Three-dimensional graphitic hierarchical porous carbon-supported SnOx@nitrogen-doped carbon composite as high-performance lithium ion battery anode material

Abstract

Utilizing tin and its oxides (SnOx, x = 0/1/2) as anode confront the main problems like large volume expansion and poor electrical conductivity during cycling. As an efficient solution, a three-dimensional (3D) graphitic hierarchical porous carbon (HPC) with highly fluffy structure was employed as a support for fabrication of HPC/SnOx@nitrogen-doped carbon (NC) composite. The resulting HPC/SnOx@NC composite presented an effective dual‑carbon confinement structure with 3D conductive network and high-quality carbon coatings. The unique structure played significant roles in restricting the expansion of Sn and its oxides as well as enhancing their ion/electron transport efficiency. The as-prepared composite exhibited a maintained reversible specific capacity of 644 mAh g−1 after 200 cycles at 1000 mA g−1. In addition, it presented a high specific capacity of 1458 mAh g−1 at 100 mA g−1 and 858 mAh g−1 at 5000 mA g−1 (58.8 % capacitance retention), and meanwhile showed a remarkable cycling stability with a high capacity retention of 63 % (333 mAh g−1) after 850 cycles at 5000 mA g−1. Therefore, the HPC/SnOx@NC composite has the potential to be a new generation of LIBs anode.