The improvement of rechargeable zinc/air batteries was a hot topic in recent years. Predominantly, the influence of water and additives on the structure of the Zn deposit and the possible dendrite formation were studied. However, the effect of the surface structure of the underlying substrate was not focused on in detail, yet. We now show the differences in electrochemical deposition of Zn onto Au(111) and Au(100) from the ionic liquid N‐methyl‐N‐propylpiperidinium bis(trifluoromethanesulfonyl)imide. The fundamental processes were initially characterized via cyclic voltammetry and in situ scanning tunnelling microscopy. Bulk deposits were then examined using Auger electron spectroscopy and scanning electron microscopy. Different structures of Zn deposits are observed during the initial stages of electrocrystallisation on both electrodes, which reveals the strong influence of the crystallographic orientation on the metal deposition of zinc on gold.

While numerous reference electrodes suitable for aqueous electrolytes exist, there is no well-defined standardfor non-aqueous electrolytes.F urthermore,r eference electrodes are often large and do not meet the sizerequirements for small cells.Inthis work, we present asimple method for fabricating stable 3D-printed micro-reference electrodes.T he prints are made from polyvinylidene fluoride,w hich is chemically inert in strong acids,b ases,a nd commonly used non-aqueous solvents.W ec hose six different reference systems based on Ag, Cu, Zn, and Na, including three aqueous and three nonaqueous systems to demonstrate the versatility of the approach. Subsequently,w ec onducted cyclic voltammetry experiments and measured the potential difference between the aqueous homemade reference electrodes and ac ommercial Ag/AgClelectrode.F or the non-aqueous reference electrodes,w ec hose the ferrocene redox couple as an internal standard. Fromthese measurements,w ed educed that this new class of microreference electrodes is leak-tight and shows as table electrode potential.

While numerous reference electrodes suitable for aqueous electrolytes exist, there is no well-defined standardfor non-aqueous electrolytes.F urthermore,r eference electrodes are often large and do not meet the sizerequirements for small cells.Inthis work, we present asimple method for fabricating stable 3D-printed micro-reference electrodes.T he prints are made from polyvinylidene fluoride,w hich is chemically inert in strong acids,b ases,a nd commonly used non-aqueous solvents.W ec hose six different reference systems based on Ag, Cu, Zn, and Na, including three aqueous and three nonaqueous systems to demonstrate the versatility of the approach. Subsequently,w ec onducted cyclic voltammetry experiments and measured the potential difference between the aqueous homemade reference electrodes and ac ommercial Ag/AgClelectrode.F or the non-aqueous reference electrodes,w ec hose the ferrocene redox couple as an internal standard. Fromthese measurements,w ed educed that this new class of microreference electrodes is leak-tight and shows as table electrode potential.

The Front Cover shows a scanning tunnelling microscopy (STM) tip that is scanning the Au(111) single crystal surface in‐situ during sodium deposition from an ionic liquid. More information can be found in the Research Article by M.‐K. Heubach et al.

Sodium‐ion batteries are promising candidates for post‐lithium‐ion batteries. While sodium has a less negative standard electrode potential compared to lithium, it is still a strong reducing agent. Ionic liquids are suitable solvents for sodium metal batteries, since metallic sodium is very reactive, particularly with water and molecules containing acidic hydrogen atoms. In this study, the initial stages of electrodeposition of sodium on Au(111) from N‐methyl‐N‐propylpiperidinium [MPPip] bis(trifluoromethanesulfonyl)imide [TFSI] were studied using voltammetry and in‐situ scanning tunnelling microscopy. Four subsequent underpotential deposition stages were observed: (i) nucleation at the Au(111) reconstruction elbows, followed by (ii) growth of small monoatomically high islands that form (iii) a smooth layer via coalescence, and (iv) further island growth on top of the existing layers. The electrocrystallisation mode changed from smooth layer formation to 3D growth, resulting in cauliflower‐like structures. The deposition process was accompanied by simultaneous alloy formation.