Aqueous Sodium-ion Batteries Research Articles

A carbonyl-rich conjugated organic compound for aqueous rechargeable Na+ storage with wide voltage window workability

Organic compounds have become an important electrode material for aqueous electrochemical energy storage. However, organic electrodes still face poor performance in aqueous batteries due to insufficient electrochemical activity. In this work, a novel conjugated quinone compound containing a rich carbonyl group was designed. The quinone compound was synthesized by a simple dehydration reaction of pyrene-4,5,9,10-tetrone (PTO) and 1,2-diaminoanthraquinone (1,2-AQ); it contains 4 pyrazines (CN) from AQ and 4 carbonyl groups (CO), as well as a large number of active sites and the excellent conductivity brought by its conjugated structure ensures the high theoretical capacity of PTO-AQ. In the context of aqueous sodium ion batteries (ASIBs), the electrode material known as PTO-AQ exhibits a notable reversible discharge capacity of 117.9 mAh/g when subjected to a current density of 1 A/g; impressively, it maintained a capacity retention rate of 74.3 % even after undergoing 500 charge and discharge cycles, a performance significantly surpassing that of pristine PTO and AQ. Notably, PTO-AQ exhibits a wide operating voltage range (-1.0–0.5 V) and a cycle life of up to 10,000 cycles. In situ Raman and ex situ measurements were used to analyze the structural changes of PTO-AQ during charge and discharge and the energy storage mechanism in NaAC. The effective promotion of Na+ storage brought by a rich carbonyl group was obtained. The structural energy level and electrostatic potential of PTO-AQ were calculated, and the active center distribution of PTO-AQ was obtained. This work serves as a guide for designing high-performance aqueous organic electrode materials that operate across a wide voltage range while also explaining their energy storage mechanism.

Synthesis and structure of anhydrous Zn2EDTA metal-organic framework

Metal-organic frameworks (MOFs) have gained significant attention in materials science due to their unique properties such as high surface area, porosity, and tunable electrochemical characteristics. Among various MOFs, Zn-EDTA compounds have shown potential for electrochemical applications. This paper presents the accident discovery and investigation of a new anhydrous Zn2(EDTA) MOF and its electrochemical performance as an electrode material for aqueous sodium-ion batteries. The study systematically explores the influence of pH and stoichiometric ratio on the formation of Zn2(EDTA) and Zn2(EDTA)(H2O) MOFs using X-ray diffraction analysis. The single-phase anhydrous Zn2(EDTA) compound is synthesized, offering advantages over the hydrated form regarding stability and electrochemical activity. Zn2(EDTA) structure is characterized, revealing a 3D network of channels suitable for interstitial ionic mobility. Thermogravimetric analysis (TGA) is used to study the thermal behavior of Zn2(EDTA), showing two weight loss steps attributed to water and carbon dioxide elimination during decomposition. Electrochemical measurements using cyclic voltammetry in alkaline and neutral electrolytes demonstrate the electrochemical activity of Zn2(EDTA) as an anode material for aqueous sodium-ion batteries. The results suggest that the electrochemical process in both electrolytes involves the reversible stripping/deposition of zinc ions. The anhydrous Zn2(EDTA) MOF exhibits higher peak current intensities and more positive potentials than the hydrated form. The study provides valuable insights for synthesizing and controlling Zn2(EDTA) MOF formation, opening the prospects for searching for new structures in considered-to-be-studied phase regions.

A Bio-Inspired Methylation Approach to Salt-Concentrated Hydrogel Electrolytes for Long-Life Rechargeable Batteries.

Hydrogel electrolytes hold great promise in developing flexible and safe batteries, but the presence of free solvent water makes battery chemistries constrained by H2 evolution and electrode dissolution. Although maximizing salt concentration is recognized as an effective strategy to reduce water activity, the protic polymer matrices in classical hydrogels are occupied with hydrogen-bonding and barely involved in the salt dissolution, which sets limitations on realizing stable salt-concentrated environments before polymer-salt phase separation occurs. Inspired by the role of protein methylation in regulating intracellular phase separation, here we transform the "inert" protic polymer skeletons into aprotic ones through methylation modification to weaken the hydrogen-bonding, which releases free hydrogen bond acceptors as Lewis base sites to participate in cation solvation and thus assist salt dissolution. An unconventionally salt-concentrated hydrogel electrolyte reaching a salt fraction up to 44 mol % while retaining a high Na+ /H2 O molar ratio of 1.0 is achieved without phase separation. Almost all water molecules are confined in the solvation shell of Na+ with depressed activity and mobility, which addresses water-induced parasitic reactions that limit the practical rechargeability of aqueous sodium-ion batteries. The assembled Na3 V2 (PO4 )3 //NaTi2 (PO4 )3 cell maintains 82.8 % capacity after 580 cycles, which is the longest cycle life reported to date.

