Aqueous Sodium-ion Batteries Research Articles

Realizing an aqueous sodium-ion battery with a super-high discharge voltage based on a novel FeSe2@rGO anode

Aqueous sodium-ion batteries (ASIBs) promise particularly increased operational safety and lower manufacturing cost than the current state-of-the-art organic electrolyte-based lithium-ion batteries.

Graphene Oxide Suspension-Based Electrolyte Promotes the Cycling Performance of Aqueous Sodium-Ion Batteries Through the Interaction between Metal Ions, Free Water Molecules and Functional Groups

Graphene Oxide Suspension-Based Electrolyte Promotes the Cycling Performance of Aqueous Sodium-Ion Batteries Through the Interaction between Metal Ions, Free Water Molecules and Functional Groups

Sodium Decavanadate Encapsulated Mn-Btc Pom@Mof as High-Capacity Cathode Material for Aqueous Sodium-Ion Batteries

Sodium Decavanadate Encapsulated Mn-Btc Pom@Mof as High-Capacity Cathode Material for Aqueous Sodium-Ion Batteries

Na+/K+-Codoped Amorphous Manganese Oxide with Enhanced Performance for Aqueous Sodium-Ion Battery

Na+/K+-Codoped Amorphous Manganese Oxide with Enhanced Performance for Aqueous Sodium-Ion Battery

Glucosamine derived hydrothermal carbon electrodes for aqueous electrolyte energy storage systems.

Nitrogen-doped porous hard carbons are synthesized by hydrothermal carbonization method (HTC) using glucosamine as biosource and treated at different carbonization temperatures in nitrogen environment (500, 750, 1000 °C). The electrochemical performances of hard carbons electrode materials for aqueous electrolyte sodium ion batteries are examined to observe the effect of two different voltage ranges (-0.8-0.0) V and (0.0-0.8) V in 1.0 M Na2SO4 aqueous electrolyte. The best electrochemical performances are acquired for the 1000 °C treated glucosamine (GA-1000) porous carbon sample that provides ~96 F/g capacitance value in the negative voltage range (between -0.8 and 0.0) V. The sodium diffusion coefficient of the GA-1000 carbon calculated by electrochemical impedance measurements is found to be 1.5 × 10-14 cm2/s.

Cathode Engineering for High Energy Density Aqueous Zn Batteries

ConspectusFrequent safety accidents of lithium-ion batteries (LIBs) originating from the utilization of flammable electrolytes urges the battery community to develop a safe substitute. This safety background is a boom for aqueous batteries (ABs) which employ aqueous electrolytes to address safety concerns. Recently, ABs have experienced a rapid advance because various battery chemistries have been successively developed, e.g., aqueous Zn batteries (AZBs), aqueous LIBs, aqueous sodium-ion battery, etc. Impeded by the narrow voltage window of aqueous electrolytes, however, the majorities of cathode materials with high operation potential employed in traditional nonaqueous batteries are excluded from the range of ABs cathodes, leading to a low energy density. Directly using metal as an anode is likely to improve the energy density, whereas most of the reported metal anodes, e.g., lithium, sodium, magnesium, etc., cannot run in aqueous electrolytes. One exceptional case is the Zn metal anode that permits theoretically high energy density AZBs due to triple merits: (1) the Zn metal anode exhibits a low redox potential (−0.76 V vs standard hydrogen electrode, SHE), taking the best advantage of the limited voltage window of aqueous electrolytes; (2) Zn metal anode with mild protection can easily maintain its chemical stability in aqueous medium; (3) Zn metal anode releases a high specific capacity of 820 mAh g–1. AZBs thus exhibit a rapid development, especially in developing high specific capacity cathode materials such as MnO2 and V2O5, and the corresponding structure modification. Despite these spurring achievements, the overall energy density of the whole AZB device is still unsatisfactory.In this Account, we initially present the energy density state of AZBs, where a detailed discussion is given to the energy bottleneck of current cathode materials. Meanwhile, the corresponding strategies that are considered as the first-stage attempt to enhance energy density are discussed, including mediating interlayer spacing, introducing oxygen vacancy, and using high-voltage cathode materials. Due to the unsatisfactory energy density, we then propose a systemic methodology of cathode engineering to renew the energy blueprint of AZBs. Specifically, we show the high possibility of employing conversion-type cathodes with the capability of multiple-electron transfer reaction, e.g., sulfur, selenium, iodine, etc., to remarkably enhance the energy density of AZBs. In addition, strengthening the utilization of cathode active material such as the activation, stabilization, or introduction of metal active centers is highlighted as a branch of cathode engineering to address the energy density issue of AZBs. Finally, we attempt to summarize the remaining challenges and possible solutions to address the energy density issue of AZBs, such as reducing the proportion of electrochemically inactive materials, increasing the cathode loading mass, and avoiding the excessive usage of Zn anode. Overall, we believe this Account can shed light on the promising directions to design a practical high energy density AZBs.

