LiMnPO_4/碳材料的合成及其电化学性能  

Synthesis and Electrochemical Properties of LiMnPO_4/C Materials

作　　者：曹永宁[1] 张正国[2] 龚波林[2] 

机构地区：[1]宁夏职业技术学院,银川750021 [2]北方民族大学化学与化学工程学院,银川750021

出　　处：《机械工程材料》2015年第9期41-44,63,共5页Materials For Mechanical Engineering

基　　金：国家自然科学基金资助项目(31271868)

摘　　要：采用湿法球磨与高温固相合成法相结合的工艺,分别以油酸、葡萄糖、石墨、硬脂酸为碳源对LiMnPO4进行包覆合成了LiMnPO4/碳材料,并研究了它的结构、形貌和电化学性能。结果表明:碳包覆对LiMnPO4的橄榄石型结构无影响;采用有机碳源包覆的LiMnPO4/碳材料形貌呈更规则的类球形;油酸包覆LiMnPO4/碳材料的电化学性能最好,其在0.1C倍率下的首次充电比容量可达140.6mAh·g-1,首次放电比容量为123.4mAh·g-1,充放电效率为87.76%;油酸包覆改善了材料的导电性和活性物质的可逆性能,能够抑制Mn2+氧化和晶粒长大,使粒径均匀。A series of LiMnPO4/C materials were synthesised by taking oleic acid, glucose, graphite and stearic acid as the carbon sources separately, which used a new process, solid state reaction and the wet milling method. The structure, morphology and electrochemical properties of the materials were studied. The results show that carbon coating had no effects on olivine-type structure of LiMnPO4, and the LiMnPO4 coated with organic carbon exhibited more regular class of spherical. Additionally the LiMnPO4 coated with oil acid had a better initial discharge capacity, that the charge capacity up to 140.6 mAh.g-1 and discharge capacity up to 123.4 mAh.g-1 at 0.1 C, and the charge/discharge efficiency was 87.76%. Oleic acid coating could improve the conductivity of the material and the reversible performance of the active substances, which could inhibit the oxidation of Mn2＋ and grains growth, made the grains size more uniform.

关 键 词：锂离子电池 磷酸锰锂 碳源 包覆 

分 类 号：TM912.9[电气工程—电力电子与电力传动]