Sodium-based Energy Storage Research Articles

Understanding Polymerized Ionic Liquids as Solid Polymer Electrolytes for Sodium Batteries.

Solid polymer electrolytes (SPEs) have emerged as promising candidates for sodium-based batteries due to their cost-effectiveness and excellent flexibility. However, achieving high ionic conductivity and desirable mechanical properties in SPEs remains a challenge. In this study, we investigated an AB diblock copolymer, PS-PEA(BuImTFSI), as a potential SPE for sodium batteries. We explored binary and ternary electrolyte systems by combining the polymer with salt and [C3mpyr][FSI] ionic liquid (IL) and analyzed their thermal and electrochemical properties. Differential scanning calorimetry revealed phase separation in the polymer systems. The addition of salt exhibited a plasticizing effect localized to the polyionic liquid (PIL) phase, resulting in an increased ionic conductivity in the binary electrolytes. Introducing the IL further enhanced the plasticizing effect, elevating the ionic conductivity in the ternary system. Spectroscopic analysis, for the first time, revealed that the incorporation of NaFSI and IL influences the conformation of TFSI- and weakens the interaction between TFSI- and the polymer. This establishes correlations between anions and Na+, ultimately enhancing the diffusivity of Na ions. The electrochemical properties of an optimized SPE in Na/Na symmetrical cells were investigated, showcasing stable Na plating/stripping at high current densities up to 0.7 mA cm-2, maintaining its integrity at 70 °C. Furthermore, we evaluated the performance of a Na|NaFePO4 cell cycled at different rates (C/10 and C/5) and temperatures (50 and 70 °C), revealing remarkable high-capacity retention and Coulombic efficiency. This study highlights the potential of solvent-free diblock copolymer electrolytes for high-performance sodium-based energy storage systems, contributing to advanced electrolyte materials.

Sodium-Beta Alumina and Its Application in a Novel Sodium-Based Solid-State Cell Concept

Post-Li-ion technologies are inevitable for solving problems connected to Li-ion cells, namely shortage of raw materials and physicochemical limits in energy density. Substitution of lithium with sodium while simultaneously replacing the liquid electrolyte with a ceramic solid electrolyte is a promising alternative.1 Sodium-beta alumina is a solid-state electrolyte with outstanding chemical, electrochemical, and mechanical properties.2 So far, high-temperature cells have been using it as a solid electrolyte.3,4 However, we recently showed that the sodium-ion conducting sodium-beta alumina solid electrolyte (BASE) is also a suitable solid electrolyte for solid-state cells operating at middle- to low temperatures. We present methods commonly used to reduce the area-specific capacity at the interfaces, stemming from the poor interaction of the rigid solid electrolyte with its adjacent electrodes. Hence, we tackle the bottleneck of middle- to low-temperature solid-state cell systems utilizing BASE, leading to enhanced cell performance.2 To increase the electrochemical performance, adjusting BASE´s properties is necessary. We showed that 3d transition metal doping tunes BASE´s properties effectively. For example, Ti4+ doping assisted a liquid sintering process, which changed the microstructure. Thus, BASE´s ionic conductivity increased by 50%. Simultaneously, we increased BASE´s fracture strength while reducing energy costs.5 Furthermore, we demonstrate the importance of proper storage conditions. We elucidate the effect of humidity on disk-shaped samples of Li-stabilized sodium-beta alumina and quantify the negative consequences of improper storage for cell systems using sodium-beta alumina. Despite detrimental effects on ionic conductivity and the chemical composition, the critical current density collapsed from the maximum of 9.1 mA cm-2, one of the highest values reported for sodium-beta alumina, to only 1.7 mA cm-2 at 25 °C. We show how impedance analysis and additional characterizations assist in clarifying occurring degradation mechanisms, namely ion exchange and subsequent buildup of surface layers.6 Combining the knowledge from previous works, we provide a proof-of-concept for a novel sodium-based solid-state cell concept utilizing sodium-beta alumina. We use sodium metal as the negative electrode, which is necessary to achieve high specific energy and the requirement to compete with existing cell systems. An environmentally friendly transition metal oxide positive electrode with high specific energy is paired with the negative electrode. A composite positive electrode ensures intra-electrode conduction while enabling a facile charge transfer due to an intimate electrolyte–electrode interface contact, leading to stable cycling over 50 cycles with good energy retention. We think that the proof-of-concept opens the door for dozens of new material combinations and enhances the utilization of sodium-beta alumina in medium- to low-temperature solid-state cell systems.All in all, the presentation points out the excellent performance and the enormous potential of sodium-beta alumina for sodium-based energy storage technologies.References Janek, J. & Zeier, W. G. A solid future for battery development. Nat. Energy 1, 1167; 10.1038/nenergy.2016.141 (2016).Fertig, M. P. et al. From High‐ to Low‐Temperature: The Revival of Sodium‐Beta Alumina for Sodium Solid‐State Batteries. Batteries & Supercaps; 10.1002/batt.202100131 (2022).Sudworth, J. The sodium/nickel chloride (ZEBRA) battery. Journal of Power Sources 100, 149–163; 10.1016/S0378-7753(01)00891-6 (2001).BASF New Business GmbH. Stationary Energy Storage. High-energy, long-duration sodium-sulfur battery (Ludwigshafen am Rhein, 2020).Dirksen, C. L., Skadell, K., Schulz, M., Fertig, M. P. & Stelter, M. Influence of 3d Transition Metal Doping on Lithium Stabilized Na-β″-Alumina Solid Electrolytes. Materials (Basel, Switzerland) 14, 5389; 10.3390/ma14185389 (2021).Fertig, M. P., Dirksen, C., Schulz, M. & Stelter, M. Humidity-Induced Degradation of Lithium-Stabilized Sodium-Beta Alumina Solid Electrolytes. Batteries 8, 103; 10.3390/batteries8090103 (2022). [Figure 1. Schematic illustrating the abstract submission´s topics. Pictures adapted from Ref. 2,6] Figure 1

