Eliminating Dendrites and Side Reactions via a Multifunctional ZnSe Protective Layer toward Advanced Aqueous Zn Metal Batteries

Abstract

The development of aqueous Zn metal batteries (AZMBs) is impeded by severe corrosion, H2 evolution, and dendrite formation issues. In addition, the inability of AZMBs to achieve a large capacity also hinders their commercialization. Here, a multifunctional ZnSe protective layer is reported to synchronously solve the above issues. The ZnSe layer can efficiently provide anticorrosion while also suppressing hydrogen evolution. Systematic analyses of the mechanism suggest that the low Zn affinity of ZnSe and the unbalanced charge distribution at the interface can promote a uniform distribution of Zn2+ and accelerate Zn2+ migration, thus realizing dendrite‐free behavior. Therefore, the Zn@ZnSe symmetric cell exhibits notable rate performance and cycling stability (1500 h). Moreover, this symmetric cell can still stabilize with a low polarization (50 mV), even at 10 mA cm−2 with 5 mAh cm−2. The full cell paired with MnO2 achieves a long lifespan (1800 cycles) with a Coulombic efficiency near 100%. Therefore, this strategy for eliminating dendrites and side reactions at a high rate with a large capacity provides a promising solution for the development of AZMBs.

Towards Understanding the Corrosion Behavior of Zinc‐Metal Anode in Aqueous Systems: From Fundamentals to Strategies

“…The design of different types of zinc alloys has become a proven strategy to inhibit HER and zinc corrosion. [50,[103][104][105][106][107][108][109][110][111] Compared to pure zinc, the formation of intermetallic phases leads to higher chemical bonding strength between phases, denser arrangement of atoms and lower Gibbs free energy (Figure 13). It increases the hydrogen precipitation overpotential and causes a positive shift in corrosion potential with a decrease in corrosion current density.…”

“…The design of different types of zinc alloys has become a proven strategy to inhibit HER and zinc corrosion [50,103–111] . Compared to pure zinc, the formation of intermetallic phases leads to higher chemical bonding strength between phases, denser arrangement of atoms and lower Gibbs free energy (Figure 13).…”

Recent Advances in Electrolytes for “Beyond Aqueous” Zinc‐Ion Batteries

“…[13] However, the using of an alkaline electrolyte always leads to the growth of Zn dendrites and the corrosion of the anode, resulting in rapid capacity fading. [14][15][16] Until 1986, the replacement of corrosive alkaline electrolyte systems by neutral aqueous electrolytes greatly improved the performance and safety of ZIBs. [17] Although the aqueous electrolytes alleviated the corrosion of the Zn electrode in some extent, the problems related to the growth of dendrites and the dissolution of the cathode, especially the limited electrochemical stability window (≈1.23 V) still are the challenge in the application of ZIBs.…”

Unraveling the Rate‐Dependent Stability of Metal Anodes and Its Implication in Designing Cycling Protocol

“…[ 13–16 ] Moreover, the dendrites with sharp tips could easily pierce the separator and cause a short circuit. [ 17–22 ]…”

“…[13][14][15][16] Moreover, the dendrites with sharp tips could easily pierce the separator and cause a short circuit. [17][18][19][20][21][22] an initial high J (IHJ) cycling protocol is proposed to increase nucleation sites and suppress dendrite growth. As a result, Zn metal anodes could stably run for 2500 h with IHJ (compared to 303 h without IHJ) at 1 mA cm −2 for 1 mAh cm −2 .…”