摘要
以LiNO3 和电解MnO2 为原料 ,以含羟基有机溶剂和水的混合溶液为分散剂 ,采用流变相法合成尖晶石型LixMn2 O4,提出了锂锰氧的分子模型并计算了其理论容量。结果表明 ,在 70 0～ 80 0℃温度范围 ,所得化合物为化学计量尖晶石型材料 ,其理论容量为14 8mAh g ;当合成温度达 90 0℃以上时 ,产物为缺氧型尖晶石 ,其理论容量为 12 0mAh g ,材料中电化学活性物质Mn3 +的含量降低是材料理论容量降低的主要原因。实验结果表明 ,当锂锰摩尔比为 0 .488时 ,锰的平均氧化价态为 3.5 2 ,在煅烧温度为 76 0℃时 ,所合成锂锰氧材料的充电容量可达 12 8.1mAh g ,放电效率为 92 .3%。
A spinel-type Li xMn 2O 4 compound was synthesized by rheologic phase reaction using LiNO 3 and electrolytic MnO 2(EMD) as raw materials and mixture solution of water and organic agent with hydroxy as dispersant. The molecular model of spinel Li-Mn-O compound was presented and theoretical capacity was calculated. The results show that perfect spinel Li xMn 2O 4 crystals could be obtained at the calcinating temperature of 700～800 ℃, with the capacity calculated to be 148 mAh/g, and oxygen-deficient spinel could be formed at the calcinating temperature up to 900 ℃, with the capacity calculated to be 120 mAh/g. Major factors responsible for the capacity loss can be attributed to the decrease of Mn 3+ in the spinel compound. The analysis above was proved by the experiment results.
出处
《矿冶工程》
CAS
CSCD
北大核心
2002年第2期67-69,共3页
Mining and Metallurgical Engineering
基金
国家教育部重点资助项目 (国教字 990 93)
关键词
尖晶石型锂锰氧
分子模型
锂离子电池
spinel-type Li xMn 2O 4
molecule model
lithium-ion battery