Constructing bimetallic heterostructure as anodes for sodium storage with superior stability and high capacity

Heterostructure materials hold promise as future-generation anodes for sodium-based energy storage. However, the complexity and time-intensity of heterojunction fabrication processes limit their large-scale application. This study utilizes an ultrafast, one-step microwave process to successfully design and fabricate bimetallic selenides heterojunction nanoparticles, anchored on a three-dimensional porous carbon substrate (NiSe2–SnSe2/C). The in-situ formation of NiSe2–SnSe2 heterostructure optimizes sodium ion adsorption and transfer, which facilitates reaction kinetics and subsequently improves both the rate capability and cycle life. The NiSe2–SnSe2/C electrodes demonstrate a high-rate capability (719.8 mAh g−1 at 0.1 A g−1, and 667.9 mAh g−1 after a 50-fold increase in current density to 5 A g−1), maintaining high stability even after 10,000 cycles at 5 A g−1. The impact of the NiSe2–SnSe2 heterostructure on reaction kinetics was examined using density functional theory. The NiSe2–SnSe2/C anode, when coupled with the Na3V2(PO4)3 cathode in a full battery, demonstrated an impressive energy density of 155 Wh kg−1. This work exemplifies an ultrafast synthetic method for constructing heterostructure materials having great rate, high capacity and strong stability for sodium storage, making them promising candidates for large-scale energy storage applications.

Ultrastable sodium metal plating/striping by engineering heterogeneous nucleation on TiO2 nanotube arrays

• 3D spaced TiO 2 nanotube arrays (STNTs) were coated with ultra-fine metal nanocrystals. • We propose an absorption-diffusion regulation strategy to regulate Na deposition. • AIMD simulations demonstrate a mixed Na-Ag layer at the interface. • STNTs-Ag||Na displays a high Coulombic efficiency ∼99.5% even after 500 cycles. • STNTs-Ag-Na exhibits an ultralow overpotential of 4 mV and long cycling life over 1400 h. Sodium metal is considered as an excellent anode material for sodium-based energy storage devices with both high energy density and low cost, but the uncontrollable growth of sodium metal seriously limits its application. Herein, we firstly propose 3D spaced TiO 2 nanotube arrays (STNTs) uniformly coated with ultra-fine metal (Ag, Cu) nanocrystals as a substrate with absorption-diffusion regulation strategy to control the sodium metal deposition behavior. TiO 2 has a higher sodiophilic activity with larger Na absorption energy than the traditional copper substrate. Moreover, it is found by ab initio molecular dynamics (AIMD) simulations that it is much easier for Na to spread upon the surface of silver compared to copper, and thus forming a mixed Na-Ag layer at the interface. As a result, sodium metal is inclined to deposit inside or along the nanotube in STNTs-Ag in nanoscale. Finally, STNTs-Ag||Na half-cell displays a high Coulombic efficiency ∼99.5% even after 500 cycles with 1 mAh cm −2 . Symmetric cell of STNTs-Ag-Na exhibits an ultralow overpotential of 4 mV and a long-term cycling life over 1400 h. Moreover, STNTs-Ag-Na anode coupling with Na 3 V 2 (PO 4 ) 3 cathode exhibits a significantly reduced polarization voltage with 22 mV and improved rate performance with 110 mAhg −1 at 10 C.

