The ZEBRA electric vehicle battery: power and energy improvements

Galloway, R. C.; Haslam, S.B.

doi:10.1016/s0378-7753(98)00259-6

Cited by 72 publications

(53 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…1,2 The ZEBRA batteries have been developed for more than 10 years and their specific energy is now 3 100 Wh/kg and specific power higher than 150 Wh/kg, which is more than sufficient to power traffic compatible electric vehicles.…”

mentioning

confidence: 99%

Investigation of the Inner Structures of ZEBRA Cells with a Microtomograph

Steinbock

Dustmann²

2001

J. Electrochem. Soc.

View full text Add to dashboard Cite

Sodium/nickel cells have high energy density and are developed as a power source for electric vehicles. A microtomograph was used in order to determine the inner structure of a commercial ZEBRA cell after fabrication. The tomograms represent the absorption density in a slice 0.05 mm thick. The different gray values of the tomogram allow the identification of different material classes: air, sodium, alumina or sodium chloride, porous nickel chloride, and solid nickel. It was found that the structure of the cathode of nickel chloride is dependent on the charging state and the height inside the cell. Tomographic imaging of such cells may serve the purposes of imaging of material changes at operating temperatures and quality control during fabrication. The sodium/nickel chloride cell has a theoretical energy density of 790 Wh/kg and prototype cells have been developed at different locations.1,2 The ZEBRA batteries have been developed for more than 10 years and their specific energy is now 3 100 Wh/kg and specific power higher than 150 Wh/kg, which is more than sufficient to power traffic compatible electric vehicles.Tokoi et al. 4 showed that computed tomography may be used to image the material distribution inside a sodium sulfur battery cell, and they extracted quantitative structural data of the battery state at room temperature. Since their batteries have a rather large diameter of 64 mm, they need a 6 MeV linear accelerator in order to penetrate the cells. In a second article they show, 5 how in situ tomography may quantify the density changes of the sulfur electrode during several charge-discharge cycles at the operating temperature of 350°C.The quality control of cells in a series production is an important issue for quality. Conventional nondestructive examination methods like ultrasound, eddy current, or shadow radiography may be used to investigate the critical regions after production, but they need a well-trained eye to judge possible defects. The tomograms of the ZEBRA-type sodium nickel chloride cells show virtual cross sections, which are easier to analyze, and the defect classification of the cells may be done with sophisticated image processing programs. ZEBRA BatteryA single ZEBRA cell of the type SL09 has a square steel casing with 37 mm base length ͑Fig. 1͒. The inner structure in the present ML-type cells was changed in order to achieve higher power density: the alumina cross section now has a cloverleaf form and the inner nickel profile is replaced by two wires. However these differences change the radiographic properties of the cells only slightly, and the results of this work would be correct for ML-type cells also. The interior of the SL09 cell is described in Fig. 2. A beta alumina tube is contacted by thin steel strip springs. At the center of the alumina tube two solid nickel collectors hold a carbon felt which divides the tube interior in two half cylinders. These half cylinders are filled with porous nickel, salt granules, and NaAlCl 4 electrolyte. After heating the cell above 270°C it ...

show abstract

mentioning

confidence: 99%

Investigation of the Inner Structures of ZEBRA Cells with a Microtomograph

Steinbock

Dustmann²

2001

J. Electrochem. Soc.

View full text Add to dashboard Cite

show abstract

“…At the separator, the current density is set equal to the applied current density, i.e. : [8] At the current collector, the ionic current density is set equal to zero, as follows:…”

Section: Model Formulationmentioning

confidence: 99%

“…7,8 Galloway and Sudworth both provide descriptions of how the replacement of a small amount of nickel with * Electrochemical Society Student Member.…”

mentioning

confidence: 99%

“…7,8 A schematic of this concept is shown in Figure 1. Part a) shows the discharge and pulse-power process of an electrode with one active material.…”

mentioning

confidence: 99%

“…7,8 Galloway and Sudworth both provide descriptions of how the replacement of a small amount of nickel with iron, which has a lower potential, can improve the pulse power at high DoD. However, these concepts have not been analyzed quantitatively, even though they are strongly supported by data from commercial cells.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Theoretical Considerations for Improving the Pulse Power of a Battery through the Addition of a Second Electrochemically Active Material

