Enhancing lithium-ion battery anode performance via heterogeneous nucleation of silver within Ti3C2-MXene frameworks

Abstract

Silver (Ag) nanoparticles are strategically integrated with 2D MXene material to engineer a high-capacity anode material suitable for lithium-ion batteries (LIBs). MXenes, renowned for their exceptional structural, mechanical, and chemical attributes, have emerged as promising candidates for advanced LIB electrode materials. However, the inherently narrow interlayer spacing within MXene poses challenges for efficient loading or modification with metal oxide nanoparticles, necessitating intricate and time-consuming processes. In this study, exfoliated MXene layers are subjected to an in-situ decoration process with Ag nanoparticles to augment interlayer spacing and enhance MXene conductivity. This augmentation is achieved through a direct reduction approach followed by a meticulously controlled two-step heat treatment process. Characterization analyses of the synthesized Ag-MXene nanoparticles unveil a uniform and homogeneous dispersion of nanoparticles, each measuring <50 nm. X-ray diffraction (XRD) confirms successful MXene formation from the MAX phase, accompanied by pure Ag nanoparticles affixed onto Ti3C2 layers, as evidenced by sharp peaks indicative of crystalline structure. Fourier-transform infrared spectroscopy (FTIR) further confirms the low amount of terminal functional groups (-OH and -F) on the MXene layers. Thermal gravimetric analysis (TGA) highlights an enhancement in the thermal stability of Ti3C2 upon Ag incorporation. Electrochemical performance evaluations demonstrate the exceptional cyclic stability of the Ag-Ti3C2 nanocomposite, showcasing a highly reversible potential of approximately 544 mAhg−1 after 100 cycles at a current rate of 0.1 C. Moreover, the rate capability is substantially improved, reaching up to 193 mAhg−1 at 10 C, a significant enhancement compared to the mere 20 mAhg−1 exhibited by pristine Ti3C2. Notably, the performance of Ag-Ti3C2 as an anode material surpasses that of pristine Ti3C2 across all evaluated metrics, attributed to the enhanced electrochemical kinetics facilitated by Ag's high electronic conductivity. These superior properties, stemming from the tailored material's unique morphology, effectively mitigate MXene layer restacking, rendering it highly advantageous for next-generation LIBs.