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In the field of electrolyte design for aqueous zinc‐ion batteries (AZIBs), additives containing hydroxyl have been demonstrated to effectively modulate the solvation structure of Zn2+. However, reported studies typically focus solely on the effectiveness of hydroxyl while neglecting the issues that emerge during solvation structure regulation. The strong electron‐attracting capability of Zn2+ attracts electrons from the oxygen in hydroxyl, thereby weakening the strength of hydroxyl, the hydrogen evolution reaction (HER) is also pronounced. This work innovatively reveals the limitation of hydroxyl‐containing additives and proposes a synergistic regulation strategy based on hybrid additives. Arginine with a high isoelectric point is introduced into the electrolyte system containing hydroxyl additives. The protonation effect and electrostatic attraction of arginine enable it to absorb protons at the anode released by the weakened hydroxyl, thereby compensating for the limitation of hydroxyl additives. Under the synergistic action of hybrid additives, the Zn|Zn battery achieved stable deposition/stripping for over 1200 hours under 10 mA cm−2 and 10 mAh cm−2. Moreover, the Zn|Cu battery cycled for over 570 hours with a high Coulombic efficiency of 99.82 %. This study presents a pioneering perspective for the further application of AZIBs. [ABSTRACT FROM AUTHOR]

To surpass the energy density limit of current Li–S batteries, attaining a long lifespan under lean‐electrolyte conditions is imperative. The persistent challenge involves suppressing electrolyte decomposition while facilitating sulfur electrode reaction. In this study, the solvating power of 1dimethoxy ethane is fine‐tuned, the main solvent, using fluorinated ether cosolvents via H–F interactions. As the fluorination degree of the cosolvent increases, the coordination of anions around the Li‐ion increases, and the solubilities of Li polysulfides decrease. By systematically varying the solvating power, moderately solvating electrolytes are prepared that can effectively suppress the dissolution of Li polysulfides without hindering the redox kinetics. The moderately solvating electrolytes induce uniform Li deposition and reduce electrolyte decomposition owing to the formation of anion‐derived solid electrolyte interphase. An assembled pouch‐type Li–S battery containing an electrolyte with an optimized solvation power delivers 405 Wh kg−1 at an E/S ratio of 2.0 µL mgs−1 with a lifespan of over 80 cycles. This study suggests a strategy to finely tune the Li+ solvation structure for achieving well‐balanced performances of sulfur cathodes and Li‐metal anodes under lean‐electrolyte conditions. [ABSTRACT FROM AUTHOR]

Polymer electrolytes are of interest in high‐energy‐density batteries. However, how the intrinsic electron‐donating capability of polymer segments involved in coordination affects lithium‐ion dissociation/transmission and rationally guides the design and fabrication of electrolytes is a highly exploratory topic. This study proposes a workable method that integrates machine learning with density functional theory to predict donor numbers (DN) for polymer building units. Using this approach, polymer chains with optimized DN are designed, effectively modulating the solvation structure of lithium‐ion. Molecular dynamics simulations confirm the positive impact of polymer chains on rapid transport of lithium ions. Experimental validation of the proposed zwitterionic polymer electrolyte (ZPE) showcases satisfactory parameters: ion conductivity (0.59 mS cm−1), ion migration numbers (0.82), and activation energy (0.016 eV). Electrochemical analysis on Li|ZPE|Li symmetric batteries demonstrate sustained plating/stripping performance exceeding 3000 hours at a current density of 0.2 mA cm−2. Assembled NCM|ZPE|Li batteries exhibit stable cycling over 1400 cycles at 4.3 V, with a capacity retention ratio of 92.3 %. Moreover, even under ultra‐high voltages of 4.5 V and 4.7 V, NCM|ZPE|Li batteries display stable cycling performances. This approach offers a paradigmatic strategy for polymer molecule design, advancing sustainable battery technologies. [ABSTRACT FROM AUTHOR]

Designing electrolytes that are compatible with graphite anodes and possess flame‐retardant features is strongly demanded in potassium‐ion batteries (PIBs) to inhibit solvent co‐insertion and graphite exfoliation, and also stabilize the highly active potassium‐based species (e.g., KC8). Herein, a nonflammable electrolyte is designed by introducing the fluoroethers to stabilize graphite anodes, particularly at an ultralow concentration (<0.43 m) that is rarely reported before. It is discovered that intermolecular interactions can form between the 1,1,2,2‐tetrafluoroethyl‐2,2,3,3‐tetrafluoropropyl ether (i.e., HFE) diluent and trimethyl phosphate (TMP) flame‐retardant by electronegative fluorine (δ−F) and electropositive hydrogen (δ+H). The intermolecular interactions can change the potassium ion (K+) solvation structure (e.g., weakening the K+‐TMP interaction), and then determine the properties of the K+‐solvent‐anion complex at the electrode interface. a molecular interfacial model is presented with a new coordination mechanism involving the diluent to elucidate the relationship between the intermolecular interactions and electrode performance (i.e., K+‐solvent co‐insertion, or reversible K+ (de)intercalation) at the molecular scale, facilitating the design of high safety and high energy density potassium‐ion sulfur batteries. This study sheds light on the importance of intermolecular interactions to tune electrolyte properties and also opens new avenues for designing electrolytes for safe and practical PIBs. [ABSTRACT FROM AUTHOR]

The reversibility and stability of aqueous zinc‐ion batteries (AZIBs) are largely limited by water‐induced interfacial parasitic reactions. Here, dimethyl(3,3‐difluoro‐2‐oxoheptyl)phosphonate (DP) is introduced to tailor primary solvation sheath and inner‐Helmholtz configurations for robust zinc anode. Informed by theoretical guidance on solvation process, DP with high permanent dipole moments can effectively substitute the coordination of H2O with charge carriers through relatively strong ion‐dipolar interactions, resulting in a water‐lean environment of solvated Zn2+. Thus, interfacial side reactions can be suppressed through a shielding effect. Meanwhile, lone‐pair electrons of oxygen and fluorinated features of DP also reinforce the interfacial affinity of metallic zinc, associated with exclusion of neighboring water to facilitate reversible zinc planarized deposition. Thus, these merits endow the Zn anode with a high‐stability performance exceeds 3800 hours at 0.5 mA cm−2 and 0.5 mAh cm−2 for Zn||Zn batteries and a high average Coulombic efficiency of 99.8 % at 4 mA cm−2 and 1 mAh cm−2 for Zn||Cu batteries. Benefiting from the stable zinc anode, the Zn||NH4V4O10 cell maintains 80.3 % of initial discharge capacity after 3000 cycles at 5 A g−1 and exhibits a high retention rate of 99.4 % against to the initial capacity during the self‐discharge characterizations. [ABSTRACT FROM AUTHOR]

