Discharge Power Density Research Articles

Significant improvement of comprehensive energy storage performance and transparency in Sr0.7La0.2TiO3-doped (K,Na)NbO3 lead-free ceramics

Although transparent ceramics are highly desirable for practical applications, it is challenging to achieve outstanding energy storage properties and high transparency simultaneously in (K, Na)NbO3 ceramics. Herein, through a combination of modifying crystal symmetry and refining domain size and grain size, a high recoverable energy storage density Wrec ≈ 4.04 J cm−3, a high efficiency η ≈ 73 %, and good optical transmittance (≈ 77 % at 2000 nm, ≈ 60 % at 780 nm) are realized. Of particular significance is that an excellent discharge energy density of ≈ 2.43 J cm−3, a superior discharge current density of ≈ 1551 A cm−2, and a high discharge power density of ≈ 233 MW cm−3 are simultaneously achieved in 0.93(K0.5Na0.5)NbO3-0.07 Sr0.7La0.2TiO3 ceramics, outperforming all reported KNN-based transparent ceramics. This work exhibits a paradigm for achieving high performance KNN-based ceramics, and the transparent dielectric ceramics reported here are expect to expand hybrid electronic device applications.

Design of the Lanthanum hexaboride based plasma source for the large plasma device at UCLA

The Large Plasma Device (LAPD) at UCLA (University of California, Los Angeles) produces an 18 m long, magnetized, quiescent, and uniform plasma at a high repetition rate to enable studies of fundamental plasma physics. Here, we report on a major upgrade to the LAPD plasma source that allows for more robust operation and significant expansion of achievable plasma parameters. The original plasma source made use of a heated barium oxide (BaO) coated nickel sheet as an electron emitter. This source had a number of drawbacks, including a limited range of plasma density (≲4.0 × 1012 cm−3), a limited discharge duration (∼10 ms), and susceptibility to poisoning following oxygen exposure. The new plasma source utilizes a 38 cm diameter lanthanum hexaboride (LaB6) cathode, which has a significantly higher emissivity, allowing for a much larger discharge power density, and is robust to exposure to air. Peak plasma density of up to 3.0 × 1013 cm−33 in helium gas has been achieved. The typical operating pressure is ∼10−5 Torr, while dynamic pressure can be achieved through the gas-puffing technique. Discharges as long as 70 ms have been produced, enabling a variety of long-time-scale studies of processes, such as turbulent particle transport. The new source has been in continuous operation for 14 months, having survived air leaks, power outages that led to rapid temperature changes on the cathode and heater, and planned machine openings. We describe the design, construction, and initial operation of this novel new large-area LaB6 plasma source.

Tailoring the discharge performance of extruded Mg-Sm-Al anode for Mg-air battery applications via control of Al content

We investigated the discharge performance and electrochemical properties of an as-extruded Mg-5Sm-xAl (x = 0,1,3) anode for Mg-air batteries. Adding Al modified the phase composition and grain size of the anode. The addition of 1 wt% Al (Mg-5Sm-1Al) induced a high discharge voltage and power density due to the stimulation of the evenly distributed, fine Al11Sm3 particles. However, these particles increased the parasitical anodic hydrogen reaction rate, resulting in a decrease in anodic efficiency. These properties make the anode suitable for high-power density applications. The addition of 3 wt % Al (Mg-5Sm-3Al) promoted the formation of an aluminium oxide film on the anode surface, which suppressed the anodic hydrogen reaction to improve the anodic efficiency. This film increased the battery's internal resistance resulting in low voltage. This anode is a good candidate for heavy-duty battery applications, where a steady voltage output and long service life are desired. By controlling the Al content, the tailoring of discharge performance of the Mg-Sm-Al anode is feasible to satisfy different battery load requirements.

