Surface Engineering for Ultrathin Metal Anodes Enabling High-Performance Zn-Ion Batteries

Abstract

Zn-ion batteries with low cost and high safety have been regarded as a promising energy storage technology for grid storage. It is well-known that the metal anode surface orientation is vital to its reversibility. Herein, we demonstrate a facile route to control the Zn metal anode surface orientation through electrodeposition with electrolyte additives. An ultrathin (101)-inclined Zn metal anode (down to 2 μm) is obtained by adding a small amount of dimethyl sulfoxide (DMSO) in the ZnSO 4 aqueous electrolyte. Scanning electron microscopy indicates the formation of flat terrace-like surfaces, while in situ optical observations demonstrate the reversible plating and stripping. DFT calculations reveal that the large reconstruction of the Zn-( 101) surface with DMSO and H 2 O adsorption to lower the interface energy is the main driving force for surface preference. Raman, XPS, and ToF-SIMS characterizations are performed to unveil the surface SEI components. Exceptional electrochemical performance is demonstrated for the (101)-inclined Zn metal anode in a half cell, which could cycle for 200 h with a low overpotential (<50 mV). The Zn||V 2 O full cells are assembled, showing much better cycle performance for the 5 μm (101)-inclined Zn metal anode as compared to the commercialized 10 μm Zn metal foil, with a maximum specific capacity of 359 mAh/g and >170 mAh/g after over 300 cycles. We hope this study will spur further interest in the control of surface crystallographic orientation for a stable ultrathin Zn metal anode.

Bimetallic Nitride TiVN Hollow Nanotubes for High-Performance Zinc-Ion Hybrid Supercapacitors

“…The TiVN-200@ZnO/ CP and VN@ZnO/CP electrodes exhibit typical redox peaks that are associated with the oxidation/reduction of V species. 37 The TiVN-200@ZnO/CP electrode delivers a higher current response than the TiN@ZnO/CP electrode without compromising the voltage window. The Nyquist plot reveals that TiVN-200@ZnO/CP exhibits better conductivity, faster charge transfer, and diffusion rates, as evidenced by the smaller intercept, radius of curvature, and larger straight slope (Figure 2e).…”

“…Indeed, as the current density increases from 0.2 to 6.4 A g −1 , the former displays a capacitance retention of 54.4% (from 183.7 to 99.9 F g −1 ), compared to 34.8% (from 79.5 to 27.7 F g −1 ) of the latter. Meanwhile, the contributions of capacitive- controlled and diffusion-controlled performance can be further quantified according to the following equations 37 :…”