An effective concept of using entropy increase to regulate the nanoscale solvation structure has been proposed to enhance the cycle performance of anode‐free lithium metal batteries (AFLMBs). It includes two mainstream types: entropy increase driven by multiple salts or solvents. However, most current research is based on low‐loading cathodes and mAh‐level battery systems. The relationship between the increase in entropy and practical battery with different high‐loading cathodes and Ah‐levels is seldom reported. In this paper, two mainstream methods of entropy increase are compared, and the relationship of their kinetics parameters, solid electrolyte interphase formation, and cycling performances are studied. It is found that the entropy increases driven by multiple‐solvents are more favorable to the pouch cell with high‐loading cathode and lean electrolytes. The coin cell consists of a copper current collector and a high‐loading cathode (10.5 mg cm−2) performs 40 cycles at discharge rates of 0.5 C, while the cell with a conventional ester electrolyte only last 10 cycles. A large‐capacity pouch cell (4 Ah), with a high‐loading cathode (7.6 mAh cm−2, single side) and lean electrolyte of 1.3 g Ah−1, achieves 500 Wh kg−1 and 20 cycles. [ABSTRACT FROM AUTHOR]

Abstract The solid‐electrolyte interphase (SEI) is a key element in anode–electrolyte interactions and ultimately contributes to improving the lifespan and fast‐charging capability of lithium‐ion batteries. The conventional additive vinyl carbonate (VC) generates spatially dense and rigid poly VC species that may not ensure fast Li+ transport across the SEI on the anode. Here, a synthetic additive called isosorbide 2,5‐dimethanesulfonate (ISDMS) with a polar oxygen‐rich motif is reported that can competitively coordinate with Li+ ions and allow the entrance of PF6– anions into the core solvation structure. The existence of ISDMS and PF6− in the core solvation structure along with Li+ ions enables the movement of anions toward the anode during the first charge, leading to a significant contribution of ISDMS and LiPF6 to SEI formation. ISDMS leads to the creation of ionically conductive and electrochemically stable SEI that can elevate the fast‐charging performance and increase the lifespan of LiNi0.8Co0.1Mn0.1O2 (NCM811)/graphite full cells. Additionally, a sulfur‐rich cathode–electrolyte interface with a high stability under elevated‐temperature and high‐voltage conditions is constructed through the sacrificial oxidation of ISDMS, thus concomitantly improving the stability of the electrolyte and the NCM811 cathode in a full cell with a charge voltage cut‐off of 4.4 V.

High‐safety potassium‐ion batteries (HPIBs) are highly intriguing owing to their green energy, low cost, high voltage, noncombustible, and simple assembly. However, most high‐voltage HPIBs use water‐in‐salt electrolytes (WISE), which lead to several problems, such as a high viscosity, which significantly reduces the performance and increases the cost of HPIBs, thus impeding their development. Unfortunately, studies regarding HPIB electrolytes remain limited, further limiting the development of HPIBs. Herein, a co‐solvent engineering electrolyte (4.0 m KOTf in a mixture of propylene carbonate (PC) and H2O with a volume ratio of 5.0:1.0) featuring low‐cost (1/4 of WISE) and high‐performance (45.43 mS cm−1) characteristics is proposed, which not only achieves a wide electrochemical stability window by reducing the activity of H2O, but also adjusts the solvation structure of K+. Consequently, the HPIBs assembled via co‐solvent engineering electrolyte demonstrated a high energy density of 88.05 Wh kg−1, and sufficiently operated at rates of 0.50–10.0 A g−1 over a wide temperature range (−25–50 °C). This study provides a promising means for developing high‐voltage HPIBs. [ABSTRACT FROM AUTHOR]

Solid polymer electrolytes are promising electrolytes for safe and high‐energy‐density lithium metal batteries. However, traditional ether‐based polymer electrolytes are limited by their low lithium‐ion conductivity and narrow electrochemical window because of the well‐defined and intimated Li+‐oxygen binding topologies in the solvation structure. Herein, we proposed a new strategy to reduce the Li+‐polymer interaction and strengthen the anion‐polymer interaction by combining strong Li+‐O (ether) interactions, weak Li+‐O (ester) interactions with steric hindrance in polymer electrolytes. In this way, a polymer electrolyte with a high lithium ion transference number (0.80) and anion‐rich solvation structure is obtained. This polymer electrolyte possesses a wide electrochemical window (5.5 V versus Li/Li+) and compatibility with both Li metal anode and high‐voltage NCM cathode. Li||LiNi0.5Co0.2Mn0.3O2 full cells with middle‐high active material areal loading (~7.5 mg cm−2) can stably cycle at 4.5 V. This work provides new insight into the design of polymer electrolytes for high‐energy‐density lithium metal batteries through the regulation of ion‐dipole interactions. [ABSTRACT FROM AUTHOR]

Abstract Lithium metal batteries offer a promising solution for high density energy storage due to their high theoretical capacity and negative electrochemical potential. However, implementing of these batteries faces challenges related to electrolyte instability and the formation of a solid electrolyte interphase (SEI) on the lithium (Li) metal anode. The decomposition of liquid electrolytes leading to the creation of the SEI emphasizes the significance of the type of Li salt, solvent, and additives designed and used, as well as their interactions during the formation of the SEI. For practical applications, ensuring both the reversibility of the Li metal anode and electrolyte stability at high voltages is crucial. In this review, we explore recent advancements in addressing these challenges through new designs of electrolytes and SEI engineering practices. Specifically, we investigate the effects of electrolyte systems, including carbonate‐based and ether‐based solutions, along with modifications to these electrolyte systems aimed at achieving a more stable interface with the Li metal anode. Additionally, we discuss various artificial SEI structures based on organic and inorganic components. By critically examining recent research in these areas, this review provides valuable insights into current state‐of‐the‐art strategies for enhancing the performance and safety of Li metal batteries.