Improved dielectric energy storage performance of Na0.5Bi0.5TiO3-based lead-free relaxation ferroelectric ceramics achieved by domain structural regulation and enhanced densification

There is still a problem of low energy storage density in dielectric capacitors which is a core component of power systems. For the improvement of the energy storage density, the linear dielectric material CaTiO3 (CT) was introduced in Na0.5Bi0.5TiO3 (NBT) ceramics in this paper. By modifying the A site, a new relaxor ferroelectric ceramic was successfully synthesized and attained a recoverable density (Wrec) of 2.34 J/cm3 at x = 0.18. Moreover, the preparation process was optimized in this paper. Through the viscous polymer process (VPP) route, the energy density (WA) of 82NBT-18CTVPP ceramic further reaches 6.45 J/cm3 at 340 kV/cm, with efficiency (η) up to 75% and a Wrec of 4.82 J/cm3. At the same time, the change of Wrec is small at temperature (30–150 °C) and frequency (1 Hz–300 Hz), which demonstrates its excellent stability. The discharge power density reaches about 180 MW/cm3 and the discharge time is 0.117 μs, which indicates its excellent pulse discharge performance. The results show that 82NBT-18CT lead-free relaxation ferroelectric material is expected to become ideal for high-energy storage applications.

Iron, Cobalt, and Nickel Phthalocyanine Tri-Doped Electrospun Carbon Nanofibre-Based Catalyst for Rechargeable Zinc-Air Battery Air Electrode.

The goal of achieving the large-scale production of zero-emission vehicles by 2035 will create high expectations for electric vehicle (EV) development and availability. Currently, a major problem is the lack of suitable batteries and battery materials in large quantities. The rechargeable zinc-air battery (RZAB) is a promising energy-storage technology for EVs due to the environmental friendliness and low production cost. Herein, iron, cobalt, and nickel phthalocyanine tri-doped electrospun carbon nanofibre-based (FeCoNi-CNF) catalyst material is presented as an affordable and promising alternative to Pt-group metal (PGM)-based catalyst. The FeCoNi-CNF-coated glassy carbon electrode showed an oxygen reduction reaction/oxygen evolution reaction reversibility of 0.89 V in 0.1 M KOH solution. In RZAB, the maximum discharge power density (Pmax) of 120 mW cm-2 was obtained with FeCoNi-CNF, which is 86% of the Pmax measured with the PGM-based catalyst. Furthermore, during the RZAB charge-discharge cycling, the FeCoNi-CNF air electrode was found to be superior to the commercial PGM electrocatalyst in terms of operational durability and at least two times higher total life-time.

Rational Design of Heterostructured Ru Cluster‐Based Catalyst for pH Universal Hydrogen Evolution Reaction and High‐Performance Zn‐H2O Battery

AbstractRuthenium (Ru) is an ideal substitute to commercial Pt/C for hydrogen evolution reaction (HER). Reducing the size of Ru to clusters can greatly increase the utilization of atoms, however, over‐strong RuH binding will be brought about. Additionally, the water dissociation ability of Ru clusters is unfavorable, leading to unsatisfactory activity in alkaline and neutral HER. Herein, a rational and versatile design strategy is proposed by exploring supports with both high work function and facilitated water dissociation ability to boost the pH‐universal HER activity of Ru clusters. As exemplified by Mo2C, density functional calculations verify that the introduction of Mo2C support can optimize the hydrogen adsorption energy and promote the kinetics of water dissociation. Guided by theoretical calculations, heterostructured Mo2C nanoparticles‐Ru clusters anchored carbon spheres (Mo2C‐Ru/C) are designed and prepared. A low overpotential of 22 mV at 10 mA cm−2 and a small Tafel slope of 25 mV dec−1 in alkaline solution is demonstrated by Mo2C‐Ru/C. The Mo2C‐Ru/C also exhibits excellent activity in alkaline seawater, acidic, and neutral solutions. When assembling Mo2C‐Ru/C with Zn foil to construct an alkaline‐acid Zn‐H2O battery, the as‐fabricated battery presents high discharge power density and excellent stability for simultaneous generation of electricity and hydrogen (H2).

