磁控溅射制备免退火钴酸锂正极薄膜的研究

Preparation of LiCoO_2 film positive electrode without post-annealing by magnetron sputtering and its application

采用射频磁控溅射法制备钴酸锂正极薄膜,通过对溅射功率的研究,制备出不需要进行退火处理仍具有60μAh/(cm2.μm)的比容量的正极薄膜。采用X射线衍射(XRD)和扫描电子显微镜(SEM)对钴酸锂薄膜的结构和形貌进行了研究,并分析了其对钴酸锂薄膜正极性能的影响。结果表明不同功率制备的钴酸锂薄膜具有不同的结晶取向和结晶度,其对正极薄膜的性能有具有决定性的影响,适合的功率下制备的钴酸锂薄膜在不退火处理的情况下仍具有较高的容量和较好的循环性能。同时研究了采用磁控溅射的铝薄膜作为集流体,代替铂或金等贵金属薄膜集流体,大幅减低了薄膜电池正极的制备成本。

The LiCoO2 thin film electrodes were prepared by radio-frequency（RF） magnetron sputtering.By study of magnetron sputtering power,a LiCoO2 film electrode,prepared without post-annealing,has a discharge capacity of 60 μAh/（cm^2·μm）.The structure and morphology of LiCoO2 films were analyzed by XRD patterns and SEM images.The results of analysis show that the preferred orientation and crystallized degree of polycrystalline LiCoO2 films is decided by the power of magnetron sputtering,which determines the electrochemical performance of LiCoO2 films.The LiCoO2 films,prepared at an appropriate magnetron sputtering power without post-annealing process,still have good specific capacity and cycle performance.And the aluminum films were prepared as current collector by magnetron sputtering,instead of noble metals,such as platinum and gold,which brings a dramatic decrease of the film positive electrode cost.