Directly using aluminum (Al) foil as anode material offers a streamlined manufacturing process by eliminating the need for conductive additives, binders, and casting procedures. Nonetheless, monolithic Al foil anodes often suffer from mechanical failure and poor cyclability, posing challenges for practical adoption. In this study, a high‐concentration ether‐based electrolyte is employed to boost the durability of the Al foil anode. In contrast to traditional low‐concentration electrolytes, the use of 5 m lithium bis(fluorosulfonyl)imide in 1,2‐dimethoxyethane promotes the priority decomposition of anions, leading to the creation of a fluoride‐rich solid electrolyte interphase (SEI) layer with exceptional structural modulus and high ion conductivity. These outcomes, coupled with Al's superior compatibility in the chosen electrolyte, enable a record‐breaking cycle life of up to 400 cycles for Li//Al half‐cells, when operated at a high areal capacity of 1 mAh cm−2. In full‐cell configurations, an outstanding capacity retention is also observed, with 96.9% after 150 cycles even under practical conditions involving a 40 µm thin Al foil and a 7.4 mg cm−2 LiFePO4 cathode. These results not only mark the pioneering use of high‐concentration ether‐based electrolyte systems in Al foil anodes but also showcase the high potential for developing low‐cost and high‐energy Al foil‐based LIBs. [ABSTRACT FROM AUTHOR]

The practical application of aqueous zinc‐ion batteries (AZIBs) is limited by serious side reactions, such as the hydrogen evolution reaction and Zn dendrite growth. Here, the study proposes a novel adoption of a biodegradable electrolyte additive, γ‐Valerolactone (GVL), with only 1 vol.% addition (GVL‐to‐H2O volume ratio) to enable a stable Zn metal anode. The combination of experimental characterizations and theoretical calculations verifies that the green GVL additive can competitively engage the solvated structure of Zn2+ via replacing a H2O molecule from [Zn(H2O)6]2+, which can efficiently reduce the reactivity of water and inhibit the subsequent side reactions. Additionally, GVL molecules are preferentially adsorbed on the surface of Zn to regulate the uniform Zn deposition and suppress the Zn dendrite growth. Consequently, the Zn anode exhibits boosted stability with ultralong cycle lifespan (over 3500 h) and high reversibility with 99.69% Coulombic efficiency. The Zn||MnO2 full batteries with ZnSO4‐GVL electrolyte show a high capacity of 219 mAh g−1 at 0.5 A g−1 and improved capacity retention of 78% after 550 cycles. This work provides inspiration on bio‐based electrolyte additives for aqueous battery chemistry and promotes the practical application of AZIBs. [ABSTRACT FROM AUTHOR]

Aqueous zinc ion batteries (AZIBs) show a great potential for next‐generation energy storage due to their high safety and high energy density. However, the severe side reactions of zinc negative electrode largely hinder the further application of AZIBs. Herein, trace tris(hydroxymethyl)aminomethane (Tris) additive with rich lone‐pair‐electrons and zincophilic sites is firstly introduced to achieve long‐term and highly reversible Zn plating/stripping. Specifically, Tris not only regulates the solvation structure of Zn2+, but is also adsorbed vertically on the Zn anode surface with a changed coordination intensity during the plating/stripping process of Zn to generate an in situ dynamic adsorption layer for the first time. The dynamic adsorption layer could successively attract the solvated Zn2+ and then promote the de‐solvation of the solvated Zn2+ owing to the orientation polarization with regularly‐changed applied electric field, the volume rejection effect, and strong intermolecular force towards H2O of the vertically‐adsorbed Tris. Therefore, an improved Zn2+‐transport kinetics as well as the inhibition of side reactions of Zn anode are successfully realized. Accordingly, the Zn||Zn symmetric cell provides an ultra‐long cycle life of 2600 h. Furthermore, the Zn||MnO2 full cell with Tris could demonstrate a high capacity and structural stability for practical applications. [ABSTRACT FROM AUTHOR]

Lithium metal batteries (LMBs) working at subzero temperatures are plagued by severe restrictions from the increased energy barrier of Li‐ion migration and desolvation. Herein, a competitive coordination strategy based on the ternary‐anion (TA) coupling of PF6−, TFSI−, and NO3− toward Li+ to achieve an anti‐freezing electrolyte with rapid kinetics is proposed. Computational and spectroscopic analyses reveal that the repulsive interaction among three anions and the preponderant coordination of the Li+‐NO3− further weaken the involvement degree of other anions in the Li+ solvation structure. As a result, the formulated TA electrolyte exhibits low binding energy of Li+‐anions (−4.62 eV), Li+ desolvation energy (17.04 kJ mol−1), and high ionic conductivity (3.39 mS cm−1 at −60 °C), simultaneously promoting anion‐derived solid electrolyte interphase on Li anode. Assembled Li||LiNi0.8Co0.1Mn0.1O2 cells employing the TA electrolyte exhibit robust capacity retention of 86.74% over 200 cycles at 25 °C and deliver a specific cathode capacity of 103.85 mAh g−1 at −60 °C. This study will enlighten the rational design of multi‐anion electrolytes to tailor the Li+ solvation/desolvation for advanced low‐temperature LMBs. [ABSTRACT FROM AUTHOR]

Highlights A novel aqueous/aprotic electrolyte with low salt concentration (i.e., 0.5 m Zn(CF3SO3)2+1 m LiTFSI) demonstrated an expanded electrochemical window, which can simultaneously stabilize Zn metal anode and increase the operation voltage of Zn-ion hybrid supercapacitors. The coordination shell of the electrolyte induced by acetonitrile and LiTFSI can not only suppress the Zn corrosion and hydrogen evolution reaction but also promote the cathodic stability and ion migration, which is depicted by the density functional theory simulations together with experimental characterizations. The Zn-ion hybrid supercapacitor based on the developed electrolyte can operate within 0–2.2 V in a wide temperature range with an ultra-long lifespan (> 120,000 cycles).

Highlights: A novel aqueous/aprotic electrolyte with low salt concentration (i.e., 0.5 m Zn(CF3SO3)2+1 m LiTFSI) demonstrated an expanded electrochemical window, which can simultaneously stabilize Zn metal anode and increase the operation voltage of Zn-ion hybrid supercapacitors. The coordination shell of the electrolyte induced by acetonitrile and LiTFSI can not only suppress the Zn corrosion and hydrogen evolution reaction but also promote the cathodic stability and ion migration, which is depicted by the density functional theory simulations together with experimental characterizations. The Zn-ion hybrid supercapacitor based on the developed electrolyte can operate within 0–2.2 V in a wide temperature range with an ultra-long lifespan (> 120,000 cycles). With the merits of the high energy density of batteries and power density of supercapacitors, the aqueous Zn-ion hybrid supercapacitors emerge as a promising candidate for applications where both rapid energy delivery and moderate energy storage are required. However, the narrow electrochemical window of aqueous electrolytes induces severe side reactions on the Zn metal anode and shortens its lifespan. It also limits the operation voltage and energy density of the Zn-ion hybrid supercapacitors. Using 'water in salt' electrolytes can effectively broaden their electrochemical windows, but this is at the expense of high cost, low ionic conductivity, and narrow temperature compatibility, compromising the electrochemical performance of the Zn-ion hybrid supercapacitors. Thus, designing a new electrolyte to balance these factors towards high-performance Zn-ion hybrid supercapacitors is urgent and necessary. We developed a dilute water/acetonitrile electrolyte (0.5 m Zn(CF3SO3)2 + 1 m LiTFSI-H2O/AN) for Zn-ion hybrid supercapacitors, which simultaneously exhibited expanded electrochemical window, decent ionic conductivity, and broad temperature compatibility. In this electrolyte, the hydration shells and hydrogen bonds are significantly modulated by the acetonitrile and TFSI− anions. As a result, a Zn-ion hybrid supercapacitor with such an electrolyte demonstrates a high operating voltage up to 2.2 V and long lifespan beyond 120,000 cycles. [ABSTRACT FROM AUTHOR]

