Operando Optoelectrochemical Analysis of Single Zinc Dendrites with a Reflective Nanopore Electrode

Abstract

Dendrites can severely impair zinc battery performance. An in-depth understanding of the dynamic morphology evolution of dendrites with operando approaches is pivotal when addressing these issues. However, in previous studies, the corresponding electrochemical signals are usually ensemble and averaged. It is very challenging to obtain detailed information about the key morphology-performance relationship. Herein, correlated high-resolution operando optical and electrochemical studies of single dendrites on Pt reflective nanopore electrodes are reported. The zinc deposi-tion and dissolution can be directly imaged by a high NA optical microscope, while corresponding galvanic charging and discharging curves are obtained. The correlated information of morphology changes and dynamic overpotential fluctuations under different circumstances unveils the competition between active growth vs. passivation. The isolated zinc formation at the single dendrite level is also evaluated. The methodology can be further extended to elucidate the direct relationship between dendrite evolution and electrochemical responses in various battery systems.

The new era of high throughput nanoelectrochemistry

“…325,337,338 At nonplasmonic (transparent) electrodes, TIR illumination allows tracking the growth of nanodendrites with nm spatial resolution. 339,340 It has particularly been used to image the formation of EDL at individual NPs. 328 Interference based techniques.…”

“…354,[391][392][393][394] By differentiating the NP volume fluctuation, one can further calculate an 'optical current' related to the growth of single NPs. 354,392 Optical microscopy has been employed for imaging the electrodeposition of more complex materials such as Ni, 357,392 Co, 393 Li, 395,396 Mg, 397 and Zn 339,340 as metal and/or as metal oxides and hydroxides (Ni, 392 Mn 398 or Zn 398 ). These studies have implications in electrocatalysis and battery processes, as well as for studying the electrocrystallization of metal oxides for energy conversion and storage.…”

The New Era of High-Throughput Nanoelectrochemistry

“…324,336,337 At nonplasmonic (transparent) electrodes, TIR illumination allows tracking the growth of nanodendrites with nanometer spatial resolution. 338,339 It has particularly been used to image the formation of EDL at individual NPs. 327 Interference Based Techniques.…”

“…353,390−393 By differentiating the NP volume fluctuation, one can further calculate an "optical current" related to the growth of single NPs. 353,391 Optical microscopy has been employed for imaging the electrodeposition of more complex materials such as Ni, 356,391 Co, 392 Li, 394,395 Mg, 396 and Zn 338,339 as metal and/or as metal oxides and hydroxides (Ni, 391 Mn, 397 or Zn 397 ). These studies have implications in electrocatalysis and battery processes, as well as for studying the electrocrystallization of metal oxides for energy conversion and storage.…”

“…TIR illumination is also used with label-free microscopies. It enables the observation of any type of nanoobject deposited on or near a thin plasmonic Au electrode in the surface plasmon resonance microscopy (SPRM) configuration. ,, At nonplasmonic (transparent) electrodes, TIR illumination allows tracking the growth of nanodendrites with nanometer spatial resolution. , It has particularly been used to image the formation of EDL at individual NPs …”