Construction of MoS/Mxene heterostructure on stress-modulated kapok fiber for high-rate sodium-ion batteries.

Molybdenum disulfide (MoS) has possession of a layered structure and high theoretical capacity, which is a candidate anode material for sodium ion batteries. However, unmodified MoS are inflicted with a poor cycling stability and an inferior rate capability upon charge/discharge processes. Considering that the shape and size of anode materials play a key role in the performance of anode materials, this paper proposes a multi-level composite structure formed by the micro-nano materials based on self-assembled molybdenum disulfide (MoS) nanoflowers, Mxene and hollow carbonized kapok fiber (CKF). The micro-nano materials can be connected to form heterojunction and agglomeration can be avoided. The load bearing of heterostructure and stress release of CKF are coordinated to form a double protection mechanism, which improves the conductivity and structural stability of hybrid materials. Based on the above advantages, it has higher specific capacity than pure MoS, and has better rate performance (639.3, 409.5, 386.2, 372, 338, 422.8 and 434.7 mAh g at the current density of 0.05, 0.1, 0.2, 0.5, 1 ,0.1 and 0.05 A·g, respectively). The stress-modulated strategies can provide new insights for the design and construction of transition metal sulfides heterostructures to achieve high performance sodium ion batteries.