본 연구에서는 구연산 처리를 통하여 폐흑연의 Li, F 등의 불순물을 제거하였으며, 이에 따른 재생 흑연의 구조적

특성, 용량 및 내구성 변화를 관찰하였다. 질소 분위기에서 전처리를 진행한 재생 흑연은 구연산에서 산처리를 진행하

였고 SEM (Scanning Electron Microscope), FT-IR (Fourier Transform Infrared spectroscopy), XRD (X-ray Diffraction),

XPS (X-ray Photoelectron Spectroscopy)를 통해 구조와 특성 분석을 진행하였다. 산처리를 진행하지 않은 폐흑연은 70

사이클 이전에서 용량이 급격하게 감소하였으나 구연산 처리를 진행한 흑연은 100 사이클에서 302.9mAh g-1의 용량과

93.1%의 용량 유지율을 나타내었다. 또한 Rate performance의 전류 밀도 변화에도 구연산 처리한 샘플은 용량의 변화

없이 1.0C에서 340.2 mAh g-1의 성능을 나타내었다. 결과적으로 구연산 처리는 효과적으로 불순물을 제거하여 높은 용

량 유지율을 나타내었을 뿐만 아니라 높은 전류 밀도에서도 안정적인 모습을 나타내는 것으로 확인하였다.

In this study, impurities such as Li and F were removed from waste graphite through citric acid treatment,

and changes in structural properties, capacity, and cycle stability of regenerated graphite were observed accordingly.

Regenerated graphite pretreated in a nitrogen atmosphere was treated with citric acid, and its structure and characteristics were

analyzed through SEM (Scanning Electron Microscope), FT-IR (Fourier Transform Infrared spectroscopy), XRD (X-ray

Diffraction), and XPS (X-ray Photoelectron Spectroscopy). Waste graphite that was not treated with acid had a rapid

decrease in capacity before 70 cycles, but graphite that had been treated with citric acid showed a capacity of 302.9 mAh g-1

and a capacity retention rate of 93.1% at 100 cycles. In addition, despite changes in current density in rate performance,

samples treated with citric acid showed 340.2 mAh g-1 performance at 1.0C without change in capacity. As a result, it

was confirmed that citric acid treatment not only effectively removed impurities and showed a high capacity retention

rate, but also showed stability even at high current densities.

Spent LIBs, Citric acid, Spent graphite, Eco-friendly acid treatment, Removal of impurities

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