Electrochemical performances through pre-lithiation of carbon materials for lithium-ion capacitor application

초록

Lithium-ion capacitors (LICs) bridge the performance gap between batteries and supercapacitors by providing high energy and power densities. However, anode limitations often constrain the overall efficiency, particularly due to initial lithium-ion loss and structural instability. This study addresses these limitations by synthesizing pre-lithiated carbon compounds (PLCCs) via electrochemical pre-lithiation. Structural and chemical analyses, including XRD, FTIR, and Raman spectroscopy, confirmed the formation of lithium-containing compounds, such as Li2CO3 and Li2O, which enhanced ion diffusion and electrode stability. This study aims to solve the problems predicted in LIC through prior research on these compounds. Comparative electrochemical evaluations revealed that pre-lithiated graphite significantly improved LIC performance by stabilizing lithium-ion diffusion and reducing impedance. Analysis through cyclic voltammetry, Tafel plots, and EIS demonstrated lower surface resistance and stable current density in pre-lithiated graphite, supporting efficient lithiation-delithiation cycles. SEM and TEM imaging further indicated a more uniform lithium distribution and reduced surface degradation, which together extended the cycle life under high-current conditions. This study highlights that electrochemically pre-lithiated graphite not only enhances the specific capacity and energy density but also contributes to improved power density and electrode durability. Overall, these findings establish electrochemically synthesized PLCCs as promising candidates for high-performance LIC anodes, offering insights into potential pathways for next-generation energy storage systems.

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