Finely Crafted 3D Electrodes for Dendrite‐Free and High‐Performance Flexible Fiber‐Shaped Zn–Co Batteries

Abstract

Rechargeable aqueous Zn-based batteries, benefiting from their good reliability, low cost, high energy/power densities, and ecofriendliness, show great potential in energy storage systems. However, the poor cycling performance due to the formation of Zn dendrites greatly hinders their practical applications. In this work, a trilayer 3D CC-ZnO@C-Zn anode is obtained by in situ growing ZIFs (zeolitic-imidazolate frameworks) derived ZnO@C coreshell nanorods on carbon cloth followed by Zn deposition, which exhibits excellent antidendrite performance. Using CC-ZnO@C-Zn as the anode and a branch-like Co(CO 3 ) 0.5 (OH) x ·0.11H 2 O@CoMoO 4 (CC-CCH@CMO) as the cathode, a Zn-Co battery is rationally designed, displaying excellent energy/power densities (235 Wh kg −1 , 12.6 kW kg −1 ) and remarkable cycling performance (71.1% after 5000 cycles). Impressively, when using a gel electrolyte, a highly customizable, fiber-shaped flexible all-solid-state Zn-Co battery is assembled for the first time, which presents a high energy density of 4.6 mWh cm −3 , peak power density of 0.42 W cm −3 , and long durability (82% capacity retention after 1600 cycles) as well as excellent flexibility. The unique 3D electrode design in this study provides a novel approach to achieve high-performance Zn-based batteries, showing promising applications in flexible and portable energy-storage systems.

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“…d) Ad igitalw atch, as martphone, and light-emitting diodes( LEDs) poweredb y three in-seriesf lexible fiber-shaped ZnÀCo batteries. [52] ther practical applications in portable and wearable energy storage.…”

“…The advantageous 1D feature means that NWs are particularly suitable for constructing flexible freestanding electrodes. [52] ther practical applications in portable and wearable energy storage. With the era of flexible electronics havinga rrived and continuously booming, the demands for lightweight and low-cost flexible energy-storage devices, which have good mechanical stabilities under varied deformations, while maintaining high electrochemicalp erformances, will be continuouslyd esired.…”

“…67 Fcm À3 (573.75 mF cm À2 )a nd an exceptionale nergy density of 33.66 mW hcm À3 (204.02 mWhcm À2 ). [52] The ZnO@C nanorod arrays acted as ar obusts caffold to allow uniform deposition of Zn, and therefore, effectively suppressed dendrite formation during charge-discharge processes. [52] The ZnO@C nanorod arrays acted as ar obusts caffold to allow uniform deposition of Zn, and therefore, effectively suppressed dendrite formation during charge-discharge processes.…”

“…It is noteworthy that the inorganic NW arrays on carbon fibers have also provided a good scaffold for further growth of other materials;t hus allowing the fabrication of hierarchical heterogeneous structures for diversep urposes.F or example, the group of Mai designed an anti-dendrite Zn anode,i nw hich Zn was deposited on carbon-coatedZ nO nanorod arrays grown on aC C ( Figure 8). [52] The ZnO@C nanorod arrays acted as ar obusts caffold to allow uniform deposition of Zn, and therefore, effectively suppressed dendrite formation during charge-discharge processes. Upon assembly into as olid-state fiber-shaped ZnÀCo battery,w ith KOH/PVAa st he gel electrolyte, the battery exhibited superior electrochemical properties under varied bending conditions and delivered ah igh capacity of 3mAhcm À3 with stable cycling (82 %a fter 1600 cycles).…”

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“…e) Electrochemical performance of the fiber-sharped Zn-Co battery. f) A LED and smartphone are powered by three batteries in series.Reproduced with permission [101]. Copyright 2018, WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.…”