Optimisation of sodium-based energy storage cells using pre-sodiation: a perspective on the emerging field

This perspective discusses how the tool of pre-sodiation can improve sodium-based electrochemical cells; the pros and cons of available pre-sodiation methods are then evaluated.

Revealing the sodium‐storage performance enhancement of adsorption‐type carbon materials after ammonia treatment: Active nitrogen dopants or specific surface area?

Adsorption-type carbon materials are promising candidates for fast sodium-ion storage via surface physisorption or chemisorption of sodium ions. Post-treatment of carbon such as ammonia can simultaneously strengthen both adsorption effects by increasing the specific surface area for physisorption, and by introducing active nitrogen dopants for chemisorption. Which factor, however, the increment of specific surface area or the introduction of active nitrogen dopants, predominantly contributes to sodium-storage capacity increment, remains a question. Answering this question is of great importance for understanding the sodium storage mechanism of adsorption-type carbon materials and thereby optimizing their sodium storage capabilities. In this work, pristine carbon is thermally treated in ammonia at temperatures from 600 to 1200°C, resulting in a simultaneous increase of specific surface area (8.6-1155 m2 g−1) and active nitrogen dopants (0.75-6.47 wt%). Correlations between sodium storage capacity and specific surface area/active nitrogen dopants are established. It is found that as the post-treatment temperature increases, the capacity increment is contributed first by sodium physisorption on active surface, and then by sodium chemisorption on nitrogen dopants. Our findings enrich the mechanistic understanding of sodium storage in adsorption-type carbon materials, which may guide the rational designs of carbon materials for high-rate sodium-based energy storage systems.

Flexible sodium-ion based energy storage devices: Recent progress and challenges

Flexible energy storage devices are gaining considerable attentions due to their great potentials in the emerging flexible electronics market, ranging from roll-up displays, bendable mobile phones, conformable health-monitoring skin sensors to implantable medical devices. The development of reliable and flexible electrodes with low cost, high performance, superior stability and safety remains a great challenge to meet the requirements for many practical applications. On the other hand, structural design can also enhance their flexibility and electrochemical performance. On account of the low cost and easily accessible sodium resources, in the present review we mainly focus on recent progress in flexible energy storage devices with sodium-ions as the charge carriers. We begin with a brief introduction of flexible energy storage systems and the current development of flexible sodium-ion based energy storage devices. Then, a more detailed overview of recent progress on pliable materials in flexible sodium-ion batteries (SIBs) is presented, including carbon-based substrates materials (e.g., graphene, carbon cloths, carbon nanofibers (CNFs) and carbon nanotubes (CNTs)), metal-based materials (e.g., stainless steel, copper (Cu) and titanium (Ti) foils), other flexible substrate materials and electrolytes. This is followed by detailed discussion of the advancements in other flexible analogous sodium-based energy systems, such as the fiber-shaped flexible SIBs, sodium-ion capacitors (SICs), Na–S batteries and Na–Se batteries. Finally, future prospects and challenges are examined and possible solutions are brought up to inspire the future flexible sodium-based energy storage devices.

Tailored crosslinking of Poly(ethylene oxide) enables mechanical robustness and improved sodium-ion conductivity

Sodium-based energy storage systems are promising candidates for electric vehicles and grid-level energy storage applications. The advancement of sodium-based energy storage systems relies on the development of high performance sodium-ion conducting electrolytes and membranes that exhibit high ionic conductivity and mechanical stability. A crosslinked poly(ethylene oxide) based polymer electrolyte was developed that demonstrates high ionic conductivity, as well as excellent mechanical stability over a wide temperature range. Ionic conductivities up to 2.0 × 10−4 S/cm at 20 °C and 7.1 × 10−4 S/cm at 70 °C are achieved for the plasticized membrane, almost four orders of magnitude greater than that of the non-plasticized membrane. The membranes are mechanically robust, and the storage modulus of the membrane is maintained at ∼1 MPa from −20 to 180 °C even with the addition of plasticizer. This study provides a synthesis approach towards the design of highly ion conducting, mechanically robust gel polymer electrolytes for Na-ion batteries, non-aqueous flow batteries, and many other applications.

