Mandal Sneha, Pillai Vijayamohanan K, Ranjana Ponraj Mano, K M Thushara, Bhagavathsingh Jebasingh, Grage Stephan L, Peng Xihong, Kang Jeon Woong, Liepmann Dorian, Kannan Arunachala Nadar Mada, Thavasi Velmurugan, Renugopalakrishnan Venkatesan
Department of Chemistry, Indian Institute of Science Education and Research (IISER) Tirupati Andhra Pradesh 517507 India
Department of Applied Chemistry, Karunya Institute of Technology and Sciences Coimbatore Tamil Nadu 641114 India
Energy Adv. 2024 Jun 21;3(8):1977-1991. doi: 10.1039/d4ya00217b. eCollection 2024 Aug 8.
Li-ion batteries stand out among energy storage systems due to their higher energy and power density, cycle life, and high-rate performance. Development of advanced, high-capacity anodes is essential for enhancing their performance, safety, and durability, and recently, two-dimensional materials have garnered extensive attention in this regard due to distinct properties, particularly their ability to modulate van der Waals gap through intercalation. Covalently intercalated Graphene oxide interlayer galleries with mono-Boc-ethylenediamine (GO-EnBoc) was synthesized the ring opening of epoxide, forming an amino alcohol moiety. This creates three coordination sites for Li ion exchange on the graphene oxide nanosheets' surface. Consequently, the interlayer -spacing expands from 8.47 Å to 13.17 Å, as anticipated. When explored as an anode, Li-GO-EnBoc shows a significant enhancement in the stable and reversible capacity of 270 mA h g at a current density of 25 mA g compared to GO (80 mA h g), without compromising the mechanical or chemical stability. Through C, Li and Li MAS NMR, XPS, IR, Raman microscopy, and density functional theory (DFT) calculations, we confirm the positioning of Li ions at multiple sites of the interlayer gallery, which enhances the electrochemical performance. Our findings suggest that these novel systematically modulated van der Waals gap GO-engineered materials hold promise as efficient anodes for Li-ion batteries.
锂离子电池在储能系统中脱颖而出，因为它们具有更高的能量和功率密度、循环寿命以及高倍率性能。开发先进的高容量负极对于提高其性能、安全性和耐用性至关重要，最近，二维材料因其独特的性能，特别是通过嵌入调节范德华间隙的能力，在这方面受到了广泛关注。通过环氧化物的开环反应合成了具有单叔丁氧羰基乙二胺（GO-EnBoc）的共价嵌入氧化石墨烯层间通道，形成了氨基醇部分。这在氧化石墨烯纳米片表面产生了三个用于锂离子交换的配位位点。因此，层间距如预期的那样从8.47 Å扩大到13.17 Å。当作为负极进行探索时，与GO（80 mA h g）相比，Li-GO-EnBoc在25 mA g的电流密度下显示出稳定可逆容量显著提高，达到270 mA h g，同时不影响机械或化学稳定性。通过碳、锂和锂的固体核磁共振、X射线光电子能谱、红外光谱、拉曼显微镜以及密度泛函理论（DFT）计算，我们证实了锂离子在层间通道多个位点的定位，这增强了电化学性能。我们的研究结果表明，这些新型的系统调节范德华间隙的氧化石墨烯工程材料有望成为锂离子电池的高效负极。