LiNO3 is a remarkable additive that can dramatically enhance the stability of ether‐based electrolytes at lithium metal anodes. However, it has long been constrained by its incompatibility with commercially used ester electrolytes. Herein, we correlated the fundamental role of entropy with the limited LiNO3 solubility and proposed a new low‐entropy‐penalty design that achieves high intrinsic LiNO3 solubility in ester solvents by employing multivalent linear esters. This strategy is conceptually different from the conventional enthalpic methods that relies on extrinsic high‐polarity carriers. In this way, LiNO3 can directly interact with the primary ester solvents and fundamentally alters the electrolyte properties, resulting in substantial improvements in lithium‐metal batteries with high Coulombic efficiency and cycling stability. This work illustrates the significance of regulating the solvation entropy for high‐performance electrolyte design. [ABSTRACT FROM AUTHOR]

Due to the intrinsic safety and cost effectiveness, aqueous Zn‐ion batteries (AZIBs) are considered a promising candidate for future energy storage systems. However, the widespread implementation of AZIBs faces significant obstacles due to various undesirable side reactions, including hydrogen evolution reaction (HER), corrosion, and uncontrolled dendrite growth at the anodes. Here, 4‐hydroxybenzoic acid sodium salt (PHB) is employed in the ZnSO4 electrolyte to enable highly‐reversible zinc anodes. PHB has a greater tendency to bind with the Zn surface, resulting in increased steric effects within the electrolyte. As a result, it hinders the direct interaction between anode and water while facilitating the uniform plating of Zn2+. Zn/Zn batteries with PHB additives realized more than 1600 h stable cycling life under 1 mA cm−2 and 1 mAh cm−2. Moreover, Zn/Cu batteries with PHB additives achieved a reversible plating/stripping process for over 500 cycles with high average CE of 98.6 %. In addition, the assembled Zn/NH4V4O10 batteries with PHB additive yielded 80.5 mAh g−1 after 1000 cycles at 10 A g−1. The inexpensive and effective application of PHB as an electrolyte additive has the potential to significantly enhance the stability and dependability of ZIBs. [ABSTRACT FROM AUTHOR]

Calcium ion batteries (CIBs) are considered as an important candidate for post‐lithium energy storage devices due to their abundance of resources and low cost. However, CIBs still suffer from slow kinetics due to the large solvation structure and high desolvation energy of Ca2+ ions. Here, a solvation regulation strategy based on donor number (DN) is reported to achieve easy‐desolvation and rapid storage of Ca2+ in sodium vanadate (Na2V6O16·2H2O, NVO). Specially, the solvent with a low DN, represented by propylene carbonate (PC), forms the first solvation shell of calcium ions with weak binding energy and small shell structure, which facilitates the migration of Ca2+ in the electrolyte. More importantly, the low DN solvent is preferentially desolvated at the cathode/electrolyte interface, promoting the insertion of Ca2+ into the NVO electrode. Mechanism studies further confirm the highly reversible uptake/release of Ca2+ in the NVO cathode, along with the VO distance change in the coordination structure. Therefore, the NVO cathode achieves high capacity (376 mAh g−1 at 0.3 A g−1) and high‐rate performance (151 mAh g−1 at 5 A g−1). The weak solvation effect strategy further improves the electrochemical performance and provides great importance for the design of the long‐term development of CIBs. [ABSTRACT FROM AUTHOR]

[Display omitted] Li||LiFePO 4 (LFP) batteries have good stability and high energy density. However, they exhibit unsatisfactory low-temperature electrochemical performance. Due to the fragile interfacial passivation layers and sluggish kinetics, commercial electrolytes fail to simultaneously achieve acceptable stabilization with dual electrodes in low-temperature Li||LFP batteries. Herein, a novel localized high-concentration electrolyte (LHCE) with great dual-electrodes compatibility is proposed to match with the low-temperature Li||LFP batteries. With increasing local concentration, the FSI- sequentially replaces the solvent molecules and enters the first solvation sheath, forming the anion-dominated solvation structures. This effectively suppresses free solvents decomposition and constructs the anion-derived passivation layers with inorganic-rich components, further contributing to the rapid transport kinetics and endowing the LHCE with great dual electrodes compatibility. These dual-electrodes co-stabilization effects of the LHCE are originally clarified in the low-temperature Li||LFP batteries. The designed LHCE also delivers low freezing point (-99.8 ℃), high ionic conductivity (2.4 mS cm−1 at −40 ℃), and superior stability (>4.7 V vs. Li/Li+). Hence, the Li||LFP batteries with LHCE possess superb cyclic stability at low temperatures, delivering a high discharge capacity of 120 mAh g−1 over 300 cycles at −20 ℃. Moreover, compared to commercial electrolytes, LHCE endows the Li||LFP batteries with superior low-temperature performances under practical conditions, including limited Li anode (3 mAh cm−2) and a wide temperature range (30 ℃ to −40 ℃). [ABSTRACT FROM AUTHOR]

Identifying an effective electrolyte is a primary challenge for hybrid ion capacitors, due to the intricacy of dual‐ion storage. Here, this study demonstrates that the electrochemical behavior of graphite oxide in ether‐solvent electrolyte outperforms those in ester‐solvent electrolytes for the cathode of potassium‐ion hybrid capacitor. The experimental and theoretical assessments verify that the anion and cation are isolated effectively in dimethyl ether, endowing a weaker interaction between cations and anions compared to that of ester‐solvent electrolytes, which facilitates the dual‐ion diffusion and thus enhances the electrochemical performance. This result provides a rational strategy to realize high‐rate cations and anions storage on the carbon cathode. Furthermore, a new low‐cost and high‐performance capacitor prototype, modified graphite oxide (MGO) cathode versus pristine graphite (PG) in ether‐solvent electrolyte (MGOǁDMEǁPG), is proposed. It exhibits a high energy density of 150 Wh kg−1cathode at a high power density of 21443 W kg−1cathode (calculation based on total mass: 60 Wh kg−1 at 8577 W kg−1). [ABSTRACT FROM AUTHOR]