Simultaneous texturing and conductivity tailoring of mesoporous NaTi2(PO4)3 nanocrystals by gadolinium doping for enhanced Na storage

Doping is an effective method to produce hybrid materials with desirable properties and functions. Herein, gadolinium ions (Gd3+) are introduced to substitute Ti in mesoporous NaTi2(PO4)3 (MNTP) nanocrystals to tailor the texture and conductivity simultaneously to improve Na storage properties. Microstructure characterization and kinetics analysis reveal that the superior electrochemical characteristics arise from the expanded cell, optimized porous structure, enhanced intrinsic electron conductivity, and better Na ion mobility as a result of Gd3+ introduction into the MNTP nanocrystals. In the half cells for sodium-ion battery, the MNTP nanocrystals with 5% Gd3+ exhibit a large ICE beyond 97% at 1 C, superior rate capability of 47.5 mAhg−1 at 50 C, and long cycling life time (>75% capacity retention at 5 C after 2000 cycles). Furthermore, using the Gd3+ doped MNTP nanocrystals as the anode and activated carbon as the cathode, the assembled sodium-ion hybrid capacitor shows a high energy density of 63 Whkg−1 at a power density of 46 Wkg-1. Even at a large current rate of 5 Ag−1, a stable capacity is maintained after 30,000 cycles without obvious degradation. Gadolinium ion doping provides a new technique to improve the electrochemical properties of NASICON-type anodes in sodium-based energy storage devices.

Scalable and sustainable synthesis of carbon microspheres via a purification-free strategy for sodium-ion capacitors

Sodium-based energy storage receives a great deal of interest due to the virtually inexhaustible sodium reserve, while the scalable and sustainable strategies to synthesize carbon-based materials with suitable interlayer spaces and large sodium storage capacities are yet to be fully investigated. Carbon microspheres, with regular geometry, non-graphitic characteristic, and stable nature are promising candidates, yet the synthetic methods are usually complex and energy consuming. In this regard, we report a scalable purification-free strategy to synthesize carbon microspheres directly from 5 species of fresh juice. As-synthesized carbon microspheres exhibit dilated interlayer distance of 0.375 nm and facilitate Na+ uptake and release. For example, such carbon microsphere anodes have a specific capacity of 183.9 mAh g−1 at 50 mA g−1 and exhibit ultra-stability (99.0% capacity retention) after 10000 cycles. Moreover, via facile activation, highly porous carbon microsphere cathodes are fabricated and show much higher energy density at high rate than commercial activated carbon. Coupling the compelling anodes and cathodes above, novel sodium-ion capacitors show the high working potential up to 4.0 V, deliver a maximum energy density of 52.2 Wh kg−1, and exhibit an acceptable capacity retention of 85.7% after 2000 cycles.

Micro/Nanostructured Materials for Sodium Ion Batteries and Capacitors.

High-efficiency energy storage technologies and devices have received considerable attention due to their ever-increasing demand. Na-related energy storage systems, sodium ion batteries (SIBs) and sodium ion capacitors (SICs), are regarded as promising candidates for large-scale energy storage because of the abundant sources and low cost of sodium. In the last decade, many efforts, including structural and compositional optimization, effective modification of available materials, and design and exploration of new materials, have been made to promote the development of Na-related energy storage systems. In this Review, the latest developments of micro/nanostructured electrode materials for advanced SIBs and SICs, especially the rational design of unique composites with high thermodynamic stabilities and fast kinetics during charge/discharge, are summarized. In addition to the recent achievements, the remaining challenges with respect to fundamental investigations and commercialized applications are discussed in detail. Finally, the prospects of sodium-based energy storage systems are also described.

