Regulating interfacial ion migration with pillar effect in layer-by-layer inter-embedded MoS2/Ti3C2 for high-performance zinc-ion batteries

Ti3C2 MXene acts as a “pillar” embedded into the MoS2 interlayer to form a layer-by-layer inter-embedded architecture at the molecular scale, effectively regulating the 2D interfacial ion migration, and thus improving the electrochemical reaction kinetics. [Display omitted] Two-dimensional (2D) layered materials have promising prospects for Zn-storage due to their flexible and adjustable interlayer architecture. The strong electrostatic interaction and high diffusion energy barrier, however, lead to slow diffusion kinetics of Zn-ions between the 2D interfaces, limiting its widespread application. Herein, Ti3C2 MXene is introduced into the MoS2 interlayer by the “pillar effect” to assemble a layer-by-layer inter-embedded structure (L-MoS2/Ti3C2), which provides sufficient diffusion channels for Zn-ions. DFT computations and GITT confirm that the L-MoS2/Ti3C2 exhibits superior Zn-ions migration kinetics. Therefore, L-MoS2/Ti3C2 shows excellent long-term cycling stability (75.6% capacity retention after 7000 cycles at 15 A g-1) and glorious high-rate capability (107 mAh g-1 at 20 A g-1). In addition, the practical application of this material is demonstrated by evaluating the performance of L-MoS2/Ti3C2 in flexible quasi-solid-state aqueous zinc ion batteries under various extreme bending conditions, which exhibits good stability under 180° during the 4000 cycles with a capacity retention of 80.5% at 2.0 A g-1.