Comparison of discharge mode transition of air plasma under pulsed and sinusoidal excitations

The transition from O3 to NO x discharge mode is common for air plasma with an increase of discharge power density, which greatly changes the chemistry of the plasma as well as its application effect. Although this discharge mode transition has been intensively studied in recent years, differences between plasmas subject to pulsed or sinusoidal excitations have rarely been reported on. In this study, a surface dielectric barrier discharge is excited using either a microsecond pulsed voltage or a sinusoidal voltage. The discharge mode transition of these two excitations is then comparatively studied. The results indicate that pulsed excitation produces more O3 in O3 mode discharge; the O3 concentration for pulsed excitation is 27.7% higher than that for sinusoidal excitation at the same power density of P = 0.08 W cm−2. On the contrary, it produces less NO and NO2 in NO x mode discharge; the NO concentration for pulsed excitation is 13.2% lower than that for sinusoidal excitation at P = 0.32 W cm−2. As a result, pulsed excitation delays the transition of the discharge mode when the discharge power density increases. This can be attributed to the higher electron and lower gas temperature of the pulse-excited plasma, which promotes O3 and inhibits NO x production.

1,2,4-triazole-assisted metal-organic framework-derived nitrogen-doped carbon nanotubes with encapsulated Co4N particles as bifunctional oxygen electrocatalysts for rechargeable zinc-air batteries

The design of high-performance oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) dual-functional catalysts is not only important for the further applications of zinc-air batteries (ZABs) but also a major challenge in the field of energy conversion. The cheap 1,2,4-triazole (1,2,4-TZ) can be decomposed easily by heat, making it a high research value in carbon catalysts derived from metal-organic frameworks (MOFs). Here, Co4N particles encapsulated at the top of N-doped carbon nanotubes (Co4N@NCNTs) were conveniently prepared by 1,2,4-TZ-assisted pyrolysis of Co-MOF-74 for the first time. Owing to the excellent activity of Co4N particles and the highly graphitized N-doped carbon nanotubes (NCNTs), Co4N@NCNTs obtained at 900 °C (Co4N@NCNT-900) exhibited astonishing catalytic performance in both ORR and OER, and high reversible oxygen bifunctional activity (ΔE = 0.685 V). Moreover, Co4N@NCNT-900 displayed a larger discharge power density (122 mW cm−2), a better specific capacity (811.8 mAh g−1), and more excellent durability during the ZAB test, implying that Co4N@NCNT-900 can act as a bifunctional high active catalyst in ZABs.

Improving efficiency and discharge power of acid-base flow battery via a bi-objective optimisation

The implementation of effective storage systems is essential for a deeper market penetration of intermittent renewable sources. One promising, environmentally friendly energy storage technology is the Acid-Base Flow Battery (AB-FB). In the charge phase it stores electricity in the form of pH and salinity gradients via Bipolar Membrane Electrodialysis, while in the discharge phase it applies the reverse process for the opposite conversion. Despite the clear benefits over other osmotic batteries, the potential of the AB-FB has been poorly explored.This study presents the first bi-objective optimisation of the AB-FB in terms of net round trip efficiency (RTEnet) and average net discharge power density per membrane area (NPDd¯). A comprehensive mathematical model previously developed by our research team was used to predict the battery performance. The ε-constraint approach was used to build curves of Pareto optimal solutions under various scenarios by letting several operating and design parameters to vary. Using current commercial membranes, optimal solutions yielded an RTEnet ranging from 32 % to 64 %, while the corresponding NPDd¯ ranged from 19.5 W m−2 to 4 W m−2. These results highlight the great potential of the AB-FB, as well as the need of a proper design of experimental stacks. Simulating hypothetical membranes with improved, yet realistic characteristics shifted the range of RTEnet and NPDd¯ to 59.1–76.3 % and 23.2–4.4 W m−2, respectively, showing that the technological advancement in membrane manufacturing is essential for the development of high-performance AB-FB systems. Although the AB-FB performs similarly to other batteries, it can be made of non-critical materials that are not subject to supply disruptions or economic dependency, making the AB-FB a sustainability-friendly option and a good candidate for the future energy storage systems scenario.