Sulfur doped ultra-thin anatase TiO2 nanosheets/graphene nanocomposite for high-performance pseudocapacitive sodium storage

Sodium-ion battery (NIBs) has emerged as a promising low-cost option for large-scale electricity storage applications compared with traditional lithium-ion battery. However, developing anode materials with robust rate capability and long cycle life is even more challenging for sodium-based energy storage devices than lithium-based ones. Here, we report a unique nanocomposite architecture of sulfur doped atomically thin, micro-sized anatase TiO2 nanosheets anchored onto graphene sheets (S-TiO2/rGO). The high surface area of two-dimensional structure, graphene preservation networks and rich Ti3+/oxygen vacancy defects induced by sulfur doping endow S-TiO2/rGO electrode with excellent reversibility and fast kinetics. The electrode delivers a high capacity of 153mAh/g at a rate of 20C (6700mA/g) without evident capacity loss even after 8000 cycles. Further kinetics analysis reveals that the high-rate performance stems from pseudocapacitive process rendered by the 2D-morphology and vacancy-rich TiO2 nanosheets.

Unveiling the controversial mechanism of reversible Na storage in TiO2 nanotube arrays: Amorphous versus anatase TiO2

Due to their inherent safety, low cost, and structural stability, TiO2 nanostructures represent a suitable choice as anode materials in sodium-ion batteries. In the recent years, various hypotheses have been proposed regarding the actual mechanism of the reversible insertion of sodium ions in the TiO2 structure, and previous reports are often controversial in this respect. Interestingly, when tested as binder- and conducting additive-free electrodes in laboratory-scale sodium cells, amorphous and crystalline (anatase) TiO2 nanotubular arrays obtained by simple anodic oxidation exhibit peculiar and intrinsically different electrochemical responses. In particular, after the initial electrochemical activation, anatase TiO2 shows excellent rate capability and very stable long-term cycling performance with larger specific capacities, and thus a clearly superior response compared with the amorphous counterpart. To obtain deeper insight, the present materials are thoroughly characterized by scanning electron microscopy and ex situ X-ray diffraction, and the insertion of sodium ions in the TiO2 bulk phases is systematically modeled by density functional theory calculations. The present results may contribute to the development of more systematic screening approaches to identify suitable active materials for highly efficient sodium-based energy storage systems.

Pseudocapacitive Sodium Storage in Mesoporous Single-Crystal-like TiO2-Graphene Nanocomposite Enables High-Performance Sodium-Ion Capacitors.

Sodium-ion capacitors can potentially combine the virtues of high power capability of conventional electrochemical capacitors and high energy density of batteries. However, the lack of high-performance electrode materials has been the major challenge of sodium-based energy storage devices. In this work, we report a microwave-assisted synthesis of single-crystal-like anatase TiO2 mesocages anchored on graphene as a sodium storage material. The architecture of the nanocomposite results in pseudocapacitive charge storage behavior with fast kinetics, high reversibility, and negligible degradation to the micro/nanostructure. The nanocomposite delivers a high capacity of 268 mAh g-1 at 0.2 C, which remains 126 mAh g-1 at 10 C for over 18 000 cycles. Coupling with a carbon-based cathode, a full cell of sodium-ion capacitor successfully demonstrates a high energy density of 64.2 Wh kg-1 at 56.3 W kg-1 and 25.8 Wh kg-1 at 1357 W kg-1, as well as an ultralong lifespan of 10 000 cycles with over 90% of capacity retention.

Electro Chemical Properties of Hard Carbon Single Particles for Anode in Sodium Ion Batteries

Nowadays, Interest of lithium-ion batteries have been increasing for use many electronic equipment and electronic vehicles. But Lithium resources are unevenly distributed. Especially, mainly in South America, and the materials cost was steeply increased during the first decade of this century due to increasing global demand for lithium-ion accumulators. Sodium is the second-lightest and smallest alkali metal next to lithium and their electrochemical equivalent and standard potential are very similar to lithium. So, sodium based energy storage is of great interest to realize lithium-free high energy and high voltage batteries. Hard carbon had been utilized as a negative electrode in the first commercial Li-ion battery, and the hard-carbon electrodes deliver comparable reversible capacity without a staging transition due to the structural disorder. In this study, we were investigated the electrochemical properties of a single particle of hard carbon (10m in diameter, provided by Aekyung Co.) using a microelectrode technique. A finely manipulated Cu-coated gold micro electrode (diameter:20m) was used to maintain electrical contact with a hard carbon single particle in the 1M NaPF6 (EC:PC=1:1) electrolyte under optical microscope and the galvanostatic charge-discharge tests carried out. This single particle technique using microelectrode gives material’s intrinsic information, without mixed effect with parameters of electrode such as compositions (binder and conductive agent), density (porosity) and loading amounts on the unit area.

