Aqueous zinc-ion batteries attract increasing attention due to their promising electrochemical performance and intrinsic safety. However, the parasitic corrosion reactions and uncontrolled Zn dendrite growth impede their practical application. Herein,...

Aqueous zinc batteries (ZBs) are one of the most compelling alternatives of lithium-ion batteries due to their intrinsic safety, eco-friendly, and economic feasibility. Organic electrode materials (OEMs) stand out as highly competitive components for advancing ZBs by virtue of resource sustainability, versatile structures, and functions. The implementation metrics of OEMs largely depend on the types of charge carriers. Compared with the high charge density of metallic Zn2+ ions, non-metal ions, benefiting from small hydrated structures and light weights, show accelerated interfacial dehydration and fast redox kinetics. It is thus a valuable and ongoing work to propel the collaboration between OEMs and non-metal ions for superior ZBs. In this review, versatile OEMs, including small molecules, conjugated polymers, and covalent organic frameworks, are first categorized, and their applications are comprehensively outlined in ZBs. Furthermore, the insights into the electrochemical reaction mechanism, implementation effectiveness, and latest progress of OEMs-based ZBs using various non-metal cationic (H+ and NH4 +) and anionic (Cl-, CF3SO3 -, and ClO4 -) carriers have been systematically discussed. Finally, the challenges and perspectives of OEMs advancing non-metal ion storage in ZBs are outlined to guide the future development of next-generation energy communities.

Aqueous zinc ion batteries (AZIBs) have received increasing attention due to their intrinsic safety, low cost, and environmental friendliness, and the design of advanced cathode materials is crucial for their practical application. Herein, the V2O3/Zn3V3O8@C heterostructured materials derived from polyoxovanadates are developed as advanced cathodes for AZIBs. The formation of a carbon protective layer originated from the coated polypyrrole leads to the abundant oxygen vacancies during the pyrolysis process. Density functional theory calculation reveals that the construction of the heterostructure effectively regulates the electronic properties of the V2O3. The collaborative effect of heterostructures with oxygen vacancies significantly facilitates the electron/ion transport and mechanical stability of V2O3/Zn3V3O8@C. As expected, the V2O3/Zn3V3O8@C cathode delivers a high specific capacity of 419.0 mAh g-1 at 0.1 A g-1 and excellent cycling stability with 80.6% capacity retention after 1000 cycles at 2 A g-1.

Synergistic effect of bio-inorganic interface engineering and redox-active components in chitosan-Ag2MoO4-AgBr/RGO nanocomposite for high-performance supercapacitor devices.

Rechargeable alkaline Zn-Ni(Co) batteries offer high output voltage and intrinsic safety; however, their practical deployment is hindered by sluggish cathodic kinetics and parasitic side reactions, which limit both energy density and power capability. Here, the design and synthesis of a crystalline-amorphous heterostructure cathode combining mixed Ni and Co sulfides (MS) with Ni-Co layered double hydroxides (LDHs) is reported. This design synergistically leverages the electrical conductivity and structural adaptability of metal sulfides with the expanded interlayer spacing and ion transport channels of LDHs. The engineered MS-LDH cathode exhibits abundant electroactive sites, enhanced hydroxide ion adsorption, and accelerated ion diffusion kinetics, delivering a high specific capacity of 773mAhg-1 at 2Ag-1. When paired with a chitosan-in-PVA gel-coated Zn anode (Zn@CP), the aqueous Zn@CP||MS-LDH battery, delivers an ultrahigh specific energy of 1309Whkg-1-among the highest reported for similar systems-and a specific power of 3.44kWkg-1, comparable to pseudocapacitors. Moreover, the battery demonstrates excellent rate capability and long-term cycling stability. These results highlight the promise of earth-abundant heterostructured materials in overcoming critical limitations of aqueous Zn-based batteries, offering a promising pathway toward sustainable, high-performance energy storage technologies.

