Extreme fast charging of Lithium-ion batteries using flash graphene additive

Abstract

The battery can be charged to 80 % of its state of charge (SOC) within 15 min, which is a significant factor contributing to the widespread adoption of electric vehicles (EVs) due to the alleviation of range anxiety. However, the realization of fast charging batteries is hindered by intricate challenges, including lithium-ion diffusion, lithium plating over the anode, charging protocols, and economic considerations. Graphene, renowned for its exceptional conductivity and facilitating lithium transport, emerges as a promising candidate for incorporation into fast-charging batteries. Cost-effectiveness is a key consideration, and alternative low-cost methods for graphene production are essential for the advancement of fast charging battery development. Flash joule heating emerges as a cost-effective approach to convert amorphous hard carbon into flash graphene (FG) as confirms by Raman characterization. Scanning electron microscopy (SEM) characterization reveals that FG exhibits a multilayer structure and a turbostratic pattern with a substantial surface area. Subsequently, FG is incorporated into the NMC811 cathode to fabricate a fast-charging lithium-ion battery. The FG-NMC battery demonstrates an initial specific capacity of 173.2 mAh.g⁻¹. The extreme fast charging (XFC) testing procedure (CC-CV protocol at 5C) results in a charging time of 13 min stores 117.6 mAh.g⁻¹ (SOC of 80.1 %), meeting the criteria for a fast-charging battery. The capacity retention after 150 cycles under extreme charging (5C) and discharging (5C) is 87.4 % demonstrates that FG possesses the potential to be a cost-effective additive for energy-dense fast charging batteries suitable for electric vehicle applications.