Nano-Ni/Co-PBA as high-performance cathode material for aqueous sodium-ion batteries

Prussian blue analogues (PBAs) are reliable and promising cathode materials for aqueous sodium-ion batteries (ASIBs) owing to their open three-dimensional frameworks, outstanding stability, and low production costs. However, PBAs containing only a single type of transition-metal ion often have limited charge-storage capacities in aqueous systems. This study reports the first example of K0.11Ni0.39Co0.79[Fe(CN)6]·2.04H2O nanoparticles (Ni/Co-PBA) being used as a high-capacity cathode material for ASIBs. Owing to multi-electron redox reactions involving Co and Fe ions, Ni/Co-PBA has an initial capacity of 65 mAh g−1 and a capacity retention rate of 80% after 1000 cycles at 1.0 A g−1, indicating its outstanding cycle performance and capacity retention. Ex-situ x-ray diffraction spectroscopy, Fourier transform infrared spectroscopy, x-ray photoelectron spectroscopy, cyclic voltammetry, electrochemical impedance spectroscopy, and the galvanostatic intermittent titration technique were used to analyze the redox mechanisms and kinetics of Ni/Co-PBA. Ni/Co-PBA-based ASIBs are among the most promising energy-storage technologies for large-scale fixed energy-storage systems because of their outstanding electrochemical performance, low costs, and high efficiency.

Enabling Fe+2.5 to Fe+3 Redox Reaction in Prussian Blue Materials for High-Performance Aqueous Sodium-Ion Batteries

Aqueous Na-ion batteries using Prussian blue materials have intrinsic advantages on safety, material sustainability, and economic cost. However, it is challenging to obtain long term cycling stability because many redox reactions have poor intrinsic stability in water. Here, we enable Fe+2.5 to Fe+3 redox reaction in Prussian blue materials by converting the monoclinic sodium iron hexacyanoferrate (m-Na1.81Fe[Fe(CN)6]·0.7H2O) to a cubic phase (c- Na1.17Fe[Fe(CN)6]·0.7H2O) and demonstrated high performance by cycling in a water-in-salt electrolyte. Systematic characterization including electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy and X-ray absorption spectroscopy have verified the phase transition and iron oxidization state evolution. The cubic phase Na1.17Fe[Fe(CN)6]·0.7H2O delivers excellent cycling stability of >18,000 cycles with >90% capacity retention. The specific capacity is ~75 mAh/g and ~67 mAh/g at 1C and 10C rate, respectively.

Carbon‐Coated NaVPO4F as a High‐Capacity Cathode for Aqueous Sodium‐Ion Battery

AbstractNaVPO4F has garnered significant attention as a promising cathode material for non‐aqueous sodium‐ion batteries due to its high theoretical specific capacity and appropriate potential. However, the dissolution of vanadium component of NaVPO4F in aqueous electrolytes has restricted its application in aqueous sodium‐ion batteries (ASIBs). Herein, we report the use of carbon‐coated NaVPO4F as a cathode material in ASIBs. This cathode material exhibited a discharge capacity of 111 mAh g−1 at 0.5 A g−1 in a concentrated 17 m NaClO4 aqueous solution and demonstrated capacity retention of 74.4 % over 100 cycles. The experimental results confirmed that the carbon coating on NaVPO4F and high‐concentration NaClO4 aqueous electrolyte exhibited positive effects in restraining vanadium dissolution. Additionally, when configuration with NaTi2(PO4)3@C as anode, the full cell exhibited a capacity of 43.9 mAh g−1 with an average operating voltage of 1.2 V at a current density of 0.5 A g−1 in a concentrated 17 m NaClO4 aqueous electrolyte. These outcomes underscore the potential of NaVPO4F@C as a promising cathode material for ASIBs.

