Synthesis and electrochemical performance of CuS nanocrystal/MXene composite anodes for high-performance lithium-ion batteries

This study presents the strategic development and synthesis of a CuS-integrated MXene composite anode tailored for lithium-ion battery (LIB) applications. This composite architecture is specifically designed to address key challenges such as the inherently poor electrical conductivity of copper sulfide and the propensity of Ti 3 C 2 T X (MXene) layers to restack, which can hinder electrochemical performance. The composite was manufactured by a simple hydrothermal technique, yielding a well-integrated heterostructure in which uniformly distributed CuS nanoparticles are anchored onto the few-layered MXene sheets. This architecture fosters efficient electron transport, accelerates lithium-ion diffusion, and provides structural integrity to buffer the volume changes of CuS during repeated charge–discharge cycles. Comprehensive structural and surface characterizations reveal strong interfacial bonding, a mesoporous morphology, and enlarged electroactive surface area features that collectively enhance redox kinetics and interfacial charge transfer. Electrochemical tests show a remarkable initial discharge capacity of approximately 1890 mAh·g −1 at a current density (CD) of 1000 mA g −1 while maintaining a remarkable capacity of about 830 mAh·g −1 even when evaluated at an elevated CD of 5000 mA g −1 . Additionally, the composite retains 90.6 % of its capacity after 500 cycles, showcasing excellent long-term cycling stability and outperforming commercial graphite anodes under identical conditions. These findings highlight the strong cooperative effect between CuS and MXene and position the CuS/MXene hybrid as a highly capable material for lithium-ion energy storage systems (ESS) with high power in the future.