An elemental sulfur/CoS2- ionic liquid based anode for high-performance aqueous sodium-ion batteries

Despite having advantages of safety and dominating consumer and electric vehicle market, the progress of aqueous rechargeable battery research is hindered by low capacity anode materials. A game-changing strategy is to use an environmentally benign aqueous electrolyte with earth abundance Na-ion and sulfur. Sulfur promises to be a next-generation electrode material due to its high theoretical capacity and energy density. But the practical application of elemental sulfur in aqueous electrolyte suffer from sharp capacity decay due to the dissolution of polysulfides. Herein, we report 70 % elemental sulfur along with CoS2 and 1‑butyl‑3-methylimidazolium o,o-bis(2-ethylhexyl) dithiophosphate (BMIm-DDTP) ionic liquid (IL) as anode (S@CoS2-IL) for aqueous rechargeable sodium-ion/sulfur batteries (ARSSB) in 2 M aq. Na2SO4 electrolyte.The S@CoS2-IL anode delivers an outstanding capacity of 977 mA h g−1 (> 91 % of the theoretical capacity of elemental sulfur i.e. 1070 mA h g−1), at 0.5 C with a stable cycling performance over 100 cycles with > 98 % of capacity retention at 2 C with 100 % of coulombic efficiency. A negligible loss of S was confirmed by UV–Vis spectroscopy and potentiometric titration and anchoring of polysulfide at S@CoS2-IL anode were evidenced by NMR, ESI-mass, Raman and X-ray photoelectron spectroscopy. The synergy between highly active CoS2 and BMIm-DDTP IL from the dynamic coordination of dithiophosphate with CoS2 provides easy access for polysulfides anchoring and fast reaction kinetics which effectively suppresses the dissolution of discharge polysulfides and HS−. The full cell studies using S@CoS2-IL anode with standard Na0.44MnO2 cathode demonstrate an outstanding capacity of 778 mA h g−1 w.r.t the weight of S and 104.98 mA h g−1 (of total electrodes weight), which is close to the theoretical capacity of 109 mA h g−1 with 100 % coulombic efficiency and 91.8 % capacity retention over 400 cycles at 2 C. The excellent performance of this aqueous battery chemistry shows that S@CoS2-IL anode has great potential towards practical application in ARSSB.

Revealing the Fast and Durable Na+ Insertion Reactions in a Layered Na3Fe3(PO4)4 Anode for Aqueous Na-Ion Batteries.

Aqueous sodium-ion batteries represent a promising approach for stationary energy storage; however, the lack of appropriate anode materials has substantially retarded their development. Herein, we demonstrated an iron-based phosphate material of Na3Fe3(PO4)4 as an inexpensive and efficacious anode alternative. While the Fe3+/Fe2+ redox couple renders a two-Na-insertion reaction with desirable potentials, its unique layered structure further facilitates the Na-insertion kinetics and reversibility. Consequently, this electrode exhibits an appealing Na-insertion performance, with a reversible capacity of ∼83 mAh g-1, suitable anode potential of -0.4 V vs Ag/AgCl, excellent rate capability of 200 C, and outstanding cycling of 6000 cycles. Utilizing operando synchrotron X-ray diffraction and X-ray absorption spectroscopy, we revealed the structural evolution of the Na3Fe3(PO4)4 anode during the two-electron reaction, where the extremely small volume expansion (∼3%) enables its fast-charging and long-cycling capability. Our work suggests new considerations of developing versatile iron phosphate compounds as appealing anode materials for energy storage in aqueous electrolytes.

High-Performant All-Organic Aqueous Sodium-Ion Batteries Enabled by PTCDA Electrodes and a Hybrid Na/Mg Electrolyte.