Ultra-Long Cycle of Prussian Blue Analogs Achieved by Equilibrium Electrolyte for Aqueous Sodium-Ion Batteries.

Aqueous sodium-ion batteries have promising prospects in large-scale electrical energy storage, which lack of suitable cathode with high specific capacity and long cycle lifespan, unfortunately. Manganese-based Prussian blue analogs (PBAs) (KMnHCF/NaMnHCF) are ideal candidates for low-cost and high theoretical specific capacity merits. But the rapid decline hinders their application, due to side reactions caused by water imbalance. Here, an equilibrium strategy, which can balance the interstitial water supplement and water attack, is proposed. As proof of the concept, xCS (x: proportion, CS: co-solvent, such as polyethylene glycol and trimethyl phosphate) equilibrium electrolytes areintroduced to solve the rapid decline. Assisting with the electrolyte, KMnHCF realizes excellent performance (10 000 cycles), which is beyond most cathode materials of sodium-ion batteries. The full batteries composed of KMnHCF cathode and NaTi2 (PO4 )3 anode also display outstanding performance (7000 cycles) and promising application prospects at low-temperature and engineering scenes. And then, the equilibrium electrolyte concept isverified by NaMn0.8 Fe0.2 HCF and NaMnHCF, proving its universality for low-cost and long-life manganese based PBAs.

Research Progress on Iron-Based Materials for Aqueous Sodium-Ion Batteries

Aqueous sodium-ion batteries (ASIBs) represent a promising battery technology for stationary energy storage, due to their attractive merits of low cost, high abundance, and inherent safety. Recently, a variety of advanced cathode, anode, and electrolyte materials have been developed for ASIBs, which not only enhance our fundamental understanding of the Na insertion mechanism, but also facilitate the research and development of practical ASIB systems. Among these electrode materials, iron-based materials are of particular importance because of the high abundance, low price, and low toxicity of Fe elements. However, to our knowledge, there are no review papers that specifically discuss the properties of Fe-based materials for ASIBs yet. In this review, we present the recent research progress on Fe-based cathode/anode materials, which include polyanionic compounds, Prussian blue, oxides, carbides, and selenides. We also discuss the research efforts to build Fe-based ASIB full cells. Lastly, we share our perspectives on the key challenges that need to be addressed and suggest alternative directions for aqueous Na-ion batteries. We hope this review paper can promote more research efforts on the development of low-cost and low-toxicity materials for aqueous battery applications.

Enabling long-cycling aqueous sodium-ion batteries via Mn dissolution inhibition using sodium ferrocyanide electrolyte additive

Aqueous sodium-ion batteries (AIBs) are promising candidates for large-scale energy storage due to their safe operational properties and low cost. However, AIBs have low specific energy (i.e., <80 Wh kg−1) and limited lifespans (e.g., hundreds of cycles). Mn-Fe Prussian blue analogues are considered ideal positive electrode materials for AIBs, but they show rapid capacity decay due to Jahn-Teller distortions. To circumvent these issues, here, we propose a cation-trapping method that involves the introduction of sodium ferrocyanide (Na4Fe(CN)6) as a supporting salt in a highly concentrated NaClO4-based aqueous electrolyte solution to fill the surface Mn vacancies formed in Fe-substituted Prussian blue Na1.58Fe0.07Mn0.97Fe(CN)6 · 2.65H2O (NaFeMnF) positive electrode materials during cycling. When the engineered aqueous electrolyte solution and the NaFeMnF-based positive electrode are tested in combination with a 3, 4, 9, 10-perylenetetracarboxylic diimide-based negative electrode in a coin cell configuration, a specific energy of 94 Wh kg–1 at 0.5 A g−1 (specific energy based on the active material mass of both electrodes) and a specific discharge capacity retention of 73.4% after 15000 cycles at 2 A g−1 are achieved.

