A common polar dye additive as corrosion inhibitor and leveling agent for stable aqueous zinc-ion batteries

The industrial application of zinc-ion batteries is restricted by irrepressible dendrite growth and side reactions that resulted from the surface heterogeneity of the commercial zinc electrode and the thermodynamic spontaneous corrosion in a weakly acidic aqueous electrolyte.Herein,a common polar dye,Procion Red MX-5b,with high polarity and asymmetric charge distribution is introduced into the zinc sulfate electrolyte,which can not only reconstruct the solvation configuration of Zn2þand strengthen hydrogen bonding to reduce the reactivity of free H_(2)O but also homogenize interfacial electric field by its preferentially absorption on the zinc surface.The symmetric cell can cycle with a lower voltage hysteresis(78.4 mV)for 1120 times at 5 mA cm^(−2)and Zn//NaV_(3)O_(8)·1.5H_(2)O full cell can be cycled over 1000 times with high capacity(average 170 mAh g^(−1))at 4 A g^(−1)in the compound electrolyte.This study provides a new perspective for additive engineering strategies of aqueous zinc-ion batteries.

Functionalizing the interfacial double layer to enable uniform zinc deposition

Due to the unsatisfactory electrode/electrolyte interface,the metallic Zn dendrites and corrosion are easily induced,severely hindering the applications of zinc-ion batteries(ZIBs).Herein,a strategy that engineers the interfacial double layer by an extremely low concentration of sulfolane is proposed to tune the Zn stripping/plating behavior.It is revealed that the highly-polar sulfolane can predominately occupy the inner Helmholtz layer over water,and then regulate the upcoming Zn2+to directly deposit downward.Simultaneously,the widened Helmholtz layer can weaken the electric field intensity,which will generate more nucleation sites and reduce the nuclei radius,thereby promoting uniform zinc deposition as well.Moreover,corrosion byproducts can be inhibited since fewer water molecules can contact the Zn electrodes.Consequently,the battery performance can be naturally optimized.With an optimum amount of sulfolane,the Zn||Zn battery can operate for more than 1,100 h under1 m A cm^(-2)and 1 m Ah cm^(-2).And the as-constructed Zn||NaV_(3)O_(8)·1.5H_(2)O battery demonstrates considerably higher cycling stability than that without sulfolane.Overall,this work has provided a deep insight into constructing a functional interfacial double layer to regulate zinc deposition,which can also act as a reference for other metal-based batteries.

Designing Zinc Deposition Substrate with Fully Preferred Orientation to Elude the Interfacial Inhomogeneous Dendrite Growth

The development of zinc-ion batteries with high energy density remains a great challenge due to the uncontrollable dendrite growth on their zinc metal anodes.Film anodes plated on the substrate have attracted increasing attention to alleviate these dendrite issues.Herein,we first point out that both the random crystal orientation and the low metal affinity of the substrate are important factors of zinc dendrite formation.Accordingly,the(1 O 1)fully preferred tin interface layer with high zinc affinity was fabricated by chemical tin plating on(1 O o)oriented copper.This tin decorated copper substrate can realize high reversible zinc plating/stripping behavior,and full cell using this zinc plated substrate can be operated for more than 1000 cycles with high capacity retention(85.3%)and low electrochemical impedance.The proposed strategy can be also applied to lithium metal batteries,which demonstrates that the substrate orientation regulation and metal affinity design are the promising approaches to achieve dendrite-free metal anode and overcome the challenges of highly reactive metal anodes.

A shape memory scaffold for body temperature self-repairing wearable perovskite solar cells with efficiency exceeding 21%

Grain boundary cracks in flexible perovskite films can be repaired by filling with self-repairing polymers during the preparation and wearable operation.However,the self-repairing polymers are commonly active through external heating or humidification treatments,which cannot match with the human body's temperature tolerance of wearable devices.Herein,a body temperature-responsive shape memory polyurethane(SMPU)is demonstrated to achieve the real-time mechanical self-repairing of grain boundary cracks(~37°C).Furthermore,the strong intermolecular interaction between SMPU and the uncoordinated Pb2+and I−,can reduce the trap density in perovskite films.The blade-coated device achieves a power conversion efficiency(PCE)of 21.33%,which is among the best reported flexible perovskite solar cells(PSCs;0.10 cm2).Importantly,the device with SMPU can recover more than 80%of the PCE after 6000 cycles(bending radius:8 mm).Finally,the flexible PSCs are used for wearable solar power supply of a smartphone,which show great potential for self-repairing wearable electronics.