Sodium Nickel Chloride Research Articles

Modeling of a SOFC-HT battery hybrid system for optimal design of off-grid base transceiver station

This work aims at the development of a simulation tool to optimize the design of a hybrid fuel cell/battery system to supply ICT equipment.In the framework of the ONSITE European project, which deals with a hybrid (fuel cell and batteries) RBS (Radio Base Stations) supply system, a modeling activity is carried out to optimize the system operations.The developed algorithms separately implement a Solid Oxide Fuel Cell system and a high temperature Sodium Nickel Chloride battery for design purpose and collect them in a unique model for devices interaction (i.e. power production, storage, and control).Moreover, a Computational Fluid Dynamics battery model is developed to analyse the heat transfer while the SOFC stack generates excessive heat during operation and outlet hot gases can be effectively used.Since the SNC batteries need heat during charging process (to maintain their operating temperature) and, conversely, the reactions are exothermic in discharge mode, the described approach aims at combining SNC batteries with micro-CHP unit to optimize the energy flows.The implementation requires several alternative designs and variant analysis to secure proper operation of battery and power generation unit. The model developed and shown in this paper is a dedicated tool for the simulation of the hybrid system proposed and for the optimal designing of each main sub component.

Application of a Simplified Thermal-Electric Model of a Sodium-Nickel Chloride Battery Energy Storage System to a Real Case Residential Prosumer

Recently, power system customers have changed the way they interact with public networks, playing a more and more active role. End-users first installed local small-size generating units, and now they are being equipped with storage devices to increase the selfconsumption rate. By suitably managing local resources, the provision of ancillary services and aggregations among several end-users are expected evolutions in the near future. In the upcoming market of household-sized storage devices, sodium-nickel chloride technology seems to be an interesting alternative to lead-acid and lithium-ion batteries. To accurately investigate the operation of the NaNiCl2 battery system at the residential level, a suitable thermoelectric model has been developed by the authors, starting from the results of laboratory tests. The behavior of the battery internal temperature has been characterized. Then, the designed model has been used to evaluate the economic profitability in installing a storage system in the case that end-users are already equipped with a photovoltaic unit. To obtain realistic results, real field measurements of customer consumption and solar radiation have been considered. A concrete interest in adopting the sodiumnickel chloride technology at the residential level is confirmed, taking into account the achievable benefits in terms of economic income, back-up supply, and increased indifference to the evolution of the electricity market.

Prediction of Electrochemical Performance of Lower Temperature Operating Na-NiCl2 Battery

Sodium nickel chloride (Na-NiCl2) batteries are gaining growing attentions as a strong potential contender for advanced electric vehicle (EV) and stationary energy storage system (ESS) applications. The cathode compartment of a Na-NiCl2 battery features by a mixture of solid NaCl and Ni granules impregnated with a liquid NaAlCl4 catholyte. During charge-discharge cycles, complicated electrochemical reactions take place, including transportation of Na+ ions through NaAlCl4 catholyte, the dissolution/coarsening of NaCl particles, formation/decomposition of NiCl2 layers on the active Ni surface, and electron transport through the Ni granules. We are developing advanced Na-NiCl2 batteries that operate at relatively lower temperatures of below 200 °C to minimize its cell degradation typically observed at high operation temperature (over ~270 °C) and to enable application of simple and cheaper polymer seals for cell manufacturing. However, the diffusion and the ionic migration kinetics of active Na+ ions are restricted at the lower temperatures that may limit cell performance. In this presentation, we introduce a multi-physics continuum computational model to capture the electrochemical behaviors of planar lower temperature Na-NiCl2 batteries. The computational results will elucidate impacts of (i) cell operation temperatures, (ii) current densities, and (iii) cathode dimensions on the electrochemical performance of prototype planar Na-NiCl2 cells. The developed prediction model is expected to provide a useful guideline for the experimental fabrication of advanced Na-NiCl2 batteries with maximized cell performance at relatively lower temperatures.