Knehr

West

2016

J. Electrochem. Soc.

View full text Add to dashboard Cite

Porous electrode theory is used to conduct case studies for when the addition of a second electrochemically active material can improve the pulse-power performance of an electrode. Case studies are conducted for the positive electrode of a sodium metal-halide battery and the graphite negative electrode of a lithium "rocking chair" battery. The replacement of a fraction of the nickel chloride capacity with iron chloride in a sodium metal-halide electrode and the replacement of a fraction of the graphite capacity with carbon black in a lithium-ion negative electrode were both predicted to increase the maximum pulse power by up to 40%. In general, whether or not a second electrochemically active material increases the pulse power depends on the relative importance of ohmic-to-charge transfer resistances within the porous structure, the capacity fraction of the second electrochemically active material, and the kinetic and thermodynamic parameters of the two active materials. To accelerate an electric vehicle, an important requirement of a battery is the ability to deliver high power pulses at all depths of discharge.1-3 Nevertheless, a high power pulse can be difficult to achieve, especially at high depths of discharge (DoD). In some cases, high power is difficult to achieve at high DoD because of an increase in the ohmic resistance during discharge. The ohmic resistance increases due to the movement of the reaction fronts within the electrodes from more favorable (less resistive) to less favorable (more resistive) locations.4,5 For instance, this behavior has been documented in the positive electrode of sodium metal-halide batteries, where the low resistivity of the electrode (nickel and/or iron) and the higher resistivity of the electrolyte (sodium tetrachloroaluminate) cause the reaction front to move from the separator to the current collector during discharge. 6,7 At high DoD, the reaction front is far from the separator and the ionic path length is increased, which increases the overall ohmic resistance in the electrode.One way to improve the pulse-power performance of an electrode is through the addition of a second active material that only reacts at higher DoD.7,8 A schematic of this concept is shown in Figure 1. Part a) shows the discharge and pulse-power process of an electrode with one active material. In this case, the reaction front starts near the separator and moves deeper into the electrode as the cell is discharged. When the electrode is pulsed at the high DoD, the reaction occurs deep within the electrode and there are high ohmic losses due to the increased ionic path length. In contrast, part b) shows the discharge and pulsepower process for an electrode with two active materials. For this case, the same initial behavior is observed, whereby the reaction front moves from the separator to the current collector during discharge. However, during the initial discharge, the second active material does not react. Therefore, when the electrode is pulsed at a high DoD, the high ohmic losses are avoided b...

show abstract

The Sodium/Nickel Chloride Battery

Ottaviani¹,

Turconi²,

Basso³

2020

Encyclopedia of Electrochemistry

View full text Add to dashboard Cite

Na–NiCl 2 thermal batteries have been developed for applications such as electric energy backup, energy storage, and automotive application. A typical Na–NiCl 2 battery consists of a molten sodium anode, a solid‐state electrolyte (β″‐alumina), and a secondary liquid electrolyte (NaAlCl 4 ) in the cathode side, with NiCl 2 as the active cathode materials. These systems, operating at high temperatures (about 270–350 °C), provide a battery completely independent of ambient temperature with high specific energy and high specific power. Special characteristics such as relatively low cost, long deep cycle life, long‐term cold‐storage life, abuse resistant, zero electrical self‐discharge, maintenance free, and safety place this technology as the best choice where environmentally strong conditions are present and other secondary battery systems fail.

show abstract

The ZEBRA electric vehicle battery: power and energy improvements

Cited by 72 publications

References 2 publications

Investigation of the Inner Structures of ZEBRA Cells with a Microtomograph

Investigation of the Inner Structures of ZEBRA Cells with a Microtomograph

Theoretical Considerations for Improving the Pulse Power of a Battery through the Addition of a Second Electrochemically Active Material

The Sodium/Nickel Chloride Battery

Contact Info

Product

Resources

About