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

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 deposition 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.