Electrocatalytic performance of Ni-promoted Co nanoclusters supported by N-doped carbon foams for rechargeable Zn-air batteries

Ni/Co diatomic clusters supported on nitrogen-doped carbon foams are prepared via molten salt method to improve the density of surface active sites of zinc-air battery catalysts and further explore metal-modified carbon-based catalysts. The influence of Co and Ni atoms on the carbon foam structure is investigated by X-ray diffraction and high-resolution electron microscopy, and the presence of metal atoms in N-doped carbon foams is confirmed by X-ray spectroscopy. The left shift of the diffraction peak of Co doped graphitic carbon indicates an increase in the interlayer spacing and a reduced graphitization degree, while the introducton of Ni atoms promotes graphitization. For Ni–Co/NFC-2, Ni inhibits the insertion of Co in carbon layer by increasing graphitization, thus exposing more Co-active substances on the surface, which is important for improving the catalytic process of ORR and OER. According to electrochemical tests, Ni–Co co-doped carbons exhibited superior bi-functional electrocatalytic performance with oxygen reduction reaction (ORR) Eonset = 0.97 V and a Tafel slope of 49.5 mV dec−1, accompanied by oxygen evolution reaction (OER) Ej = 10 mA cm−2 = 1.46 V. Zinc-air battery (ZAB) cell, utilizing the developed material as a catalyst, exhibited a high discharge power density of 138 mW cm−2 with stable performance for up to 200 h.

Bamboo-like N-doped carbon tubes encapsulated Co2P–Fe2P derived from zeolitic imidazolate framework as an efficient trifunctional electrocatalyst for water splitting and Zn-air batteries

The development of high-performance and stable trifunctional electrocatalysts is a pressing challenge for the practical application of water splitting and regenerative Zn-air batteries. Herein, bamboo-like N-doped carbon tubes encapsulated Co2P–Fe2P nanoparticles (CoFe-PN/C) was fabricated via a facile template-sacrificial approach by using CoZn-ZIF trapping Fe3+ (CoFeZn/C) as the precursor. The incorporation of Fe3+ was achieved by the one-pot synthesis approach during crystallization of ZIF, which led to the generation of the unique bamboo-like tube structure under the condition of simultaneous phosphating and carbonization. Benefiting from the large surface area, the optimized electronic structure of active sites and the unique bamboo-like nanotube, the resultant CoFe-PN/C can be used as the trifunctional electrocatalyst possessing a small overpotential at 10 mA cm−2 for the HER (178 mV) and OER (300 mV), as well as a high half-wave potential of 0.884 V for ORR (40 mV more positive than that of commercial 20 wt% Pt/C). Moreover, the self-designed CoFe-PN/C||CoFe-PN/C alkaline electrolyzer driving 50 mA cm−2 only need operating potential of 1.84 V and the maximum discharge power density of the CoFe-PN/C-assembled ZABs could achieve 152.0 mW cm−2, superior to those of Pt/RuO2 couple. This work will facilitate the development and application of trifunctional electrocatalysts based on bi-transition metallic phosphides for energy conversion and storage technology.

Cobalt loaded on concave hollow carbon octadecahedron for zinc–air batteries

For the development of high-performance zinc–air batteries, it is necessary to increase the kinetics of oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) as much as possible. In this work, different coordination structures of Co loaded on concave hollow carbon octadecahedron (CNQD/CoNBs) were prepared by adding g-C3N4 into the synthesis process of Co-based zeolitic imidazolate framework and adjusting the stress balance of the framework structure in the pyrolysis process. This method can greatly increase the specific surface area and the number of micropores of the material for exposing more active sites to accelerate the reaction kinetics. The prepared catalyst shows excellent bi-functional performance for OER and ORR, and it is applied in efficient rechargeable zinc–air battery to achieve high discharge power density of 210 mW/cm2 and favorable stability over long charge/discharge cycles. This research provides an effective strategy to design high-efficiency bi-functional electrocatalysts.

