Mn_(3)O_(4)微观结构对固相合成类单晶锰酸锂的影响  

Effect of Mn_(3)O_(4) microstructure on solid-phase synthesis of mono-like lithium manganate

作　　者：尹金佩 王洋 朱林剑 刘泽萍 范广新[1,2] YIN Jinpei;WANG Yang;ZHU Linjian;LIU Zeping;FAN Guangxin(School of Materials Science and Engineering,Henan Polytechnic University,Jiaozuo 454003,Henan,China;Jiaozuo Companion Nano Materials Engineering Co.,Ltd.,Jiaozuo 454000,Henan,China)

机构地区：[1]河南理工大学材料科学与工程学院,河南焦作454003 [2]焦作伴侣纳米材料工程有限公司,河南焦作454000

出　　处：《精细化工》2023年第3期608-613,共6页Fine Chemicals

基　　金：国家自然科学基金重点项目(U1804135,51671080);河南省科技创新人才计划(194200510019)。

摘　　要：探究了Mn_(3)O_(4)的微观结构对高温固相法制备类单晶锰酸锂(LiMn_(2)O_(4))的影响。结果表明,前驱体对LiMn_(2)O_(4)的结构和形貌有决定性的影响。粒度小、比表面积大的类球形Mn_(3)O_(4)更易制得类单晶锰酸锂,其颗粒团聚致密、表面光滑,且晶胞参数小、能量密度大、Li+浓度高。类单晶锰酸锂的综合电化学性能和热稳定性远高于非类单晶材料,在0.2 C倍率下首次放电比容量和库仑效率分别高达112.50 mA·h/g、96.5%,8 C倍率下放电比容量仍有102.11 mA·h/g,200次循环后容量保持率为90.1%。类单晶锰酸锂优异的性能归因于其具有稳定的晶体结构和外露表面、较高的Li+浓度,在电化学反应中结构稳定、锂离子迁移速率快、电极极化和电荷转移阻抗小。The influence of Mn_(3)O_(4) microstructure on the synthesis of mono-like lithium manganate(LiMn_(2)O_(4))by high temperature solid state reaction was investigated,and the results showed that the precursors had a great influence on the structure and morphology of LiMn_(2)O_(4).The spheroid Mn_(3)O_(4) with small particle size and large specific surface area was more likely to produce mono-like lithium manganate,which had dense particle agglomeration,smooth surface,small cell parameters,high density and Li-ion concentration.The mono-like lithium manganate exhibited first discharge specific capacity of 112.50 mA·h/g and coulomb efficiency at 0.2 C rate of 96.5%,with the discharge specific capacity remained as high as 102.11 mA·h/g at 8 C rate and the capacity retention of 90.1% even after 200 recycles,indicating much higher comprehensive electrochemical performance and thermal stability in comparison to non-like single crystal material.The excellent performance of mono-like lithium manganate was attributed to its more stable crystal structure,larger exposed surface,and higher Li-ion concentration.Moreover,the mono-like lithium manganate displayed stable structure,fast lithium ion migration rate,small electrode polarization and charge transfer impedance during the electrochemical reaction process.

关 键 词：前驱体 类单晶锰酸锂 锂离子浓度 微观结构 热稳定性 电子化学品 

分 类 号：TQ152[化学工程—电化学工业] TM911[电气工程—电力电子与电力传动]