Synthesis and Performance of NaTi2(PO4)3/VGCF@C Anode Composite Material for Aqueous Sodium-Ion Batteries

This study combines self-prepared NaTi2(PO4)3 (NTP) with commercial vapor-grown carbon fiber (VGCF) using a solid state calcination, then coats it with carbon to synthesize the composite anode material NaTi2(PO4)3/VGCF@C (NTP/VGCF@C). The microstructure and electrochemical properties of the composite material were then analyzed using microstructure analysis and electrochemical testing equipment. Single phase NTP shows nanoparticles with a polyhedral structure, and there is good contact at the interface between the nanoparticles and the VGCFs. The carbon coating formed on the NTP particles displays a nearly 6.5 nm thick layer of amorphous carbon. From the coin-cell battery performance measurements, after 850 cycles, the composite material NTP/VGCF@C exhibits an excellent retention rate of 96.3% compared to that of the pure NTP material when the current density is 200 mA/g. As a result, the composite material and lithium manganate (denoted as LMO) were assembled into an LMO-NTP/VGCF@C aqueous sodium-ion soft pack full battery system. The full battery shows an initial capacity of 31.07 mAh at a rate of 0.5C, and a reversible discharge capacity retention rate of 95.8% after 480 cycles, exhibiting a good long-cycle stability performance.

New construction of polypyrrole interphase layers to improve performance stability of NaTi2(PO4)3 anode for aqueous Na-ion batteries

NaTi2(PO4)3 (NTP) as a promising anode material for aqueous sodium-ion batteries has attracted widespread attention. However, the NTP material commonly exhibits significant capacity fade, possibly mainly attributing to the change of the chemical stability of NTP in the aqueous electrolytes. Coating NTP with polypyrrole (PPY) conductive polymers is a promising strategy to solve this problem, but in situ synthesis of the PPY polymer in the presence of the NTP active materials seems not to be easy, reported by the previous work, owing to the inferior adhesion of the synthesized PPY to the NTP surface. Thereby, this work has attempted ex situ synthesis of PPY coatings on the carbon-coated NTP (NTP/C) anode surface in the presence of small amounts of carbon conductive additives and organic binders, and then it shows that synthesized conductive PPY interphase layer can readily adhere to the NTP surface with no visible phase separation through the electrochemical oxidation polymerization under certain potentials in the pyrrole (PY)-containing electrolytes. The corresponding optimized oxidation modification conditions of the anode can be obtained, and the evolution law of the anode interface with the content of the electrolyte additives, the oxidation potential and the oxidation time can be established. Thus, the as-synthesized optimal modified anodes, with the thickness of about 24 μm for the PPY coating, are observed to have fairly large charge/discharge capacity of 228.6 mAh·g−1, high coulombic efficiency (> 95%) and enhanced cycling stability. Furthermore, a schematic for the charge/discharge processes involving possible reaction pathways at the modified anodes with the PPY layers in Na2SO4 aqueous electrolytes has been proposed.

Fast-Charging Capability of Thin-Film Prussian Blue Analogue Electrodes for Aqueous Sodium-Ion Batteries.

Prussian blue analogues are considered as promising candidates for aqueous sodium-ion batteries providing a decently high energy density for stationary energy storage. However, suppose the operation of such materials under high-power conditions could be facilitated. In that case, their application might involve fast-response power grid stabilization and enable short-distance urban mobility due to fast re-charging. In this work, sodium nickel hexacyanoferrate thin-film electrodes are synthesized via a facile electrochemical deposition approach to form a model system for a robust investigation. Their fast-charging capability is systematically elaborated with regard to the electroactive material thickness in comparison to a ″traditional″ composite-type electrode. It is found that quasi-equilibrium kinetics allow extremely fast (dis)charging within a few seconds for sub-micron film thicknesses. Specifically, for a thickness below ≈ 500 nm, 90% of the capacity can be retained at a rate of 60C (1 min for full (dis)charge). A transition toward mass transport control is observed when further increasing the rate, with thicker films being dominated by this mode earlier than thinner films. This can be entirely attributed to the limiting effects of solid-state diffusion of Na+ within the electrode material. By presenting a PBA model cell yielding 25 Wh kg-1 at up to 10 kW kg-1, this work highlights a possible pathway toward the guided design of hybrid battery-supercapacitor systems. Furthermore, open challenges associated with thin-film electrodes are discussed, such as the role of parasitic side reactions, as well as increasing the mass loading.

