富锂锰基材料(LMNC)由于电压平台高、比容量高,在锂电池材料研究中受到广泛关注。针对LMNC材料在首次充放电过程中不可逆容量损失较大、倍率性能差等问题,运用包覆改性方法改善材料性能。首先采用溶胶-凝胶法制备LMNC富锂锰基材料,采用Nb2O5、SiO2、钛酸锂进行包覆改性,并通过激光粒度测试仪、XRD、SEM等方法对材料的宏观形貌和微观结构进行测试表征。结果发现,Nb2O5、SiO2包覆改性使材料性能变差,钛酸锂包覆改性后材料的放电比容量提升了10～20mAh/g。
Lithium-rich manganese-based materials (LMNC) have attracted extensive attention in lithium battery materials due to their high voltage platform and high specific capacity.The irreversible capacity loss and poor rate performance of LMNC materials during the first charge and discharge process were large problems.It was used by coating modification methods to improve material properties.Firstly,LMNC prepared by sol-gel method were coated with Nb2O5,SiO2 and lithium titanate,and passed laser particle size tester,XRD,SEM and other test methods.The macroscopic morphology and microstructure of the material were tested and characterized.Nb2O5 and SiO2 coating modification deteriorated the material properties.Lithium titanate coating modification increased the discharge specific capacity of the material by 10～20 mAh/g.
[1] 刘祥欢,庄卫东,彭敏,等.锂离子电池富锂锰基正极材料的研究进展[J].稀有金属,2017,41(5):534-552.
[2] 吴锋,李宁,安然,等.基于Li2MnO3的富锂类高比容量锂离子电池正极材料的研究进展[J].北京理工大学学报,2012,32(1):1-11.
[3] 梁有维,李世友,李春雷,等.锂离子电池富锂锰基正极材料的研究进展[J].化工新型材料,2018,46(8):46-50.
[4] 孙颖颖.高比容量正极材料Li1.2Mn0.54Ni0.13Co0.13O2的制备及改性研究[D].哈尔滨:哈尔滨工业大学,2018.
[5] Katharine R C,Dong W S,Li W,et al.Octahedral and truncated high-voltage spinel cathodes:the role of morphology and surface planes in electrochemical properties[J].Journal of Materials Chemistry A,2013(1):3347-3354.
[6] Robertson A D,Bruce P G.Mechanism of electrochemical activity in Li2MnO3[J].Chemistry of Materials,2003,10(10):1984-1992.
[7] Liu X,Wu J,Huang X,et al.Predominant growth orientation of Li1.2(Mn0.4 Co0.4)O2 cathode materials produced by the NaOH compound molten salt method and their enhanced electrochemical performance[J].Journal of Materials Chemistry A,2014,2(36):15200-15208.
[8] Yu H,Zhou H,High-energy cathode materials (Li2MnO3-LiMO2) for lithium-ion batteries[J].The Journal of Physical Chemistry Letters,2013,4(8):1268-1280.
[9] Zheng J,Xu P,Gu M,et.al.Structural and chemical evolution of Li- and Mn-rich layered cathode material[J].Chemistry of Materials,2015,27(4):1381-1390.
[10] 文浩然,习小明,廖达前,等.富锂锰基材料Li1.2Ni0.13Co0.13Mn0.54O2的改性与电化学性能研究[J].矿冶工程,2018,38(5):131-134.
[11] Chen B Z,Zhao B C,Zhou J F,et al.Surface modification with oxygen vacancy in Li-rich layered oxide Li1.2Ni0.13Co0.13Mn0.54O2 for lithium-ion batteries[J].Journal of Materials Science & Technology,2019,35(6):994-1002.
[12] 高玉梅,杨文鑫,黄岚.层状富锂锰基镍钴锰正极材料制备工艺改性的研究进展[J].化工新型材料,2018,46(12):31-35.
[13] 吴汉杰,梁兴华.锂离子电池正极材料Li1.2Ni0.13Co0.13Mn0.54O2掺杂Cu2+改性研究[J].电源技术,2018,42(4):482-484,519.
基金资助
河南省高等学校重点科研项目计划(16A530005)
PDF