Synergistic enhanced energy storage performance of NBT-KBT ceramics by K0.5Na0.5NbO3 composition design

(1–x)(0.8Na0.5Bi0.5TiO3-0.2K0.5Bi0.5TiO3)-xK0.5Na0.5NbO3 (x = 0, 0.1, 0.2, 0.3, 0.4) (NBT-KBT-KNN) ceramic solid solution was synthesized by solid phase method through designing KNN composition. XRD, Raman and SEM results show that NBT-KBT-KNN ceramics form solid solutions with a stable perovskite structure. The dielectric temperature spectrum and impedance spectrum analysis confirmed that the relaxor ferroelectrics (RFE) properties enhanced with increasing KNN content. The piezoresponse force microscopy (PFM) results reveal that the introduced KNN disrupts the microdomains of NBT-KBT ceramics and promotes the formation of nanodomains, leading to enhanced energy storage properties. The breakdown electric field strength (BDS) was also increased with increasing KNN content, and maximum value was obtained at x = 0.2. The addition of KNN can obviously improve energy storage performance (ESP). At 255 kV cm–1, x = 0.2 produced excellent ESP with recoverable energy storage density (Wrec), amazingly normalized response (ξ), efficiency (η) and maximum polarization (Pmax) are 3.38 J cm–3, 132.55 J kV–1 m–2, 85.4 %, and 45.76 μC cm–2, respectively. ESP is also stable in terms of frequency and temperature at (1–100 Hz) and (20–140 °C). At 120 kV cm–1, the discharge energy density (Wdis), power density (PD), Current density (CD) and time for releasing 90 % of total energy density (t0.9), are 0.202 J cm–3, 23.43 MW cm–3, 390.42 A cm–2, and 56.6 ns. These findings demonstrate that NBT-KBT-KNN ceramics have the ability to be reliable energy storage and pulse power capacitors.

Enhanced breakdown strength and excellent energy storage stability by B site hetero-valent doping in Sr0.7Bi0.2TiO3-based lead-free ceramic

Environment-friendly energy storage materials are embraced in global researches. Aiming at improving the energy storage performances of lead-free dielectric ceramics, the Sr0.7Bi0.2Ti(1–1.25x)NbxO3 (SBT-xN, x = 0 ∼ 0.125) lead-free ceramics were synthesized via the conventional solid state method in this work. Outstanding total energy storage density (Wtotal = 3.998 J/cm3), recoverable energy storage (Wrec = 3.43 J/cm3), and high energy storage efficiency (η of 85.84%) were obtained when x = 0.075 under the electric field of 385 kV/cm. Meanwhile, a satisfied temperature (30 ℃−110 ℃ variation less than 14%), frequency stability (10–400 Hz variation less than 1%), and anti-fatigue characteristic (107 cycles variation less than 1%) were achieved. Furthermore, the sample exhibited a remarkable discharge energy density (Wd = 3.885 J/cm3), ultrafast discharge speed (t0.9 = 73 ns), and giant discharge power density (Pd = 327.01 MW/cm3) at 400 kV/cm in charge-discharge tests. Great temperature stability (30 ℃−150 ℃ variation less than 8%) and pulse repetition frequency discharge stability (2×105 times variation less than 3.5%) were also obtained. The excellent characteristics suggest that the ceramic is a prospective candidate for advanced pulse power equipment.

