Regulating Dendrite‐Free Zinc Deposition by 3D Zincopilic Nitrogen‐Doped Vertical Graphene for High‐Performance Flexible Zn‐Ion Batteries

Abstract

The rapidly growing demand for wearable and portable electronics has driven the recent revival of flexible Zn‐ion batteries (ZIBs). However, issues of dendrite growth and low the flexibility of Zn metal anode still impede their practical application. Herein, 3D nitrogen‐doped vertical graphene nanosheets in situ grown on carbon cloth (N‐VG@CC) are proposed to enable uniform Zn nucleation, thereby obtaining a dendrite‐free and robust Zn anode. The introduced zincopilic N‐containing groups in N‐VG effectively reduce the Zn nucleation overpotential by enhancing the interaction between Zn2+ ion and carbon substrate, as confirmed by density functional theory calculations, thus achieving uniform distribution of Zn nucleus. Moreover, the 3D nanosheet arrays can homogenize electric distribution, which optimizes the subsequence Zn deposition process and realizes the highly reversible Zn plating/stripping process. Consequently, the as‐prepared Zn@N‐VG@CC anode exhibits an improved overall electrochemical performance compared with Zn@CC. As a proof‐of‐concept application, the high‐performance Zn@N‐VG@CC electrodes are successfully employed as anodes for coin and flexible quasi‐solid‐state ZIBs together with MnO2@N‐VG@CC (deposited MnO2 nanosheets on N‐VG@CC) as cathodes. More importantly, the flexible ZIB exhibits impressive cycling stability with 80% capacity retention after 300 cycles and outstanding mechanical flexibility, indicating a promising potential for portable and wearable electronics.

Confining Sn nanoparticles in interconnected N-doped hollow carbon spheres as hierarchical zincophilic fibers for dendrite-free Zn metal anodes

“…S35D). The electrochemical performance of Sn@NHCF-Zn is comparable to that of many previous studies using different hosts (table S2) ( 15 , 23 – 25 , 27 , 37 – 39 ).…”

Nitrogen‐Doped Carbon Fibers Embedded with Zincophilic Cu Nanoboxes for Stable Zn‐Metal Anodes

“…The cycling performance of Cu NBs@NCFs-Zn is also comparable to most of recently reported composite Zn on different hosts (Table S1, Supporting Information). [22,24,26,28,30,31,34,36,[46][47][48] Furthermore, the voltage hysteresis of the Cu NBs@NCFs-Zn electrode shows a gradual increment with the current density increasing from 0.5 to 5 mA cm −2 (Figure S29, Supporting Information), indicating the low polarization and good stability.…”

“…However, it is hard to regulate the interfacial Zn 2+ ions' distribution and enable uniform Zn deposition by only 3D hosts due to the high energy barriers of Zn nucleation. [30,31] To further prolong the lifespan of ZMAs, zincophilic species (N-doping, [31,32] Cu, [33] Zn, [34,35] TiO 2 , [21,36] Sn, [19] Ag, [37] etc.) with high adsorbing ability for Zn 2+ ions are usually introduced into the 3D conductive hosts to reinforce the interfacial interaction between substrate and Zn 2+ ions.…”

“…For example, Cao et al demonstrated that 3D N-doped graphene sheets could lower the Zn nucleation overpotential and homogenize electric field distribution, ensuring highly reversible Zn plating/ stripping with dendrite-free morphology. [31] In addition to the reduced energy barriers of Zn nucleation, Cu and Ag have been reported to react with Zn to form zincophilic CuZn 5 or AgZn 3 alloy and solid-solution interface, [26,30,37] which can strengthen the affinity with Zn and facilitate the homogeneous growth of Zn. Based on the above considerations, it is highly imperative to develop 3D robust hosts with zincophilic nature for ZMAs to regulate Zn nucleation and deposition, promoting the uniform Zn plating/stripping and long-term cycling stability.…”

Enabling Multi-Chemisorption Sites on Carbon Nanofibers Cathodes by an In-situ Exfoliation Strategy for High-Performance Zn–Ion Hybrid Capacitors

“…The relatively low Δ E b (Fig. 4 f, i) of the NQ site may be derived from its saturated electron orbital [ 57 ], which has a negligible effect on Zn 2+ adsorption [ 58 ]. In summary, the effects of pyridine/pyrrole nitrogen dopants and carbonyl groups on the adsorption of Zn 2+ on the surface of carbon cathodes can be divided into two aspects: First, the pyridine/pyrrole nitrogen atoms adjacent to the carbonyl groups can greatly reduce the binding energy between carbonyl groups and Zn 2+ by inducing charge delocalization of carbonyl groups.…”