Interface-engineered current collectors for improved rate performance in solid-state lithium-ion batteries

Lithium-ion batteries (LIBs) serve as essential power sources in consumer electronics, electric vehicles, and stationary energy storage systems owing to their high energy density, long cycle life, and versatility. However, conventional LIBs based on liquid electrolytes encounter notable safety risks, including electrolyte leakage, flammability, and limited electrochemical stability at high voltages. As a safer alternative, solid polymer electrolytes—particularly those based on polyethylene oxide—have attracted growing attention. To improve their practical applicability, catholyte configurations have been explored. However, these configurations have been reported to increase internal resistance, hindering practical implementation. Hence, in this study, we propose an alternative strategy involving the sequential deposition of graphene and carbon nanotube (G//CNT) coatings on Al current collectors. This approach enhances both interfacial stability and electronic conductivity without requiring additional inorganic components. Notably, G//CNT-coated current collectors demonstrate improved electrochemical performance, delivering an initial specific capacity of 200.1 mAh g⁻¹ at 0.2 C and maintaining a capacity of 45.08 mAh g⁻¹ at 2 C. Thus, this study presents a simple and scalable pathway to boost the practical performance of next-generation solid-state LIBs.