Contrasting direct contact and electrochemical pre-lithiation: Impact on interfacial stability and full cell longevity of graphite anodes

초록

Pre-lithiation of graphite anodes is a promising strategy to compensate for lithium loss during the formation stage of lithium-ion batteries. Here, we compare electrochemical (EC) and direct contact (DC) pre-lithiation methods in full cell configurations using graphite/LiNi0.8Co0.15Mn0.05O2 electrodes. The DC method enables rapid lithium loading and forms a Li2CO3-rich surface layer, which enhances interfacial stability and long-term performance. Despite slightly higher initial impedance, DC-treated graphite shows suppressed dendrite formation, reduced electrolyte decomposition, and preserved crystallinity after extended cycling, unlike EC-treated graphite, which suffers from SEI degradation and increased LiF and LixPOyFz formation. These results highlight the effectiveness of DC pre-lithiation not only in improving electrode durability but also in providing a practical framework for reliable graphite anode preparation and full cell evaluation.

키워드