Synergistic Anode/Cathode Optimization Engineering by Hierarchical Porous N‐Doped Carbon Fibers for Efficient Zinc Batteries

ABSTRACT The poor Zn chemistry of Zn metal anode and sluggish reaction kinetics of cathodes at high mass loadings are two crucial issues for hindering the application of aqueous Zn‐ion batteries (AZIBs). Herein, the hierarchical porous N‐doped carbon fibers (HPNCFs) were proposed to simultaneously optimize the reversibility of Zn plating/stripping of Zn anode and accelerate the reaction kinetics of cathodes at high mass loadings for building efficient AZIBs. Specifically, the HPNCFs serve as an interfacial layer at the anode side to uniformly distribute the electric field and Zn 2+ flux, thereby realizing a highly reversible Zn anode, and as a superior support with rapid electron/ion transport at the cathode side for high mass loadings. As a result, this synergistic anode/cathode optimization strategy significantly enhances AZIBs performance with the extended lifespan of Zn@HPNCFs symmetrical cell of 3372 h at 1 mA cm −2 /1 mAh cm −2 (31.81 times higher than Zn//Zn cell), higher capacity of Zn@HPNCFs//MnO 2 @HPNCFs full cell with 355.62 mAh g −1 at 0.5 A g −1 (1.52 times higher than Zn//MnO 2 cell), and remarkable cycling stability over 2000 cycles with 91.59% initial capacity retained at 5 A g −1 , which paves a new route for high performance AZIBs and beyond.