Although Zn metal has been regarded as the most promising anode for aqueous batteries, it persistently suffers from serious side reactions and dendrite growth in mild electrolyte. Spontaneous Zn corrosion and hydrogen evolution damage the shelf life and calendar life of Zn-based batteries, severely affecting their industrial applications. Herein, a robust and homogeneous ZnS interphase is built in situ on the Zn surface by a vapor-solid strategy to enhance Zn reversibility. The thickness of the ZnS film is controlled via the treatment temperature, and the performance of the protected Zn electrode is optimized. The dense ZnS artificial layer obtained at 350 °C not only suppresses Zn corrosion by forming a physical barrier on the Zn surface, but also inhibits dendrite growth via guiding the Zn plating/stripping underneath the artificial layer. Accordingly, a side reaction-free and dendrite-free Zn electrode is developed, the effectiveness of which is also convincing in a MnO2 /ZnS@Zn full-cell with 87.6% capacity retention after 2500 cycles.

An In-Depth Study of Zn Metal Surface Chemistry for Advanced Aqueous Zn-Ion Batteries.

Aqueous zinc-ion batteries are largely restricted by the unsatisfactory performance of zinc (Zn) anodes, including their poor stability and irreversibility. In particular, the mechanism behind the electrochemical contrast caused by the surface crystal plane, which is a decisive factor of the electrochemical characteristics of the hostless Zn anode, is still relatively indistinct. Hence, new insight into a novel anode with a surface-preferred (002) crystal plane is provided. The interfacial reaction and morphology evolution are revealed by theoretical analysis and post-mortem/operando experimental techniques, indicating that Zn anodes with more exposed (002) basal planes exhibit free dendrites, no by-products, and weak hydrogen evolution, in sharp contrast to the (100) plane. These features benefit the Zn (002) anode by enabling a long cyclic life of more than 500 h and a high average coulombic efficiency of 97.71% for symmetric batteries, along with delivering long cycling stability and reversibility with life spans of over 2000 cycles for full batteries. This work provides new insights into the design of high-performance Zn anodes for large-scale energy storage and can potentially be applied to other metal anodes suffering from instability and irreversibility.

Surface-Preferred Crystal Plane for a Stable and Reversible Zinc Anode

The article contains sections titled:



