Creating Nitrogen-Doped Hollow Multiyolk@Shell Carbon as High Performance Electrodes for Flow-Through Deionization Capacitors

Abstract

A novel electrode material for flow-through deionization capacitors consisting of the hollow multiyolk@shell carbon (HMYSC) with effective nitrogen doping has been rationally designed and originally prepared by a template-directed coating method. The HMYSC can be divided into several hollow carbon spheres cores and the nitrogen-doped shell. The as-obtained HMYSC shows many favorable features for flow-through deionization capacitors, such as large specific surface area (910 m2 g–1), hierarchical pores, high conductivity and good wettability. With the multiple synergistic effects of the above features, the as-prepared HMYSC electrode has higher specific capacitance, lower inner resistance and good stability. In the deionization test, the HMYSC electrode exhibits a high salt adsorption capacity of 16.1 mg g–1 under the applied voltages of 1.4 V in a 500 mg L–1 NaCl solution. Furthermore, it has been demonstrated that the HMYSC electrodes presented faster salt adsorption rate under the applied voltages of 0.8...