摘要
采用喷雾干燥法合成了富锂层状氧化物正极材料0.6Li[Li_(1/3)Mn_(2/3)]O2·0.4LiNi_(5/12)Mn_(5/12)Co_(1/6)O_2(简称LNMCO),并使用Zr(CH3COO)4进行ZrO_2的包覆改性。TEM测试结果显示纳米级的ZrO_2颗粒附着在LNMCO的表面。包覆质量分数为1.5%的ZrO_2包覆样品的首圈库伦效率和放电比容量有着显著提升,在室温下其首圈库伦效率和放电比容量(电流密度:20 m A·g-1,电压:2.0~4.8 V)分别为87.2%,279.3 m Ah·g-1,而原样则为75.1%,224.1 m Ah·g-1,循环100圈之后,1.5%ZrO_2包覆样品的放电比容量为248.3 m Ah·g-1,容量保持率为88.9%,高于原样的195.9 m Ah·g-1和87.4%。
Lithium-rich layered oxide materials 0.6Li[Li1/3Mn2/3]O2·0.4LiNi5/12MnsmCo1/6O2 （named as LNMCO） have been prepared by spray-drying method and followed by high temperature annealed and surface coated with ZrO2. The TEM results show that the ZrO2 layer with nano size particles is located on the surface of the particles. The initial coulombic efficiencies and discharge capacities of the 0.6Li[Liv3Mnz3]Oz＇0.4LiNismMnsmCol/6021ithium-rich layered oxide material are largely improved by ZrO2 coating, and the value is 87.2%, 279.3 mAh-g-t, compared to 75.1%, 224.1 mAh＂ g-~, respectively, for the bare sample at the room temperature and at a current density of 20 mA.g-2 in the voltage range of 2.0 to 4.8 V when the content of ZrO2 is 1.5%. After 100 cycles, the 1.5% ZrO2- coated sample shows a high discharge capacity of 248.3 mAh·g-1 with a capacity retention of 88.9%, while the bare LNMCO presents a lower discharge capacity of 195.9 mAh·g-1 with a capacity retention of 87.4%.
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
2017年第7期1236-1242,共7页
Chinese Journal of Inorganic Chemistry
关键词
锂离子电池
正极材料
富锂层状氧化物正极
氧化锆包覆
lithium-ion batteries
cathode material
lithium-rich layered oxide cathode
Zirconium oxide coating
