Nanomicellar Electrolyte To Control Release Ions and Reconstruct Hydrogen Bonding Network for Ultrastable High-Energy-Density Zn–Mn Battery

Abstract

Zn−Mn batteries with two-electron conversion reactions simultaneously on the cathode and anode harvest a high voltage plateau and high energy density. However, the zinc anode faces dendrite growth and parasitic side reactions while the Mn 2+ / MnO 2 reaction on the cathode involves oxygen evolution and possesses poor reversibility. Herein, a novel nanomicellar electrolyte using methylurea (Mu) has been developed that can encapsulate ions in the nanodomain structure to guide the homogeneous deposition of Zn 2+ /Mn 2+ in the form of controlled release under an external electric field. Consecutive hydrogen bonding network is broken and a favorable local hydrogen bonding system is established, thus inhibiting the water-splitting-derived side reactions. Concomitantly, the solid−electrolyte interface protective layer is in situ generated on the Zn anode, further circumventing the corrosion issue resulting from the penetration of water molecules. The reversibility of the Mn 2+ /MnO 2 conversion reaction is also significantly enhanced by regulating interfacial wettability and improving nucleation kinetics. Accordingly, the modified electrolyte endows the symmetric Zn∥Zn cell with extended cyclic stability of 800 h with suppressed dendrites growth at an areal capacity of 1 mAh cm −2 . The assembled Zn−Mn electrolytic battery also demonstrates an exceptional capacity retention of nearly 100% after 800 cycles and a superior energy density of 800 Wh kg −1 at an areal capacity of 0.5 mAh cm −2 .

Constructing a Topologically Adaptable Solid Electrolyte Interphase for a Highly Reversible Zinc Anode

“…The above analysis evaluates the potential practical applicability of the current system in challenging environments. To further emphasize the efficacy of Gln additives, we also conducted a performance comparison of Zn//Zn symmetric cells with other reported strategies. ,,,,− As shown in Figure h, the utilization of Gln additives for in situ formation of a topologically adaptable SEI confers ultralong cycle life on Zn anodes across a wide range of current densities when compared to previous studies, thereby elucidating the favorable impact exerted by Gln additives.…”

Hybrid Co‐Solvent‐Induced High‐Entropy Electrolyte: Regulating of Hydrated Zn2+ Solvation Structures for Excellent Reversibility and Wide Temperature Adaptability

“…In contrast, EA has a minimal effect on the hydrated solvation structure due to its weak interaction effect with water molecules. [26] Besides, it is worth noting that the new Zn 2+ solvation structures induce more hydrogen bonding among water molecules, inhibiting the decomposition of water molecules at the electrode. Nevertheless, strong interactions among solvent molecules including hydrogen bonding have the potential to increase the viscosity of the electrolyte, thereby impeding the ionic mobility in the electrolyte.…”

Aqueous MnO2/Mn2+ electrochemistry in batteries: progress, challenges, and perspectives

“…For example, Yan et al designed a nanomicellar electrolyte in which the asymmetric hydrophilic and hydrophobic of methylurea broke the consecutive hydrogen bonding network and established a favorable local hydrogen bonding system, thereby suppressing the undesirable OER. 117 Besides, the redox mediator strategy is introduced to recover the lost capacity of ''dead Mn'' and improve the reversibility of the reaction. 98,[118][119][120][121] The specific operation mechanism of the redox mediator, such as I À /I 3 À , is shown in Fig.…”