Browsing by Author "Xu, Jun"
Now showing 1 - 3 of 3
Results Per Page
Sort Options
Item Carbon Binder Domain Inhomogeneity in Silicon-Monoxide/Graphite Composite Anode by 2D Multiphysics Modeling(Advanced Science, 2024-05-22) Gao, Xiang; Xu, JunThe Carbon-binder domain (CBD) plays a pivotal role in the performance of lithium-ion battery electrodes. The heterogeneous distribution of CBD across the electrode has garnered significant attention. However, a thorough understanding of how this CBD inhomogeneity affects anode performance remains a crucial pursuit, especially when considering the inherent material variations present in the SiO/Graphite (SiO/Gr) composite anode. In this study, an electro-chemo-mechanical model is established that provides a detailed geometric description of the particles. This model allows to quantitatively uncover the effects of CBD inhomogeneity on the fundamental behaviors of the SiO/Gr composite anode. The findings indicate that reducing the proportion of CBD in the upper domain (near the anode surface) compared to the lower domain (near the current collector) positively influences electrochemical performance, particularly in terms of capacity and Li plating. However, such an arrangement introduces potential risks of mechanical failures, and it is recommended to incorporate a higher proportion of CBD alongside the SiO particles. Finally, an anode design with a lower CBD proportion in the upper domain exhibits superior rate performance. This study represents a pioneering modeling exploration of CBD inhomogeneity, offering a promising multiphysics model with significant potential for informing advanced battery design considerations.Item Electrochemical Modeling of Fast Charging in Batteries(Advanced Energy Materials, 2024-04-18) Duan, Xudong; Hu, Dayong; Chen, Weiheng; Li, Jiani; Wang, Lubing; Sun, Shuguo; Xu, JunThe acceleration of fast charging capabilities has emerged as a pivotal objective within the realms of the battery, electric vehicle, and energy storage sectors. However, the classical electrochemical models are not able to describe voltages of the cell (Ucell), anode (Ua), and cathode (Uc) at high C-rates. Herein, Ucell, Ua,, and Uc are experimentally obtained under various C-rates (0.1–2C) and identified the charge transfer resistance of the cathode (RCT,c) as the primary rate-limiting factor. Thus, the anode is established as a multi-scale coupling model with Fick's law and phase separation model applied, to discuss their effect on Ua and Li-ion concentration prediction. 2D reconstruction structures for the cathode is established with RCT,c effect considered. Finally, the Ua, Uc, and Ucell are successfully predicted at different C-rates. Results propose an accurate and versatile electrochemical model and highlight the importance of considering limiting factors in electrochemical modeling for fast charging.Item Investigation of the lithium plating triggering criterion in graphite electrodes(Journal of Materials Chemistry A: materials for energy and sustainability, 2024-04-16) Li, Jiani; Wang, Lubing; Xu, JunLithium plating is considered an undesirable side reaction because it can induce capacity fading and pose safety concerns in Li-ion batteries. The timely detection of lithium plating onset is crucial for both mechanistic investigations and ensuring the safe and durable operation of batteries. In this study, discharging tests were conducted by varying the set capacity in graphite/Li cells to induce lithium plating on the graphite electrode. Based on a comprehensive analysis of the voltage curves and the morphological characterization of disassembled cells, the inflection point on the differential voltage curve during the discharging process was identified as the precise onset time of lithium plating. Electrochemical models were developed to further elucidate the mechanisms governing the onset of lithium plating. Compared with the model based on the potential criterion, the model employing the concentration criterion demonstrated enhanced precision in predicting lithium plating, particularly under high C rates. Based on the model with the concentration criterion, the discharging protocol was optimized parametrically to achieve high discharging efficiency and restrain lithium plating. This nuanced understanding contributes to determining the onset of lithium plating more accurately, thereby facilitating a more robust battery design and durable yet fast charging protocols.