Highly Reversible Zn Metal Anode Securing by Functional Electrolyte Modulation

The inferior reversibility of Zn metal anode caused by undesired Zn dendrite and severe interfacial side reactions has to be addressed for the commercial application of Zinc ion batteries (ZIBs). Here, a multiple functional sodium benzaldehyde 2,4‐disulfonate(B24DADS) additives with various blocks of polar sulfonate group, Lewis basic aldehyde groups, and hydrophobic benzene ring is proposed to regulate the solvation structure of Zn2+, construct an H2O‐poor and zincophilic dual electric layer structure, and create a passive SEI on the Zn anode surface, thus restaining dendrite growth and interfacial side reactions. Furthermore, uniform deposition mechanics of the Zn are revealed by the synergistic effect of induced deposition, additive‐derived SEI formation, and texture regulation. In addition, Na+ can also limit the growth of zinc dendrites based on electrostatic shielding mechanisms. Therefore, the multifunctional B24DADS additive grants the anode to deliver remarkable electrochemical performance. Under critical test conditions (20 mA cm−2/20 mAh cm−2), the zinc provides superior long cycling (3700 h) with a low polarization voltage (0.02 V). B24DADS containing electrolyte is well matched with manganese dioxide cathode. This effort renders a promising way to explore advanced additives with unique molecular structures for addressing zinc dendrite growth and rampant side effects.

Simultaneous Modulation on Solvation Shell and Electrode Interface for Reversible Zinc Anode Realized by a Mutiplefunctional Additive

Cao,

Ma,

Liu

et al. 2024

Constructing a Multifunctional SEI Layer Enhancing Kinetics and Stabilizing Zinc Metal Anode

Li,

Liu

et al. 2024

Zn dendrite growth and parasitic reactions at the interface of zinc anode/electrolyte in aqueous zinc batteries severely hinder its lifespan in application. Herein, the zinc anode is effectively stabilized by introducing trace amounts of 4‐aminobutane‐1‐phosphate (ABPA) into the ZnSO4 electrolyte. The ABPA adsorbs onto the surface of zinc anode and then further decomposes to a high conductive organic/inorganic composite in situ SEI layer including amino, partial carbon chain, and zinc phosphate. In the SEI layer, the residual undecomposed carbon chain promotes the desolvation of Zn2+, the amino induces uniform Zn2+ plating and zinc phosphate facilitates the migration of Zn2+. Thus, this in situ SEI layer not only suppresses water‐related side reactions but also enhances the Zn2+ transport kinetics. As a result, Zn||Zn symmetric cell delivers an ultralong cycle life of over 13 000 cycles at 50 mA cm−2 and 1 mAh cm−2. A high average Coulombic efficiency of 99.72% is achieved in over 1000 cycles in Zn||Cu half‐cell. The Zn||I2 full cell delivers a high‐capacity retention of 91.42% after 40,000 cycles. Moreover, a 49 mAh Zn||I2 pouch cell maintains 80.28% capacity retention over 300 cycles and 61.22% after 1000 cycles.

Suppressing Zinc Metal Corrosion by an Effective and Durable Corrosion Inhibitor for Stable Aqueous Zinc Batteries

Ren,

Zhang,

Wei

et al. 2024

The development of aqueous zinc‐ion batteries (AZIBs) for large‐scale industrial applications is substantially constrained by the persistent issue of zinc anode corrosion. This study introduces fucoidan (FCD), a corrosion inhibitor, to effectively mitigate the corrosion‐related challenges in zinc metal anodes. FCD forms a robust, covalently bonded layer on the zinc surface at a low concentration of 25 mm through interactions between the lone pairs on its polar atoms and the d orbitals of zinc. This layer is ultrathin, which does not deteriorate ion transfer but effectively shields the zinc from corrosive electrolytes and promotes uniform zinc deposition, resulting in suppressed corrosion, passivation, and dendrite formation. Consequently, the Zn||Zn cells exhibit excellent reversibility, stably operating for 2700 h at 1 mA cm−2 under 1 mAh cm−2 and 400 h at 10 mA cm−2 under 10 mAh cm−2. Furthermore, a large‐sized Zn||I2 pouch cell with a high iodine loading of 2 g and a discharge capacity of ≈300 mAh is demonstrated, which shows minimal capacity degradation—<3% after 300 cycles—and maintains a high Coulombic efficiency of ≈99.5%. The corrosion inhibition strategy proposed in this study provides crucial insights for enhancing the durability and practicability of AZIBs.