Ti3C2Tx MXene nanobelts with alkali ion intercalation: Dual-purpose for enhanced lithium-ion batteries and microwave absorption

Abstract

MXene, a two-dimensional (2D) material known for tunable surface chemistry and distinctive chemical composition has garnered much interest in diverse potentials, such as energy storage, electrocatalysis, and microwave absorption. Unfortunately, MXene nanosheets encounter substantial challenges arising from the aggregation and restacking primarily driven by van der Waals forces, significantly impeding ion transport to the active materials and cycling instability of the anode. Incorporating alkali cationic intercalation into the 2D MXene nanosheets to enhance the interlayer spacing effectively boosts lithium-ion storage performance. Herein, we synthesized Ti₃C₂T_x MXene nanobelts by employing alkali intercalation, which involved the sustained shaking of pristine Ti₃C₂T_x MXene in KOH solution, ultimately integrating in situ formed three-dimensional (3D) interrelated porous networks for boosted ion storage and structure stability. Consequently, the Ti₃C₂T_x MXene nanobelts demonstrate impressive lithium storage characteristics, with a cyclability that maintains a capacity of 350.4 mA h g⁻¹ beyond 500 cycles. Furthermore, benefitting from the structural and compositional advantages of the expanded interlayer spacing, Ti₃C₂T_x MXene nanobelts achieve a minimum reflection loss (RL) of −38.14 dB at a thickness of 2.0 mm. This development holds considerable promise for the advancement of lithium-ion batteries and microwave absorbers.