摘要
用共沉淀法制备了固溶体正极材料Li[Li0.2Mn0.54Co0.13Ni0.13]O2,并用偏铝酸锂(α-LiAlO2)进行包覆改性。XRD和场发射扫描电子显微镜(FEsEM)测试表明:包覆前后的材料均属于α-NaFeO2六方层状结构,R3m空间群;包覆后的样品颗粒表面形成了一层不均匀絮状包覆物α-LiAlO2。包覆量为3%的样品性能较好:以低电流(0.05c)在2.0~4.8v循环,首次放电比容量达273.0mAh/g;当电流提高到1.00C时,放电比容量为173.2mAh/g。倍率性能的提高,得益于包覆样品具有的较低的界面电阻与反应电阻,电化学阻抗谱(EIS)测试结果证明了这一点。
Co-precipitation method was used to synthesize the solid solution cathode material Li [ Li0.2Mn0. 54Co0.13Ni0. 13 ] O2 and the performance of this material coated with lithium aluminate (α-LiAlO2) was studied. XRD and field-emission scanning electron microscopy (FESEM) test showed that beth the materials before and after coating belonged to α-NaFeO2 hexagonal layered struc- ture with R3m space group, the thick inhomogeneous floceus layers were coated on the surface of particle. The better performance was achieved by sample with coating amount of 3 % : when cycled in 2.0 - 4.8 V at a low current (0.05 C), the specific discharge capacity was 273.0 mAh/g, when the current increased to 1.00 C, the specific discharge capacity reached to 173.2 mAh/g. The rate capability was benefitted from the lower surface impedance and reaction impedance as indicated by the electrochemical impedance spectroscopy(EIS) test result.
出处
《电池》
CAS
CSCD
北大核心
2012年第5期242-244,共3页
Battery Bimonthly
基金
国家自然科学基金(51172023)
新世纪优秀人才支持计划(NCET-09-0215)