A Liquid-Phase reaction strategy to construct aqueous Sodium-Ion batteries anode with enhanced redox reversibility and cycling stability

NASICON-type NaTi2(PO4)3 compound is strongly considered to be a promising anode material for aqueous sodium-ion batteries, but suffering from low redox reversibility and poor cycling stability due to severe side reactions in aqueous electrolytes. Herein, a novel liquid-phase reaction strategy is reported for in-situ constructing carbon-coated NaTi2(PO4)3 nanocrystals (C-NTP) with enhanced redox reversibility and cycling stability. The construction mechanism, structural properties and electrochemical performance of the C-NTP material are carefully investigated. It is suggested that the material possesses a mesoporous carbon-coating structure and delivers outstanding performance with a high reversible capacity of 114.5 mAh·g−1 at 100 mA·g−1 and an impressive capacity retention of 82.1% after 1000 cycles at 1000 mA·g−1. The enhanced redox reversibility and cycling stability are attributed to the unique carbon-coating structure that improves the reaction kinetics and structural stability of the material owing to the high electronic conductivity and corrosion-resistant ability.

Bimetallic Synergies Help the Application of Sodium Vanadyl Phosphate in Aqueous Sodium-Ion Batteries.

Aqueous sodium-ion batteries (ASIB) offer many potential applications in large-scale power grids since they are inexpensive, safe, and environmentally friendly. Sodium superionic conductors (NASICON), especially carbon-coated Na3 V2 (PO4 )3 (NVP), have attracted much attention due to the full use of their high ion migration speed. However, the poor cycle lifespan and capacity retention of NVP hinder its application in ASIB. Herein, a novel bimetal-doped Na3 V1.3 Fe0.5 W0.2 (PO4 )3 (NV1.3 Fe0.5 W0.2 P) cathode is designed and synthesized to achieve outstanding cycling stability (95 % of initial capacity at 50th cycle). The electrochemical behavior and charge storage mechanism of NV1.3 Fe0.5 W0.2 P are systematically investigated by various in situ and ex situ characterizations. The Fe and W codoping could stabilize the NASICON framework to suppress the proton attack on the Na site in the aqueous electrolyte, thus resulting in excellent cycling stability. DFT calculations show that bimetallic doping increases the structural stability of NVP. Moreover, an ASIB fabricated using a NV1.3 Fe0.5 W0.2 P cathode and a NaTi2 (PO4 )3 anode delivers 64 mAh g-1 at room temperature, 95 % capacity retention after 50 cycles (1 A g-1 ).

Boosting sodium-storage behaviors of NASICON-type NaTi2(PO4)3 anode by synergistic modulations in both materials and electrolytes towards aqueous Na-ion batteries

NASICON-type NaTi2(PO4)3 (NTP) is one of the most competitive anode materials for aqueous sodium-ion batteries (ASIBs), thanks to its unique three-dimensional open framework structure, high ionic conductivity and good chemical stability. However, the low electrical conductivity of NTP and the oxygen reduction induced side reactions seriously affect its practical applications. To well address the above issues, the synergistic regulation strategy in electrode materials and electrolytes is motivatively put forward. The porous single-crystal NTP micro-sized framework coated with conductive carbon nano-layer (denoted as NTP@C) is designed with significantly improved electronic conductivity and structural stability. With further regulations in both the dissolved oxygen content and pH values of aqueous Na2SO4 electrolyte, the enhanced reversible capacities and cyclic stability especially at high rates are achieved by effectively alleviating side reactions. As a result, the fabricated NTP@C anode is optimized with a high-rate capability and remarkable long-duration electrochemical stability in the N2-purged aqueous Na2SO4 electrolyte with pH = 8.0. Furthermore, the assembled NTP@C//Na0.44MnO2 ASIBs exhibit high energy density of ∼40.0 Wh kg‒1 along with excellent cycling stability. More significantly, our work provides an insightful guideline for rational construction of other advanced aqueous rechargeable batteries.

Nanoarchitected graphene/copper oxide nanoparticles/MoS2 ternary thin films as highly efficient electrodes for aqueous sodium-ion batteries.

Sodium-ion batteries (SIBs) operating in aqueous electrolyte are an emerging technology that promises to be safer, cheaper, more sustainable and more efficient than their lithium-based counterparts. One of the great challenges associated with this technology is the development of advanced materials with high specific capacity to be used as electrodes. Herein, we describe an ingenious strategy to prepare unprecedented tri-component nanoarchitected thin films with superior performance when applied as anodes in aqueous SIBs. Taking advantage of the broadness and versatility of the liquid-liquid interfacial route, three transparent nanocomposite films comprising graphene, molybdenum sulphide and copper oxide nanoparticles have been prepared. The samples were characterized using several techniques, and the results demonstrated that depending on the specific experimental strategy, different nanoarchitectures are achieved, resulting in different and improved properties. An astonishing capacity of 1377 mA h g-1 at 0.1 A g-1 and a degree of recovery of 100% were observed for the film in which the interactions among the components were optimized. This is among the highest capacity values reported in the literature and demonstrates the potential of these tri-component materials to be used as anodes in aqueous sodium-ion batteries.