5Wh Class Planar Sodium Nickel Chloride (Na-NiCl2) Battery Operated at below 200oc for Grid Scale Energy Storage

Sodium nickel chloride (Na/NiCl2) battery is one of the most promising candidates as a large scale electrochemical energy storage device. The battery comprises molten Na and NiCl2 as negative and positive electrodes, respectively, in its charged state, separating them by a β”-Al2O3 solid electrolyte (BASE). In order to facilitate fast sodium ion transport in the cathode compartment, molten NaAlCl4, as a secondary electrolyte (or catholyte), is infiltrated into the cathode materials powder. The battery typically operates at 250~300oC so as to maximize the ionic flux in the NaAlCl4 and through the solid electrolyte, and to minimize the dissolution of NiCl2into the melt. However, this efficient battery is yet to be widely used in grid scale energy storage applications since it is still expensive and hard to dramatically reduce the cell price mainly due to its use of expensive sealing technologies. The presentation introduces Korea-US collaborative efforts to develop a lower temperature operating sodium beta-alumina battery (LT-NBB) with a Na/NiCl2 chemistry. Since the novel battery runs at below 200oC, it can be fabricated at an ultra low manufacturing cost by introducing a new planar cell design with a greatly reduced number of cell components, and by eliminating expensive conventional sealing technologies. Enhanced degradation resistance of cathode materials is another important advantage of this technology. In this presentation, challenges and progress in building 5Wh class prototype LT-NBB cells using BASE with 70 mm in diameter will be discussed. Figure 1

Relationship between resistance, TCR and stabilization temperature of amorphous Ni-P alloy

PurposeThe paper aims to present a research on the impact of the stabilization process of a thin metallic layer (Ni-P) produced on a ceramic surface (Al2O3) by means of electroless metallization on its electric parameters and structure. On the basis of the research conducted, the existence of a relationship between resistance (R) and the temperature coefficient of resistance (TCR) of the test structure with a Ni-P alloy-based layer and the temperature of stabilization was proposed.Design/methodology/approachMetallic Ni-P layers were deposited on sensitized and activated substrates. Metallization was conducted in an aqueous solution containing two primary ingredients: sodium hypophosphite and nickel chloride. The concentration of both ingredients was (50-70) g/dm3. The process lasted 60 min, and the metallization bath pH was kept at 2.1-2.2, whereas the temperature was maintained at 363 K. The thermal stabilization process was conducted in different temperatures between 453 and 623 K. After the technological processes, the resistance and TCR of the test structures were measured with a micro ohmmeter. The composition and the morphology of the resistive layer of the structures examined was also determined.FindingsThe dependence of the resistance on the temperature of the stabilization process for the temperature range 553 to 623 K was described using mathematical relationships. The TCR of test resistors at the same thermal stabilization temperature range was also described using a mathematical equation. The measurements show that the resistive layer contains 82.01 at.% of nickel (Ni) and 17.99 at.% of phosphorus (P).Originality/valueThe results associate a surface morphology Ni-P alloy with the resistance and TCR according to temperature stabilization. The paper presents mathematical relationships that have not been described in the literature available.

Development of a solar powered hydrogen fueling station in smart cities applications

This paper reports main criteria for design, realization and validation of a solar-powered hydrogen fueling station in a smart city application relevant to an on-site hydrogen production plant. The program has been developed by CNR-ITAE together with other industrial partners in the framework of the Italian research project called i-NEXT (innovation for greeN Energy and eXchange in Transportation). The i-NEXT hydrogen production plant is located in the Municipality of Capo d’Orlando, Sicily, it is fed by a microgrid able to receive energy from solar radiation by a 100 kW rooftop photovoltaic plant and connected with a battery energy storage of 300 kWh (composed by 16 sodium nickel chloride high temperature batteries). The plant is able to deliver hydrogen and electricity for an electric and hydrogen vehicles fleet. The hydrogen fueling station includes four subsystems: a hydrogen production system by electrolysis, a compression system, a high-pressure storage system and a hydrogen dispenser for automotive applications. It is able to generate in the hydrogen production subsystem through an alkaline electrolyzer of 30 kWh: 6.64 Nm3/h of H2 with a gas purity of 99.995% (O2 < 5 ppm and dew point < −60 °C). The compression subsystem has a three stage compressor with a rated gas flow rate of 5,2 Nm3/h and a delivery pressure of 360 bar. The compressed H2 gas is stored in a high-pressure tanks of 350 L capacity allowing, in this way, a supply through a dispenser system of two automotive's tanks of 150 L @ 350 bar in less than 30 min. This paper reports the design and the development results coming from a first test campaign.

