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 Ti3C2TX (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.