Shielding Fluoride Ion Basicity through Diurea Coordination for Nonaqueous Fluoride Shuttle Batteries.

The strong basicity of fluoride ions leads to detrimental nucleophilic attack on organic components in the electrolytes, such as β-hydrogen elimination reactions with organic cations and solvents, converting "naked" F into corrosive and unstable bifluoride (HF ) ions. These reactions significantly constrain the choice of suitable solvents and salts to develop electro(chemical) stable fluoride ion electrolytes. In this work, we replaced the triple water ligands typically present in industrial organic fluoride salts with dual 1,3-diphenylurea (DPU) coordination via hydrogen bonding interaction.

High Efficiency Alkaline Iodine Batteries with Multi-Electron Transfer Enabled by Bi/BiO Redox Mediator.

The multi-electron transfer I/IO redox couple is attractive for high energy aqueous batteries. Shifting from an acidic to an alkaline electrolyte significantly enhances the IO formation kinetics due to the spontaneous disproportionation reaction, while the alkaline environment also offers more favorable Zn anode compatibility. However, sluggish kinetics during the reduction of IO persists in both acidic and alkaline electrolytes, compromising the energy efficiency of this glorious redox couple.

Energetic Hypervalent Organoiodine Electrochemistry for Aqueous Zinc Batteries.

Hypervalent organoiodine compounds have been extensively utilized in organic synthesis, yet their electrochemical properties remain unexplored despite their theoretically high redox potential compared with inorganic iodine, which primarily relies on the I/I redox couple in battery applications. Here, the fundamental redox mechanism of hypervalent organoiodine in a ZnCl aqueous electrolyte is established for the first time using the simplest iodobenzene (PhI) as a model compound. We validated that the PhI to PhICl transition is a single-step and reversible reaction, enabling two-electron transfer of I/I redox chemistry (1.

Universal Copolymerization of Crosslinked Polyether Electrolytes for All-Solid-State Lithium-Metal Batteries.

Solid polymer electrolytes (SPEs) are pivotal in advancing the practical implementation of all-solid-state batteries. Poly(1,3-dioxane) (PDOL)-based electrolytes have attracted significant attention due to the pseudo-high conductivity achieved through sophisticated in situ polymerization methods; however, such PDOL-based electrolytes present challenges of crystallization over time and monomers residual during processing. In this study, integrating LiTFSI and LiDFOB as a universal copolymerization strategy for developing high-performance PDOL electrolytes with a wide range of epoxy crosslinkers is proposed.

Butadiene Sulfone Based Binary Deep Eutectic Electrolyte for High Performance Lithium Metal Batteries.

Deep eutectic electrolytes (DEEs) have attracted significant interest due to the unique physiochemical properties, yet challenges persist in achieving satisfactory Li anode compatibility through a binary DEE formula. In this study, we introduce a nonflammable binary DEE electrolyte comprising of lithium bis(trifluoro-methane-sulfonyl)imide (LiTFSI) and solid butadiene sulfone (BdS), which demonstrates enhanced Li metal compatibility while exhibiting high Li ion migration number (0.52), ionic conductivity (1.

Triflate anion chemistry for enhanced four-electron zinc-iodine aqueous batteries.

I hydrolysis, sluggish iodine redox kinetics and the instability of Zn anodes are the primary challenges for aqueous four-electron zinc-iodine batteries (4eZIBs). Herein, the OTf anion chemistry in aqueous electrolyte is essential for developing advanced 4eZIBs. It is elucidated that OTf anions establish weak hydrogen bonds (H bonds) with water to stabilize I species while optimizing a water-lean Zn coordination structure to mitigate Zn dendrites and corrosion.

Molecule Engineering of Sugar Derivatives as Electrolyte Additives for Deep-Reversible Zn Metal Anode.

The cycling performance of zinc-ion batteries is greatly affected by dendrite formation and side reactions on zinc anode, particularly in scenarios involving high depth of discharge (DOD) and low negative/positive capacity (N/P) ratios in full cells. Herein, drawing upon principles of host-guest interaction chemistry, we investigate the impact of molecular structure of electrolyte additives, specifically the -COOH and -OH groups, on the zinc negative electrode through molecular design. Our findings reveal that molecules containing these groups exhibit strong adsorption onto zinc anode surfaces and chelate with Zn, forming a HO-poor inner Helmholtz plane.

Aqueous Electrolyte With Weak Hydrogen Bonds for Four-Electron Zinc-Iodine Battery Operates in a Wide Temperature Range.

In the pursuit of high-performance energy storage systems, four-electron zinc-iodine aqueous batteries (4eZIBs) with successive I/I/I redox couples are appealing for their potential to deliver high energy density and resource abundance. However, susceptibility of positive valence I to hydrolysis and instability of Zn plating/stripping in conventional aqueous electrolyte pose significant challenges. In response, polyethylene glycol (PEG 200) is introduced as co-solvent in 2 m ZnCl aqueous solution to design a wide temperature electrolyte.

Rocking-Chair Aqueous Fluoride-Ion Batteries Enabled by Hydrogen Bonding Competition.