Enhanced stability performance of nickel nanowire with 3D conducting network for planar sodium-nickel chloride batteries

High temperature sodium batteries with inorganic electrolytes are attracting increasing attention due to their high thermal stability, reliability, long-cycle life and safety. Despite the intensive investigation of Na-NiCl2 batteries during last decades, designing a stable conducting network in the cathode is still challenging but desirable. In this work, a new cathode structure composed of Ni nanowires with an effective electron conducting network is proposed for planar sodium–nickel chloride batteries. During the first stage of charge, Ni nanowires reacted with Cl ion to form NiCl2 on the surface and the excessive Ni nanowires inside can serve as conducting framework to facilitate the fast electron transport. As expected, the metal nanowires show a high specific capacity of 130 mA h g−1 (∼14 mAh cm−2) at 0.05 C after 100 cycles. Meanwhile, the batteries show stable cycling performance at 0.05 C with a high cut-off energy density of 360 W h kg−1, much higher than the traditional tubular sodium-nickel chloride batteries (∼100 Wh kg−1). Scanning electron microscope (SEM) images of the cathode after long cycling reveal the ultra-slow growth of Ni particles, confirming the excellent stability of the prepared nanowires cathode.

Development of Intermediate Temperature Sodium Nickel Chloride Rechargeable Batteries: Polymer Seals and Cathode Formula

Large scale battery technologies have gained more attention as electric energy storage devices for renewable energy applications and grid stabilization. Due to growing safety concerns, high material costs and a limited cycle life, conventional lithium ion battery technologies have a limited portfolio for stationary applications. Recently, the sodium-nickel chloride (Na-NiCl2) battery has been under consideration as an alternative battery technology for stationary energy applications.[1] Yet, there are a number of challenges, such as the high operating temperature and high cost of hermetic sealing technologies, that hinder a further market penetration. Typically, a tubular type Na-NiCl2 battery is operated at a high temperature above 280°C to obtain a reasonable electrochemical performance. Our recent work has demonstrated that a planar type Na-NiCl2 battery can achieve remarkable electrochemical performance over 1000 cycles even at an intermediate temperature (IT) of 190°C.[2] The lower operating temperature allows for the development of cost-effective sealing technology that uses conventional high temperature polymers as sealing materials.[3] We also demonstrate the Ni content in the cathode can be greatly reduced by 30% compared to that of the conventional Na-NiCl2 battery. Long term cell tests using the advanced cathode formula show a stable battery performance over 250 cycles.[4] Therefore, our work suggests that developing polymer sealing technology and advanced low Ni-content cathode materials at intermediate operating temperatures might provide a new breakthrough to Na-NiCl2 batteries for practical stationary energy storage applications.REFERENCES J. L. Sudworth, J. Power Sources, 51 (1994) 105-114. G.S. Li, X.C. Lu, J.Y. Kim, K.D. Meinhardt, H.J. Chang, N.L. Canfield, V.L. Sprenkle, Nat. Commun., 7 (2016) 10683. H. J. Chang, X. Lu, J. F. Bonnett, N. L. Canfield, S. Son, Y. Park, K. Jung, V. L. Sprenkle, and G. Li. (submitted) H. J. Chang, X. Lu, K. Jung, V. L. Sprenkle, and G. Li. (in preparation)

건물 에너지관리용 NANITM 전기저장장치 실증을 통한 사업화 모델 연구

As an Energy Storage Systems (ESS) can be a possible emergency power source, the market for ESS has increased to respond to the energy demands in commercial buildings. To demonstrate the ESS for commercial buildings located in urban areas, the Sodium Nickel Chloride (NANISUPTM/SUP) battery systems was chosen because it is chemically safe. The system has been operated for more than a year to verify the stability and profitability. Therefore, a business model of an ESS for commercial buildings is proposed based upon the long-term actual proof operation.

