Molecular Structure Evaluation and Image-Guided Atomistic Representation of Hard Carbon Electrodes

Construction of large-scale atomistic representations of hard carbon electrodes aids exploration of structure-property relationships. These representations of practical value need to agree with experimental data, specifically the distribution of structural features. The molecular structure of a commercial hard carbon was evaluated by HRTEM image analysis in combination with LDIMS, FT-IR, XPS, XRD, SAXS, and gas sorption. In particular, an improved algorithm was applied to automatically calculate the interlayer spacing by finding LCS (longest common subsequence), which can extract more high fidelity data of fringe pairs from the HRTEM image analysis. Hard carbon is a partially ordered system, with order varying over length scales. Thus, a large-scale atomistic representastion (C48025H1857O811N198S127) in a 100 x 100 x 100 angstrom cubic cell was generated using an image-guided construction approach, better capturing the structural diversity, micropore distribution, and spatial arrangement necessary to represent carbon electrode behavior. A wide variety of chemical and physical parameters were consistent with experimental data. Such structural model that depicts experimentally-determined characteristics will provide valuable strategies for the development of high-performance carbon electrodes. (C) 2022 The Electrochemical Society ("ECS"). Published on behalf of ECS by IOP Publishing Limited.