Aqueous fluoride ion batteries (FIBs) have garnered attention for their high theoretical energy density, yet they are challenged by sluggish fluorination kinetics, active material dissolution, and electrolyte instability. Here, we present a room temperature rocking-chair aqueous FIBs featuring KOAc-KF binary salt electrolytes, enabling concurrent fluorination and defluorination reactions at both cathode and anode electrodes. Experimental and theoretical results reveal that acetate ions in the electrolyte compete with fluoride ions in hydrogen bonding formation, weakening the excessively strong solvation between HO and F ions.

Stabilized four-electron aqueous zinc-iodine batteries by quaternary ammonium complexation.

Four-electron aqueous zinc-iodine batteries (4eZIBs) leveraging the I/I/I redox couple have garnered attention for their potential high voltage, capacity, and energy density. However, the electrophilic I species is highly susceptible to hydrolysis due to the nucleophilic attack by water. Previous endeavors to develop 4eZIBs primarily relied on highly concentrated aqueous electrolytes to mitigate the hydrolysis issue, nonetheless, it introduced challenges associated with dissolution, high electrolyte viscosity, and sluggish electrode kinetics.

Practical four-electron zinc-iodine aqueous batteries enabled by orbital hybridization induced adsorption-catalysis.

The successive I/I/I redox couples in the four-electron zinc-iodine aqueous battery (4eZIB) is plagued by the instability of the electrophilic I species, which could either be hydrolyzed or be neutralized by the I redox intermediates. We present an adsorption-catalysis approach that effectively suppresses the hydrolysis of ICl species and also provides an enhanced reaction kinetics to surpass the formation of triiodide ions. We elucidate that the improved stability is attributed to the pronounced orbital hybridization between the d orbitals of Fe-N moieties (atomic Fe supported on nitrogen doped carbon) and the p orbitals of iodine species (I and ICl).

A twelve-electron conversion iodine cathode enabled by interhalogen chemistry in aqueous solution.

The battery chemistry aiming for high energy density calls for the redox couples that embrace multi-electron transfer with high redox potential. Here we report a twelve-electron transfer iodine electrode based on the conversion between iodide and iodate in aqueous electrolyte, which is six times than that of the conventional iodide/iodine redox couple. This is enabled by interhalogen chemistry between iodine (in the electrode) and bromide (in the acidic electrolyte), which provides an electrochemical-chemical loop (the bromide-iodate loop) that accelerates the kinetics and reversibility of the iodide/iodate electrode reaction.

Unravelling rechargeable zinc-copper batteries by a chloride shuttle in a biphasic electrolyte.

The zinc-copper redox couple exhibits several merits, which motivated us to reconstruct the rechargeable Daniell cell by combining chloride shuttle chemistry in a zinc chloride-based aqueous/organic biphasic electrolyte. An ion-selective interface was established to restrict the copper ions in the aqueous phase while ensuring chloride transfer. We demonstrated that the copper-water-chloro solvation complexes are the descriptors, which are predominant in aqueous solutions with optimized concentrations of zinc chloride; thus, copper crossover is prevented.

Segmental Motion Adjustment of the Polycarbonate Electrolyte for Lithium-Metal Batteries.

Carbonyl oxygen atoms are the primary active sites to solvate Li salts that provide a migration site for Li ions conducting in a polycarbonate-based polymer electrolyte. We here exploit the conductivity of the polycarbonate electrolyte by tuning the segmental motion of the structural unit with carbonyl oxygen atoms, while its correlation to the mechanical and electrochemical stability of the electrolyte is also discussed. Two linear alkenyl carbonate monomers are designed by molecular engineering to combine methyl acrylate (MA) and the commonly used ethylene carbonate (EC), w/o dimethyl carbonate (DMC) in the structure.

Electrolyte Solvation Chemistry for the Solution of High-Donor-Number Solvent for Stable Li-S Batteries.

Passivation of the sulfur electrode by insulating lithium sulfide (Li S) restricts the reversibility and sulfur utilization of lithium-sulfur (Li-S) batteries. Although electrolytes with high donor number (DN) solvents induce tri-sulfur radical intermediate thus 3D nucleation of Li S with fast kinetics can be achieved, their catastrophic reactivities with Li metal hinder practical applications. Here, the use of high DN solvent as an additive instead of as co-solvent to solve their incompatibility between cathode and anode is proposed, by adopting N-methyl-2-pyrrolidone (NMP) as a proof-of-concept.

Co -Rich Na CoP O Phosphates as Efficient Bifunctional Catalysts for Oxygen Evolution and Reduction Reactions in Alkaline Solution.

Implementing sustainable energy conversion and storage technologies is highly reliant on crucial oxygen electrocatalysis, such as the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). However, the pursuit of low cost, energetic efficient and robust bifunctional catalysts for OER and ORR remains a great challenge. Herein, the novel Na-ion-deficient Na CoP O catalysts are proposed to efficiently electrocatalyze OER and ORR in alkaline solution.

Polarization dressed multi-order fluorescence of Pr³⁺:Y₂SiO₅.

We report polarization dressed second-, fourth- and sixth-order fluorescence processes in a Pr(3+):Y2SiO5 crystal. By changing the polarization states of dressing fields and generating fields, the fluorescence baselines, suppression and Autler-Townes splitting of emission peaks can be controlled. The polarization dependencies of fluorescence generated from two inequivalent crystallographic sites are compared.