Magnesium metal batteries (MMBs) offer the promise of low cost, intrinsic safety, and high volumetric energy density, but their development is hindered by the scarcity of cathodes capable of reversible Mg2+ storage and by cathode-electrolyte incompatibilities. Here, we demonstrate that coupling molecularly engineered polyimide (PI) cathodes with tailored electrolyte speciation enables fast and durable Mg storage. Two PIs, poly(naphthalene tetracarboxylic dianhydride-urea imide) (NUPI) and poly(perylene tetracarboxylic dianhydride-urea imide) (PUPI), with analogous backbones but distinct degrees of π-conjugation were systematically evaluated in both chloride-containing and chloride-free electrolytes. Systematic studies indicate that chloride-free electrolytes, characterized by weakly coordinating anions, enable reversible enolization (C═O ⇌ C─O-/[C─O-]2Mg2+) while suppressing side reactions. Additionally, NUPI, featuring stronger π─π stacking and more ordered layered structures, facilitates Mg2+ transport and interfacial charge transfer. When combined with a graphene oxide-modified separator, the NUPI cathode delivers 175mAhg-1 at 50mAg-1 and exhibits ultralow capacity fading (≈0.05% per cycle over 1000 cycles at 500mAg-1). Operando/ex situ spectroscopy analyses and theoretical calculations further confirm the enolization-dominated redox mechanism. This work establishes a molecular-electrolyte co-design paradigm for high-rate, durable MMBs based on carbonyl polymer chemistry.

Zinc-air batteries (ZABs) are regarded as one of the most promising next-generation energy storage technologies owing to their high theoretical energy density, intrinsic safety, and cost-effectiveness. However, their practical deployment is largely hindered by the sluggish kinetics of the oxygen reduction reaction (ORR) during discharge and the oxygen evolution reaction (OER) during charge. The development of robust bifunctional electrocatalysts that can efficiently and stably catalyse both reactions is therefore critical for advancing ZAB technology. Covalent organic frameworks (COFs), a class of crystalline porous polymers, have emerged as a versatile platform, and achieving intrinsic conductivity and improving electronic mobility within the framework are two benefits of customizing the electrical structure, especially by doping or adding conductive linkers. These properties are crucial for electrochemical applications. Because of their high conductivity, which promotes effective catalysis and charge transfer, as well as the arrangement and accessibility of reactive centers inside the COF, engineered COFs offer special platforms for enhanced materials design. In this review, we provide a comprehensive overview of recent progress in the rational design of bifunctional electrocatalysts, with a particular emphasis on COFs and their derived materials. We discuss design strategies, including heteroatom doping, metal coordination, pore engineering, and electronic structure modulation that enhance intrinsic catalytic activity, charge transport, and mass diffusion. Mechanistic insights from density functional theory (DFT) calculations and in-situ/operando spectroscopies are highlighted to unravel active-site structures and catalytic pathways. Furthermore, we summarize the impact of COF-based bifunctional catalysts on key ZAB performance indicators such as power density, discharge capacity, round-trip efficiency, and long-term cycling stability. Finally, we outline current challenges, including scalable synthesis, interfacial engineering, and durability and provide future perspectives on integrating machine learning and advanced characterization to accelerate the discovery of next-generation ZAB electrocatalysts. Collectively, this review underscores the pivotal role of bifunctional catalyst design in unlocking the practical potential of high-performance, sustainable, and rechargeable zinc-air batteries.

Abstract Magnesium metal batteries (MMBs) offer the promise of low cost, intrinsic safety, and high volumetric energy density, but their development is hindered by the scarcity of cathodes capable of reversible Mg 2+ storage and by cathode–electrolyte incompatibilities. Here, we demonstrate that coupling molecularly engineered polyimide (PI) cathodes with tailored electrolyte speciation enables fast and durable Mg storage. Two PIs, poly(naphthalene tetracarboxylic dianhydride‐urea imide) (NUPI) and poly(perylene tetracarboxylic dianhydride‐urea imide) (PUPI), with analogous backbones but distinct degrees of π‐conjugation were systematically evaluated in both chloride‐containing and chloride‐free electrolytes. Systematic studies indicate that chloride‐free electrolytes, characterized by weakly coordinating anions, enable reversible enolization (C═O ⇌ C─O − /[C─O − ] 2 Mg 2+ ) while suppressing side reactions. Additionally, NUPI, featuring stronger π─π stacking and more ordered layered structures, facilitates Mg 2+ transport and interfacial charge transfer. When combined with a graphene oxide‐modified separator, the NUPI cathode delivers 175 mAh g −1 at 50 mA g −1 and exhibits ultralow capacity fading (≈0.05% per cycle over 1000 cycles at 500 mA g −1 ). Operando/ex situ spectroscopy analyses and theoretical calculations further confirm the enolization‐dominated redox mechanism. This work establishes a molecular‐electrolyte co‐design paradigm for high‐rate, durable MMBs based on carbonyl polymer chemistry .

