| Abstract |
| We employed electrophoretic deposition (EPD) using AC voltage to prepare lithium iron phosphate (LFP) Li-ion battery electrodes with varying the LFP thickness, to compare bulk-limited electro chemical reaction with the surface-limited electrochemical reactions. We analyzed the electrochemical performances of the thin and thick LFP electrodes at various scan rates. They revealed that with increasing scan rates, both electrode types showed a greater reliance on surface capacitive effects for charge storage. Significantly, the thin LFP electrode predominantly exhibited capacitive charge storage, surpassing diffusion-based storage mechanisms. This was in contrast to the performance of the thicker electrode, which had a lower capacitive contribution. Quantitative assessment using the Randles-Sevcik equation further confirmed the superior performance of the thin LFP electrode. The Li-ion diffusion coefficient of the thin LFP electrode was substantially higher (9.6×10-9 cm2·V-1·s-1) compared to the thick electrode (2.0×10-9 cm2·V-1·s-1), indicating enhanced ionic mobility in the surface-limited electrochemical reaction. These findings emphasize the significant advantages of thinner LFP electrodes, and induced surface limited electrochemical reaction, in high-rate applications, including higher capacitive charge storage and more favorable ion diffusion characteristics. The advantages conferred by the enhanced capacitive charge storage and superior ion diffusion in thin LFP electrodes have profound implications for the design and optimization of next-generation high-rate batteries. By focusing on tailoring electrode thickness, we can harness the full potential of surfacelimited reactions, pushing the boundaries of what is currently achievable in terms of power density, charging speed, and cycle life in LFP-based energy storage technologies. These enhancements align with the growing need for high-performing, reliable energy storage solutions in an increasingly electrified and energy-conscious world. |
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| Key Words |
| Lithium Iron Phosphate, Bulk, Surface-limited, Li-ion Battery, Cathode |
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