A rechargeable calcium-oxygen battery that operates at room temperature.

Calcium-oxygen (Ca-O2) batteries can theoretically afford high capacity by the reduction of O2 to calcium oxide compounds (CaOx) at low cost1-5. Yet, a rechargeable Ca-O2 battery that operates at room temperature has not been achieved because the CaOx/O2 chemistry typically involves inert discharge products and few electrolytes can accommodate both a highly reductive Ca metal anode and O2. Here we report a Ca-O2 battery that is rechargeable for 700 cycles at room temperature. Our battery relies on a highly reversible two-electron redox to form chemically reactive calcium peroxide (CaO2) as the discharge product. Using a durable ionic liquid-based electrolyte, this two-electron reaction is enabled by the facilitated Ca plating-stripping in the Ca metal anode at room temperature and improved CaO2/O2 redox in the air cathode. We show the proposed Ca-O2 battery is stable in air and can be made into flexible fibres that are weaved into textile batteries for next-generation wearable systems.

Step-by-step desolvation enables high-rate and ultra-stable sodium storage in hard carbon anodes.

Hard carbon is regarded as the most promising anode material for sodium-ion (Na-ion) batteries, owing to its advantages of high abundance, low cost, and low operating potential. However, the rate capability and cycle life span of hard carbon anodes are far from satisfactory, severely hindering its industrial applications. Here, we demonstrate that the desolvation process defines the Na-ion diffusion kinetics and the formation of a solid electrolyte interface (SEI). The 3A zeolite molecular sieve film on the hard carbon is proposed to develop a step-by-step desolvation pathway that effectively reduces the high activation energy of the direct desolvation process. Moreover, step-by-step desolvation yields a thin and inorganic-dominated SEI with a lower activation energy for Na+ transport. As a result, it contributes to greatly improved power density and cycling stability for both ester and ether electrolytes. When the above insights are applied, the hard carbon anode achieves the longest life span and minimum capacity fading rate at all evaluated current densities. Moreover, with the increase in current densities, an improved plateau capacity ratio is observed. This step-by-step desolvation strategy comprehensively enhances various properties of hard carbon anodes, which provides the possibility of building practical Na-ion batteries with high power density, high energy density, and durability.

Recent advances in zinc-ion dehydration strategies for optimized Zn-metal batteries.

Aqueous Zn-metal batteries have attracted increasing interest for large-scale energy storage owing to their outstanding merits in terms of safety, cost and production. However, they constantly suffer from inadequate energy density and poor cycling stability due to the presence of zinc ions in the fully hydrated solvation state. Thus, designing the dehydrated solvation structure of zinc ions can effectively address the current drawbacks of aqueous Zn-metal batteries. In this case, considering the lack of studies focused on strategies for the dehydration of zinc ions, herein, we present a systematic and comprehensive review to deepen the understanding of zinc-ion solvation regulation. Two fundamental design principles of component regulation and pre-desolvation are summarized in terms of solvation environment formation and interfacial desolvation behavior. Subsequently, specific strategy based distinct principles are carefully discussed, including preparation methods, working mechanisms, analysis approaches and performance improvements. Finally, we present a general summary of the issues addressed using zinc-ion dehydration strategies, and four critical aspects to promote zinc-ion solvation regulation are presented as an outlook, involving updating (de)solvation theories, revealing interfacial evolution, enhancing analysis techniques and developing functional materials. We believe that this review will not only stimulate more creativity in optimizing aqueous electrolytes but also provide valuable insights into designing other battery systems.

Sustainable Electrosynthesis of N,N-Dimethylformamide via Relay Catalysis on Synergistic Active Sites.

