Making Room for Silicon: Including SiO<sub>x</sub> in a Graphite-Based Anode Formulation and Harmonization in 1 Ah Cells

Transitioning to more ambitious electrode formulations facilitates developing high-energy density cells, potentially fulfilling the demands of electric car manufacturers. In this context, the partial replacement of the prevailing anode active material in lithium-ion cells, graphite, with silicon-bas...

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Bibliographic Details
Main Authors: Imanol Landa-Medrano, Idoia Urdampilleta, Iker Castrillo, Hans-Jürgen Grande, Iratxe de Meatza, Aitor Eguia-Barrio
Format: Article
Language:English
Published: MDPI AG 2024-03-01
Series:Energies
Subjects:
Online Access:https://www.mdpi.com/1996-1073/17/7/1616
Description
Summary:Transitioning to more ambitious electrode formulations facilitates developing high-energy density cells, potentially fulfilling the demands of electric car manufacturers. In this context, the partial replacement of the prevailing anode active material in lithium-ion cells, graphite, with silicon-based materials enhances its capacity. Nevertheless, this requires adapting the rest of the components and harmonizing the electrode integration in the cell to enhance the performance of the resulting high-capacity anodes. Herein, starting from a replacement in the standard graphite anode recipe with 22% silicon suboxide at laboratory scale, the weight fraction of the electrochemically inactive materials was optimized to 2% carbon black/1% dispersant/3% binder combination before deriving an advantage from including single-wall carbon nanotubes in the formulation. In the second part, the recipe was upscaled to a semi-industrial electrode coating and cell assembly line. Then, 1 Ah lithium-ion pouch cells were filled and tested with different commercial electrolytes, aiming at studying the dependency of the Si-based electrodes on the additives included in the composition. Among all the electrolytes employed, the EL2 excelled in terms of capacity retention, obtaining a 48% increase in the number of cycles compared to the baseline electrolyte formulation above the threshold capacity retention value (80% state of health).
ISSN:1996-1073