1.	Introduction	
2.	Electron Detection	
2.1.	X-Ray Photoelectron Spectroscopy (XPS)	
2.1.1.	Principles	
2.1.2.	Instrumentation	
2.1.2.1.	Vacuum Requirements	
2.1.2.2.	X-Ray Sources	
2.1.2.3.	Synchrotron Radiation	
2.1.2.4.	Electron Energy Analyzers	
2.1.2.5.	Spatial Resolution	
2.1.3.	Spectral Information and Chemical Shifts	
2.1.4.	Quantification, Depth Profiling, and Imaging	
2.1.4.1.	Quantification	
2.1.4.2.	Depth Profiling	
2.1.4.3.	Imaging	
2.1.5.	The Auger Parameter	
2.1.6.	Applications	
2.1.6.1.	Catalysis	
2.1.6.2.	Polymers	
2.1.6.3.	Corrosion and Passivation	
2.1.6.4.	Adhesion	
2.1.6.5.	Superconductors	
2.1.6.6.	Interfaces	
2.2.	Ultraviolet Photoelectron Spectroscopy (UPS)	
2.3.	Auger Electron Spectroscopy (AES)	
2.3.1.	Principles	
2.3.2.	Instrumentation	
2.3.2.1.	Vacuum Requirements	
2.3.2.2.	Electron Sources	
2.3.2.3.	Electron Energy Analyzers	
2.3.3.	Spectral Information	
2.3.4.	Quantification and Depth Profiling	
2.3.4.1.	Quantification	
2.3.4.2.	Depth Profiling	
2.3.5.	Applications	
2.3.5.1.	Grain Boundary Segregation	
2.3.5.2.	Semiconductor Technology	
2.3.5.3.	Thin Films and Interfaces	
2.3.5.4.	Surface Segregation	
2.4.	Scanning Auger Microscopy (SAM)	
2.5.	Other Electron-Detecting Techniques	
2.5.1.	Auger Electron Appearance Potential Spectroscopy (AEAPS)	
2.5.2.	Electron Energy Loss Methods	
2.5.2.1.	Electron Energy Loss Spectroscopy (EELS) and Core-Electron Energy Loss Spectroscopy (CEELS)	
2.5.2.2.	High-Resolution Electron Energy Loss Spectroscopy (HREELS)	
2.5.3.	Diffraction Methods	
2.5.3.1.	Low-Energy Electron Diffraction (LEED)	
2.5.3.2.	Reflection High-Energy Electron Diffraction (RHEED)	
2.5.4.	Ion-Excitation Method	
2.5.4.1.	Ion (Excited) Auger Electron Spectroscopy (IAES)	
2.5.4.2.	Ion-Neutralization Spectroscopy (INS)	
2.5.4.3.	Metastable Quenching Spectroscopy (MQS)	
2.5.5.	Inelastic Electron Tunneling Spectroscopy (IETS)	
3.	Ion Detection	
3.1.	Secondary Ion Mass Spectrometry	
3.1.1.	Static Secondary Ion Mass Spectrometry (SSIMS)	
3.1.1.1.	Principles	
3.1.1.2.	Instrumentation	
3.1.1.2.1.	Ion Sources	
3.1.1.2.2.	Mass Analyzers	
3.1.1.3.	Quantification	
3.1.1.4.	Spectral Information	
3.1.1.5.	Applications	
3.1.1.5.1.	Oxide Films	
3.1.1.5.2.	Interfaces	
3.1.1.5.3.	Polymers	
3.1.1.5.4.	Biosensors	
3.1.1.5.5.	Surface Reactions	
3.1.1.5.6.	Imaging	
3.1.1.5.7.	Ultrashallow Depth Profiling	
3.1.2.	Dynamic SIMS	
3.1.2.1.	Principles	
3.1.2.2.	Instrumentation	
3.1.2.2.1.	Ion Sources	
3.1.2.2.2.	Mass Analyzers	
3.1.2.2.3.	Detectors	
3.1.2.3.	Spectral Information	
3.1.2.4.	Quantification	
3.1.2.5.	Mass Spectra	
3.1.2.6.	Depth Profiles	
3.1.2.7.	Imaging	
3.1.2.8.	Applications	
3.1.2.8.1.	Implantation Profiles	
3.1.2.8.2.	Layer Analysis	
3.1.2.8.3.	3D Bulk Element Distribution	
3.2.	Secondary Neutral Mass Spectrometry (SNMS)	
3.2.1.	General Principles	
3.2.2.	Electron-Beam and HF-Plasma SNMS	
3.2.2.1.	Principles	
3.2.2.2.	Instrumentation	
3.2.2.3.	Spectral Information	
3.2.2.4.	Quantification	
3.2.2.5.	Element Depth Profiling	
3.2.2.6.	Applications	
3.2.3.	Laser-SNMS	
3.2.3.1.	Principles	
3.2.3.1.1.	Nonresonant Laser-SNMS	
3.2.3.1.2.	Resonant Laser-SNMS	
3.2.3.1.3.	Experimental Setup	
3.2.3.1.4.	Ionization Schemes	
3.2.3.2.	Instrumentation	
3.2.3.3.	Spectral Information	
3.2.3.4.	Quantification	
3.2.3.5.	Applications	
3.2.3.5.1.	Nonresonant Laser-SNMS	
3.2.3.5.2.	Resonant Laser-SNMS	
3.3.	Ion-Scattering Techniques	
3.3.1.	Rutherford Backscattering Spectroscopy (RBS)	
3.3.1.1.	Principles	
3.3.1.2.	Instrumentation	
3.3.1.3.	Spectral Information	
3.3.1.4.	Quantification	
3.3.1.5.	Applications	
3.3.2.	Low-Energy Ion Scattering (LEIS)	
3.3.2.1.	Principles	
3.3.2.2.	Instrumentation	
3.3.2.3.	Information	
3.3.2.4.	Quantification	
3.3.2.5.	Applications	
3.4.	Other Ion-Detecting Techniques	
3.4.1.	Desorption Methods	
3.4.1.1.	Electron-Stimulated Desorption (ESD) and Electron-Stimulated Desorption Ion Angular Distribution (ESDIAD)	
3.4.1.2.	Thermal Desorption Spectroscopy (TDS)	
3.4.2.	Glow Discharge Mass Spectroscopy (GDMS)	
3.4.3.	Fast Atom Bombardment Mass Spectroscopy (FABMS)	
3.4.4.	Atom Probe Microscopy	
3.4.4.1.	Atom Probe Field-Ion Microscopy (APFIM)	
3.4.4.2.	Position-Sensitive Atom Probe (POSAP)	
4.	Photon Detection	
4.1.	Total-Reflection X-ray Fluorescence Analysis (TXRF)	
4.1.1.	Principles	
4.1.2.	Instrumentation	
4.1.3.	Spectral Information	
4.1.4.	Quantification	
4.1.5.	Applications	
4.1.5.1.	Particulate and Film-Type Surface Contamination	
4.1.5.2.	Semiconductors	
4.1.5.2.1.	Depth Profiling by TXRF and Multilayer Structures	
4.1.5.2.2.	Vapor Phase Decomposition (VPD) and Droplet Collection	
4.2.	Glow Discharge Optical Emission Spectroscopy (GD-OES)	
4.2.1.	Principles	
4.2.2.	Instrumentation	
4.2.3.	Spectral Information	
4.2.4.	Quantification	
4.2.5.	Depth Profiling	
4.2.6.	Applications	
4.3.	Surface-Sensitive IR and Raman Spectroscopy; Ellipsometry	
4.3.1.	Reflection - Absorption IR Spectroscopy (RAIRS)	
4.3.1.1.	Principles	
4.3.1.2.	Instrumentation and Applications	
4.3.2.	Surface Raman Spectroscopy	
4.3.2.1.	Principles	
4.3.2.2.	Surface-Enhanced Raman Scattering (SERS)	
4.3.2.2.1.	Instrumentation	
4.3.2.2.2.	Spectral Information	
4.3.2.2.3.	Applications	
4.3.2.3.	Nonlinear Optical Spectroscopy	
4.3.3.	UV - VIS - IR Ellipsometry (ELL)	
4.3.3.1.	Principles	
4.3.3.2.	Instrumentation	
4.3.3.3.	Applications	
4.4.	Other Photon-Detecting Techniques	
4.4.1.	Appearance-Potential Methods	
4.4.1.1.	Soft X-Ray Appearance-Potential Spectroscopy (SXAPS)	
4.4.1.2.	Disappearance-Potential Spectroscopy (DAPS)	
4.4.2.	Inverse Photoemission Spectroscopy (IPES) and Bremsstrahlung Isochromat Spectroscopy (BIS)	
4.4.3.	Ion-Beam Spectrochemical Analysis (IBSCA)	
5.	Scanning Probe Microscopy	
5.1.	Atomic Force Microscopy (AFM)	
5.1.1.	Principles	
5.1.2.	Instrumentation	
5.1.3.	Applications	
5.2.	Scanning Tunneling Microscopy (STM)	
5.2.1.	Principles	
5.2.2.	Instrumentation	
5.2.3.	Lateral and Spectroscopic Information	
5.2.4.	Applications	
6.	Summary and Comparison of Techniques	
7.	Surface Analytical Equipment Suppliers	
8.	Acknowledgement