Binder plays a pivotal role in the development of lithium‐ion batteries as it must be used to adhere electrode materials on current collectors tightly to guarantee stability. Then, many binder molecules have been designed to enhance the adhesion capability, and conductivity, and/or form a robust solid electrolyte interphase layer for better performance. However, the binder effect on the lithium‐ion (i.e., Li+) de‐solvation on the electrode surface has never been reported before. Herein, it is reported that the binder can influence the Li+ (de‐)solvation process significantly, where its functional group can serve as a probe to detect the dynamic Li+ (de‐)solvation process. It is discovered that different binder functional groups (e.g., *─COO− versus *─F) can affect the Li+‐solvent arrangement on the electrode surface, leading to different degrees of side‐reactions, rate capabilities, and/or the tolerance against Li+‐solvent co‐insertion for the graphite anode, such as in the propylene carbonate‐based electrolyte. A molecular interfacial model related to the electrolyte component's behaviors and binder functional group is proposed to interpret the varied electrode performance. This discovery opens a new avenue for studying the interactions between the binder and electrolyte solvation structure, in turn helping to understand electrode performances underlying the micro‐structures. [ABSTRACT FROM AUTHOR]

Uncontrolled Zn dendrites and undesirable side reactions such as Zn self‐corrosion and hydrogen evolution reaction (HER) remain major challenges for the further development of aqueous Zn batteries (AZBs). In this study, macrolide antibiotics are proposed to be added to aqueous electrolyte, serving as Zn ionophores to modulate Zn2+ solvation structure, regulate Zn electrodeposition, and suppress undesirable parasitic reactions. Azithromycin (Azi), a representative macrolide antibiotic, is demonstrated to undergo bidentate coordination with Zn ions and remodel the solvation structure into [ZnAzi(H2O)4]2+. Meanwhile, the self‐corrosion and HER at the Zn anode side are significantly suppressed, evidenced quantitatively by the on‐line hydrogen production monitoring. Furthermore, the promotion of dense and uniform Zn electrodeposition by the ionophores is also confirmed. The repeated Zn plating/stripping test with 0.1 m Azi in electrolyte reaches a high cumulative capacity of 10 Ah cm−2 at a current density of 10 mA cm−2 and an area capacity of 10 mAh cm−2. Moreover, the corresponding Zn‐V2O5 pouch cell achieves stable operation for 100 cycles without bulging caused by gas evolution. Thus, the electrolyte engineering approach presents a practically viable strategy for the development of AZBs. [ABSTRACT FROM AUTHOR]

Abstract Lithium‐ion batteries (LIBs) have monopolized energy storage markets in modern society. The reliable operation of LIBs at cold condition (

Lithium–sulfur (Li–S) batteries are famous for their high energy density and low cost, but prevented by sluggish redox kinetics of sulfur species due to depressive Li ion diffusion kinetics, especially under low‐temperature environment. Herein, a combined strategy of electrocatalysis and pore sieving effect is put forward to dissociate the Li+ solvation structure to stimulate the free Li+ diffusion, further improving sulfur redox reaction kinetics. As a protocol, an electrocatalytic porous diffusion‐boosted nitrogen‐doped carbon‐grafted‐CoP nanosheet is designed via forming the NCoP active structure to release more free Li+ to react with sulfur species, as fully investigated by electrochemical tests, theoretical simulations and in situ/ex situ characterizations. As a result, the cells with diffusion booster achieve desirable lifespan of 800 cycles at 2 C and excellent rate capability (775 mAh g−1 at 3 C). Impressively, in a condition of high mass loading or low‐temperature environment, the cell with 5.7 mg cm−2 stabilizes an areal capacity of 3.2 mAh cm−2 and the charming capacity of 647 mAh g−1 is obtained under 0 °C after 80 cycles, demonstrating a promising route of providing more free Li ions toward practical high‐energy Li–S batteries. [ABSTRACT FROM AUTHOR]

The application of Li metal batteries is hindered by the uncontrollable growth of Li dendrites due to the lack of control over Li ion transfer and the formation of solid electrolyte interphase (SEI). Herein, polypropylene (PP) separator modified with acyclic polyaminoborane (PAB, (NH2‐BH2)n) and polyiminoborane (PIB, (NH═BH)n) is developed to regulate electrolyte solvation chemistry and simultaneously facilitate the construction of robust SEI. The mediating effect of PAB and PIB promotes favorable formation of (O)2Li+N to weaken the Li bonds between Li ion and solvent in the electrolyte, which homogenizes Li ion diffusion and reduces the desolvation barrier of Li ions. Additionally, the increase of anions content in the solvation sheath and the reaction between Li metal and PAB and PIB can induce the formation of [LiNBH]n‐enhanced SEI enriched with LiF and Li3N that have Li ion conductivity and mechanical strength to tolerate the volume change of Li metal anode. Therefore, the symmetric cell exhibits a cycling lifetime of over 4000 h. [ABSTRACT FROM AUTHOR]

Traditional rechargeable Zn batteries fail to work in cold regions due to the high freezing point (Tf) and severe corrosivity of the aqueous electrolytes with excessive association (solvent‐solvent and solute‐solvent interactions). In this study, a nonflammable weak‐associated electrolyte (WASE) consisting of ZnCl2 salt and methanol/dichloromethane mixture as a solvent is developed to achieve high reversible Zn plating/stripping at low temperatures. The low self‐association interaction of the mixed solvent not only endures WASE with a low Tf of −119.2 °C but also facilitates the desolvation of interfacial Zn2+ and induces smooth Zn plating at low temperatures. Moreover, the water‐free WASE inhibits the hydrolysis of ZnCl2 and thus restrains the corrosion of Zn electrodes. Thanks to the above merits, the Zn||Zn, Zn||Cu, and Zn||polyaniline cells with WASE exhibit superb electrochemical performance at temperatures as low as −78.5 °C. [ABSTRACT FROM AUTHOR]

