SnSe2/SnO2 heterostructures confined in graphene nano-ribbons for superior lithium storage performance

Tin-based materials have been widely concerned as a competitor among various anode materials for lithium-ion battery (LIBs), due to their high theoretical capacities and relatively low lithiation potential. However, intrinsic drawbacks of poor electrical conductivity and severe volume expansion have hindered practical application of tin-based anode materials. Herein, we design and construct a novel multiphase-structure of SnSe 2 -SnO 2 confined in graphene nanoribbons (SnSe 2 -SnO 2 @GNRs) as anode materials for LIBs. The composite can deliver a specific discharge capacity of 998.0 mA h g −1 at a rate of 0.1 A g −1 . When the current density is increased to 5.0 A g −1 , the specific capacity is still maintained to be 416.0 mA h g −1 . The excellent electrochemical performance can be ascribed to the flexible and interlaced GNRs network in nanocomposite, which can not only improve the electrical conductivity of SnSe 2 -SnO 2 and alleviate its drastic volume change upon lithiation and delithiation, but also bring in abundant surface defects, which is conducive to electrochemical pseudo-capacitance energy storage. Meanwhile, the SnSe 2 -SnO 2 heterostructures can further enhance the electrochemical reaction kinetics of the anode materials and promote the anchoring of Li atoms at the interface. This opens a new pathway to synthesize Tin-based nano-structure as superior anode materials for high-performance LIBs.