American Chemical Society
nl9b01127_si_001.pdf (2.88 MB)

Three-Dimensional Ordered Macroporous Metal–Organic Framework Single Crystal-Derived Nitrogen-Doped Hierarchical Porous Carbon for High-Performance Potassium-Ion Batteries

Download (2.88 MB)
journal contribution
posted on 2019-07-18, 12:10 authored by Xuefeng Zhou, Lanlan Chen, Wenhua Zhang, Jiawei Wang, Zhenjie Liu, Sifan Zeng, Rui Xu, Ying Wu, Shufen Ye, Yuezhan Feng, Xiaolong Cheng, Zhangquan Peng, Xifei Li, Yan Yu
The biggest challenge of potassium-ion batteries (KIBs) application is to develop high-performance electrode materials to accommodate the potassium ions large size. Herein, by rational design, we carbonize three-dimensional (3D) ordered macroporous ZIF-8 to fabricate 3D interconnected nitrogen-doped hierarchical porous carbon (N-HPC) that shows excellent rate performance (94 mAh g–1 at 10.0 A g–1), unprecedented cycle stability (157 mA g–1 after 12000 cycles at 2.0 A g–1), and superior reversible capacity (292 mAh g–1 at 0.1 A g–1). The 3D hierarchical porous structure diminishes the diffusion distance for both ions/electrons, while N-doping improves the reactivity and electronic conductivity via producing more defects. In addition, the bicontinuous structure possesses a large specific surface area, decreasing the current density, again improving the rate performance. In situ Raman spectra analysis confirms the potassiation and depotassiation in the N-HPC are highly reversible processes. The galvanostatic intermittent titration measurement and first-principles calculations reveal that the interconnected macropores are more beneficial to the diffusion of the K+. This 3D interpenetrating structure demonstrates a superiority for energy storage applications.