Cyclic Ether–Water Hybrid Electrolyte-Guided Dendrite-Free Lamellar Zinc Deposition by Tuning the Solvation Structure for High-Performance Aqueous Zinc-Ion Batteries

Abstract

The serious zinc dendrites and poor cyclability at high cathode loading owing to the strong solvation effect of traditional aqueous electrolytes are the main bottlenecks to the development of aqueous rechargeable zinc-ion batteries (ARZIBs). Here, we design an ether−water hybrid zinc-ion electrolyte with bifunctional roles of not only unplugging the dendrites bottleneck at the Zn anode but also extending the cycle life at high cathode loading. A cyclic ether (1,4-dioxane (DX)) is incorporated into traditional ZnSO 4 -based electrolytes to finely tune the solvation sheath of Zn 2+ . DX is found to guide the deposition orientation of zinc along the (002) plane, leading to not a dendritic structure but distinctively dense lamellar deposition due to the stronger affinity of the cyclic DX molecules toward Zn(002) than that of water, which is proven by density functional theory calculations. The cycling lifespan of the Zn anode extends up to over 600 h at 5.0 mA cm −2 and maintains extremely high Coulombic efficiency of 99.8%, thereby further enabling the Zn-MnO 2 full cells to stably cycle at an ultrahigh mass loading of 9.4 mg cm −2 , paving the way to their practical applications. This work also provides a novel electrolyte regulating solution for other aqueous multivalent metal-ion batteries.

Two for one: propylene carbonate co-solvent for high performance aqueous zinc-ion batteries – remedies for persistent issues at both electrodes

“…These observations show that PC could cause a partial breakdown of hydrogen bonding in water as reported in earlier studies. 28,34–36 The interaction between PC and H 2 O can also be inferred from the C–H stretching vibrations (at 2885.80 cm −1 , 2940.90 cm −1 , 2999.40 cm −1 and 3026.10 cm −1 ), which shift to higher frequencies upon addition of H 2 O in PC (Fig. 1d).…”

Strategies of regulating Zn2+solvation structures for dendrite-free and side reaction-suppressed zinc-ion batteries

“…Except the alcohol additives, other organic solvent additives such as acetonitrile (AN), 184–188 dimethyl carbonate (DMC), 189 diethyl ether, 190 1,4-dioxane (DX), 191 1,2-dimethoxy ethane (DME), 192 trimethyl phosphate (TMP), 193,194 and dimethyl sulfoxide (DMSO) 79,80,195–197 have been widely reported. Acetonitrile (AN), which is commonly known to cooperate with Zn 2+ , 198,199 is recognized as a suitable electrolyte additive to regulate the cooperation environment of Zn 2+ .…”

“…The electrochemical performances of zinc anode with various organic solvent additives are summarized in Table 2. 17,79,170,174,176–178,184,186–195,202–205 Generally, these organic solvent additives always show excellent solubility in water and can preferentially solvate with Zn 2+ ions. Besides, they have a strong interaction with H 2 O, which can reduce the activity of free H 2 O molecules.…”

Initiating a high-temperature zinc ion battery through a triazolium-based ionic liquid

“…6,7 Although highperformance cathodes have been developed to overcome the above-mentioned problems, [8][9][10] the electrolyte also directly affects the performance of ZIBs. 11 Concentrated salt and other additives (organic solvents and ionic liquids) [12][13][14][15] were incorporated in aqueous electrolytes by tuning the solvation sheath of Zn 2+ to promote the plating/stripping and migration of Zn 2+ . 16 However, the water-induced side reactions are inevitable, and thus the development of new electrolytes without water, such as organic electrolytes and solid (or quasi-solid) electrolytes, is very important.…”