Rechargeable batteries that use energy dense metal anodes such as Li, Na, and Zn are promising candidates for long duration electrochemical energy storage to supplement intermittent electricity generated from renewable sources. In these systems, charge storage requires reversible electro-reduction/crystallization of metal ions from concentrated solutions and electrodissolution of the metal film back into the electrolyte. A key challenge during the electrocrystallization process is the propensity of the metal ions to undergo mossy deposition under practical conditions, which lowers electrode reversibility. These processes are in turn responsible for aggressive capacity fading due to metal orphaning and premature battery failure as the orphaned metal deposits can accumulate on the separator and block ion transport across the electrolyte in a closed electrochemical cell. We report that oriented dissolution of metals at electrochemical interfaces in reactive liquid electrolytes offers a new approach for improving reversibility of metal anodes. Analogous to crystallographically-induced directed electroposition at metal substrates, the substrates are found to preferentially dissolve along planes with high surface energy. We leverage this phenomenon to fabricate Zn anodes with 3D-nanoarchitectured channels oriented along the (101) plane and show that such nanochannels are effective hosts in suppressing mossy and dendritic metal deposition via epitaxial electrocrystallization process. Preliminary electrochemical characterization data shows that the as-fabricated electrodes enable stable cycling over repeated cycles of charge and discharge, confirming the utility of our findings in practical applications.
