论文标题
官能化的MXENE作为锂亚属电池的有效多聚酯素固定器：密度功能理论（DFT）研究
Functionalized MXenes as Effective Polyselenides Immobilizer for Lithium-Selenium Batteries: A Density Functional Theory (DFT) Study
论文作者
论文摘要
锂硒（LI-SE）电池的实际应用主要是由于高阶多聚酯烯（LI2SEN）溶解和迁移到电解质（称为航天飞机效应）和低阶多聚苯乙烯的不活跃沉积。 MXENES的高电导率和机械强度使它们成为合适的候选者，以提供足够的锚定，以防止多性苯甲酸酯溶解和改善的电化学性能。本文中，我们使用密度功能理论（DFT）计算来了解Li2sen对石墨烯和表面功能化TI3C2 MXENES的结合机制。我们使用石墨烯作为参考材料来评估功能化TI3C2X2（其中X = S，O，F和CL）上的LI2SEN结合强度。我们观察到与石墨烯，TI3C2F2和TI3C2CL2相比，TI3C2S2和TI3C2O2具有出色的锚定行为。 S和O终止TI3C2提供的计算出的LI2SEN吸附强度比常用的基于以太的电解液强，这是有效抑制Li2sen Suttling的必要条件。 Ti3c2x2上的吸附Li2sen和石墨烯保留其结构完整性，而无需化学分解。状态（DOS）分析的密度表明，即使在LI2SEN吸附后，TI3C2X2的导电行为也可以保留，这可以刺激涉及的LI2SEN化学的电化学活性。基于我们前所未有的结果，发现Ti3C2S2和Ti3C2O2表现出对LI2SEN吸附的优越锚定行为，可以利用这些行为来设计有效的基于硒的天主管，以增强Li-Se电池系统的电化学性能
The practical applications of lithium selenium (Li-Se) batteries are impeded primarily due to the dissolution and migration of higher order polyselenides (Li2Sen) into the electrolyte (known as shuttle effect) and inactive deposition of lower order polyselenides. The high electrical conductivity and mechanical strengths of MXenes make them a suitable candidate to provide adequate anchoring to prevent polyselenides dissolution and improved electrochemical performance. Herein, we used density functional theory (DFT) calculations to understand the binding mechanism of Li2Sen on graphene and surface functionalized Ti3C2 MXenes. We used graphene as reference material to assess Li2Sen binding strengths on functionalized Ti3C2X2 (where X = S, O, F, and Cl). We observed that Ti3C2S2 and Ti3C2O2 exhibit superior anchoring behavior compared to graphene, Ti3C2F2, and Ti3C2Cl2. The calculated Li2Sen adsorption strength provided by S and O terminated Ti3C2 are stronger than the commonly used ether-based electrolyte, which is a requisite for effective suppression of the Li2Sen shuttling. The adsorbed Li2Sen on Ti3C2X2 and graphene retains their structural integrity without a chemical decomposition. The density of states (DOS) analysis exhibits that the conductive behavior of the Ti3C2X2 is preserved even after Li2Sen adsorption, which can stimulate the electrochemical activity of involved Li2Sen chemistry. Based on our unprecedented results, Ti3C2S2 and Ti3C2O2 are found to exhibit superior anchoring behavior for Li2Sen adsorption, which can be leveraged for designing effective selenium-based cathode materials to boost the electrochemical performance of the Li-Se battery system