Lithium metal (LM) is a promising anode material for next generation lithium ion based electrochemical energy storage devices. Critical issues of unstable solid electrolyte interphases (SEIs) and dendrite growth however still impede its practical applications. Herein, a composite gel polymer electrolyte (GPE), formed through in situ polymerization of pentaerythritol tetraacrylate with fumed silica fillers, is developed to achieve high performance lithium metal batteries (LMBs). As evidenced theoretically and experimentally, the presence of SiO2 not only accelerates Li+ transport but also regulates Li+ solvation sheath structures, thus facilitating fast kinetics and formation of stable LiF‐rich interphase and achieving uniform Li depositions to suppress Li dendrite growth. The composite GPE‐based Li||Cu half‐cells and Li||Li symmetrical cells display high Coulombic efficiency (CE) of 90.3% after 450 cycles and maintain stability over 960 h at 3 mA cm−2 and 3 mAh cm−2, respectively. In addition, Li||LiFePO4 full‐cells with a LM anode of limited Li supply of 4 mAh cm−2 achieve capacity retention of 68.5% after 700 cycles at 0.5 C (1 C = 170 mA g−1). Especially, when further applied in anode‐free LMBs, the carbon cloth||LiFePO4 full‐cell exhibits excellent cycling stability with an average CE of 99.94% and capacity retention of 90.3% at the 160th cycle at 0.5 C. [ABSTRACT FROM AUTHOR]

Integral equation theory (IET) provides an effective solvation model for chemical and biological systems that balances computational efficiency and accuracy. We present a new software package, the expanded package for IET‐based solvation (EPISOL), that performs 3D‐reference interaction site model (3D‐RISM) calculations to obtain the solvation structure and free energies of solute molecules in different solvents. In EPISOL, we have implemented 22 different closures, multiple free energy functionals, and new variations of 3D‐RISM theory, including the recent hydrophobicity‐induced density inhomogeneity (HI) theory for hydrophobic solutes and ion‐dipole correction (IDC) theory for negatively charged solutes. To speed up the convergence and enhance the stability of the self‐consistent iterations, we have introduced several numerical schemes in EPISOL, including a newly developed dynamic mixing approach. We show that these schemes have significantly reduced the failure rate of 3D‐RISM calculations compared to AMBER‐RISM software. EPISOL consists of both a user‐friendly graphic interface and a kernel library that allows users to call its routines and adapt them to other programs. EPISOL is compatible with the force‐field and coordinate files from both AMBER and GROMACS simulation packages. Moreover, EPISOL is equipped with an internal memory control to efficiently manage the use of physical memory, making it suitable for performing calculations on large biomolecules. We demonstrate that EPISOL can efficiently and accurately calculate solvation density distributions around various solute molecules (including a protein chaperone consisting of 120,715 atoms) and obtain solvent free energy for a wide range of organic compounds. We expect that EPISOL can be widely applied as a solvation model for chemical and biological systems. EPISOL is available at https://github.com/EPISOLrelease/EPISOL. [ABSTRACT FROM AUTHOR]

High‐voltage Li||LiNi0.6Co0.6Mn0.2O2 (NCM622) batteries have obtained great interest owing to their high energy density. However, some obstacles hinder their practical applications, e.g., the structural failure of NCM622 and corrosion of the Al current collector, which lead to limited cycling life. Herein, an electrolyte additive strategy is proposed for constructing localized high‐concentration PF6− zone near the cathode to form an efficient cathode electrolyte interphase (CEI) for protecting NCM622 and preventing Al current collector from the corrosion. Potassium 1,1,2,2,3,3‐hexafluoropropane‐1,3‐disulfonimide is used as the additive to regulate the sheath structure of Li+ solvation to force PF6− anions away from the solvated Li+. During the charge process, the nonsolvated PF6− anions gather on NCM622 surface to form a localized high‐concentration PF6− zone to facilitate the formation of F‐rich CEI on NCM622 for protecting its structural stability and Al current collector. [ABSTRACT FROM AUTHOR]

Lithium metal batteries (LMBs) have gained increasing attention owing to high energy density for large-scale energy storage applications. However, serious side reactions between Li anodes and organic electrolytes lead to low Columbic efficiency and Li dendrites. Although progress has been achieved in constructing electrode structures, the interfacial instability of Li anodes is still challenging. Solvation chemistry significantly affects the electrolyte properties and interfacial reactions, but the reaction mechanisms and the roles of each component in electrolytes are still vague. This review spotlights the recent development of electrolyte regulation with concentration and composition adjustments, aiming to understanding the correlation between solvation structures and Li anode stability. Further perspectives on the solvation design are provided in light of anode interfacial stability in LMBs. [ABSTRACT FROM AUTHOR]

Lithium‐sulfur batteries are famous for high energy density but prevented by shuttling effect and sluggish electrochemical conversion kinetics due to the high energy barriers of Li+ transport across the electrode/electrolyte interface. Herein, the Li+‐solvents dissociation kinetics is catalyzed and stimulated by designing a carbon bridged metal‐organic framework (MOF@CC), aimed at realizing increased bare Li+ transport for the rapid conversion kinetics of sulfur species. Theoretical simulations and spectroscopic results demonstrate that the bridged MOF@CC well grants a special transport channel for accelerating Li+ benefited from aggregated anion/cation clusters. Moreover, the CN bridge between ‐NH2 ligand in MOF and carbon shell enhances electron exchange, and thus promotes polysulfide catalytic efficiency and hinder polysulfide aggregation and accumulation. With the MOF@CC‐modified separators, the assembled Li/S batteries deliver a reversible capability of 1063 mAh g‐1 at 0.5 C, a capacity retention of 88% after 100 cycles, and a high‐rate performance of 765 mAh g−1 at 5 C. Moreover, the large areal pouch cell with 100 µm Li foil and lean electrolyte is capable of stabilizing 855 mAh g−1 after 70 cycles. These results well demonstrate the efficiency of catalyzing desolvation for fast Li+ transport kinetics and the conversion of polysulfides. [ABSTRACT FROM AUTHOR]

Separator modification is an efficient strategy to handle with the challenges of lithium metal batteries but its success is primarily subject to the modification of the materials. Herein, a cationic covalent organic framework (COF) composed of positively charged organic units and weakly bonded fluoride ions (F−) is introduced to modify the commercial polypropylene separator (COF−F@PP). It is found that the organic unit has abundant nanopores to homogenize the lithium ions (Li+) flux and can interact with electrolyte solvent molecules to form a desolvation structure of Li+. Meanwhile, the F− within the nanopores is proved to assist in building a robust LiF−riched solid electrolyte interphase to avoid the side reactions between lithium anode and electrolyte. Hence, the COF−F@PP delivers feasible practicality for the outstanding cycling stability, high Coulombic efficiency, and superior rate capability of Li//LFP coin cell at 5 C, low N/P ratio (2.19) full cell, and pouch cell at 1 C. [ABSTRACT FROM AUTHOR]

The lithium (Li) dendrite and parasitic reactions are the two major challenges for the Li-metal anode, which is the most prominent anode for high-energy-density storage. However, in recent years, most studies have still focused on the increasingly complex design of electrolytes or solid electrolyte interfaces, and the essence of Li + ion electrodeposition has been overlooked. Herein, we demonstrate a simple but useful strategy to control the Li solvation species in a classical electrolyte and promote its stable electrodeposition. In commonly used electrolytes consisting of ethylene carbonate (EC) and dimethyl carbonate, the first solvation shell of Li + ions converts from EC-coordination-dominant to anion-diluent-dominant by simply reducing the EC content. Molecular simulations are performed to reveal that the latter solvation species could promote Li + ions to become coordination-unsaturated in the electrical double layer and prefer to be reduced at the anode interface. Consequently, the simple tuning of local polarity around Li + ions not only extends the cycling performance of the Li-metal anode significantly but also effectively suppresses Li-dendrite and parasitic reactions, which may inspire a rethinking of simple approaches for Li-metal anode challenges.