Aqueous sodium‐ion batteries (ASIBs) are aspiring candidates for low environmental impact energy storage, especially when using organic electrodes. In this respect, perylene‐3,4,9,10‐tetracarboxylic dianhydride (PTCDA) is a promising anode active material, but it suffers from extensive dissolution in conventional aqueous electrolytes. As a remedy, we here present a novel aqueous electrolyte, which inhibits the PTCDA dissolution and enables their use as all‐organic ASIB anodes with high capacity retention and Coulombic efficiencies. Furthermore, the electrolyte is based on two, hence “hybrid”, inexpensive and non‐fluorinated Na/Mg‐salts, it displays favourable physico‐chemical properties and an electrochemical stability window >3 V without resorting to the extreme salt concentrations of water‐in‐salt electrolytes. Altogether, this paves the way for ASIBs with both relatively high energy densities, inexpensive total cell chemistries, long‐term sustainability, and improved safety.

A Trifluoroacetate-based Concentrated Electrolyte for Symmetrical Aqueous Sodium-ion Battery with NASICON-type Na<sub>2</sub>VTi(PO<sub>4</sub>)<sub>3</sub> Electrodes

A Trifluoroacetate-based Concentrated Electrolyte for Symmetrical Aqueous Sodium-ion Battery with NASICON-type Na<sub>2</sub>VTi(PO<sub>4</sub>)<sub>3</sub> Electrodes

High-Performance Aqueous Sodium-Ion Battery Based on Graphene-Doped Na2MnFe(CN)6–Zinc with a Highly Stable Discharge Platform and Wide Electrochemical Stability

High-Performance Aqueous Sodium-Ion Battery Based on Graphene-Doped Na₂MnFe(CN)₆–Zinc with a Highly Stable Discharge Platform and Wide Electrochemical Stability

Cost attractive hydrogel electrolyte for low temperature aqueous sodium ion batteries

Low temperature tolerance of aqueous sodium ion batteries (ASIBs) represents a high challenge, eventhough ASIBs are attractive for large scale energy-storage application due to their high safety, low cost and environmental friendliness. For the first time, this work reports a Na2SO4-SiO2 hydrogel type electrolyte operated at low temperature as -30℃ using fumed silica as the gel matrix and methyl alcohol as the anti-freezing additive. Due to the inter-molecular bonding between SiO2 and Na2SO4, the precipitation of Na2SO4 and the continue growth of the Na2SO4 grain in supersaturated electrolyte is highly suppressed at low temperature. The Na2SO4-SiO2 hydrogel electrolyte possesses a high ionic conductivity as 0.070 mS cm−1 at -30℃. An aqueous sodium ion cell with the as-proposed SiO2Na2SO4 hydrogel electrolyte has been developed based on active carbon (AC) as the cathode and carbon coated NaTi2(PO4)3 (NTP@C) as the anode. At -30℃, the cell possesses a reversible capacity of 61.8 mAh g−1 (based on NTP@C) at a current density as 0.13 A g−1 (0.13 mA cm−2) with a high cycling stability. This work provides a new path for the development of aqueous sodium ion batteries for low temperature operation.

High‐Energy Aqueous Sodium‐Ion Batteries

AbstractWater‐in‐salt electrolytes (WISE) have largely widened the electrochemical stability window (ESW) of aqueous electrolytes by formation of passivating solid electrolyte interphase (SEI) on anode and also absorption of the hydrophobic anion‐rich double layer on cathode. However, the cathodic limiting potential of WISE is still too high for most high‐capacity anodes in aqueous sodium‐ion batteries (ASIBs), and the cost of WISE is also too high for practical application. Herein, a low‐cost 19 m (m: mol kg−1) bi‐salts WISE with a wide ESW of 2.8 V was designed, where the low‐cost 17 m NaClO4 extends the anodic limiting potential to 4.4 V, while the fluorine‐containing salt (2 m NaOTF) extends the cathodic limiting potential to 1.6 V by forming the NaF–Na2O–NaOH SEI on anode. The 19 m NaClO4–NaOTF–H2O electrolyte enables a 1.75 V Na3V2(PO4)3∥Na3V2(PO4)3 full cell to deliver an appreciable energy density of 70 Wh kg−1 at 1 C with a capacity retention of 87.5 % after 100 cycles.