Investigation of high-entropy Prussian blue analog as cathode material for aqueous sodium-ion batteries

Aqueous rechargeable sodium-ion batteries (ARSIBs) have received considerable attention as promising alternatives to lithium-ion batteries (LIBs) owing to their safety, environmental friendliness, low cost, and high charge/discharge capacities.

Inlaying Bismuth Nanoparticles on Graphene Nanosheets by Chemical Bond for Ultralong‐Lifespan Aqueous Sodium Storage

AbstractRechargeable aqueous sodium ion batteries (ASIBs) are rising as an important alternative to lithium ion batteries, owing to their safety and low cost. Metal anodes show a high theoretical capacity and nonselective hydrated ion insertion for ASIBs, yet their large volume expansion and sluggish reaction kinetics resulted in poor electrochemical stability. Herein, we demonstrate an electrode cyclability enhancement mechanism by inlaying bismuth (Bi) nanoparticles on graphene nanosheets through chemical bond, which is achieved by a unique laser induced compounding method. This anchored metal‐graphene heterostructure can effectively mitigate volume variation, and accelerate the kinetic capability as the active Bi can be exposed to the electrolyte. Our method can achieve a reversible capacity of 122 mAh g−1 at a large current density of 4 A g−1 for over 9500 cycles. This finding offers a desirable structural design of other metal anodes for aqueous energy storage systems.

Inlaying Bismuth Nanoparticles on Graphene Nanosheets by Chemical Bond for Ultralong-Lifespan Aqueous Sodium Storage.

Rechargeable aqueous sodium ion batteries (ASIBs) are rising as an important alternative to lithium ion batteries, owing to their safety and low cost. Metal anodes show a high theoretical capacity and nonselective hydrated ion insertion for ASIBs, yet their large volume expansion and sluggish reaction kinetics resulted in poor electrochemical stability. Herein, we demonstrate an electrode cyclability enhancement mechanism by inlaying bismuth (Bi) nanoparticles on graphene nanosheets through chemical bond, which is achieved by a unique laser induced compounding method. This anchored metal-graphene heterostructure can effectively mitigate volume variation, and accelerate the kinetic capability as the active Bi can be exposed to the electrolyte. Our method can achieve a reversible capacity of 122 mAh g-1 at a large current density of 4 A g-1 for over 9500 cycles. This finding offers a desirable structural design of other metal anodes for aqueous energy storage systems.

Na+/K+-codoped amorphous manganese oxide with enhanced performance for aqueous sodium-ion battery

The cycling performance of aqueous rechargeable metal-ion batteries is highly dependent on the cathodes. Metal-ion doping is an effective means to improve the ion mobility, surface reactivity, and structural stability of metal oxide cathodes. In this paper, we report on the synthesis and electrochemical performance of Na+-, K+-, and Na+/K+-codoped amorphous manganese oxide (NAMO, KAMO, and NKAMO) cathodes for aqueous sodium-ion battery (ASIB). Na+ ion is more easily doped in the AMO matrix than K+ ion, whether single-ion doping or Na+/K+-codoping, presenting NAMO, KAMO, and NKAMO with different doping levels. Also, the specific surface area (SBET), Mn3+ concentration, and surface defect are linearly correlated with the doping level. NKAMO with high doping level manifests improved electrode performance as compared with NAMO, KAMO, and commercially available MnO2, due to the large SBET, high Mn3+ concentration, and more surface defects. The charge/discharge mechanism is mainly attributed to the reversible extraction/insertion of Na+ ions from/into the AMO matrix. NKAMO can deliver a discharge specific capacity (Cdis) of 41.3 mA h g1 after 1000 cycles at 1 A g1. Moreover, a typical ASIB with NKAMO cathode and NaTi2(PO4)3 (NTP) anode can retain a Cdis of 33.2 mA h g1 after 5000 cycles with continuously changing the current density from 1 to 5 C, showing capacity retention of ca. 72% relative to the initial cycle.