Ether-free PDMS-based composite electrolytes with intrinsic safety, high ionic conductivity and wide electrochemical window for solid state Li-metal batteries

Orienting dendrite resistant behavior via heteroatom regulation toward high areal capacity zinc metal anode.

Tailoring polyaniline with dual dopant engineering as a high efficiency cathode material for aqueous zinc ion batteries.

Aqueous Zn-S batteries are promising candidates for future energy storage due to their intrinsic safety, environmental friendliness, and low cost. However, their practical application is hindered by sluggish sulfur redox kinetics and rapid zinc anode degradation. Here, we introduce choline iodide (ChI) as a multifunctional electrolyte additive that enables bidirectional catalysis of sulfur conversion and simultaneous protection of the zinc anode. During discharge, Ch+ promotes the formation of soluble polysulfide intermediates, which rapidly combine with Zn2+ to form ZnS via a solid-liquid-solid pathway, accelerating reaction kinetics. During charge, iodine species catalyze the conversion of ZnS back to sulfur. Moreover, Ch+ adsorbs on the zinc anode, suppressing dendrite growth and the hydrogen evolution reaction. Importantly, Ch+ also inhibits polyiodide shuttling at high iodine concentrations, maximizing catalytic efficiency. Coupled with a CoNC solid-phase catalyst, the Zn-S cell achieves a record-low polarization of 0.26V at 0.1C, delivers 780mAhg-1 at 10C, and maintains 380mAhg-1 after 5500 cycles.

The global opioid crisis has been accelerated by fentanyl and its analogues, compounds optimized for potency but burdened by vanishingly narrow safety margins. This mini-review integrates chemical, pharmacological, toxicological, and regulatory evidence to interrogate the “more-potent-is-better” paradigm. We synthesize in vivo data across representative analogues, highlighting those compounds that are much more potent than fentanyl and the risks of their use. Moreover, several analogues exhibit markedly low protection indices, indicating that doses producing analgesia lie perilously close to those causing hypoventilation. Reversing the effects of overdose remains pharmacologically feasible, although in vitro evidence suggests that antagonists such as naloxone may require higher or repeated doses to counteract ultra-potent fentanyl analogs. Forensic and public-health signals, rapid marketplace turnover, metabolic complexity, polysubstance exposure, and episodic mass poisonings, underscore the risks of continuing to chase potency. We also map the regulatory gap at the health–security nexus and flag dual-use concerns, including AI-enabled design of ultra-potent scaffolds with poor therapeutic windows. We argue for a strategic pivot: prioritize intrinsic safety over potency by targeting wider therapeutic windows, mechanism-level dissociation of analgesia from respiratory depression, standardized antagonist requirements, and class-aware scheduling that preserves legitimate research. Redirecting discovery toward safety-first opioids is both scientifically tractable and ethically imperative.

Aqueous zinc-ion batteries (AZIBs) offer intrinsic safety and low cost, positioning them as promising candidates for large-scale energy storage. However, uncontrolled Zn dendrite growth and parasitic hydrogen evolution reactions (HER) at the anode impede practical deployment. To address this, a dual-interfacial layer (BN@Sn@Zn) combining zincophilic Sn and zincophobic boron nitride (BN) is engineered. This architecture regulates initial Zn2⁺ nucleation and subsequent deposition, suppressing dendrite formation while exploiting BN's high hydrogen adsorption energy to inhibit HER. The low ionic diffusion barrier of this bilayer synergistically enhances kinetics and enables rapid Zn2⁺ transport, facilitating homogeneous deposition. Consequently, the modified anode achieves a prolonged cycling lifespan of 1050h at 6mA cm-2, 6mAh cm-2. In full-cell configuration with MnO2 cathode, it retains 75mAh g-1 after 2000 cycles, demonstrating superior stability versus bare Zn counterparts. This work innovates dual-functional interfaces to optimize Zn deposition dynamics, advancing high-performance AZIBs for sustainable energy storage systems.

