论文标题
硅和碳在si-ni $ _ {3.4} $ sn $ _4 $ -AL-C阳极的结构和电化学特性中的作用
Role of silicon and carbon on the structural and electrochemical properties of Si-Ni$_{3.4}$Sn$_4$-Al-C anodes for Li-ion batteries
论文作者
论文摘要
随着硅和碳的不同数量，通过Si，Ni $ _ {3.4} $ sn $ _4 $，Al and C. Silicon和C硅含量的球磨制制备了不同的复合材料，而硅和碳的含量在10到30wt。％si和0到20wt。％C.％C.％C. Compient和Electroginate diffresities companies the x ride n a x ride x n x n x n x-ray x n x ress x-ra扫描电子显微镜（SEM）和电化学电静态循环高达1000个循环。比较并讨论了硅和碳含量对相发生，电化学能力和周期寿命的影响。对于c-content的含量为9至13 wt。％和si-content> = 20 wt。％，Si纳米颗粒嵌入在Ni $ _ {3.4} $ _4} $ sn $ _4 $ _4 $ -AL-C矩阵中，该矩阵在微尺度上是化学均匀的。对于其他碳含量和低si-amount（10 wt。％），在Si纳米颗粒周围没有形成均匀基质。当形成同质矩阵时，ni $ _3 $ sn $ _4 $，而Si则参与了可逆的固定机制，而ni $ _3 $ _3 $ sn $ _4 $之间没有任何反应，而li and li and li and n no Ho polagenosios基质矩阵都没有。此外，当Si纳米颗粒嵌入均匀基质中时，获得最佳的循环寿命，而Si-Content则是中等的（<= 20 wt。％）。带有碳在9-13 wt的范围和20 wt的硅的复合材料可在骑自行车时的容量和寿命之间达到最佳平衡。这项工作在实验上表明，将SI嵌入金属间/碳基质中可以有效地适应循环时的Si体积变化，以确保长期循环寿命。
Varying the amounts of silicon and carbon, different composites have been prepared by ball milling of Si, Ni$_{3.4}$Sn$_4$, Al and C. Silicon and carbon contents are varied from 10 to 30 wt.% Si, and 0 to 20 wt.% C. The microstructural and electrochemical properties of the composites have been investigated by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and electrochemical galvanostatic cycling up to 1000 cycles. Impact of silicon and carbon contents on the phase occurrence, electrochemical capacity and cycle-life are compared and discussed. For C-content comprised between 9 and 13 wt.% and Si-content >= 20 wt.%, Si nanoparticles are embedded in a Ni$_{3.4}$Sn$_4$-Al-C matrix which is chemically homogeneous at the micrometric scale. For other carbon contents and low Si-amount (10 wt.%), no homogeneous matrix is formed around Si nanoparticles. When homogenous matrix is formed, both Ni$_3$Sn$_4$ and Si participate to the reversible lithiation mechanism, whereas no reaction between Ni$_3$Sn$_4$ and Li is observed for no homogenous matrix. Moreover, best cycle-life performances are obtained when Si nanoparticles are embedded in a homogenous matrix and Si-content is moderate (<= 20 wt.%). Composites with carbon in the 9-13 wt.% range and 20 wt.% silicon lead to the best balance between capacity and life duration upon cycling. This work experimentally demonstrates that embedding Si in an intermetallic/carbon matrix allows to efficiently accommodate Si volume changes on cycling to ensure long cycle-life.