Porous heterostructured MXene/carbon nanotube composite paper with high volumetric capacity for sodium-based energy storage devices

The global availability of sodium and a possibility to avoid the use of copper current collectors make electrochemical sodium-ion storage attractive for battery and metal-ion capacitor applications. However, the use of Na instead of Li ions requires different electrode materials that can accommodate larger Na ions and still provide high charging rate and high volumetric capacity. Herein we report on the fabrication of porous Ti3C2 MXene/CNT composite paper electrodes for sodium-based energy storage devices. The heterostructure formation was realized by electrostatic attraction between negatively charged 2D MXene nanosheets and positively charged 1D CNTs. This method efficiently prevented restacking of MXene nanosheets and produced a well-defined porous structure, thereby facilitating electrolyte transport and access of ions to the electrode and producing functional MXene-based electrodes for sodium-ion storage. When applied as freestanding electrodes for sodium-ion storage, the built-to-order Ti3C2 MXene/CNTs porous films showed high volumetric capacity of 421mAhcm−3 at 20mAg−1, good rate performances, and excellent cycling stability. Prototype sodium-ion cells were also assembled using the as-prepared Ti3C2/CNTs anode and Na0.44MnO2 cathode. The fabrication of porous MXene/CNT composites, using simple self-assembly, opens the door to developing electrode materials with high volumetric capacity for sodium-ion storage.

A Highly Reversible Room-Temperature Sodium Metal Anode.

Owing to its low cost and high natural abundance, sodium metal is among the most promising anode materials for energy storage technologies beyond lithium ion batteries. However, room-temperature sodium metal anodes suffer from poor reversibility during long-term plating and stripping, mainly due to formation of nonuniform solid electrolyte interphase as well as dendritic growth of sodium metal. Herein we report for the first time that a simple liquid electrolyte, sodium hexafluorophosphate in glymes (mono-, di-, and tetraglyme), can enable highly reversible and nondendritic plating–stripping of sodium metal anodes at room temperature. High average Coulombic efficiencies of 99.9% were achieved over 300 plating–stripping cycles at 0.5 mA cm–2. The long-term reversibility was found to arise from the formation of a uniform, inorganic solid electrolyte interphase made of sodium oxide and sodium fluoride, which is highly impermeable to electrolyte solvent and conducive to nondendritic growth. As a proof of concept, we also demonstrate a room-temperature sodium–sulfur battery using this class of electrolytes, paving the way for the development of next-generation, sodium-based energy storage technologies.

ChemInform Abstract: Sodium and Sodium‐Ion Energy Storage Batteries

AbstractReview: 101 refs.

A Novel Sodium-Ion Rechargeable Battery

Energy storage is always an important issue and will be far more important in the future than at any time in the past. Storing large amounts of electricity cheaply, something that will be essential for making renewable energy the primary source, rather than just the supplemental source it is a current challenge. Such storage will make it practical to store energy from wind turbines and solar farms for later use. To achieve these, sodium-based energy storage systems have been identified as a key technology for the future as the lithium technology is more expensive. Existing sodium technologies work at high temperature, where molten sodium and molten sulphur are the anode and cathode respectively and they have never found widespread use. An alternative strategic approach used in this study is water-based sodium-ion intercalation cell (MnO2|NaOH|NaCo1/3Ni1/3Mn1/3PO4) for a promising low temperature energy storage device.

Aromatic porous-honeycomb electrodes for a sodium-organic energy storage device

Rechargeable batteries using organic electrodes and sodium as a charge carrier can be high-performance, affordable energy storage devices due to the abundance of both sodium and organic materials. However, only few organic materials have been found to be active in sodium battery systems. Here we report a high-performance sodium-based energy storage device using a bipolar porous organic electrode constituted of aromatic rings in a porous-honeycomb structure. Unlike typical organic electrodes in sodium battery systems, the bipolar porous organic electrode has a high specific power of 10 kW kg(-1), specific energy of 500 Wh kg(-1), and over 7,000 cycle life retaining 80% of its initial capacity in half-cells. The use of bipolar porous organic electrode in a sodium-organic energy storage device would significantly enhance cost-effectiveness, and reduce the dependency on limited natural resources. The present findings suggest that bipolar porous organic electrode provides a new material platform for the development of a rechargeable energy storage technology.