Rechargeable magnesium batteries (RMBs) have recently attracted considerable attention as promising next-generation energy storage systems due to their high volumetric capacity, abundant natural reserves, low cost, and intrinsic safety. However, despite these inherent advantages, their practical implementation remains challenging. A major bottleneck lies in the formation of non-uniform magnesium deposition during repeated plating/stripping cycles, which leads to the development of unstable interfaces, high overpotentials, and rapid capacity degradation. Therefore, the development of novel Mg anode host materials that can facilitate uniform deposition while suppressing dendritic growth is essential for advancing the practical use of RMBs. In this study, we propose a rationally designed three-dimensional (3D) carbon scaffold derived from a zeolitic imidazolate framework (ZIF-8), synthesized via an electrospinning method combined with subsequent thermal treatment. During the pyrolysis process, ZIF-8 particles embedded within a PAN-derived carbon nanofibers transform into hollow carbon cages, resulting in a highly porous architecture with interconnected mesopores. This structure not only ensures efficient ion transport but also suppresses localized current density by providing abundant nucleation sites. Moreover, the porous carbon nanofiber framework is embedded with atomically dispersed Zn single atoms, which act as magnesiophilic agents to promote ultra-uniform Mg nucleation. As a result, carbon host with Zn single atoms electrodes demonstrate outstanding electrochemical performance, achieving stable and dendrite-free cycling for over 1500 hours at a current density of 5 mA cm⁻² and 5 mAh cm-2. Importantly, this approach offers a scalable and cost-effective route to fabricating high-performance anodes for RMBs, representing a significant advancement toward the realization of practical magnesium-based energy storage technologies.

Zinc-ion hybrid capacitors (ZHCs) are attracting considerable interest as next-generation energy storage devices due to their intrinsic safety, environmental friendliness, and cost-effectiveness. However, their practical implementation is limited by challenges such as zinc dendrite formation, interfacial instability of the Zn anode, and inadequate performance of cathode materials. In this study, we report the synthesis of manganese-based nanofibers via electrospinning, followed by controlled thermal treatment, to serve as efficient cathode materials for ZHCs. [1,2] The unique one-dimensional fibrous morphology provides a continuous conductive network, enhanced ion diffusion pathways, and improved structural stability. The resulting electrode exhibits high specific capacitance of 201.89 mAh g-1 (454.25 F g-1) with excellent rate capability up to 5000 galvanostatic charge discharge cycles. A solution resistance of 16.9 W and a charge transfer resistance of 48 ohm is observed which is due to the diffusion rate of Zn2+ ion in presence of electrolyte and adsorption kinetics of electrolyte ions respectively. [1-4] The above results imply that the designed ZIC in the aqueous electrolyte possesses good electrochemical performance and stability. This work offers a scalable strategy for designing advanced cathode architectures and contributes to overcoming key limitations in the development of high-performance zinc-ion energy storage systems.Reference: S. Wang, Q. Wang, W. Zeng, M. Wang, L. Ruan, Y. Ma, Nano-Micro Lett. 2019, 11, 70.K. Li, J. Li, L. Wang, X. Li, X. Yang, W. Lu, J. Alloys Comp. 2022, 928, 167153.K. Zhang, Y. Bai, L. Wang, Y. Gao, X. Li, X. Yang, W. Lü, Langmuir 2024, 40, 50, 26561–26569.Y. Bai, K. Li, L. Wang, Y. Gao, X. Li, X. Yang, W. Lü, J. Power Sources 2024, 591, 233878. Figure 1

