High rate-performance supercapacitor based on nitrogen-doped hollow hexagonal carbon nanoprism arrays with ultrathin wall thickness in situ fabricated on carbon cloth

Abstract

Free-standing carbon materials are promising supercapacitor electrode materials due to their outstanding properties, such as simple assemble process, high rate performance and good stability etc. We present here the fabrication of novel nitrogen-doped hollow hexagonal carbon nanoprism arrays on carbon fiber cloth for supercapacitor via chemical vapor deposition with ZnO as the sacrifice template. The hexagonal nanoprism structure of ZnO template can be well duplicated by ultrathin nitrogen-doped carbon layer through an in situ carbon deposition process. In this method, the template-removing step is not necessary attributed to the carbothermal reduction reaction between ZnO and carbon during the chemical vapor deposition process. The carbon fibers serve as highways for rapid electron transfer. Meanwhile, the in situ growth of nanoprism arrays on carbon fiber results in intact interface and low interface resistance. The open channel structure of the carbon arrays can shorten the ions diffusion path and facilitate the fast electrolyte transport. All these structural advantages contribute to the excellent rate performance of the fabricated carbon composite with scan rate and current density reaching up to 20 V s−1 and 300 mA cm−2, respectively. The present work paves a new way for designing high-rate and highly stable carbon electrode materials for supercapacitors.