http://www.gbv.de/dms/ilmenau/toc/341367753.PDF

Surface and Thin-Film Analysis

The formation, composition, and structure of electrodeposited zinc–nickel alloys were investigated. It has been shown that both anomalous and normal codeposition of zinc and nickel can be realized by changing the bath composition and deposition conditions, with the nickel content in the resultant deposit being varied in a wide range (from 2 to 90 at.%). It has been also shown that the ammonical diphosphate electrolyte allows deposition of Zn–Ni coatings with a homogeneous phase structure (Ni5Zn21 and Ni3Zn22 intermetallides, a solid solution of Zn in Ni, or a solid solution of Ni in Ni5Zn21), whereas the weak acid chloride electrolyte produces two-phase coatings consisting of Ni5Zn21 with the admixture of polycrystalline Zn or Ni. The Zn–Ni coating with a nickel content of 19 at.% consisting of Ni5Zn21 intermetallic phase exhibits the highest corrosion resistance.

Effect of electrodeposition conditions on the composition, microstructure, and corrosion resistance of Zn–Ni alloy coatings

Aqueous electrolytes are the leading candidate to meet the surging demand for safe and low-cost storage batteries. Aqueous electrolytes facilitate more sustainable battery technologies due to the attributes of being nonflammable, environmentally benign, and cost effective. Yet, water's narrow electrochemical stability window remains the primary bottleneck for the development of high-energy aqueous batteries with long cycle life and infallible safety. Water's electrolysis leads to either hydrogen evolution reaction (HER) or oxygen evolution reaction (OER), which causes a series of dire consequences, including poor Coulombic efficiency, short device longevity, and safety issues. These are often showstoppers of a new aqueous battery technology besides the low energy density. Prolific progress has been made in the understanding of HER and OER from both catalysis and battery fields. Unfortunately, a systematic review on these advances from a battery chemistry standpoint is lacking. This review provides in-depth discussions on the mechanisms of water electrolysis on electrodes, where we summarize the critical influencing factors applicable for a broad spectrum of aqueous battery systems. Recent progress and existing challenges on suppressing water electrolysis are discussed, and our perspectives on the future development of this field are provided.

R Ramanauskas

Papers

Structural factor in Zn alloy electrodeposit corrosion