In situ construction of Sn-based metal–organic frameworks on MXene achieving fast electron transfer for rapid lithium storage

Abstract

Due to the poor electron transfer characteristics of metal–organic frameworks (MOFs), they always exhibit subpar kinetic performance in Li-ion storage. To address this issue, herein we innovatively devised an in-situ growth technique to enable the construction of Sn-based MOFs on MXene (MXene@Sn-MOF), thereby enhancing its electron transfer capabilities. According to this optimization, the resulting MXene@Sn-MOF composite exhibits excellent Li-ion storage performance, with a remarkable reversible storage capacity of 1009 mAh/g at 0.1 A/g after 100 cycles. It is worth noting that even at a high current density of 2 A/g, the MXene@Sn-MOF composite still maintains a reversible specific capacity of 540 mAh/g after 500 cycles, demonstrating exceptional rate performance and cycling stability. Continuous electrochemical impedance spectroscopy and galvanostatic intermittent titration technique measurements reveal a significant reduction in electron transfer impedance at various states of charge with the introduction of MXene, accompanied by enhanced ion diffusion capabilities, further confirming the beneficial role of MXene in augmenting the Li-ion storage capacity of Sn-based MOFs. We believe that our work provides a promising avenue for the design of anodes with enhanced fast electron transfer ability for Li-ion storage.