Suppressing Dendrite Growth and Side Reactions via Mechanically Robust Laponite-Based Electrolyte Membranes for Ultrastable Aqueous Zinc-Ion Batteries

Abstract

The development of aqueous zinc-ion batteries (AZIBs) faces significant challenges because of waterinduced side reactions arising from the high water activity in aqueous electrolytes. Herein, a quasi-solid-state electrolyte membrane with low water activity is designed based on a laponite (LP) nanoclay for separator-free AZIBs. The mechanically robust LP-based membrane can perform simultaneously as a separator and a quasi-solidstate electrolyte to inhibit dendrite growth and water-induced side reactions at the Zn/electrolyte interface. A combination of density functional theory calculations, theoretical analyses, and experiments ascertains that the water activities associated with self-dissociation, byproduct formation, and electrochemical decomposition could be substantially suppressed when the water molecules are absorbed by LP. This could be attributed to the high water adsorption and hydration capabilities of LP nanocrystals, resulting from the strong Coulombic and hydrogenbinding interactions between water and LP. Most importantly, the separator-free AZIBs exhibit high capacity retention rates of 94.10% after 2,000 cycles at 1 A/g and 86.32% after 10,000 cycles at 3 A/g, along with enhanced durability and record-low voltage decay rates over a 60-day storage period. This work provides a fundamental understanding of water activity and demonstrates that LP nanoclay is promising for ultrastable separator-free AZIBs for practical energy storage applications.

Selenium doping induced phase transformation and interlayer expansion boost the zinc storage performance of molybdenum disulfide

“…19 Meanwhile, a peak at 10.9° emerged when the discharge reached 0.4 V (point C), which may belong to Zn x (CF 3 SO 3 ) y (OH) 2 x – y · n H 2 O (ZFH) resulting from the insertion of H + into the host material. 47,48 The intensity of the peak reached its maximum in the fully discharged state (point D) and progressively weakened and vanished during the charging process, demonstrating the reversible H + insertion/extraction behavior in the electrode. The above results suggested that the MoS 1.8 Se 0.2 /rGO cathode underwent an H + /Zn 2+ co-insertion/extraction process during discharging/charging.…”

Inducing preferential growth of the Zn (002) plane by using a multifunctional chelator for achieving highly reversible Zn anodes

“…This indicated that SG molecules were chemically stable and remained effective during charge/discharge. 34,35 Fig. 5b depicts the rate performance of the full cells at current densities ranging from 0.1 to 5 A g −1 .…”

The role of Mn in widening the potential window of solid solution derived electrodes for aqueous supercapacitors

“…5a, due to the fact that there are few free water molecules and a large amount of polar hydroxyl groups (˙OH) in the PVA gel, it can effectively combine with dissolved Mn 2+ ions through coordination and exhibit a strong interaction. 55,56 To a certain extent, this obviously slows the chemical dissolution of Mn substance and thus improves the device cycle life. The capacitance retention rate can reach 91% after 5000 cycles (refer to Fig.…”