High-energy-density aqueous sodium-ion batteries enabled by chromium hexacycnochromate anodes

Aqueous sodium-ion batteries (A-SIBs) are a cost-effective and safe battery candidate for stationary energy storage systems. Prussian blue and its analogues (PBAs) have been studied as cathode materials in A-SIBs. However, few studies have used PBAs as anode materials because of their small specific capacity and low cell voltages. Herein, we report that chromium hexacycnochromate (CrCr PBA) can serve as an efficient anode material to enable high-performance A-SIBs. CrCr PBA contains Cr ions at two types of sites coordinated by C and N, offering two redox pairs at −0.62/−0.65 V and −0.73/−0.77 V (vs. Ag/AgCl electrode), respectively. X-ray photoelectron and electron energy loss spectroscopic characterizations of CrCr PBA at different charge/discharge stages show that Cr at both types of coordinated sites can efficiently participate in Na+ storage, delivering a high specific capacity of 108.2 mAh g−1 at a discharge rate of 0.5 A g−1. Besides, low redox potentials of CrCr PBA also contribute to a higher battery voltage. Coupled with a manganese hexacyanoferrate cathode in a water-in-salt electrolyte (17 M NaClO4), full coin cells exhibit a high energy density of 81.6 Wh kg−1 and a high capacity of 52.8 mAh g−1 at an average voltage of 1.55 V. They also display a long-cycle-life with 93.01% capacity retention over 500 cycles at 30C with around 100% Coulombic efficiency. Their performance is one of the best among recently reported A-SIBs. Because of their similar energy storage mechanisms, CrCr PBA may also serve as promising anode materials in other types of aqueous alkaline metal-ion batteries (e.g., lithium-ion battery and potassium-ion battery).

High-capacity and cycling-stable polypyrrole-coated MWCNT@polyimide core-shell nanowire anode for aqueous rechargeable sodium-ion battery

Aqueous rechargeable sodium-ion batteries (ARSBs) have potential applications in large-scale electric energy storage systems because of the non-flammable and fast charge-discharge performance of the aqueous neutral electrolyte as well as low cost and abundance of sodium resources. Herein, we demonstrate polypyrrole-coated MWCNT@polyimide core-shell nanowire based on pyromellitic dianhydride (PMDA) and 4,4′-oxydianiline (ODA) as a high-capacity and cycling-stable anode material for ARSBs. The as-synthesized MWCNT@polyimide core-shell nanowire exhibits excellent initial discharge capacity as high as 234.9 mA h g −1 , which is 83.6% of the theoretical value, owing to the bicontinuous electron/ion transport pathway. During 100 cycles of charge-discharge, however, the considerable swelling of PMDA-ODA polyimide and structural degradation of core-shell structure result in significant deterioration in the performance from 234.9 to 74.6 mAh g −1 . In order to improve the cycling stability, conducting polypyrrole is coated on its surface. After 100 charge-discharge cycles, the polypyrrole-coated MWCNT@polyimide core-shell nanowire retains a specific capacity of 209.3 mA h g −1 , corresponding to 77.8% of the initial capacity, without any swelling and structural degradation. In impedance study, the changes in the surface and charge transfer resistances during charge-discharge cycles are significantly reduced. As a result, the polypyrrole layer successfully inhibits the structural degradation of the MWCNT@polyimide core-shell nanowire, and consequently improves the cycling performance. • MWCNT@polyimide nanowire is used as an anode for aqueous sodium-ion battery. • Commercially available PMDA-ODA polyimide is used as active material. • The specific capacity is 209.3 mA h g −1 after 100 cycles at 280 mA g −1 (1C). • Polypyrrole layer on polyimide inhibits the degradation of PMDA-ODA polyimide.

Assessment and progress of polyanionic cathodes in aqueous sodium batteries

An assessment of the latest ground-breaking advances of polyanionic materials as cathodes for aqueous sodium-ion batteries is given. Future research directions and challenges on material development are provided.

