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 degrees 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(-3) 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 lithiumion and sodium-ion batteries.