Sulfonated Diels-Alder Poly(phenylene) Membrane for Efficient Ion-Selective Transport in Aqueous Metalorganic and Organic Redox Flow Batteries

Redox flow batteries (RFBs) can achieve long lifetimes and high performance when employing highly selective and conductive membranes. Neutral and alkaline RFBs suffer from higher resistances due to lower cation conductivity, compared to acidic RFBs utilizing proton transport. We report the use of a sulfonated Diels-Alder poly(phenylene) membrane that exhibits low and stable potassium area specific resistance and high efficiency RFB cycling relative to Nafion, as well as undetectable ferricyanide crossover. An alkaline (pH 12) organic anthraquinone derivative RFB using this membrane demonstrates over 10 days of cycling without capacity loss from crossover. A neutral chelated chromium complex RFB using this membrane demonstrates a peak discharge power of 1.23 W cm−2, and 80% energy efficiency (EE) cycling at an average discharge power density of 446.3 mW cm−2. Finally, the membrane exhibits similar favorable conductivity for many monovalent cations, opening the opportunity to improve the cycling and crossover performance of other acidic, neutral, and alkaline RFBs.

A submillimeter bundled microtubular flow battery cell with ultrahigh volumetric power density

Flow batteries are a promising energy storage solution. However, the footprint and capital cost need further reduction for flow batteries to be commercially viable. The flow cell, where electron exchange takes place, is a central component of flow batteries. Improving the volumetric power density of the flow cell (W/Lcell) can reduce the size and cost of flow batteries. While significant progress has been made on flow battery redox, electrode, and membrane materials to improve energy density and durability, conventional flow batteries based on the planar cell configuration exhibit a large cell size with multiple bulky accessories such as flow distributors, resulting in low volumetric power density. Here, we introduce a submillimeter bundled microtubular (SBMT) flow battery cell configuration that significantly improves volumetric power density by reducing the membrane-to-membrane distance by almost 100 times and eliminating the bulky flow distributors completely. Using zinc-iodide chemistry as a demonstration, our SBMT cell shows peak charge and discharge power densities of 1,322 W/Lcell and 306.1 W/Lcell, respectively, compared with average charge and discharge power densities of <60 W/Lcell and 45 W/Lcell, respectively, of conventional planar flow battery cells. The battery cycled for more than 220 h corresponding to >2,500 cycles at off-peak conditions. Furthermore, the SBMT cell has been demonstrated to be compatible with zinc-bromide, quinone-bromide, and all-vanadium chemistries. The SBMT flow cell represents a device-level innovation to enhance the volumetric power of flow batteries and potentially reduce the size and cost of the cells and the entire flow battery.

Biomass-derived carbon immobilized ultrafine Pt nanoparticle as a highly efficient catalyst for hydrogen fuel cell

Ultrafine Pt nanoparticle immobilized catalysts were developed via a facile one-step biomass-derived carbon thermal curing process. The electrochemical investigation confirms that benefits from the lower oxygen mass transfer resistance and electron transfer resistance, the as-prepared catalysts displayed a discharge power density of 1.246 W cm−2 at 2000 mA cm−2 when assembled in an H2-air fuel cell. This research not only develops a new electrocatalyst but also paves the way for the rational design and synthesis of superior electrocatalysts for energy storage and conversion.

Improving the purification of aqueous solutions by controlling the production of reactive oxygen species in non-thermal plasma; a systematic review.

Treatment with non-thermal plasma is a reliable technology to oxidize chemical impurities that exist inpolluted water, wastewater, and leachate, those degradation-resistant and cannot be removed by conventional treatment methods. In this study, the effective factors affecting in the formation ofreactive oxygen species in non-thermal plasma treatment process, as a new advanced oxidation process method explianed. In this manner, all associated manuscripts existed in the main databases including Google Scholar, Science Direct, PubMed, and Open Access Journal Directory from 1990 until 2022 were explored. The utilized keywords were involved non-thermal plasma, Cold plasma, Measurement, •OH, O3 and UV. Overall, 8,813 articles were gathered and based on the relevance titles and abstracts, 18 paper were selected for further reviewing. In several studies, plasma techniques have been used to treat water, wastewater and leachate, but few studies have evaluated the factors influencing the production of ROS species by non-thermal plasma. The non-thermal plasma destroys pollutants by reactive free radicals spices (hydroxyl, hydrogen atoms, etc.) a combination effect of strong electric fields, energetically charged particles, and ultrasound. Some factors such as water vapor, hydraulic retention time, inter-electrode spacing, discharge power density, and aeration of the effluent as well as use of catalyst have direct effect on the reactive oxygen species formation. If these factors controlled within the best ranges, it will promote the oxidizing radical production and system performance. Also, high-energy electrons and oxidizing species produced in the cold plasma system can well degrade most of pollution in water and wastewater.

