采用固相烧结法制备了纯相Li2MnO3正极材料及靶材,采用脉冲激光沉积(PLD)法在氧气气氛、不同温度下沉积了Li2MnO3薄膜.通过X射线衍射(XRD)和拉曼(Raman)光谱表征了薄膜的晶体结构,采用扫描电镜(SEM)观察薄膜形貌及厚度,利用电化学手段测试了Li2MnO3薄膜作为锂离子电池正极材料性能.结果表明,PLD方法制备的纯相Li2MnO3薄膜随着沉积温度升高薄膜结晶性变好.25℃沉积的薄膜难以可逆充放电,400℃沉积的薄膜具有较高的电化学活性和循环稳定性.相对于粉末材料,400与600℃制备的Li2MnO3薄膜电极平均放电电位随着循环次数的衰减速率明显低于相应的粉体材料.
Li2MnO3 materials were synthesized by solid state reactions. A series of Li2MnO3 thin films were fabricated at different temperatures under 02 by pulsed laser deposition (PLD) using a home-made Li2MnO3 target. The structure and morphology of the as-prepared Li2MnO3 thin films were characterized by X-ray diffraction (XRD), Raman spectroscopy, and scanning electron microscopy (SEM). Their electrochemical performance was also investigated. The results show that the crystallinity of the thin films increased with an increase in deposition temperature, and the thin film electrode prepared at lower than 25℃ did not work well. The highest electrochemical activity was achieved by the thin film deposited at 400 ℃, and this result is consistent with our previous report on powder materials. The Li2MnO3 thin film electrodes deposited at 400 and 600℃ exhibited lower discharge voltage decay upon cycling compared with the powder electrode.