纯相尖晶石型锰酸锂纳米粉体的熔盐法制备

Synthesis of pure phase spinel LiMn_2O_4 nano-powders by molten salt method

以碳酸锂为锂源,自制的纳米级三氧化二锰为锰源,通过熔盐法合成了纯相的纳米级的尖晶石型锰酸锂粉体.利用热重-差热分析、XRD物相分析和SEM形貌分析等,对前驱体碳酸锰、自制的三氧化二锰和合成物锰酸锂进行了系列表征.研究结果显示：在以碳酸氢铵为沉淀剂、溶液pH=9、搅拌速度为400 r/min的条件下,制得了纯相、超细（粒径在1μm左右）、粒径均匀的球形碳酸锰粉体;在升温速率为10 ℃/min、550℃焙烧6h的条件下,制得了纯相的、纳米级（75～100 nm）、无团聚、分散性好、球形及哑铃形的三氧化二锰粉体;在锂锰物质的量比为1.1∶2.0,以氯化钾为熔盐,700℃焙烧10h的条件下,合成了纯相、纳米级（粒径为100nm）、粒径均匀的尖晶石型锰酸锂粉体.

The nanometer powders of pure phase spinel LiMn2O4 were synthesized by molten salt method with Li2CO3 and self- made nanometer Mn2O3.The properties of precursor MnCO3, self-made Mn2O3, and LiMn2O4 were characterized by TG/DTA, XRD, and SEM.Results indicated that the pure phase, ultrafine （particle size about 1 um）, and spherical MnCO3 powders with even particle size and narrow distribution were prepared by NH3HCO3 as the precipitant, pH=9, and stirring speed of 400 r/min; the pure phase,nanometer （75-100 nm）,no agglomeration,good dispersity,spherical,and dumbbell Mn203 powders were prepared by roasting at 550 ℃ for 6 h, and heating rate of 10 ℃/min ;the pure phase, nanometer （100 nm） powders of spinel LiMn2O4 with even uniform particle size were prepared at amount-of-substance ratio of Li/Mn was 1.1：2.0, KCl as molten salt, and roasting at 700 ℃ for 10 h.