Electrified synthesis of high-value organonitrogen chemicals from low-cost carbon- and nitrogen-based feedstocks offers an economically and environmentally appealing alternative to traditional thermocatalytic methods. However, the intricate electrochemical reactions at electrode surfaces pose significant challenges in controlling selectivity and activity, especially for producing complex substances such as N,N-dimethylformamide (DMF). Herein, we tackle this challenge by developing relay catalysis for efficient DMF production using a composite WO2-NiOOH/Ni catalyst with two distinctive active sites. Specifically, WO2 selectively promotes dimethylamine (DMA) electrooxidation to produce strongly surface-bound (CH3)2N*, while nearby NiOOH facilitates methanol electrooxidation to yield more weakly bound *CHO. The disparity in binding energetics of the key C- and N-intermediates expedites C-N coupling at the WO2-NiOOH interface. In situ infrared spectroscopy with isotope-labeling experiments, quasi-in situ electron paramagnetic resonance trapping experiments, and electrochemical operating experiments revealed the C-N coupling mechanism and enhanced DMF-synthesis selectivity and activity. In situ X-ray absorption spectroscopy (XAS) and postreaction transmission electron microscopy (TEM) studies verified the stability of WO2-NiOOH/Ni during extended electrochemical operation. A Faradaic efficiency of ∼50% and a production rate of 438 µmol cm-2 h-1 were achieved at an industrially relevant current density of 100 mA cm-2 over an 80 h DMF production period. This study introduces a new paradigm for developing electrothermo relay catalysis for the sustainable and efficient synthesis of valuable organic chemicals with industrial potential.

Unlocking Dynamic Solvation Chemistry and Hydrogen Evolution Mechanism in Aqueous Zinc Batteries.

Understanding the interfacial hydrogen evolution reaction (HER) is crucial to regulate the electrochemical behavior in aqueous zinc batteries. However, the mechanism of HER related to solvation chemistry remains elusive, especially the time-dependent dynamic evolution of the hydrogen bond (H-bond) under an electric field. Herein, we combine in situ spectroscopy with molecular dynamics simulation to unravel the dynamic evolution of the interfacial solvation structure. We find two critical change processes involving Zn-electroplating/stripping, including the initial electric double layer establishment to form an H2O-rich interface (abrupt change) and the subsequent dynamic evolution of an H-bond (gradual change). Moreover, the number of H-bonds increases, and their strength weakens in comparison with the bulk electrolyte under bias potential during Zn2+ desolvation, forming a diluted interface, resulting in massive hydrogen production. On the contrary, a concentrated interface (H-bond number decreases and strength enhances) is formed and produces a small amount of hydrogen during Zn2+ solvation. The insights on the above results contribute to deciphering the H-bond evolution with competition/corrosion HER during Zn-electroplating/stripping and clarifying the essence of electrochemical window widened and HER suppression by high concentration. This work presents a new strategy for aqueous electrolyte regulation by benchmarking the abrupt change of the interfacial state under an electric field as a zinc performance-enhancement criterion.

From Oxygen Redox to Sulfur Redox: A Paradigm for Li-Rich Layered Cathodes.

The utilization of anionic redox chemistry provides an opportunity to further improve the energy density of Li-ion batteries, particularly for Li-rich layered oxides. However, oxygen-based hosts still suffer from unfavorable structural rearrangement, including the oxygen release and transition metal (TM)-ion migration, in association with the tenuous framework rooted in the ionicity of the TM-O bonding. An intrinsic solution, by using a sulfur-based host with strong TM-S covalency, is proposed here to buffer the lattice distortion upon the highly activating sulfur redox process, and it achieves howling success in stabilizing the host frameworks. Experimental results demonstrate the prolonged preservation of the layered sulfur lattice, especially the honeycomb superlattice, during the Li+ extraction/insertion process in contrast to the large structural degeneration in Li-rich oxides. Moreover, the Li-rich sulfide cathodes exhibited a negligible overpotential of 0.08 V and a voltage drop of 0.13 mV/cycle, while maintaining a substantial reversible capacity upon cycling. These superior electrochemical performances can be unambiguously ascribed to the much shorter trajectories of sulfur in comparison to those of oxygen revealed by molecular dynamics simulations at a large scale (∼30 nm) and a long time scale (∼300 ps) via high-dimensional neural network potentials during the delithiation process. Our findings highlight the importance of stabilizing host frameworks and establish general guidance for designing Li-rich cathodes with durable anionic redox chemistry.

Intercepting Dendrite Growth With a Heterogeneous Solid Electrolyte for Long-Life All-Solid-State Lithium Metal Batteries.