Vanadium oxide (VO)-based aqueous zinc-ion batteries (AZIBs) are emerging as attractive candidates for next-generation grid-scale energy storage systems (ESSs), owing to their intrinsic safety, environmental friendliness, cost-effectiveness, and high energy density. The high capacity of VO stems from the multivalent redox activity of vanadium (V3+/V4+/V5+) and the open-layered structure that facilitates Zn2+ intercalation by mitigating strong electrostatic interactions within the host lattice.[1] These features, coupled with neutral or mildly acidic electrolytes, most commonly ZnSO4 solution, offer a compelling route to scalable aqueous batteries. However, VO-based AZIBs continue to suffer from poor long-term cycling stability, particularly under moderate current densities (<500 mA g−1), which are essential for delivering consistent power output in ESS applications.[2] This issue is mainly attributed to vanadium dissolution, which is exacerbated at lower current densities due to prolonged exposure to active water molecules in the electrolyte.[2] While various strategies, such as electrode engineering, electrolyte modification, and protective coatings, have improved cycling performance, a significant gap remains between stability at low and high current densities. Critically, most studies have focused solely on suppressing VO dissolution at the cathode, without fully considering the impact of dissolved V-species on the zinc metal anode (ZMA) or the full-cell dynamics.In this study, we identify and characterize a previously unrecognized degradation mechanism in VO-based AZIBs, governed by a vanadium redox shuttling process that induces cathode–anode cross-talk (Fig. 1). Using a representative hydrated VO cathode (V2O5·nH2O) and 2 M ZnSO4 aqueous electrolyte, we examine interfacial behaviors through synchrotron-based XANES analysis, focusing on full-cell-level dynamics under varying current densities and voltages.Our findings reveal that during charging, dissolved V5+ species migrate from the VO cathode to the ZMA and are spontaneously reduced to lower-valent species (e.g., V3+), forming either surface deposits or remaining as soluble intermediates. During discharge or rest, these reduced species return to the cathode and re-oxidize, establishing a parasitic redox shuttle. This cycle leads to unintended Zn consumption, increased interfacial resistance, decrease in Coulombic efficiency, and self-discharge. Notably, this shuttling becomes more pronounced at lower current densities due to the pronounced vanadium dissolution and less kinetically suppressed vanadium mobility. Eventually, the shuttle persists until the ZMA surface becomes passivated by V-rich layers, which suppress further reactions but at the cost of degraded interface structure.This study reveals cathode–anode cross-talk as a key degradation pathway in AZIBs and suggests that tailored interfacial chemistries to suppress vanadium shuttling offer a promising solution.Overall, our work highlights the necessity of full-cell-level diagnostic approaches and integrated design strategies encompassing electrode–electrolyte–interface interactions. By elucidating the dynamic behavior of vanadium redox species and their role in full-cell level degradation, this study provides a foundation for developing more robust and durable aqueous battery systems for grid-scale applications. Figure 1

All-solid-state batteries (ASSBs) have emerged as a next-generation energy storage solution, offering superior safety and energy density compared to conventional lithium-ion batteries. Oxide-ceramic cell concepts, based on the garnet-type solid electrolyte Li7La3Zr2O12 (LLZO), stand out due to their excellent chemical and electrochemical stability, high ionic conductivity, and intrinsic safety. In particular, LLZO exhibits remarkable compatibility with lithium metal anodes, enabling the development of high-energy-density ASSBs. However, the challenge remains to combine LLZO and cathode active materials (CAM) to form a stable mixed cathode. High-temperature sintering steps, which are indispensable in ceramic processing, often lead to severe material degradation, resulting in high interfacial resistance and capacity loss. Previous work has made significant advances in investigating material interaction and enabling composite cathodes based on Lithium cobalt oxide (LCO) CAM and LLZO. To realize the full potential of the oxide-ceramic ASSB, it is necessary to use cathode active materials with high energy and power densities. For this reason, we are addressing the challenge of using nickel-rich NCM with a theoretical capacity > 200 mAh g-1 in fully ceramic NCM/LLZO composite cathodes.First, the chemical compatibility of doped LLZO:X (X = Ta, Al or Ga) and NCM cathode active material was evaluated in a bilayer model system. Material degradation, cation interdiffusion, and parasitic reactions were investigated by XRD, Raman, SEM, EDS, and ToF-SIMS. The electrochemical properties of the LLZO were examined by electrochemical impedance spectroscopy (EIS). It became evident that the phase degradation of the LLZO and secondary phase evolution caused by nickel interdiffusion strongly depend on the dopant-induced stability of LLZO, its internal grain boundaries, and its microstructure. These insights allowed us to develop optimization strategies for the LLZO starting material, based on its composition and the sintering method. The updated material shows improved chemical stability while retaining its ionic conductivity during high-temperature processing steps in contact with NCM.However, high-temperature sintering steps involved in ceramic processing remain a challenge in manufacturing LLZO-based composite cathodes. Therefore, we utilized the Field-assisted sintering technique / spark plasma sintering (FAST/SPS) to move the processing window to lower temperatures < 750 °C and reduced dwell times < 10 min by applying a high uniaxial pressure to the sample. This enhances the sintering, leading to very dense samples, while simultaneously reducing the energy consumption of the process. Additionally, FAST/SPS allows us to go directly from the starting materials to the composite without the use of binders and other additives. The free-standing composite cathodes with thicknesses between 100 µm and 150 µm made from NCM and LLZO produced in this study are highly dense (ρrel > 99 %) and show good interfacial contact with limited degradation. We obtain a high CAM loading of > 25 mg cm-2 and first cell tests show promising areal discharge capacities of up to 3.25 mAh cm-2 in the first cycle.In conclusion, we demonstrate the feasibility of manufacturing functional, fully ceramic, additive-free NCM/LLZO composite cathodes for all-solid-state batteries. Our results are based on a systematic material selection and optimization study, varying the dopant elements of the LLZO solid electrolyte, and were realized using a novel processing route with the innovative use of FAST/SPS to realize oxide-ceramic electrolyte based ASSBs.