Low-cost graphite has emerged as the most promising anode material for potassium-ion batteries (PIBs). Constructing the inorganic-rich solid electrolyte interface (SEI) on the surface of graphite anode is crucial for achieving superior electrochemical performance of PIBs. However, the compositions of SEI formed by conventional strongly solvating electrolytes are mainly organic, leading to the SEI structure being thick and causing the co-intercalation behavior of ions with the solvent. Herein, a weakly solvating electrolyte is applied to weaken the cation-solvent interaction and alter the cation solvation sheath structures, conducing to the inorganic composition derived from anions also participating in the formation of SEI, together with forming a uniformly shaped SEI with superior mechanical properties, and thus improving the overall performance of PIBs. The electrolyte solvation structure rich in aggregated ion pairs (AGGs) (69%) enables remarkable potassium-ion intercalation behavior at the graphite anode (reversible capacity of 269 mAh g -1 ) and highly stable plating/stripping of potassium metal anode (96.5%). As a practical device application, the assembled potassium-ion full-battery (PTCDA//Graphite) displays superior cycle stability. The optimizing strategy of cation solvation sheath structures offers a promising approach for developing high-performance electrolytes and beyond., (© 2024 Wiley‐VCH GmbH.)

In alkali metal-ion battery systems, the electrolyte enables being decomposed on the electrode surface to form a solid electrolyte interphase (SEI) film. In principle, a thin, uniform SEI film facilitates the enhancement of the performance of the cell. Herein, we successfully distinguish the effects of desolvation behavior and SEI process on the kinetic behavior of hard carbon (HC) electrodes by adopting the strategy of switching the electrolyte interface model to modulate the properties of SEI film. Our findings reveal that although the SEI film is generally responsible for significantly affecting the HC's capacity, the equally crucial desolvation process must not be overlooked. The trade-off between the two factors is found to be determined by the structural features of HCs. Specifically, in the context of a more ordered HC, the desolvation of ions emerges as the rate-limiting step for Na + transport across the electrode/electrolyte interface, exerting a more pronounced effect rather than the SEI. Thus, a close correlation was established between the SEI, solvation structure effects, hard carbon structure, and electrode performance. This linkage is thereof fundamental for the strategic design of electrolytes and the targeted enhancement of cell performance., (© 2025 Wiley-VCH GmbH.)

The advancements of lithium‐ion batteries indubitably call for advanced electrolytes with superior environmental adaptability and long‐term stability. Propylene carbonate (PC) proves to be a competitive solvent with the high permittivity and wide‐liquid range, while the application is intrinsically hindered by the poor graphite compatibility and high viscosity. Here, a PC‐based electrolyte with wide‐temperature range is developed by tuning the strength and topology of the Li+‐PC interactions via non‐solvating interactions without altering the solvation structure. Thus, the problem of graphite exfoliation caused by Li+‐PC co‐intercalation can be successfully mitigated. Consequently, such electrolyte shows compatibility with both graphite and high‐nickel cathode, exhibiting an expanded liquid range from −90 to 90 °C. This work, breaking from the traditional EC‐based formula, provides a new strategy for designing PC‐enabled electrolyte featuring high performance, wide‐temperature compatibility, and sustainability [ABSTRACT FROM AUTHOR]

Challenges from high‐energy‐density storage applications have boosted the pursuit of designing high‐rate and low‐temperature lithium (Li) metal batteries (LMBs). Formulating high‐concentration electrolytes (HCEs) with a high transference number (t+) is an alternative solution to satisfy these demands. However, the implementation of HCEs is impeded by their lower ionic conductivity, higher viscosity, poorer wettability, and higher melting point, which are harmful to the practical applications. Herein, an anionic coordination manipulation strategy is proposed to break the constraints presented by HCEs. By manipulating the anionic species with different coordinating abilities, a high t+ up to 0.9 can be achieved even in the low‐concentration electrolytes of 1 mol L−1. By further forming a multilayer solvation structure in the anion manipulated electrolyte using non‐polar diluents, high Li Coulombic efficiency superior to 99% can be maintained under a high current density of 3 mA cm−2, and much‐improved performance is also demonstrated in high‐loading Li metal pouch cells. Furthermore, when applying multilayer solvated structure in electrolyte engineering, Li metal anodes at subzero temperature and LMBs at 0 °C also exhibit impressive cycling stability. This work provides a new guideline for designing advanced electrolytes for high‐rate LMBs under practical conditions. [ABSTRACT FROM AUTHOR]

Electrolyte engineering strategy has attracted high expectations for addressing the universally existed serious dynamics and thermodynamics issues in potassium-ion batteries (PIBs), especially for the batteries adopted with organic electrode materials. Herein, a new kind of ester-ether hybrid electrolytes (EEHEs) was developed with widely manipulatable solvation structures from solvent-separated ion pair (SSIP) to aggregate (AGG)-dominated states for PIBs. The optimized EEHEs of 5 M KFSI/EC+DME enabled high Coulombic efficiency and ultra-stable K plating/stripping stability in K||Cu cells and K||K symmetric cells, respectively. When the developed novel organic anode material of 2-Bromobenzene-1,3-dialdehyde/carbon nanotube (BBD/CNT) was matched with the 5 M KFSI/EC+DME electrolyte, it delivered a reversible capacity of about 288 mAh g−1 at 50 mA g−1 and approximately 244 mAh g−1 at 200 mA g−1 with negligible capacity fade. The excellent performance should be attributed to the surface capacitive-dominated mechanism with fast K-storage kinetics guaranteed by the AGG-dominated solvation structures. [Display omitted] • Several possible ester-ether hybrid systems are explored for potassium-ion batteries. • KFSI/EC+DME have widely manipulated solvation structures. • A new aldehyde-based organic K-storage anode of BBD/CNT was proposed. • Solvation structures realized fast K-storage kinetic and solubility suppression. [ABSTRACT FROM AUTHOR]

