Evaluating ZEBRA Battery Module under the Peak-Shaving Duty Cycles

Abstract

With the recent rapid increase in demand for reliable, long-cycle life, and safe battery technologies for large-scale energy-storage applications, a battery module based on ZEBRA battery chemistry is extensively evaluated for its application in peak shaving duty cycles. First, this module is tested with a full capacity cycle consisting of a charging process (factory default) and a discharging process with a current of 40 A. The battery energy efficiency (discharge vs. charge) is about 90%, and the overall energy efficiency is 80.9%, which includes the auxiliary power used to run the battery management system electronics and self-heating to maintain the module operating temperature (265 °C). Generally, because of the increased self-heating during the holding times that exist for the peak shaving duty cycles, the overall module efficiency decreases slightly for the peak-shaving duty cycles (70.7–71.8%) compared to the full-capacity duty cycle. With a 6 h, peak-shaving duty cycle, the overall energy efficiency increases from 71.8% for 7.5 kWh energy utilization to 74.1% for 8.5 kWh. We conducted long-term cycling tests of the module at a 6 h, peak-shaving duty cycle with 7.5 kWh energy utilization, and the module exhibited a capacity degradation rate of 0.0046%/cycle over 150 cycles (>150 days).

Alkali and alkaline earth metals in liquid salts for supercapatteries

“…Relatively high specific energy (120 W h kg −1 ) can be achieved at 300 °C with energy efficiency varying from 90 to 95%. 163 Besides, Shamim et al 156 reported a 90% energy efficiency at 265 °C for a ZEBRA battery module (48TL200) from FzSoNick with promising stability (a degradation rate of 0.0046%/cycle over 150 cycles). In 2022, Zhu et al 157 reported, as shown in Fig.…”

“…150 As in room temperature electrolytes, metallic negatrodes, such as Li, Na, Mg, Al and Fe, have been investigated extensively in molten salt batteries. [151][152][153][154][155][156][157][158][159][160][161][162] For instance, Giordani et al 152 reported a Li-O 2 battery with 95% energy efficiency achieved in a molten LiNO 3 -KNO 3 eutectic at 150 °C. However, the cycling stability was poor (<50 cycles, 2.6 mA h cm −2 at 0.6 mA cm −2 ), due to the oxidation of carbon and consequent formation of Li 2 CO 3 at the positrode.…”

“…Introducing redox additives in the molten salts should also be considered to enhance the charge capacity of the capacitive positrode. 156 It is worth mentioning that because molten salts freeze at room temperature, a fully charged molten salt EESD can be kept on a shelf for a long period until the next designated time of discharge without suffering from any self-discharge. This is because the solidied salt is an insulator to both electrons and ions.…”

Stabilizing Metallic Na Anodes via Sodiophilicity Regulation: A Review

“…Among the Na-based batteries considered for large-scale grid storage applications, molten sodium-metal batteries have recently regained popularity mostly due to the recent advancements in the development of intermediate-temperature molten sodium-metal batteries (SMBs), including Na-metal halide (Na-MH) and Na-S batteries based on a β"-Al 2 O 3 solid electrolyte (BASE) [3,4,[20][21][22][23]. BASE electrolytes have a high ionic conductivity (∼1 and 250 mS cm −1 at 25 and 300 • C, respectively), an outstanding mechanical stability, and a wide electrochemical window.…”

“…Originally, SMBs were based on molten Na-S batteries or Na-MH batteries operating at around 300 • C with β"-Al 2 O 3 solid electrolyte (BASE). While both types of molten SMBs are of technological interest and have been commercialized, Na-MH batteries, such as Na-NiCl 2 batteries, are particularly promising due to their inherent safety in terms of cell failure relative to Na-S batteries, the less corrosive active materials compared to S and polysulfides, and easier cell assembly in the discharged state without handling hazardous Na metal and metal halides [3,4]. Unfortunately, the widespread adoption of both Na-S and Na-MH batteries in grid-level energy storage has been dwarfed by the safety concerns associated with their high operation temperature, plus the unstoppable emergence of Li-ion batteries.…”