更新时间：07-01 （飞舞的丝带）提供原创文章
摘 要：通过化学气相沉积法在铜箔上沉积CoSb3纳米薄膜，不添加任何粘合剂将其直接应用作为锂离子电池的电极。电化学性能测试显示CoSb3纳米薄膜具有高电荷存储容量和稳定性能，其在第二个充放电周期内的电容量可达到378.8毫安时/克，然后到第五十个周期时下降到55.4毫安时/克。
对CoSb3纳米薄膜的XRD实验结果显示所有的强度峰值可以被方钴矿型CoSb3相（JCPDS 78-0976）编入索引。此外，没有检测到如Co和Sb的杂质相。对CoSb3纳米薄膜的FESEM实验结果显示该产品是直径在200~400nm范围内的CoSb3纳米粒子。通过化学气相沉积获得的CoSb3纳米粒子的形态不同于通过固相法或共同沉淀制备的CoSb3纳米粒子，产生了球状晶粒。此外，CoSb3纳米粒子彼此互相联系，形成了一层1μm厚的薄膜。对CoSb3纳米薄膜的能量扩散X射线光谱结果显示了Co和Sb的原子比大约是1:3。
对CoSb3纳米薄膜的50次充放电周期的电化学性能测试结果显示CoSb3纳米薄膜的初始放电容量为378.8毫安/克；在初始充电过程中观察到容量为205.2毫安/克、库仑效率为54.1%，在第二个充放电周期获得了低了些的放电容量为222.6毫安/克和相应的充电容量205.2毫安/克，所以库仑效率为92.2%；在50个充放电周期后CoSb3纳米薄膜的电容量下降到55.4毫安/克。我们分析，在CoSb3纳米薄膜的充放电周期中如此重大的电容量损失是归因于在锂化过程中产生了大型结构变化。
关键词：锂离子电池；正极材料；化学气相沉积；纽扣电池；循环伏安法
Abstract：Cobblestone-like CoSb3 nanoparticles have been prepared via chemical vapor transport and condensation. The resultant CoSb3 nanoparticles deposited on Cu foils were directly used as lithium ion battery anodes without the addition of any binder. Electrochemical analyses revealed that the CoSb3 nanoparticles depicted high charge storage capacities and stable performance. The capacity was 378.8 mAh/g during the second cycle, which decreased to 55.4 mAh/g during the 50th cycle at a rate of 0.2 C.
The XRD pattern of CoSb3 nanoparticles shows all the intensity peaks can be indexed to skutterudite-type CoSb3 phase (JCPDS 78-0976). Moreover, no impurity phases, such as Co and Sb, were detected. The FESEM images of CoSb3 nanoparticles reveal that the products are CoSb3 cobblestone-like nanoparticles with diameters in a range of 200-400 nm. Furthermore, the CoSb3 nanoparticles interconnect with each other and form a film with the thickness of 1 µm. The energy dispersive X-ray spectroscopy of CoSb3 nanoparticles shows that Co and Sb were in atomic ratio of about 1:3.
The electrochemical properties of CoSb3 nanoparticle films after 50 charging and discharging cycles test shows the CoSb3 nanoparticle films displayed an initial discharge capacity of 378.8 mAh/g. A capacity of 205.2 mAh/g was observed during the initial charging process, and a Coulombic efficiency of 54.1% was obtained. A lower discharge capacity of 222.6 mAh/g and a corresponding charge capacity of 205.2 mAh/g were obtained in the second cycle, leading to a Coulombic efficiency of 92.2%. The capacity of CoSb3 nanoparticle films decreased to 55.4 mAh/g after 50 cycles. The significant capacity loss during the cycling of CoSb3 nanoparticle films was ascribed to the large structural strain generated during the lithiation process.
Key words：Lithium Ion Battery、Positive Materials、Chemical Vapor Deposition、Button Cell、Cyclic Voltammetry