Oli Nischal, Liza Castillo Diana C, Weiner Brad R, Morell Gerardo, Katiyar Ram S
Department of Physics, University of Puerto Rico-Rio Piedras Campus, San Juan, PR 00925, USA.
Department of Chemistry, University of Puerto Rico-Rio Piedras Campus, San Juan, PR 00925, USA.
Molecules. 2024 Oct 8;29(19):4750. doi: 10.3390/molecules29194750.
Silicon (Si) has attracted worldwide attention for its ultrahigh theoretical storage capacity (4200 mA h g), low mass density (2.33 g cm), low operating potential (0.4 V vs. Li/Li), abundant reserves, environmentally benign nature, and low cost. It is a promising high-energy-density anode material for next-generation lithium-ion batteries (LIBs), offering a replacement for graphite anodes owing to the escalating energy demands in booming automobile and energy storage applications. Unfortunately, the commercialization of silicon anodes is stringently hindered by large volume expansion during lithiation-delithiation, the unstable and detrimental growth of electrode/electrolyte interface layers, sluggish Li-ion diffusion, poor rate performance, and inherently low ion/electron conductivity. These present major safety challenges lead to quick capacity degradation in LIBs. Herein, we present the synergistic effects of nanostructured silicon and SrTiO (STO) for use as anodes in Li-ion batteries. Si and STO nanoparticles were incorporated into a multiwalled carbon nanotube (CNT) matrix using a planetary ball-milling process. The mechanical stress resulting from the expansion of Si was transferred via the CNT matrix to the STO. We discovered that the introduction of STO can improve the electrochemical performance of Si/CNT nanocomposite anodes. Experimental measurements and electrochemical impedance spectroscopy provide evidence for the enhanced mobility of Li-ions facilitated by STO. Hence, incorporating STO into the Si@CNT anode yields promising results, exhibiting a high initial Coulombic efficiency of approximately 85%, a reversible specific capacity of ~800 mA h g after 100 cycles at 100 mA g, and a high-rate capability of 1400 mA g with a capacity of 800 mA h g. Interestingly, it exhibits a capacity of 350 mAh g after 1000 lithiation and delithiation cycles at a high rate of 600 mA hg. This result unveils and sheds light on the design of a scalable method for manufacturing Si anodes for next-generation LIBs.
硅(Si)因其超高的理论存储容量(4200 mA h g)、低质量密度(2.33 g cm)、低工作电位(相对于Li/Li为0.4 V)、储量丰富、环境友好且成本低廉而受到全球关注。它是下一代锂离子电池(LIBs)中一种很有前景的高能量密度负极材料,由于蓬勃发展的汽车和储能应用中不断增长的能量需求,有望取代石墨负极。不幸的是,硅负极的商业化受到锂化-脱锂过程中大量体积膨胀、电极/电解质界面层不稳定且有害的生长、锂离子扩散缓慢、倍率性能差以及固有低离子/电子导电性的严重阻碍。这些主要的安全挑战导致锂离子电池的容量迅速下降。在此,我们展示了纳米结构的硅和SrTiO(STO)用作锂离子电池负极的协同效应。通过行星球磨工艺将硅和STO纳米颗粒掺入多壁碳纳米管(CNT)基质中。硅膨胀产生的机械应力通过碳纳米管基质传递到STO。我们发现引入STO可以改善硅/碳纳米管复合负极的电化学性能。实验测量和电化学阻抗谱为STO促进锂离子迁移提供了证据。因此,将STO掺入Si@CNT负极产生了有前景的结果,在100 mA g下循环100次后,初始库仑效率约为85%,可逆比容量约为800 mA h g,在1400 mA g的高倍率下容量为800 mA h g。有趣的是,在600 mA hg的高倍率下进行1000次锂化和脱锂循环后,它的容量为350 mAh g。这一结果揭示并阐明了一种用于制造下一代锂离子电池硅负极的可扩展方法的设计。