The application of lithium metal anode in all-solid-state batteries has the potential to achieve both high energy density and safety performance. However, the presence of serious dendrite issues hinders this potential. Here, the ion transport pathways and orientation of dendrite growth are regulated by utilizing the differences of ionic conductivity in heterogeneous electrolytes. The in situ formed Li-Ge alloy phases from the spontaneous reaction between Li10GeP2S12 and the attracted dendrites greatly enhance the ability to resist dendrite growth. As an outcome, the heterogeneous electrolyte achieves a high critical current density of 2.1 mA cm-2 and long-term stable symmetrical battery operation (0.3 mA cm-2 for 17 000 h and 1.0 mA cm-2 for 2000 h). Besides, due to the superior interfacial stability and low interface impedance between the heterogeneous electrolyte and lithium anode, the Li||LiNi0.8Co0.1Mn0.1O2 full battery exhibits great cycling stability (80.5% after 500 cycles at 1.0 mA cm-2) and rate performance (125.4 mAh g at 2.0 mA cm-2). This work provides a unique strategy of interface regulation via heterogeneous electrolytes design, offering insights into the development of state-of the-art all-solid-state batteries.

Lithium Metal Recovery from Sea Water by a Flexible and Scalable Membrane with Lithium-Ion Exclusive Channels.

Sea water is abundant in lithium reserves, and extracting lithium metal from it holds the potential to not only mitigate the shortage of lithium in light of the fast-growing electric vehicle industry, but also serve as an anode electrode to provide electricity. The task, however, is challenging due to the harsh reactions and low lithium concentration in sea water. Here, we present a single-channel strategy based on a flexible and scalable lithium ion-sieve membrane for efficient lithium extraction. Our composite membrane exhibits high separation factor ßLi/Na of more than 2.87 × 107 with an ionic conductivity of 6.2×10-5 S cm-1. Lithium metal was electrolytically extracted from sea water through a hybrid-electrolyte system, which yielded a high Coulombic efficiency of 98.04% and a low energy consumption of 17.4 kWh kgLi-1 at an optimized extracting current of 200 µA cm-2. The extracted lithium metal can be directly integrated into a lithium-sulfur battery, delivering an energy output of 395 Wh kg-1. To demonstrate its industrial viability, we also fabricate a pouch cell with Li metal anode extracted by an amplified extraction prototype. This study has the potential to dispel concerns of lithium depletion and facilitate the sustainable development of lithium-based energy storage systems.

Solvation-Tailored PVDF-Based Solid-State Electrolyte for High-Voltage Lithium Metal Batteries.

Poly(vinylidene fluoride) (PVDF)-based polymer electro-lytes are attracting increasing attention for high-voltage solid-state lithium metal batteries because of their high room temperature ionic conductivity, adequate mechanical strength and good thermal stability. However, the presence of highly reactive residual solvents, such as N, N-dimethylformamide (DMF), severely jeopardizes the long-term cycling stability. Herein, we propose a solvation-tailoring strategy to confine residual solvent molecules by introducing low-cost 3 Šzeolite molecular sieves as fillers. The strong interaction between DMF and the molecular sieve weakens the ability of DMF to participate in the solvation of Li+, leading to more anions being involved in solvation. Benefiting from the tailored anion-rich coordination environment, the interfacial side reactions with the lithium anode and high-voltage NCM811 cathode are effectively suppressed. As a result, the solid-state Li||Li symmetrical cells demonstrates ultra-stable cycling over 5100 h at 0.1 mA cm-2, and the Li||NCM811 full cells achieve excellent cycling stability for more than 1130 and 250 cycles under the charging cut-off voltages of 4.3 V and 4.5 V, respectively. Our work is an innovative exploration to address the negative effects of residual DMF in PVDF-based solid-state electrolytes and highlights the importance of modulating the solvation structures in solid-state polymer electrolytes.

Molecular Engineering Enabling High Initial Coulombic Efficiency and Rubost Solid Electrolyte Interphase for Hard Carbon in Sodium-Ion Batteries.

Hard carbon (HC) as a potential candidate anode for sodium-ion batteries (SIBs) suffers from unstable solid electrolyte interphase (SEI) and low initial Coulombic efficiency (ICE), which limits its commercial applications and urgently requires the emergence of a new strategy. Herein, an organic molecule with two sodium ions, disodium phthalate (DP), was successfully engineered on the HC surface (DP-HC) to replenish the sodium loss from solid electrolyte interphase (SEI) formation. A stabilized and ultrathin (≈7.4 nm) SEI was constructed on the DP-HC surface, which proved to be simultaneously suitable in both ester and ether electrolytes. Compared to pure HC (60.8 %), the as-designed DP-HC exhibited a high ICE of >96.3 % in NaPF6 in diglyme (G2) electrolyte, and is capable of servicing consistently for >1600 cycles at 0.5 A g-1 . The Na3 V2 (PO4 )3 (NVP)|DP-HC full-cell with a 98.3 % exceptional ICE can be cycled stably for 450 cycles, demonstrating the tremendous practical application potential of DP-HC. This work provides a molecular design strategy to improve the ICE of HC, which will inspire more researchers to concentrate on the commercialization progress of HC.

