Water‐Induced Growth of a Highly Oriented Mesoporous Graphitic Carbon Nanospring for Fast Potassium‐Ion Adsorption/Intercalation Storage

• Published in: Angewandte Chemie International Edition 2019-12, Vol.58 (50), p.18108-18115
• Main Authors: Qian, Yong, Jiang, Song, Li, Yang, Yi, Zheng, Zhou, Jie, Tian, Jie, Lin, Ning, Qian, Yitai
• Format: Article
• Language: English
• Subjects: Adsorption; Carbon; Diffusion rate; Epoxy resins; graphitic carbon nanospring; Hydrothermal treatment; Intercalation; Ion adsorption; long-term stability; mesoporous materials; Potassium; potassium-ion batteries; Storage; ultra-high capacity
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201912287

A highly oriented mesoporous graphitic carbon nanospring (OGCS) with graphitic layers that are perpendicular to the axis is prepared by hydrothermal treatment of epoxy resin at 500 °C and annealing at 1400 °C. Water plays an important role in not only forming the graphitic carbon nanospring with a high [002] orientation and a large amount of active edge‐plane sites, but also in the generation of the mesoporous structure, which facilitate fast K‐ion adsorption and diffusion. In situ and ex situ measurements confirm that OGCS undergoes K‐adsorption in mesopores and then K‐intercalation in the graphite layer to form KC8 with a low discharge voltage. The spring‐like nanostructure can expand one‐dimensionally along the axial direction to accommodate the volume variation. The OGCS electrode thus shows a much better K‐storage performance than that of unoriented graphitic carbon. Spring loaded: A spring‐like highly oriented mesoporous graphitic carbon anode (OGCS) undergoes K‐adsorption in mesopores then K‐intercalation in the graphite layer to form KC8 with a low discharge voltage. It provides a large number of active edge‐plane sites and expands one‐dimensionally along the long axis, resulting in ultra‐high capacity and long‐term stability over 10 000 cycles.