LAUSR

SnSe2 is regarded as an auspicious anode material for sodium-ion batteries owing to its high theoretical capacity and large interlayer spacing. The moderate conductivity, inevitable aggregation, and tremendous volumetric expansion (more than 300%) of SnSe2 still plague the use of it for the large scale. Thus, a sheet to layer structure of SnSe2/Ti3C2Tx (MXene) composite materials have been synthesized in this work by the electrostatic assembling procedure. The SnSe2/Ti3C2Tx composite electrode delivered superior sodium storage performance in a high specific capacity of 245 mA h g-1 at 1 A g-1 (5.4 times than SnSe2 and 4.1 times than Ti3C2Tx) with a capacity attenuation rate of only ∼0.06% per cycle after 445 cycles. This electrode material not only combined the advantages (high theoretical capacity SnSe2 and high conductivity of Ti3C2Tx) of these two components but also show a synergistic effect, can achieve, including 1) inserted SnSe2 nanosheets can inhibit the self-stacking problem of Ti3C2Tx and Ti3C2Tx can prevent the aggregation of SnSe2 nanosheets and alleviate the volume expansion of SnSe2 nanosheets during cycling; 2) the increased surface area with the mesoporous structure is favorable for sodium ion kinetics and simultaneously conducive to electrolyte penetration and rapid ion diffusion during cycling.