Tailoring the Electrode-Electrolyte Interface for Reliable Operation of All-Climate 4.8†V Li||NCM811 Batteries.

Combining high-voltage nickel-rich cathodes with lithium metal anodes is among the most promising approaches for achieving high-energy-density lithium batteries. However, most current electrolytes fail to simultaneously satisfy the compatibility requirements for the lithium metal anode and the tolerance for the ultra-high voltage NCM811 cathode. Here, we have designed an ultra-oxidation-resistant electrolyte by meticulously adjusting the composition of fluorinated carbonates. Our study reveals that a solid-electrolyte interphase (SEI) rich in LiF and Li2O is constructed on the lithium anode through the synergistic decomposition of the fluorinated solvents and PF6 - anion, facilitating smooth lithium metal deposition. The superior oxidation resistance of our electrolyte enables the Li||NCM811 cell to deliver a capacity retention of 80 % after 300 cycles at an ultrahigh cut-off voltage of 4.8 V. Additionally, a pioneering 4.8 V-class lithium metal pouch cell with an energy density of 462.2 Wh kg-1 stably cycles for 110 cycles under harsh conditions of high cathode loading (30 mg cm-2), low N/P ratio (1.18), and lean electrolytes (2.3 g Ah-1).

Integrating Prelithiation and Interface Protection to Achieve High-Energy All-Solid-State Batteries.

All-solid-state batteries (ASSBs), particularly those with Li-free anodes or even anode-free configurations, have attracted extensive attention due to high safety and energy density. However, chemical-mechanical degradation typically deteriorates the cycle life and energy of Li-free anode ASSBs with the absence of Li inventory. Here, the prelithiation agent Li5FeO4 (LFO) coated Ni-rich layered oxide is developed as the cathode for Li-free anode ASSBs. The coated LFO acts as an interfacial protective layer to prevent the highly oxidizing Ni-rich cathode from reacting with sulfide solid-state electrolytes (SSEs), mitigating the structural degradation of Ni-rich cathodes and the decomposition of SSE, resulting in excellent cycle life. Beneficial from the coated LFO in the cathode of the Li-free anode ASSBs, the reversible capacity improves from 174.7 mAh g-1 to 199.7 mAh g-1, and the capacity retention is enhanced from 33.8% to 84.8% after 100 cycles. Additionally, an ultrahigh energy density of 440 Wh kg-1, based on the mass of the composite cathode, Li-free anode, and SSE, is obtained in a Li-free anode all-solid-state pouch cell equipped with the LFO-coated cathode.

A P2/P3 Biphasic Layered Oxide Composite as a High-Energy and Long-Cycle-Life Cathode for Potassium-Ion Batteries.

Layered transition metal oxides are extensively considered as appealing cathode candidates for potassium-ion batteries (PIBs) due to their abundant raw materials and low cost, but their further implementations are limited by slow dynamics and impoverished structural stability. Herein, a layered composite having a P2 and P3 symbiotic structure is designed and synthesized to realize PIBs with large energy density and long-term cycling stability. The unique intergrowth of P2 and P3 phases in the obtained layered oxide is plainly characterized by X-ray diffraction refinement, high-angle annular dark field and annular bright field-scanning transmission electron microscopy at atomic resolution, and Fourier transformation images. The synergistic effect of the two phases of this layered P2/P3 composite is well demonstrated in K+ intercalation/extraction process. The as-prepared layered composite can present a large discharge capacity with the remarkable energy density of 321 Wh kg-1 and also manifest excellent capacity preservation after 600 cycles of K+ uptake/removal.

Chelating Additive Regulating Zn-Ion Solvation Chemistry for Highly Efficient Aqueous Zinc-Metal Battery.