Solid‐state lithium‐metal batteries attract great attention due to their high energy density and superior safety. However, the sluggish Li+ kinetics of solid electrolyte and poor interface compatibility between electrolyte and lithium anode lead to unsatisfied performance at room temperature, which severely limit their practical application. Herein, a Janus quasi‐solid electrolyte (JSE) design is reported, which modifies the Li+ solvation environment in succinonitrile (SN) plastic crystal electrolyte and creates 1D Li+ transportation channels. Density functional theory calculations and Raman results reveal that Li1.3Al0.3Ti1.7(PO4)3 changes the Li+ solvation environment from SN units to aggregated ion pairs, which accelerates the diffusion rate of Li+. As a result, JSE presents excellent ionic conductivity (0.73 mS cm−1) and high lithium transference number (0.72). With this efficient JSE, Li symmetric cells deliver excellent cycle stability over 600 h with a low over potential of 60 mV. LiFePO4|JSE|Li solid‐state battery delivers an impressive performance with a specific discharge capacity of 152 mAh g−1 after 100 cycles at room temperature under 0.5 C. Moreover, the corresponding pouch cell also shows outstanding performance (140 mAh g−1 under 0.5 C) and withstands abuse tests such as bending and cutting, demonstrating its superior safety for future utilization. [ABSTRACT FROM AUTHOR]

Redox‐active organic materials, as a new generation of sustainable resources, are receiving increasing attention in zinc‐ion batteries (ZIBs) due to their resource abundance and tunable structure. However, organic molecules with high potential are rare, and the voltage of most reported organic cathode‐based ZIBs is less than 1.2 V. Herein, we explored the redox process of p‐type organics and figured out the relationship between energy change and voltage output during the process. Then, we proposed a dual‐step strategy to effectively tune the energy change and eventually improve the output voltage of the organic electrode. Combining the regulation of the electron cloud of organic molecules and the manipulation of the solvation structure, the output voltage of an organosulfur compound based ZIB was greatly increased from 0.8 V to 1.7 V. Our results put forward a specific pathway to improve the working voltage and lay the foundation for the practical application of organic electrodes. [ABSTRACT FROM AUTHOR]

Abstract The performance of Li batteries is influenced by the Li+ solvation structure, which can be precisely adjusted by the components of the electrolytes. In this review, we overview the strategies for optimizing electrolyte solvation structures from three different perspectives, including anion regulation, binding energy regulation, and additive regulation. These strategies can optimize the composition of the electrode‐electrolyte interface, enhance the anti‐oxidative stability of electrolytes as well as regulate the behaviors of anions, solvents, and Li+ during the cycling process. Moreover, we also provide our insights into these aspects as well as present perspectives on high‐performance Li batteries.

Sodium metal batteries (SMBs) are promising candidates for low‐cost but high‐energy energy storage applications. Both long‐term stability and safety of SMBs can be largely enhanced when liquid electrolytes (LEs) are replaced by gel polymer electrolytes (GPEs). However, the low room‐temperature (RT) ionic conductivity and inferior interfacial compatibility of GPEs severely restrain their practical use. Herein, a poly(butyl acrylate)‐based GPE with a high RT ionic conductivity of 1.6 mS cm−1 is developed by in‐situ polymerization. Symmetrical cells assembled with this GPE show ultralong cyclability over 900 h at 0.2 mA cm−2, and ultralow overpotential of 233 mV at 1 mA cm−2. Full cells based on Na3V2(PO4)3(NVP) cathodes (NVP||GPE||Na) display significantly improved rate capability than that of LEs, benefiting from the solvation structure of Na+ in the GPE with much lower desolvation energy. Furthermore, the NVP||GPE||Na pouch cells exhibit a stable capacity of ≈92 mA h g−1 for 50 cycles at 1 C and excellent flexibility. The work not only provides a reliable GPE to develop RT SMBs but also offers new insight into the role of polymer frameworks in the rate performance of SMBs. [ABSTRACT FROM AUTHOR]

Aqueous Zn||vanadium oxide batteries (ZVBs) have recently received considerable attention owing to their high capacity, safety, environmental friendliness, and cost effectiveness. However, the limited cycling stability caused by the irreversible dissolution in traditional aqueous electrolytes still restricts their further application. Herein, a novel 3 m Zn(CF3SO3)2 electrolyte with a mixture solvent of propylene carbonate (PC) and H2O is adopted for aqueous vanadium‐based zinc‐ion batteries. With the manipulation of the electrolyte solvation structure, the optimized P20 (20% PC in volume ratio) electrolyte enables super‐stable cycling performance with high‐capacity retention of 99.5%/97% after 100/1000 cycles at 0.1/5 A g−1 at ambient environment in the Zn||NaV3O8·1.5H2O batteries. Systematical electrochemical testing and characterizations illustrate the addition of PC effectively reduces the active water molecule in Zn2+‐solvent cations and H+ in the electrolyte, thereby suppressing the cathode dissolution caused by the inserted H+ and co‐inserted H2O during the discharge/charge process. Impressively, the PC addition also enabled the Zn||NaV3O8·1.5H2O batteries present high specific capacity of 183/168 mAh g‐1 and high‐capacity retention of 100%/100% over 300/400 cycles at 0.1/0.2 A g‐1 at −40 °C, thus efficiently broadening the practical application for ZVB. This research may provide a promising strategy for designing high‐performance electrolytes for aqueous vanadium‐based batteries. [ABSTRACT FROM AUTHOR]

Aqueous Zn‐ion batteries have aroused much attention recently, yet challenges still exist in the lack of low‐cost, highly stable electrolytes to tackle the serious side reactions at Zn anode–electrolyte interface. Herein, a ZnSO4‐based low‐cost aqueous electrolyte is demonstrated with a small amount of eco‐friendly silk peptide as an efficient additive. Compared with silk sericin and fibroin, silk peptide with abundant strong polar groups (COOH and NH2) suppresses the side reactions. Namely, silk peptide regulates the solvation structure of Zn2+ to decrease coordinated active H2O and SO42−, and tends to anchor on Zn anode surface for the isolation of contact H2O/SO42− as well as electrostatic shielding, demonstrating synergistic solvation and interface regulating effect. Consequently, the excellent cycle life (3000 h) and Coulombic efficiency (99.7%) of Zn anodes are revealed in 2 m ZnSO4 electrolyte with only 5 mg mL−1 of silk peptide (≈0.49 USD L−1), promising practical applications of reversible zinc‐ion batteries. [ABSTRACT FROM AUTHOR]