Mesoporous C-covered Sn/SnO2-Ni nanoalloy particles as anode materials for high-performance lithium/sodium-ion batteries

Abstract

Nanoscale Sn-based alloy materials are high-performance anode materials for both lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs), however, the insertion and extraction of Li+/Na+ during the charging and discharging process can lead to dramatic expansion of the electrode volume as well as collapse and crushing of the structure. Therefore, we successfully synthesized a new mesoporous Sn/SnO2-Ni@C composite anode material. Mesoporous Sn/SnO2-Ni@C has excellent electrochemical properties and can reach large reversible capacities after 200 cycles at 0.2 A g−1 (LIBs: 1020.7 mAh g−1, SIBs: 342.6 mAh g−1) as well as remarkable stability after 1000 cycles at 1.0 A g−1 (LIBs: 864.6 mAh g−1, SIBs: 219.3 mAh g−1). In addition, mesoporous Sn/SnO2-Ni@C also has outstanding rate performance (LIBs: 564.6 mAh g−1 at 5.0 A g−1, SIBs: 212.5 mAh g−1 at 1.0 A g−1). In particular, the unique mesoporous structure not only provides additional transport channels for Li+/Na+ and electrons, but also enables the electrode material to be fully immersed in the electrolyte. Meanwhile, the synergistic effect between Sn/SnO2-Ni alloy can prevent shuttle effect and alleviate volume expansion, the presence of Ni can prevent the coarsening of Sn. Thus, mesoporous Sn/SnO2-Ni@C has fast kinetics and is a promising anode material for LIBs/SIBs.