High N-doped hierarchical porous carbon networks with expanded interlayers for efficient sodium storage
hierarchical porous carbon networks, high N doping, expanded interlayer spacing, anode, sodium-ion batteries
Sodium-ion batteries (SIBs) have been attracting considerable attention as a promising candidate for large-scale energy storage because of the abundance and low-cost of sodium resources. However, lack of appropriate anode materials impedes further applications. Herein, a novel self-template strategy is designed to synthesize uniform flowerlike N-doped hierarchical porous carbon networks (NHPCN) with high content of N (15.31 at.%) assembled by ultrathin nanosheets via a self-synthesized single precursor and subsequent thermal annealing. Relying on the synergetic coordination of benzimidazole and 2-methylimidazole with metal ions to produce a flowerlike network, a self-formed single precursor can be harvested. Due to the structural and compositional advantages, including the high N doping, the expanded interlayer spacing, the ultrathin two-dimensional nano-sized subunits, and the three-dimensional porous network structure, these unique NHPCN flowers deliver ultrahigh reversible capacities of 453.7 mAh·g−1 at 0.1 A·g−1 and 242.5 mAh·g−1 at 1 A·g−1 for 2,500 cycles with exceptional rate capability of 5 A·g−1 with reversible capacities of 201.2 mAh·g−1. The greatly improved sodium storage performance of NHPCN confirms the importance of reasonable engineering and synthesis of hierarchical carbon with unique structures.
Tsinghua University Press
Dongqin Su,Man Huang,Junhao Zhang,Xingmei Guo,Jiale Chen,Yanchun Xue,Aihua Yuan,Qinghong Kong, High N-doped hierarchical porous carbon networks with expanded interlayers for efficient sodium storage. NanoRes.2020, 13(10): 2862–2868