Synergistic Modulation of Mass Transfer and Parasitic Reactions of Zn Metal Anode via Bioinspired Artificial Protection Layer

Abstract

Rechargeable aqueous zinc–ion batteries are regarded as promising energy storage devices due to their attractive economic benefits and extraordinary electrochemical performance. However, the sluggish Zn2+ mass transfer behavior and water‐induced parasitic reactions that occurred on the anode–electrode interface inevitably restrain their applications. Herein, inspired by the selective permeability and superior stability of plasma membrane, a thin UiO‐66 metal‐organic framework layer with smart aperture size is ex‐situ decorated onto the Zn anode. Experimental characterizations in conjunction with theoretical calculations demonstrate that this bio‐inspired layer promotes the de‐solvation process of hydrated Zn2+ and reduces the effective contact between the anode and H2O molecules, thereby boosting Zn2+ deposition kinetics and restraining interfacial parasitic reactions. Hence, the Zn||Zn cells could sustain a long lifespan of 1680 h and the Zn||Cu cells yielded a stable coulombic efficiency of over 99.3% throughout 600 cycles under the assistance of the bio‐inspired layer. Moreover, pairing with δ‐MnO2 cathode, the full cells also demonstrate prominent cycling stability and rate performance. From the bio‐inspired design philosophy, this work provides a novel insight into the development of aqueous batteries.

Unveiling the multifunctional regulation effect of a glutamine additive for highly reversible Zn metal anodes

“…Moreover, higher current densities at redox peaks with Gln indicated promoted electrochemical performance in the battery. 40,41 With ZnSO 4 + 0.3 M Gln electrolyte, the Zn//NH 4 V 4 O 10 battery yielded a specific capacity of 90.3 mA h g −1 after 800 cycles at 5 A g −1 , which was higher than the battery with pristine ZnSO 4 electrolyte (11.1 mA h g −1 ) (Fig. 5a).…”

Electrolyte Modulation of Biological Chelation Additives toward a Dendrite-Free Zn Metal Anode

“…A higher BE is more advantageous, as it indicates a stronger binding of the additive to Zn 2+ and facilitates the replacement of a water molecule from the solvation structure. 31,32 Therefore, these theoretical calculation results are consistent with the characterization results. Additionally, electrochemical impedance spectroscopy (EIS) characterization was utilized to determine the ionic con- ductivities of the electrolyte with different additives.…”

“…where σ represents the ionic conductivity, L denotes the distance between the inert electrodes, S represents the electrode area, and R corresponds to the ohmic resistance obtained from the EIS characterization. 32,34 As depicted in Figures 1h and S4, the ionic conductivities of the electrolytes containing pure ZnSO 4 , Glu, and Asp are calculated to be 1.86, 2.01, and 2.05 S m −1 , respectively. These results are attributed to the amphoteric characteristics of Glu and Asp molecules.…”

“…The calculated BE value of [Zn­(H 2 O) 6 ] 2+ is determined to be −0.23 eV, which is lower compared to those of [Zn­(H 2 O) 5 (Glu)] 2+ (−2.49 eV) and [Zn­(H 2 O) 5 (Asp)] 2+ (−0.85 eV) species. A higher BE is more advantageous, as it indicates a stronger binding of the additive to Zn 2+ and facilitates the replacement of a water molecule from the solvation structure. , Therefore, these theoretical calculation results are consistent with the characterization results.…”

“…Additionally, electrochemical impedance spectroscopy (EIS) characterization was utilized to determine the ionic conductivities of the electrolyte with different additives. The ionic conductivity (σ) can be calculated using the following equation: where σ represents the ionic conductivity, L denotes the distance between the inert electrodes, S represents the electrode area, and R corresponds to the ohmic resistance obtained from the EIS characterization. , As depicted in Figures h and S4, the ionic conductivities of the electrolytes containing pure ZnSO 4 , Glu, and Asp are calculated to be 1.86, 2.01, and 2.05 S m –1 , respectively. These results are attributed to the amphoteric characteristics of Glu and Asp molecules.…”