Introducing a Pseudocapacitive Lithium Storage Mechanism into Graphite by Defect Engineering for Fast-Charging...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Fast charging is crucial for electric vehicles (EVs), but current graphite anodes in lithium-ion batteries (LIBs) are insufficient.
• Developing advanced anode materials is essential to meet the demands of rapid charging technologies.

Purpose of the Study:

• To engineer graphite anodes for improved fast-charging capabilities in LIBs.
• To investigate the impact of intrinsic lattice defect engineering on graphite anode performance.

Main Methods:

• Graphite was thermally treated in CO2 to introduce intrinsic lattice defects, creating activated graphite (AG).
• Electrochemical performance was evaluated using galvanostatic cycling and rate capability tests.
• Lithium ion intercalation kinetics were analyzed using distribution of relaxation times (DRT) and density functional theory (DFT) calculations.

Main Results:

• Activated graphite (AG) demonstrated a significantly enhanced rate capability (209 mAh g-1 at 10 C) compared to pristine graphite (15 mAh g-1).
• A LiFePO4||AG full cell achieved 82% and 96% state of charge (SOC) within 6 and 15 minutes, respectively.
• CO2 treatment improved lithium ion intercalation kinetics, attributed to introduced carbon defects.

Conclusions:

• Intrinsic lattice defect engineering via CO2 thermal treatment is an effective strategy for developing fast-charging LIB anodes.
• This facile method offers a novel approach for enhancing the performance of carbon-based anode materials for energy storage applications.