Construction of Bio‐inspired Film with Engineered Hydrophobicity to Boost Interfacial Reaction Kinetics of Aqueous Zinc–Ion Batteries

Abstract

Aqueous zinc–ion batteries typically suffer from sluggish interfacial reaction kinetics and drastic cathode dissolution owing to the desolvation process of hydrated Zn2+ and continual adsorption/desorption behavior of water molecules, respectively. To address these obstacles, a bio‐inspired approach, which exploits the moderate metabolic energy of cell systems and the amphiphilic nature of plasma membranes, is employed to construct a bio‐inspired hydrophobic conductive poly(3,4‐ethylenedioxythiophene) film decorating α‐MnO2 cathode. Like plasma membranes, the bio‐inspired film can “selectively” boost Zn2+ migration with a lower energy barrier and maintain the integrity of the entire cathode. Electrochemical reaction kinetics analysis and theoretical calculations reveal that the bio‐inspired film can significantly improve the electrical conductivity of the electrode, endow the cathode–electrolyte interface with engineered hydrophobicity, and enhance the desolvation behavior of hydrated Zn2+. This results in an enhanced ion diffusion rate and minimized cathode dissolution, thereby boosting the overall interfacial reaction kinetics and cathode stability. Owing to these intriguing merits, the composite cathode can demonstrate remarkable cycling stability and rate performance in comparison with the pristine MnO2 cathode. Based on the bio‐inspired design philosophy, this work can provide a novel insight for future research on promoting the interfacial reaction kinetics and electrode stability for various battery systems.

In Situ Induced Coordination between a “Desiccant” Interphase and Oxygen‐Deficient Navajoite towards Highly Efficient Zinc Ion Storage

“…Moreover, GP-HVO d exhibits a greatly improved ZF electrolyte wettability than HVO d with the contact angle decreases from 16.3° to 3.8° within only one second (Figure 5e), indicating the high hydrophilicity of GP. Notably, this result seems contradict with previous researches that a hydrophobic interface helps promote the desolvation, [29] since reduced activation energy is also achieved in our case with a more hydrophilic one. However, considering the strong water adsorption and low solubility of gypsum in daily use scenarios, as well as the difficulty for [Zn(H 2 O) 6 ] 2+ to pass through, we speculate that GP possessing abundant surface O-H bonds might exert strong adsorption toward the water solvent shells and help strip off them from [Zn(H 2 O) 6 ] 2+ like a "desiccant," which is essentially similar with the effect achieved by constructing a hydrophobic interface.…”

Modulating Surface Electron Density of Heterointerface with Bio‐Inspired Light‐Trapping Nano‐Structure to Boost Kinetics of Overall Water Splitting

“…[1,2] Numerous scientists have advocated that intermediate energy conversion and storage is a viable technique for increasing the concentration and stability of renewable energy output. [3] Since hydrogen does indeed have a high energy density and releases no toxic emissions, it is considered a promising energy carrier. [4] Owing to its high energy-conversion efficiency, electrocatalytic water splitting, which includes hydrogen evolution reaction (HER) on the cathode and oxygen evolution reaction (OER) on the anode, is believed to be one of the most promising technologies for H 2 production.…”

Cathode–Electrolyte Interface Modification by Binder Engineering for High‐Performance Aqueous Zinc‐Ion Batteries

“…Deduced from DFT calculation, the binding energies for one water molecule can be ranked as PTFE < PVDF < SA. With the application of pristine SA as the binder, the strong adsorption energy with water of −31.43 kcal mol −1 allows water molecules pass through the cathode‐electrolyte interface prohibiting the desolvation of [Zn(H 2 O) 6 ] 2+ to Zn 2+ , [ 52 , 53 ] thus resulting in a severe sluggish energy storage mechanism. Referring to electrochemical results, SA exhibits the lowest specific capacity in all current densities and a fast capacity decay compared to PVDF and PTFE.…”