Ultrastable and ultrafast 3D charge-discharge network of robust chemically coupled 1 T-MoS2/Ti3C2 MXene heterostructure for aqueous Zn-ion batteries

Aqueous zinc-ion batteries (AZIBs) are a green, low-cost and high-safety energy storage technology. Although MoS2 is a promising electrode material, low conductivity and poor stability still limit their application in AZIBs. Constructing conductive heterostructures is an effective strategy to overcome these problems. Herein, metallic 1 T-MoS2 nanosheets are innovatively combined with conductive Ti3C2 MXene, resulting in enlarged 1 T-MoS2 interlayers (from 9.5 to 9.9 angstrom) and enhanced hydrophilicity. This novel 1 T-MoS2/Ti3C2 MXene heterostructure exhibits exceptional high-rate capability (284.3 mAh/g at 0.10 A/g with 105.2 mAh/g at 10.00 A/g) and long-term cycling stability (93.2 % capacity retention after 3000 cycles). High capacity comes from the expanded ion storage space caused by the extended layer spacing of the metallic 1 T-MoS2. Outstanding rate capability thanks to ultrafast electrons and ions transport from Ti3C2 MXene. Prominent long-term cycling stability is attributed to the efficient synergistic effect of 1 T-MoS2 and Ti3C2 MXene in the 3D interconnected networks. As a proof of concept, the wearable quasi-solid-state Zn-ion battery employing the 1 T-MoS2/Ti3C2 MXene cathode exhibits stable electrochemical performance under different bending conditions. This work explores a new route to design high-performance layered cathode materials for AZIBs.