线面碳包覆的LiMn0.6Fe0.4PO4复配低钴NCM的电化学性能研究
Study on Electro-Chemical Properties of LiMn0.6Fe0.4PO4 Coated by Linear-Surface Dimension Carbon Mixed with Low-Cobalt NCM
张绮兰 1张胜男 1仇未星 1韩玮 1王波 1柴同1
作者信息
- 1. 兰州石化职业技术大学机械工程学院,兰州,甘肃 730060
- 折叠
摘要
锂离子电池LiFePO4的能量密度改进已迅速接近极限,为了提高能量密度,降低瓦时成本,满足消费者续航需求,需要开发一种低成本,高能量密度的材料,LiMnPO4既具有LiFePO4的长循环能力,又具有LiMnPO4的高电压平台特点,可以很好地结合LiMnPO4和LiFePO4的优点.磷酸锰铁锂理论容量与磷酸铁锂相同,为172mAh/g,但是它相对于Li+/Li的电极电势为4.1V,远高于磷酸铁锂的3.2V,其能量密度将比磷酸铁锂提高15％.但是LiMn0.6Fe0.4PO4因为Mn溶出导致循环性能恶化,以及导电性差,低温性能恶化严重,为了改善循环以及低温性能需要对LiMn0.6Fe0.4PO4进行改性.通过线状CNT混面状石墨烯包覆磷酸锰铁锂,并且将其与NCM低钴三元材料复配达到长循环,低温容量保留率高,无双电压平台的优异的电化学性能.
Abstract
The lithium-ion battery LiFePO4 has approached the limit energy-density.To increase the energy density,reduce the cost of battery and meet the needs of consumers,a low-cost,high-energy-density material needs to be developed.LiMn0.6Fe0.4PO4 has both the long-cycle capability of LiFePO4 and the high-voltage platform characteristics of LiMnPO4,which can well combine the advantages of LiMnPO4 and LiFePO4.The theoretical capacity of lithium both are 172 mAh/g,but the electrode potential of LiMnPO4 relative to Li+/Li is 4.1 V,which is much higher than 3.2V of LiFePO4,and its energy density is 15％higher than that of LiFePO4.However,LiMn0.6Fe0.4PO4 has poor cycling performance because of Mn Dissolution,and its conductivity is low,and the low-temperature performance is deteriorated seriously.In order to improve the cycling and low-temperature performance,it is necessary to modify LiMn0.6Fe0.4PO4.In this paper,LiMn0.6Fe0.4PO4 is coated by linear-surface dimension carbon,and mixed with NCM of low-cobalt to achieve long cycle,high low-temperature capacity retention,without double-voltage platform of excellent electro-chemical performance.
关键词
磷酸锰铁锂/三元/碳包覆/循环性能/低温性能Key words
LiMn0.6Fe0.4PO4/NCM/coating with C/cycle performance/low-temperature performance引用本文复制引用
基金项目
兰州石化职业技术大学科研项目(2023KY-08)
出版年
2024
NETL
NSTL
万方数据