Enhancing Anode-Free Lithium Metal Batteries: A Lightweight MPTS-MXene Current Collector for Superior Performance and Energy Density

Anode-free lithium metal batteries (AFLMBs) offer unparalleled energy density by eliminating excess lithium, making them a transformative candidate for next-generation energy storage. However, their commercialization faces significant challenges, including uncontrolled lithium dendrite growth, interfacial instability, and the limitations of conventional copper current collectors, which suffer from excessive weight and poor lithiophilicity. This study presents a breakthrough mercaptopropyl trimethoxysilane (MPTS)-functionalized MXene current collector that enables stable, high-efficiency AFLMB operation without pre-lithiation requirements. Through our study, we demonstrate that the Si–O structure-rich surface of MPTS-MXene facilitates a homogenous Li-ion flux, while its mechanically robust lamellar architecture promotes dendrite-free, compact lithium deposition. Moreover, the engineered interface fosters the formation of LiF-rich solid-electrolyte interphase (SEI), drastically reducing parasitic reactions and achieving an exceptional Coulombic efficiency of 99.15% at 2 mAh cm⁻². When integrated into MPTS-MXene||LiFePO₄ full cell, the system demonstrates outstanding cycling stability (99.60% efficiency) and retains 57.79% capacity over 100 cycles. A critical advantage of the MPTS-MXene collector is its ultralight weight, only 15% of that of the copper per unit volume. By correlating MXene nanoengineering with electrochemical performance, this work provides a material-by-design blueprint to replace copper current collectors, paving the way for practical anode-free batteries with enhanced energy density and longevity.