Developing Potential Energy Surfaces for Graphene-based 2D-3D Interfaces from Modified High Dimensional Neural Networks for Applications in Energy Storage
Vidushi Sharma, Dibakar Datta
备注：
29 Pages
发表信息：
J. Electrochem. En. Conv. Stor. Nov 2022, 19(4): 041006
Mixed-dimensional heterostructures composed of two-dimensional (2D) and three-dimensional (3D) materials are undisputed next-generation materials for engineered devices due to their changeable properties. The present work computationally investigates the interface between 2D graphene and 3D tin (Sn) systems with density functional theory (DFT) method. It uses computationally demanding simulation data to develop machine learning (ML) based potential energy surfaces (PES). The approach to developing PES for complex interface systems in the light of limited data and transferability of such models has been discussed. To develop PES for graphene-tin interface systems, high dimensional neural networks (HDNN) are used that rely on atom-centered symmetry function to represent structural information. HDNN are modified to train on the total energies of the interface system rather than atomic energies. The performance of modified HDNN trained on 5789 interface structures of graphene|Sn is tested on new interfaces of the same material pair with varying levels of structural deviations from the training dataset. Root mean squared error (RMSE) for test interfaces fall in the range of 0.01-0.45 eV/atom, depending on the structural deviations from the reference training dataset. By avoiding incorrect decomposition of total energy into atomic energies, modified HDNN model is shown to obtain higher accuracy and transferability despite limited dataset. Improved accuracy in ML-based modeling approach promises cost-effective means of designing interfaces in heterostructure energy storage systems with higher cycle life and stability.
A Record-High Ion Storage Capacity of T-Graphene as Two-Dimensional Anode Material for Li-ion and Na-ion Batteries
近年来，开发具有高性能，特别是具有高离子存储容量的可应用的二维（2D）电极材料已成为越来越令人着迷的追求。基于第一性原理计算，我们报道了一种新型碳基二维材料T-石墨烯具有创纪录的Li/Na存储容量。T-石墨烯对Li的容量高达2233.2 mA h g-1，对Na的容量可达2357.2 mA h g-1，是商用石墨的6倍，是迄今为止鉴定的2D负极材料中最高的。研究表明，T型石墨烯的储能能力主要得益于其较低的原子质量和特殊的周期性晶格结构。T-石墨烯不仅具有储能容量，而且具有稳定的离子吸附、良好的导电性、快的离子扩散速度和低的开路电压等优点，是锂离子电池和钠离子电池储能容量的优良负极材料。
Lithium and sodium decorated PHE-graphene for high capacity hydrogen storage: A DFT and GCMC study
Jiangsu Provincial Engineering Research Center of Low-Dimensional Physics and New Energy, College of Science, Nanjing University of Posts and Telecommunications（南京邮电大学理学院低维物理与新能源江苏省工程研究中心）
Oxidation-resilient structural modifications in Nickel-functionalized 3D-graphene for hydrogen storage applications
Istituto Nanoscienze–CNR（意大利国家研究委员会纳米科学研究所）；NEST-Scuola Normale Superiore（新实验科学与技术学院-高等师范学校）；Department of Physical Science, Earth, and Environment, University of Siena（锡耶纳大学地球与环境物理科学系）；Institute of Sensor and Actuator Systems, TU Wien（维也纳工业大学传感器与致动器系统研究所）；CNR - Istituto Officina dei Materiali (IOM)（意大利国家研究委员会材料工厂研究所）
Magnesium-graphene interphase boundaries created by high-pressure torsion enhance hydrogen storage kinetics:Mechanisms and significance of activation energy and frequency factor
WPI, International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University（九州大学碳中和能源研究国际研究所（WPI-I2CNER））；Department of Automotive Science, Kyushu University（九州大学汽车科学系）；Faculdade de Engenharia Mecânica (FEM), Universidade Estadual de Campinas (UNICAMP)（坎皮纳斯州立大学机械工程学院）；Université de Lorraine, Laboratoire d’Etude des Microstructures et de Mécanique des Matériaux (LEM3 UMR 7239)（洛林大学微观结构与材料力学实验室（LEM3））；Université de Lorraine, Laboratory of Excellence on Design of Alloy Metals for low-mass Structures (DAMAS)（洛林大学低质量结构合金设计卓越实验室（DAMAS））
Fast Activation of Graphene with Corrugated Surface and its Role in Improved Aqueous Electrochemical Capacitors
在石墨烯基材料中，通常通过具有极高表面积的丰富多孔结构来提高储能能力。通过利用表面波纹，这项工作显示了一种替代策略，以激活石墨烯材料的大电容。我们展示了如何简单地制造这种活化的石墨烯以及这些表面结构如何帮助实现相当大的比电容（例如，在5 mV s-1下的~340 F g-1的电极电容和在1.7A g-1下的~ 343 F g-1的器件电容）和功率性能（例如，分别在~10.7和1.53 Wh kg-1的能量密度下的50和2500 W kg-1的功率密度），其与具有超高表面积的高度活化的石墨烯材料的那些相当并且甚至更好。这项工作展示了一种提高碳基材料容量的新途径，可以开发并与其他系统结合，用于各种改进的储能应用。
Enhanced Li capacity at high lithiation potentials in graphene oxide
我们已经使用第一性原理计算研究了氧化石墨烯（GO）的锂化作为氧覆盖度的函数。我们的研究结果表明，可以通过控制氧覆盖率或还原程度来调节GO中的锂化电位和容量。我们发现了一系列的覆盖率，其中锂化电位高于固体电解质界面（SEI）形成阈值，但具有与石墨相当或大于石墨的容量。我们观察到，在高度氧化和轻度还原的片材中，通过形成Li-O键发生锂化，而在还原GO（rGO）（0：C = 12.5%）典型的低覆盖率下，观察到Li-O键和LiC 6构型。共价Li-O键比在LiC 6环中形成的键强得多，并且在高和中等覆盖率下环氧化物的锂化电势通常很大（> 1 eV）。对于这些构造，如在Li 4 Ti 5 O 12阳极的情况下，将不形成SEI，但具有比Li 4 Ti 5 O 12具有更高的锂储存容量的额外优点。在还原的GO片中，残留氧原子的存在允许形成共价Li-O键，其导致比石墨更高的存储容量和锂化电势。最后，我们的计算表明石墨烯纳米带的边缘具有高的锂化电位，这将阻碍SEI的形成，从而导致大的可逆容量。
Three-dimensional graphene skeletons supported nickel molybdate nanowire composite as novel ultralight electrode for supercapacitors
采用水热法在化学气相沉积法生长的三维石墨烯骨架上制备了NiMoO（$_{4}$）纳米线。X射线衍射和拉曼光谱结果表明，NiMoO $_{4}$为$α$相。这种无粘合剂的超轻石墨烯/ NiMoO $_{4}$复合材料用作超级电容器的正极。该电极在12 mA cm $^{-2}$下的比电容为1194 F g $^{-1}$，1000次循环后的循环效率为97.3%。此外，在1319 W kg $^{-1}$的稳定功率密度下，能量密度达到41 Wh kg $^{-1}$的能量密度。这些结果证明了所设计的复合材料在未来柔性和轻质储能方面的潜力。