Research progress of tunnel-structural Na0.44MnO2 cathode for sodium-ion batteries: A mini review

Sodium-ion battery has been widely studied because of its abundant sodium resources and expectable electrochemical performance. The unique tunnel Na0.44MnO2 has attracted wide attention as one of the available cathode materials because of its low cost, as well as long cycle stability and rate capability in the non-aqueous and aqueous batteries. During the past decades, much efforts have been made to improve the electrochemical performance of the Na0.44MnO2. This review concisely describes the research progress of Na0.44MnO2 cathode for both non-aqueous and aqueous sodium-ion batteries, mainly focuses on the crystal structure, morphology, charge–discharge mechanism and influence of different synthesis and modification methods on the morphology and electrochemical performance. In addition, the main opportunities and challenges in this field are briefly commented and discussed.

Effect of Electrolyte Anion on Electrochemical Behavior of Nickel Hexacyanoferrate Electrode in Aqueous Sodium-Ion Batteries

Nickel hexacyanoferrate (NiHCF) has a three-dimensional open framework structure, excellent long-cycling stability and rate performance as a cathode for aqueous sodium-ion batteries. However, the specific capacity of NiHCF is lower than that of present cathodes for aqueous batteries. A sodium-ion electrolyte was explored to achieve optimum capacity with NiHCF. Powder-type NiHCF was fabricated by coprecipitation with the atomic composition K0.065Ni1.44Fe(CN)6·4.4H2O. The presence of Fe vacancies in the atomic composition is attributable to the inclusion of coordinating and zeolitic water during coprecipitation. Two sodium-ion electrolytes, 1 M Na2SO4 and 1 M NaNO3, were employed to analyze the electrochemical behavior of the NiHCF electrode. Identical redox potentials to 0.58 V (vs. NHE) were measured in both electrolytes. However, a lower overpotential was observed in NaNO3 compared to Na2SO4 as a result of the smaller interfacial charge transfer resistance. The lower charge transfer resistance in the NaNO3 solution produced a higher specific capacity of 57 mAh g<sup>-1</sup> (1 C-rate) and the superior capacity retention of 46.6% at 20 C-rate. The anion in the aqueous electrolyte changed the charge transfer resistance at the electrode/electrolyte interface, confirming the electrolyte anion has a crucial effect on the charge capacity and rate performance of NiHCF.

(Invited) Fast Charging Anodes for Aqueous Sodium-Ion Batteries

Aqueous sodium-ion batteries are attractive battery alternatives for stationary energy storage due to their inherently low cost and high safety. The development of advanced electrode materials with excellent performance and low cost is crucial for the success of aqueous Na-ion batteries. Our group recently has studied several types of iron phosphate-based electrodes including NASICON and layered materials as promising anodes alternative for aqueous Na-ion batteries. We found these anodes can exhibit very fast ionic diffusion that enables the fast charging rate (up to 200C), long cycling life (6000 cycles), high capacity retention (~70%) and rate capability. In combination of electrochemical characterization and multimodal synchrotron X-ray scattering and spectroscopy methods, we further reveal the reaction mechanism associated with these high performance ionic conducting ceramics. Our work also underlines the importance of fabricating aqueous batteries on the basis of the Earth-abundant, cost- effective, and non-toxic elements.

Nanostructured LiTi2(PO4)3 anode with superior lithium and sodium storage capability aqueous electrolytes

Aqueous alkali metal ion batteries show great promise as the next generation secondary batteries with low cost, high power density and better safety. However, they suffer from inferior cycle stability at a higher current density and displays poor coulombic efficiency. In this work, LiTi2(PO4)3@C/CNTs (LTP@C/CNTs) with three-dimensional mesoporous nanostructure was investigated in both aqueous lithium-ion batteries (ALIBs) and aqueous sodium-ion battery (ASIBs). Improved rate and cycling performance at high current densities were demonstrated in contrast to LiTi2(PO4)3@C (LTP@C). Typically, the LTP@C/CNTs electrode achieves a discharge capacity of 97.37 mAhg−1 and 90.88 mAhg−1 in ALIBs and ASIBs half cells at 3 A g-1 current density. LTP@C/CNTs//LiMn2O4 and LTP@C/CNTs//Na0.44MnO2 full cells show the capacity retention of 72.9% and 79.4% after 500 cycles. Besides, new electrochemical behavior is reported for the first time, that the anode materials present a two-step sodium ion insertion/extraction in ASIBs. After cycling, LTP anode converts into (NaTi2(PO4)3) NTP phase with maintained crystallinity. LTP@C/CNTs composite anode thus shows a great potential application in next-generation aqueous energy storage systems.