High Mass Loading 3D-Printed Sodium-Ion Hybrid Capacitors

摘要

Sodium-ion hybrid capacitors (SIHCs) have been regarded as one of the promisingenergy devices thanks to its low cost and compromise between energydensity and power density, yet remain a challenge towards practical levels ofmass loading (>10 mg cm~(?2)). Herein, the fabrication of a 1D core–shell structureis reported with N-doped porous carbon encapsulating ZnV_2O_4 nanofibers(ZnV_2O_4NFs@N-PC), which features an open framework and favorable propertiesfor facilitating ion diffusion, mass transportation, and electron transfer,enabling it to perform impressively for sodium ions storage. A 3D printedSIHC is conceptually proposed by coupling the 3D printed ZnV_2O_4NFs@N-PCanode with a 3D printed active carbon cathode, which can deliver a highenergy/power density of 145.07 Wh kg~(?1)/3677.1 W kg~(?1) with a durable cyclinglifespan. It is demonstrated that the 3D printed SIHC, even at a high massloading of up to 16.25 mg cm~(?2), can release a high areal energy/power densityof 1.67 mWh cm~(?2)/38.96 mW cm~(?2), outperforming most of the SIHCs developedso far. The present work sheds light on the role of the design of electrodematerials and verifies the promise of 3D-printed technology for next-generationelectrochemical energy devices.