Advanced Na-NiCl2 Battery Using Nickel-Coated Graphite with Core-Shell Microarchitecture.

Stationary electric energy storage devices (rechargeable batteries) have gained increasing prominence due to great market needs, such as smoothing the fluctuation of renewable energy resources and supporting the reliability of the electric grid. With regard to raw materials availability, sodium-based batteries are better positioned than lithium batteries due to the abundant resource of sodium in Earth's crust. However, the sodium-nickel chloride (Na-NiCl2) battery, one of the most attractive stationary battery technologies, is hindered from further market penetration by its high material cost (Ni cost) and fast material degradation at its high operating temperature. Here, we demonstrate the design of a core-shell microarchitecture, nickel-coated graphite, with a graphite core to maintain electrochemically active surface area and structural integrity of the electron percolation pathway while using 40% less Ni than conventional Na-NiCl2 batteries. An initial energy density of 133 Wh/kg (at ∼C/4) and energy efficiency of 94% are achieved at an intermediate temperature of 190 °C.

Development of intermediate temperature sodium nickel chloride rechargeable batteries using conventional polymer sealing technologies

Abstract Developing advanced and reliable electrical energy storage systems is critical to fulfill global energy demands and stimulate the growth of renewable energy resources. Sodium metal halide batteries have been under serious consideration as a low cost alternative energy storage device for stationary energy storage systems. Yet, there are number of challenges to overcome for the successful market penetration, such as high operating temperature and hermetic sealing of batteries that trigger an expensive manufacturing process. Here we demonstrate simple, economical and practical sealing technologies for Na-NiCl2 batteries operated at an intermediate temperature of 190 °C. Conventional polymers are implemented in planar Na-NiCl2 batteries after a prescreening test, and their excellent compatibilities and durability are demonstrated by a stable performance of Na-NiCl2 battery for more than 300 cycles. The sealing methods developed in this work will be highly beneficial and feasible for prolonging battery cycle life and reducing manufacturing cost for Na-based batteries at elevated temperatures (

Sodium-nickel chloride battery experimental transient modelling for energy stationary storage

The paper presents the analysis of Sodium Nickel chloride batteries in transient operation, and proposes a simple but very precise model to represent both the transient and steady battery behaviours. Hence, the main purpose of this model is to foresee the battery voltage during the most important network services, which require very fast transitions from the battery charge operation to the discharge one. In order to validate the model, several comparisons between experimental measures and model results are shown.

Development of a Lower Temperature Operating Sodium Beta-Alumina Battery (LT-NBB): Strategies and Technical Challenges

The sodium nickel chloride (Na/NiCl2) battery is one of the most promising candidates for a large scale electrochemical energy storage device. The battery comprises NiCl2 and molten Na as positive and negative electrodes in its charged state, and uses a Na+ ion conducting β"-Al2O3 solid electrolyte (BASE) to separate the cathode and anode. In order to facilitate fast sodium ion transport in the cathode compartment, molten NaAlCl4, as a secondary electrolyte (or catholyte), is infiltrated into the powdered cathode material. The battery typically operates at 250~300°C to maximize the ionic flux in the NaAlCl4 and through the solid electrolyte, and to minimize the dissolution of NiCl2into the melt. However, this efficient battery has yet to be widely used in grid scale energy storage applications, since it is still expensive; it is difficult to dramatically reduce the cell price in its present form mainly due to its use of expensive sealing technologies. The presentation introduces U.S.-Korea collaborative efforts to develop a sodium beta-alumina battery with a Na/NiCl2 chemistry that operates at a lower temperature. Since the novel battery runs below 200°C, it can be fabricated at an ultralow manufacturing cost by (1) introducing a new planar cell design with a greatly reduced number of cell components, and (2) eliminating expensive sealing technologies. Enhanced degradation resistance of cathode materials is another important advantage of this technology. This presentation will start by stating problems found in traditional sodium beta-alumina batteries, and our strategies to resolve the issues will be described. Technical challenges and progress in materializing prototype LT-NBB cells and related core technologies will be briefly discussed, which include cell design, a highly toughened BASE, an enhanced wetting agent, and an inexpensive sealing method.