Aqueous zinc-metal batteries (AZMBs) usually suffered from poor reversibility and limited lifespan because of serious water induced side-reactions, hydrogen evolution reactions (HER) and rampant zinc (Zn) dendrite growth. Reducing the content of water molecules within Zn-ion solvation sheaths can effectively suppress those inherent defects of AZMBs. In this work, we originally discovered that the two carbonyl groups of N-Acetyl-ϵ-caprolactam (N-ac) chelating ligand can serve as dual solvation sites to coordinate with Zn2+, thereby minimizing water molecules within Zn-ion solvation sheaths, and greatly inhibit water-induced side-reactions and HER. Moreover, the N-ac chelating additive can form a unique physical barrier interface on Zn surface, preventing the harmful contacting with water. In addition, the preferential adsorption of N-ac on Zn (002) facets can promote highly reversible and dendrite-free Zn2+ deposition. As a result, Zn//Cu half-cell within N-ac added electrolyte delivered ultra-high 99.89 % Coulombic efficiency during 8000 cycles. Zn//Zn symmetric cells also demonstrated unprecedented long life of more than 9800 hours (over one year). Aqueous Zn//ZnV6O16 ⋅ 8H2O (Zn//ZVO) full-cell preserved 78 % capacity even after ultra-long 2000 cycles. A more practical pouch-cell was also obtained (90.2 % capacity after 100 cycles). This method offers a promising strategy for accelerating the development of highly efficient AZMBs.

A Customized Strategy Realizes Stable Cycle of Large-Capacity and High-Voltage Layered Cathode for Sodium-Ion Batteries.

High-voltage P2-Na0.67Ni0.33Mn0.67O2 layered oxide cathode exhibits significant potential for sodium-ion batteries, owing to the elevated operating voltage and theoretical energy density beyond lithium iron phosphate, but the large-volume phase transition is the devil. Currently, this type cathode still suffers from stability-capacity trade-off dilemma. Herein, a concept of customized strategy via multiple rock-forming elements trace doping is presented to address the mentioned issue. The customized Mg-Al-Ti trace doped cathode maintains a notable capacity of 140.3 mAh g - 1 with an energy density approaching 500 Wh kg - 1, and shows good cycle stability, retaining 89.0% of its capacity after 50 cycles at 0.1C. Additionally, the full cell, paired with a hard carbon anode, achieves an advanced energy density of 303.3 Wh kg-1. The multiple characterizations reveal the failure mechanism of contrast sample involving severe intragranular cracks coupled with layer to rock salt transformation, which reduces active substance and increases charge transfer resistance. The doped sample with increased sliding energy barrier well suppresses this phenomenon. Impressively, the customized strategy can be extended to Mg-Fe-Ti system. This research provides a novel concept for the design of high energy sodium-ion cathode.

A Rechargeable "Rocking Chair" Type Zn-CO2 Battery.

Rising global temperatures and critical energy shortages have spurred researches into CO2 fixation and conversion within the realm of energy storage such as Zn-CO2 batteries. However, traditional Zn-CO2 batteries employ double-compartment electrolytic cells with separate carriers for catholytes and anolytes, diverging from the "rocking chair" battery mechanism. The specific energy of these conventional batteries is constrained by the solubility of discharge reactants/products in the electrolyte. Additionally, H2O molecules tend to trigger parasitic reactions at the electrolyte/electrode interfaces, undermining the long-term stability of Zn anodes. In this report, we introduce an innovative "rocking chair" type Zn-CO2 battery that utilizes a weak-acidic zinc trifluoromethanesulfonate aqueous electrolyte compatible with both cathode and anode. This design minimizes side reactions on the Zn surface and leverages the high catalytic activity of the cathode material, allowing the battery to achieve a substantial discharge capacity of 6734 mAh g-1 and maintain performance over 65 cycles. Moreover, the successful production of pouch cells demonstrates the practical applicability of Zn-CO2 batteries. Electrode characterizations confirm superior electrochemical reversibility, facilitated by solid discharge products of ZnCO3 and C. This work advances a "rocking chair" Zn-CO2 battery with an enhanced specific energy and a reversible pathway, providing a foundation for developing high-performance metal-CO2 batteries.

Constructing An Oxyhalide Interface for 4.8†V-Tolerant High-Nickel Cathodes in All-Solid-State Lithium-Ion Batteries.