Aqueous zinc-ion batteries (AZIBs) are promising candidates for large-scale energy storage systems due to their intrinsic safety, cost-effectiveness, and high volumetric energy density. However, the formation of Zn dendrites and parasitic reactions at the Zn anode significantly hinder their practical application. To overcome these challenges, we developed a sonochemical method to directly synthesize a crystalline–amorphous mixed 2D nanocarbon film, termed “Leopard-patterned graphene (Leo-G),” on Zn substrates. This method leverages cavitation in p-xylene to locally decompose carbon precursors, enabling direct growth under ambient conditions. The unique Leo-G structure provides uniform Zn nucleation sites and high Zn2+ ion permeability, effectively suppressing dendrite formation. Electrochemical evaluations demonstrate that Leo-G@Zn exhibits a significantly lower Zn nucleation overpotential, reduced Zn²⁺ redox activation energy, and enhanced cycling stability, maintaining over 2000 hours of stable operation in symmetric cells at a current density of 3 mA cm-2. In full-cell tests with an α-MnO₂ cathode, the Leo-G@Zn anode retained 96.1% of its capacity after 300 cycles. This study presents a scalable, room-temperature strategy for the direct growth of 2D nanocarbon on Zn, offering a promising route to improve the performance and safety of AZIBs for practical energy storage applications.

Rechargeable aluminum–sulfur (Al–S) batteries are considered promising candidates for next-generation energy storage owing to the natural abundance, intrinsic safety, low cost, and high gravimetric capacities of aluminum and sulfur (2980 mAh g⁻¹ and 1675 mAh g⁻¹, respectively). However, their practical deployment has been hindered by the scarcity of electrolytes that can simultaneously support reversible aluminum electrodeposition and sulfur electroreduction, while also minimizing polarization losses. Alkali chloroaluminate molten salts (AlCl₃–NaCl–KCl) were recently used as electrolytes for Al–S batteries instead of conventional AlCl₃–EMImCl (1-ethyl-3-methylimidazolium chloride) ionic liquids, demonstrating significantly reduced polarization at elevated temperature (e.g., 110 °C), though its origins are poorly understood.In this work, we investigate how electrolyte speciation, ion mobility, and soluble intermediates in these two electrolyte systems influence polarization losses in rechargeable Al–S batteries. Variable-temperature liquid-state 27Al, 23Na, and 1H single-pulse and relaxation nuclear magnetic resonance (NMR) measurements were conducted under quantitative conditions to probe electrolyte speciation and ion dynamics. 23Na and 1H pulsed-field-gradient (PFG) NMR experiments were also performed to quantify cation diffusion coefficients and their activation energies for diffusion. Additionally, integrated 27Al and 23Na NMR signal intensities of the molten salt electrolyte enabled accurate measurements of its freezing and melting temperature range, which coupled with changes in ion mobility, yielded insights into the optimum operating temperature. Differential scanning calorimetry (DSC) was also performed to measure these thermodynamic phase transitions and analyzed with respect to the NMR data. Solid-state 27Al and 23Na single-pulse NMR measurements of both pristine and cycled molten salt electrolytes provided mechanistic insights into the electrochemical conversion reaction, including the formation of electrolyte soluble polysulfide-like intermediates. In addition, we formulated quaternary electrolyte mixtures comprising AlCl₃, NaCl, KCl, and a fourth component (e.g., [EMIm]Cl, urea, or LiCl) with the objective of lowering the operating temperature and understanding the effects on cell polarization. Al-S batteries were prepared using the different electrolytes to compare their overpotentials, as well as specific capacities, cycle life, and cell impedance. Overall, the roles of electrolyte speciation, ion mobility and soluble intermediates in governing the overpotential in Al-S batteries were elucidated, providing new insights for the rational design of low cost, energy dense electrolytes for Al-S batteries.