【作者】 吴显明； 陈上； 何则强； 麻明友； 肖卓炳；

【Author】 WU Xian-ming~1 CHEN Shang~1 HE Ze-qiang~(1,2) MAMing-you~1 XIAO Zhuo-bing~1 (1.College of Chemistry and Chemical Engineering,Jishou University,Jishou 416000,China;2.College of Chemistry and Chemical Engineering,Central South Unversity,Changsha 410083,China)

【机构】 吉首大学化学化工学院；

【摘要】 采用溶液沉积法制备不同厚度的 LiMn₂O₄薄膜,用 X 射线衍射及扫描电子显微镜检测和分析薄膜的物相及形貌；采用恒电流充放电及交流阻抗技术研究 LiMn₂O₄薄膜的电化学性质。结果表明不同厚度的 LiMn₂O₄薄膜均匀,晶粒大小相近,晶粒尺寸在20～ 50nm 之间,当放电电流密度为100μA/cm²时,不同厚度的 LiMn₂O₄薄膜比容量相差不大,其值在42～47 μAh/（cm²·μm）之间。薄膜循环性能随着薄膜厚度的增加而变差。经50次循环后,薄膜每次循环的容量损失从0．18μm 的0．012%升高到1．04μm 的0．16%。电化学阻抗表明不同厚度的 LiMn₂O₄薄膜的锂离子扩散系数差别不大,数量级为10^-11cm²/s。更多还原

【Abstract】 LiMn₂O₄ thin films of different thickness were prepared by solution deposition.The phase identification and surface morphology were studied by X-ray diffraction and scanning electron microscopy.The electrochemical properties of thin films were carried out by galvanostatic charge-discharge experiments and electrochemical impedance spectroscopy. The films of different thickness are homogeneous with the grain size between 20 and 50nm.The specific capacity of the films is between 42 and 47 μAh/（cm²·μm）at the discharge current density of 100μAh/cm².The capacity loss per cycle increases from 0.012% to 0.16% after being cycled 50 times as the thickness of thin film increases from 0.18μm to 1.04 μm.The diffusion coefficients of lithium ion in the films of different thickness are close with the order of 10^-11cm²/s.更多还原