Quenching-induced interfacial amorphous layer containing atomic Ag on Fe2O3 nanosphere for high-performance lithium-ion batteries and mechanism.

The interfacial effect of nanomaterials plays a key role in their electrochemical performance when used in lithium-ion batteries (LIBs), but interfacial modification is a big challenging. Herein, a composite Fe2O3 nanoparticles with atomic Ag/amorphous layers were successfully prepared by co-deposition and subsequent quenching method. Compared to pristine Fe2O3, it maintains a higher capacity and longer cycle life in LIBs, with a capacity of 1150 mAh g-1 after 600 cycles at 0.5 Ag-1, and a long 1800 cycles at a current density of 5 Ag-1 after activation. Detailed experiments and Ex-situ TEM demonstrate that the fusion of surface particles occurred after calcination and quenching treatment, resulting in amorphous layers. The amorphous layer can act as a stabilizer during cycling, which protects the overall nanospheres structure from collapsing and thus leads to ultra-long cycling life. Our findings shed light on the surface modification of nanoscale materials and provides a manner to enhance the electrochemical performance of nanomaterials for LIBs.