Enhanced β"-Alumina Solid Electrolytes for Lower Temperature Operating Planar Sodium Beta-Alumina Batteries (LT-NBBs)

The sodium beta-alumina battery (NBB), which employs molten sodium as an anode and sodium-ion conducting β"-alumina as a solid electrolyte, is an attractive device for grid scale energy storage thanks to its long lifetime with negligible self-discharge and potentially low cost by use of naturally abundant elements. Commercialized NBBs, such as sodium sulfur (Na/S) and sodium nickel chloride (Na/NiCl2) batteries, are typically being operated at 280~350oC in order to facilitate ionic conduction through the solid electrolyte. However, this high operation temperature disturb additional cell cost reduction, which is continuously exacted by demanding forecast, since it is difficult to replace conventional expensive sealing technologies (such as glass sealing, thermal compression bonding, electron beam welding and so on) with lower cost substitutes. If the cell operation temperature is lowered down to below 200oC, a wider range of choices for sealing technology can be considered such as inexpensive polymer sealing. Suppressed cell degradation at lower temperatures would be another important benefit. However, a number of hurdles need to be overcome in order to lower the cell operation temperature. One of the most difficult challenges to make it is an issue regarding the exponential resistance rise of the solid electrolyte with decreased temperature, which can result in substantial performance loss. One can consider that reducing the thickness of the β"-alumina solid electrolyte (BASE) may resolve the issue. However, as the BASE thickness decreases below 1.5~2.0 mm, its flexural strength becomes not acceptable to be used in cell fabrication. Therefore, our target has set to develop a BASE (1) to be thin to compensate the resistance increase at lower temperatures, (2) with enhanced mechanical properties to minimize unwanted cell failure. The target can be achieved by fabricating highly toughened thin composite electrolytes. In this presentation, our on-going efforts on developing thin composite electrolytes made of β"-alumina and oxygen conducting oxides. Results showed that the flexural strength of this novel electrolyte could be greatly increased maintaining its area specific resistivity (ASR) as low as that of a conventional BASE.

Investigation of Al-Ni Alloys Deposition during Over-discharge Reaction of Na-NiCl2Battery

The over-discharging phenomena in sodium-nickel chloride batteries were investigated in relation to decomposition of molten salt electrolyte and consequent metal co-deposition. From XRD analysis, the material deposited on graphite cathode current collector was revealed to be by-product of molten salt electrolyte decomposition. In particular, the result showed that the Ni-Al alloys (<TEX>$Al_3Ni_2$</TEX>, <TEX>$Ni_3Al$</TEX> and <TEX>$Al_3Ni$</TEX>) were electrochemically deposited on graphite current collectors in line with over-discharging behaviors. It is assumed that the <TEX>$NiCl_2$</TEX> solubility in molten salt electrolytes leads to the co-deposition of Ni-Al alloys by increasing metal deposition potential above 1.6 V (vs. <TEX>$Na/Na^+$</TEX>). The cell tests have revealed that the composition of molten salt electrolytes modified by various additives makes a decisive influence on the over-discharging behaviors of the cells. It was revealed that NaOCN addition to molten salt electrolytes was advantageous to suppress over-discharge reactions by modifying the characteristics of molten salt electrolytes. NaOCN addition into molten salt electrolytes seems to suppress Ni solubility by maintaining basic melts. The cell using modified molten salt electrolyte with NaOCN (Cell D) showed relatively less cell degradation compared with other cells for long cycles.

