the phase, reduce the particle size of spinel LiMn2O4, and provide more active sites for Li intercalation. The microwave-polymer network process is a new method not only for synthesizing cathode material of Li ion cells,but also for synthesizing other advanced oxide ceramic materials.