Electrospun SnSe/C nanofibers as binder-free anode for lithium–ion and sodium-ion batteries

The design of electrodes with superior mechanical flexibility is the key to developing energy storage devices with mechanical durability and excellent electrochemical performance. Herein, a flexible SnSe/C nanofiber membrane is successfully synthesized by electrospinning technology and subsequent calcination. From the macroscopic view, the SnSe/C nanofiber membrane can tolerate a bending angle of 180° without any breakage, indicating its superior mechanical flexibility. From the microscopic view, SnSe nanoparticles are uniformly distributed along the carbon nanofiber framework. The carbon nanofiber framework serves not only as a conductive matrix that improves the electrical conductivity of the composite, but also as a buffer material that alleviates the volume expansion during electrochemical reaction. These merits endow excellent electrochemical performance to SnSe/C nanofibers when used as a binder-free and current collector-free anode for lithium/sodium ion batteries. The SnSe/C nanofiber anode delivers a stable discharge capacity of 405 mAh g⁻¹ at 1000 mA g⁻¹ after 500 cycles in lithium ion battery and 290 mAh g⁻¹ at 200 mA g⁻¹ after 200 cycles in sodium ion battery. These results demonstrate that the SnSe/C nanofiber is a promising anode material for flexible lithium-ion and sodium-ion batteries.