Novel amorphous CoSnO3@rGO nanocomposites highly enhancing sodium storage

Highlights: • Amorphous CoSnO₃@rGO nanocomposites are designed by a facile approach. • All of self-matrices, rGO-wrapping and amorphous texture of CoSnO₃@rGO benefit sodium storage. • The optimized CoSnO₃@rGO displays remarkable cycling stability and rate capability. • Novel Amorphous CoSnO₃@rGO Nanocomposites Highly Enhancing Sodium Storage. -- Abstract: Mixed transition-metal oxides (MTMOs) are regarded as advanced electrode materials for sodium-ion batteries (SIBs). In this study, amorphous CoSnO₃ nanocubes wrapped by reduced graphene oxide (marked as a-CoSnO₃@rGO) are successfully designed via a facile solvothermal method accompanied by a simple calcination process. To examine this design, sodium storage behaviors of a-CoSnO₃@rGO nanocomposites are investigated in detail. Compared with the pristine a-CoSnO₃, a-CoSnO₃@rGO nanocomposite with 25.1 wt% rGO exhibits enhanced electrochemical performance, for instance, it delivers a high specific capacity of 229.9 mAh g⁻¹ after 100 cycles at 50 mA g⁻¹ with a Coulombic efficiency close to 99%, and it is capable of maintaining a specific capacity of 205.7 mAh g⁻¹ even at a high current density of 800 mA g⁻¹. Superior electrochemical performance of a-CoSnO₃@rGO is primarily attributed to intrinsic "self-matrices", rGO-wrapping network, and crystalline texture engineering. Indeed, the unique 3D-rGO-wrapping architecture of a-CoSnO₃@rGO manifests compelling advantages, such as developing a high conductive three-dimensional network, facilitating the ion/electron diffusion, accommodating volume change, and strengthening interaction between rGO and a-CoSnO₃. It is believed that the proposed strategy may provide new insights to design hybrid anode nano-materials for advanced SIBs.