높은 충⋅방전 속도에서 탄소나노튜브(CNTs)가 전극 내 전자전도에 미치는 영향 = Effect of Carbon Nanotubes(CNTs) on Electronic Conductivity within Electrodes under High Charge/Discharge Rates

다국어 초록 (Multilingual Abstract)

High energy density lithium-ion batteries(LIBs) are essential for large-scale application such as electric vehicles(EVs) and energy storage systems(ESSs). In this work, we fabricated high-loading electrodes(12∼13 mg cm-2) based on the high-nickel cathode LiNi0.92Co0.07Mn0.01O2(NCM9271) to meet the growing energy demands of such systems. However, the thick electrodes with high mass loading often suffer from sluggish lithium-ion and electronic transport. Under high-rate conditions, the longer ion transport pathways induce a concentration polarization within the electrode and an increase the internal resistance. To overcome these limitations, a small amount(1-2 wt%) of multi-walled carbon nanotubes(MWCNTs) was incorporated to the electrode as a conductive additive. The well-dispersed MWCNTs network significantly improved the internal electronic conductivity and reduced resistance. As a result, the NCM9271 + 2 wt% MWCNTs electrode exhibited a capacity retention of 87.2% after 60 cycles at 0.1 C, which was more than eight times higher than that of the pristine electrode.
Furthermore, the electrode containing 2 wt% MWCNTs demonstrated rapid capacity recovery from 1 C to 0.1 C. These findings highlight a simple and effective electrode engineering strategy to enable superior performance of LIBs under extreme loading conditions, providing valuable insights for the design of next-generation batteries.