Tran Thi Nhan, Son Nguyen Hoang, Hieu Nguyen Minh, Nguyen Thuy Trang, Kawazoe Yoshiyuki, Duc Luong Huu, Dang Minh Triet, Nguyen Phi Long, Phung Thi Viet Bac
Hanoi University of Industry 298 Cau Dien Street, Bac Tu Liem Hanoi 100000 Vietnam
Faculty of Physics, University of Science, Vietnam National University - Hanoi Hanoi Vietnam.
RSC Adv. 2025 Jul 14;15(30):24575-24587. doi: 10.1039/d5ra04616e. eCollection 2025 Jul 10.
Heterostructures composed of graphene (G) and WS have recently been proposed as a promising new two-dimensional carbon allotrope for an anode material in sodium-ion batteries. Actively controlling material defects by substituting sulfur (S) atoms on the surface of WS with alternative dopants is anticipated to be a potential strategy for enhancing the electrochemical performance of WS/G heterostructures. Here, we employ first-principles density functional theory (DFT) calculations to systematically investigate the impact of boron (B) and carbon (C) doping on the sodium intercalation and diffusion mechanisms within the heterostructures. The results reveal that doped WS/G heterostructures show electronic characteristics of metallic materials, which are beneficial for their application as high-performance anode materials. The introduction of B/C dopants significantly enhance the binding affinity for sodium intercalation at active sites, both on the surface and at interfacial region, with binding energies reaching up to -1.702 eV, which can mitigate sodium dendrite formation during electrochemical cycling. Notably, the presence of B/C dopants can create energetically favorable diffusion pathway both on the surface and in the interfacial region of the WS/G bilayers for sodium ions with energy barriers ranging from 0.091 to 0.494 eV, underscoring their potential to support high-rate charge/discharge processes. Additionally, B/C-doped WS/G heterostructures exhibit inconsiderably structural deformation during sodium intercalation, making them suitable candidates as anode materials in batteries with high cycling stability. Our findings provide valuable insights into the effect of the dopants within the sodium intercalation mechanisms of WS/G heterostructures, paving the way for the rational design of next-generation anode materials for high-performance sodium-ion batteries.
由石墨烯（G）和WS组成的异质结构最近被提议作为钠离子电池负极材料中一种有前景的新型二维碳同素异形体。通过用替代掺杂剂取代WS表面的硫（S）原子来主动控制材料缺陷，有望成为提高WS/G异质结构电化学性能的潜在策略。在此，我们采用第一性原理密度泛函理论（DFT）计算，系统地研究硼（B）和碳（C）掺杂对异质结构中钠嵌入和扩散机制的影响。结果表明，掺杂的WS/G异质结构具有金属材料的电子特性，这有利于它们作为高性能负极材料的应用。B/C掺杂剂的引入显著增强了在活性位点（包括表面和界面区域）对钠嵌入的结合亲和力，结合能高达-1.702 eV，这可以减轻电化学循环过程中钠枝晶形成。值得注意的是，B/C掺杂剂的存在可以在WS/G双层的表面和界面区域为钠离子创造能量上有利的扩散途径，能垒范围为0.091至0.494 eV，突出了它们支持高速率充放电过程的潜力。此外，B/C掺杂的WS/G异质结构在钠嵌入过程中表现出微不足道的结构变形，使其成为具有高循环稳定性的电池负极材料的合适候选者。我们的研究结果为WS/G异质结构钠嵌入机制中掺杂剂的作用提供了有价值的见解，为高性能钠离子电池下一代负极材料的合理设计铺平了道路。