Realized potential as neutral pH flow batteries achieve high power densities

High power density operation of redox flow batteries (RFBs) is essential for lowering system costs, but until now, only acid-based chemistries have achieved such performance, primarily due to rapid membrane proton (H + ) transport. Here, we report a neutral pH RFB using the highly reducing Cr-(1,3-propylenediaminetetraacetate) (CrPDTA) complex that achieves acid-like power performance while utilizing potassium ion (K + ) transport. We investigate RFB resistance components and demonstrate the high and consistent K + conductivity of the Fumasep E-620(K) membrane. When combined with a robust bismuth electrocatalyst, this membrane enables constant voltage efficiency operation of a CrPDTA|Fe(CN) 6 RFB for 200 cycles. An optimized CrPDTA|Fe(CN) 6 RFB, which combines a high cell potential with a low area-specific resistance (0.46 Ω cm 2 ), demonstrates a maximum discharge power density of 1.63 W cm −2 and an average discharge power density over 500 mW cm −2 while maintaining 80% round-trip energy efficiency cycling, which are records for non-acid-based RFBs. • High-power flow battery operates at neutral pH with potassium membrane transport • Record discharge-power performance for a flow battery not using proton transport • Inexpensive membrane provides high conductivity and constant efficiency cycling • Chelated metal electrolyte enables high voltage battery and high-power operation High-power flow battery operation lowers system costs but has previously required proton transport. By combining high voltage with low resistance from a highly selective and conductive membrane, Robb et al. demonstrate an aqueous flow battery that achieves record non-acidic power performance while utilizing potassium membrane transport at neutral pH.

A Co-Axial Microtubular Flow Battery Cell with Ultra-High Volumetric Power Density

Flow batteries are a promising energy storage solution. However, the footprint and capital cost need to be further reduced for flow batteries to be commercially viable. The flow cell, where electron exchange takes place, is a central component in flow batteries. Improving the volumetric power density of the flow cell (W/Lcell) can reduce the size and cost of flow batteries. While significant progress has been made on flow battery redox, electrode and membrane materials to improve energy density and durability, conventional flow batteries based on planar cell configuration exhibit a large cell size with multiple bulky accessories such as flow distributors, resulting in low volumetric power density. In this talk, I will introduce a new co-axial microtubular (CAMT) flow battery cell configuration that significantly improves volumetric power density by reducing the membrane-to-membrane distance by almost 100 times and eliminating completely the bulky flow distributors. Using zinc-iodide chemistry as a demonstration, our CAMT cell shows peak charge and discharge power densities of 1322 W/Lcell and 306.1 W/Lcell compared to average charge and discharge power densities of < 60 W/Lcell and 45 W/Lcell of conventional planar flow battery cells. The battery cycled for more than 220 hours, corresponding to > 2,500 cycles at off-peak conditions. Furthermore, the CAMT cell has been demonstrated to be compatible with zinc-bromide, quinone-bromide, and all-vanadium chemistries. The CAMT flow cell represents a device-level revolution to enhance the volumetric power of flow batteries and potentially reduce the size and cost of the cells and the entire flow battery.Publication:https://chemrxiv.org/engage/chemrxiv/article-details/62070e98bd05a04ae103fa7e Figure 1