磁控溅射制备钴酸锂薄膜及其性能研究

RESEARCH ON PREPARATION OF LITHIUM COBALT OXIDE THIN FILM BY MAGNETRON SPUTTERING AND ITS PERFORMANCE

李婕

11930450

硕士

材料工程

娄飞

2021-05-20

2021-06-07

南方科技大学

深圳

半导体技术的不断提高推动了电子器件朝着集成化、微型化、低能耗方向的 发展。飞速发展的半导体技术不仅促进电子器件快速更新换代，还对其供电能源 提出了新一代的挑战。传统能源系统体积大且笨重，目前在尺寸以及性能方面还 不能满足微型系统的需求。因此，传统能源系统需要完成新一轮的技术革命，朝 着薄膜化、微型化、低热损耗、长周期寿命的方向进行，为器件提供长久稳定的 能源。薄膜锂电池因为其优异的电化学性能备受关注，被认为是理想的微型系统 供电能源之一。而正极材料是微型锂电池的重要组成部分，拥有优异电化学性能 的正极薄膜材料无疑是薄膜锂电池电池制备成功的关键因素之一。正极材料性能 会直接表现在整个电池的性能当中。钴酸锂因为比能量较高、工作电压高、循环 性能稳定、导电性良好等优点而被广泛应用于锂电池正极材料。在本论文中，用磁控溅射方法制备出电化学性能优异的钴酸锂薄膜电极是本 研究的重点。通过优化磁控溅射过程中的工艺参数，如衬底温度、溅射功率、工 作气压、气体流量、氩氧比等，并利用 XRD、Raman、SEM、ICP-MS、CV、恒 流充放电等仪器对薄膜进行表征，系统研究钴酸锂薄膜电极制备工艺、晶体结构 和电化学性能之间的关系。研究结果如下:首先，通过实验发现在基底施加一定温度能够有效提高钴酸锂薄膜结晶性和电化学性能;其次，增大溅射功率有利于改善薄膜结晶状态，提高电极容量，但功率太大会增加裂靶的风险;接着改变不同工作气压后发现，在低工作气压 0.4 Pa时制备的钴酸锂电化学性能最为优异;最后改变气体总流量和氩氧比，发现在 70sccm 气体流量、氩氧比 6:1 条件下制备出来的钴酸锂电极薄膜比容量达到了 82.39 -2 -1μAh·cm ·μm 。实验证明了优化溅射工艺参数有利于提高钴酸锂薄膜电极整体性 能。

The continuous improvement of semiconductor technology promotes the development of electronic devices towards integration, miniaturization and low energy consumption. The rapid development of technology not only promotes the upgrading of electronic devices, but also presents a new generation of challenges to their power supply. Traditional energy systems are massive, which can not meet the requirements of microsystem in terms of size and performance. Therefore, in order to provide long-term and stable energy for devices, the battery needs to be completed a new round of technological revolution towards the direction of thin film, miniaturization, low heat loss, long cycle life. Because of its excellent electrochemical performance, thin-film lithium battery has attracted much attention and is considered as one of the ideal power sources for micro-systems. Cathode material is an important part of thin-film lithium battery. Undoubtedly, the cathode film with excellent electrochemical performance is one of the key factors for the successful preparation of thin-film lithium batteries. The performance of the cathode material is directly reflected in the performance of the entire battery. Because of its high specific energy, high working voltage, stable circulation, good electrical conductivity, LiCoO2 is also widely used.In this dissertation, the preparation of LiCoO2 films with excellent electrochemical properties by magnetron sputtering is the focus of this research. In order to the relationship between preparation process, crystal structure and electrochemical performance of thin film electrode was systematically studied, through optimizing the parameters in the process of magnetron sputtering, such as substrate temperature, sputtering power, working pressure, gas flow rate and ratio of argon oxygen, then use XRD, Raman, SEM, ICP-MS, CV and galvanostatic method to characterize thin film. The current researches are as follow:Firstly, the crystallinity and electrochemical properties of LiCoO2 films could be improved effectively at a certain temperature on the substrate; Secondly, increasing the sputtering power is beneficial to improve the crystallinity of the film and increase the capacity of film electrode, but too much power will increase the risk of crack target; Then, the crystallization and electrochemical properties of the lithium cobalt oxide films prepared at the low working pressure of 0.4 Pa are the best when changed the working pressure; Finally, by changing the total gas flow rate and the argon oxygen ratio, thespecific capacity of the lithium cobalt oxide electrode film prepared at 70 sccm and-2 -1Ar:O2=6:1 reaches 82.39 μAh·cm ·μm . It is proved that changing the sputteringparameters is beneficial to improve the overall performance of LiCoO2 film electrode.

钴酸锂薄膜 磁控溅射 全固态锂电池 电化学性能

LiCoO2 thin film Magnetron sputtering All-solid-state lithium battery Electrochemical performance

中文

独立培养

南方科技大学

李婕. 磁控溅射制备钴酸锂薄膜及其性能研究[D]. 深圳. 南方科技大学,2021.