Sn nanoparticles anchored on three-dimensional N-doped graphene for fast and durable Na-ion storage

Tin (Sn) has been recognized as a viable anode material for sodium-ion batteries due to its non-toxic nature, affordability, and high specific capacity. Nonetheless, Sn experiences substantial volume changes during charge–discharge processes, which results in accelerated capacity degradation. Herein, a novel solvothermal method is developed to synthesize a composite of tin nanoparticles covalently bonded to nitrogen-doped three-dimensional graphene (Sn/3DNG) through stable C-Sn bonds. The design of the Sn/3DNG composite effectively mitigates the volume changes of tin during sodium insertion/extraction process by using the robust framework of 3DNG to confine and support Sn nanoparticles. The presence of C-Sn bonds prevents the tin nanoparticles from clumping together, thereby enhancing the electrode's durability. Owing to these improvements, the Sn/3DNG anode exhibits a cyclic retention of 87.7 % after 800 cycles and maintains a substantial specific capacity of 350 mAh g^-1 at 5 A g^-1. This advancement underscores the potential of Sn-based nanocomposites in advancing the next generation of rechargeable batteries.