All-solid-state lithium batteries (ASSBs) have received increasing attentions as one promising candidate for the next-generation energy storage devices. Among various solid electrolytes, sulfide-based ASSBs combined with layered oxide cathodes have emerged due to the high energy density and safety performance, even at high-voltage conditions. However, the interface compatibility issues remain to be solved at the interface between the oxide cathode and sulfide electrolyte. To circumvent this issue, we propose a simple but effective approach to magic the adverse surface alkali into a uniform oxyhalide coating on LiNi0.8Co0.1Mn0.1O2 (NCM811) via a controllable gas-solid reaction. Due to the enhancement of the close contact at interface, the ASSBs exhibit improved kinetic performance across a broad temperature range, especially at the freezing point. Besides, owing to the high-voltage tolerance of the protective layer, ASSBs demonstrate excellent cyclic stability under high cutoff voltages (500 cycles~94.0 % at 4.5 V, 200 cycles~80.4 % at 4.8 V). This work provides insights into using a high voltage stable oxyhalide coating strategy to enhance the development of high energy density ASSBs.

Achieving a Deeply Desodiated Stabilized Cathode Material by the High Entropy Strategy for Sodium-ion Batteries.

Manganese-based layered oxides are currently of significant interest as cathode materials for sodium-ion batteries due to their low toxicity and high specific capacity. However, the practical applications are impeded by sluggish intrinsic Na+ migration and poor structure stability as a result of Jahn-Teller distortion and complicated phase transition. In this study, a high-entropy strategy is proposed to enhance the high-voltage capacity and cycling stability. The designed P2-Na0.67Mn0.6Cu0.08Ni0.09Fe0.18Ti0.05O2 achieves a deeply desodiation and delivers charging capacity of 158.1 mAh g-1 corresponding to 0.61 Na with a high initial Coulombic efficiency of 98.2 %. The charge compensation is attributed to the cationic and anionic redox reactions conjunctively. Moreover, the crystal structure is effectively stabilized, leading to a slight variation of lattice parameters. This research carries implications for the expedited development of low-cost, high-energy-density cathode materials for sodium-ion batteries.

Revealing the Dynamic Evolution of Electrolyte Configuration on the Cathode-Electrolyte Interface by Visualizing (De)Solvation Processes.

Electrolyte engineering is crucial for improving cathode electrolyte interphase (CEI) to enhance the performance of lithium-ion batteries, especially at high charging cut-off voltages. However, typical electrolyte modification strategies always focus on the solvation structure in the bulk region, but consistently neglect the dynamic evolution of electrolyte solvation configuration at the cathode-electrolyte interface, which directly influences the CEI construction. Herein, we reveal an anti-synergy effect between Li+-solvation and interfacial electric field by visualizing the dynamic evolution of electrolyte solvation configuration at the cathode-electrolyte interface, which determines the concentration of interfacial solvated-Li+. The Li+ solvation in the charging process facilitates the construction of a concentrated (Li+-solvent/anion-rich) interface and anion-derived CEI, while the repulsive force derived from interfacial electric field induces the formation of a diluted (solvent-rich) interface and solvent-derived CEI. Modifying the electrochemical protocols and electrolyte formulation, we regulate the "inflection voltage" arising from the anti-synergy effect and prolong the lifetime of the concentrated interface, which further improves the functionality of CEI architecture.

Functional CNTs@EMIM+ -Br- Electrode Enabling Polysulfides Confining and Deposition Regulating for Solid-State Li-Sulfur Battery.

With an extremely high theoretical energy density, poly(ethylene oxide) (PEO)-based solid-state lithium-sulfur (Li-S) batteries are emerging as one of the most feasible and safest battery storage systems. However, the long-term cycling performance is severely impeded by polysulfides (Li2 Sn , n = 4-8) shuttling and terrible electrode passivation from the electronic insulating Li2 S. Here, a novel cathode through chemically grafted 1-Ethyl-3-methylimidazolium bromide (EMIM+ -Br- ) to carbon nanotube (CNTs) for PEO-based Li-S batteries is reported (CNTs@EMIM-Br/S). Concretely, bi-functional mediator EMIM+ -Br- not only inhibits the polysulfides shuttling by strong chemical interactions via EMIM+ , but also facilitates the electrochemical kinetics for promoting the formation of 3D particulate Li2 S through high donor anion (Br- ). Satisfactorily, dual-function CNTs@EMIM-Br/S cathode exhibits high sulfur utilization with the capacity of up to 1298 mAh g-1 , and keeps high capacity retention of 80.2% at 0.2 C after 350 cycles, exceeding that of many reported PEO-based solid-state Li-S batteries. This work will open a new door for rationally designed architecture to enable the practical applications of advanced Li-S batteries.