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SnO 2 is a theoretically excellent transformed anode material with high theoretical capacity for SIBs. However, SnO 2 faces serious volume effect and high resistance, which greatly damages its electrochemical performance. Given that, the SnSÀ SnO 2 heterostructures is constructed with special internal electric field, which is beneficial to promote the transfer ability of sodium ions. Besides, the graphene oxide (GO) modification is carried out to isolate the intrinsic materials from direct contact with electrolyte, and alleviate volume expansion of the anode, ultimately promote the electrochemical performance. Furthermore, the structure and the conductivity characteristics of SnS, SnO 2 , SnSÀ SnO 2 and SnSÀ SnO 2 @ GO are simulated respectively by first principles and are compared with the correspondence experiment results to verify the accuracy of established models. Owing to the special p-n junction in SnSÀ SnO 2 @GO heterostructures, the resistance of SnSÀ SnO 2 @GO can be reduced to 36.23 Ω, much lower than that of SnO 2 (Rct = 341.9 Ω). Notably, the combination of GO has effectively alleviated the volume expansion of SnSÀ SnO 2 @GO electrodes, and present excellent capacity higher than 384.7 mAh g À 1 after 100 cycles. Thus, the efficient synthesis of SnSÀ SnO 2 @GO heterostructure electrodes with excellent performance for sodium storage is expected to provide valuable direction for SIBs anode materials.

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