Feasibility Study of a Planar‐type Sodium–Nickel Chloride Battery

The sodium–nickel chloride (Na/NiCl2 ) battery has many advantages over the Na–S battery, such as a higher operating voltage, ease of assembly in the discharge state, less corrosive cathode materials, a safer cell failure mode, and better tolerance against overcharging. In this study, to solve the problem of low electrical conductivity, a planar‐type Na/NiCl2 cell was designed by optimizing the cathode through the use of both Ni mesh and excess Ni powder. A β″‐Al2O3 membrane, which plays a role in the conducting path for Na+ ions, was glass‐sealed and attached to a thicker external α″‐Al2O3 ring. For carbon coating, the anode side of the membrane was covered with carbon paste. The prototype cell was operated successfully and showed excellent electrochemical characteristics in terms of high Na utilization and stable charge/discharge cycleability.

Thermal integration of a SOFC power generator and a Na–NiCl2 battery for CHP domestic application

In this study the integration of a Solid Oxide Fuel Cell (SOFC) prime mover and a high temperature electrochemical Sodium Nickel Chloride (SNC) battery as storage has been investigated. The aim is to fulfil a domestic user energy demand and to reduce the primary energy consumption in comparison with a reference conventional scenario, thereby, to enhance the total efficiency in a μ-CHP (Combined Heat and Power) application on a yearly basis. A realistic operational sequence of the SOFC-battery integration has been calculated using simple logic conditions. Both thermal and electric integration have been considered, where the innovative thermal integration has been proposed in order to exploit the SOFC residual heat for the battery stand-by feeding. The key advantage of this system architecture is that the SOFC is operated without major load variations close to constant load, resulting in longer lifetime and thus reducing total costs of operation. The thermal integration provides additional advantages, as calculated in this study. Eventually, a comparison with alternative μ-CHP technologies has been carried out, highlighting the potential of the system based on the SOFC. Benefits are mainly shown in terms of primary energy savings and admissible costs.

Sodium nickel chloride battery steady-state regime model for stationary electrical energy storage

The purpose of this paper is presenting a reliable modelling of sodium-nickel chloride battery in order to have a powerful tool which is able to foresee the steady state battery behaviour in both discharge and charge operations. The proposed modelling approach allows representing both constant current operations and variable charge or variable discharge current ones, but it does not allow passing instantaneously from one battery mode to another one. This method is based on experimental measures. All the main modelling steps are described and a comparison between the model results and real battery measures, with the same conditions, is presented. The very good agreement between measures and model confirms the robustness of the approach for steady state applications. The paper proposes to adopt a set of standard battery measures from which it is possible to infer a simple but very precise modelling structure.

Advanced intermediate temperature sodium-nickel chloride batteries with ultra-high energy density.

Sodium-metal halide batteries have been considered as one of the more attractive technologies for stationary electrical energy storage, however, they are not used for broader applications despite their relatively well-known redox system. One of the roadblocks hindering market penetration is the high-operating temperature. Here we demonstrate that planar sodium–nickel chloride batteries can be operated at an intermediate temperature of 190 °C with ultra-high energy density. A specific energy density of 350 Wh kg−1, higher than that of conventional tubular sodium–nickel chloride batteries (280 °C), is obtained for planar sodium–nickel chloride batteries operated at 190 °C over a long-term cell test (1,000 cycles), and it attributed to the slower particle growth of the cathode materials at the lower operating temperature. Results reported here demonstrate that planar sodium–nickel chloride batteries operated at an intermediate temperature could greatly benefit this traditional energy storage technology by improving battery energy density, cycle life and reducing material costs.

Influence of Carbon Coating on Beta‐Alumina Membrane for Sodium–Nickel Chloride Battery

Sodium–nickel chloride batteries have been used as energy storage devices because of their high operating voltage, ease of assembly in a discharged state, the less corrosive nature of the cathode materials, safer cell failure mode, and better tolerance against overcharging. In this study, we fabricated a planar‐type cell equipped with an elastic spring rod in the anode to maintain effective sodium utilization. In addition, we investigated the influence of carbon coating on the β″‐Al2O3 membrane. The carbon coating layer on the β″‐Al2O3 membrane showed improved wettability for sodium metal. The carbon‐coated alumina membrane delivered a higher initial charge/discharge capacity than the pristine membrane cells.