Molten Zinc Alloys for Lower Temperature, Lower Cost Liquid Metal Batteries

Abstract

(1 of 9) 1600035 wileyonlinelibrary.com grid storage. To date, much research in EES has focused on batteries with lithium as a charge carrier, spurred by success in portable electronics, but high costs, short lifetimes, and safety issues make lithium technology less than ideal for grid storage. [4][5][6][7] The chemistry of all-vanadium redox fl ow batteries has yielded promising cycle lifetimes, but this technology is hindered by the high cost of vanadium and low energy densities and round-trip efficiencies. [8][9][10] For EES technologies to be practical for grid storage, systems must utilize low-cost, abundant, and safe materials.Liquid metal batteries (LMBs), which contain molten metal electrodes and molten salt electrolytes, have recently re-emerged as candidates for grid storage technologies. [ 11,12 ] These batteries, which contain socalled "structureless" electrodes, are not susceptible to mechanical degradation inherent with intercalation-type electrochemistry. Until now LMB technologies have featured a design in which the immiscible molten materials naturally stratify into three layers, where the density of the electrolyte lies between that of the two electrodes. While this design simplifi es battery fabrication, the relative density requirement (i) limits materials choices, precluding the use of many low-cost materials, (ii) necessitates exceedingly high operating temperatures, and/or (iii) compromises on safety due to material reactivity. [ 13,14 ] Recently reported LMBs contain highly reactive metals such as Ca, Mg, or Li and operate at high temperatures (450-700 °C). Furthermore, the stratifi ed LMB design is susceptible to electrode dissolution and magnetohydrodynamic instabilities at high current densities, which could lead to cell shorting and thermal runaway. [ 11 ] Other recent examples of batteries containing a liquid metal electrode include Na-NiCl 2 batteries and Na-S batteries; these electrodes are separated by a ceramic membrane and do not have the strict requirements of relative densities and immiscibility and can reach lower operating temperatures. However, the performance of these batteries is limited by the inclusion of nonconducting materials in the electrode (NiCl 2 or S), and the batteries still pose dangers because they contain corrosive liquids and brittle membranes. [15][16][17] In the present work, we sought to address the shortcomings of the above technologies while keeping material and energy costs low by creating a zinc-based LMB. Zinc (Zn), an inexpensive multivalent energy carrier, has a high theoretical energy density of 820 mAh g −1 , and, in an all-molten cell design, Molten Zinc Alloys for Lower

Rechargeable Batteries for Grid Scale Energy Storage

“…The LMBs are basically composed of stainless steel cases, insulating ceramics, current collectors, and other components . Moreover, there have been many exciting studies pertaining to LMBs comprising different metal systems. ,,− ,− In this section, we discuss several representative LMBs for potential applications in GSES.…”

“…MSBs are exclusively known for their electrochemical energy storage capacity using molten salts as electrodes and electrolytes. , These batteries offer a multitude of potential advantages, such as nonvolatility, nonflammability, and high conductivity of molten salts, high energy, and impressive power densities for stationary applications. − In order to keep the electrodes and electrolytes in molten states, the MSBs are generally operated under relatively high temperatures. To date, several MSB systems have been successfully developed, including traditional high-temperature (HT) and intermediate-temperature (IT) Na–S batteries, ZEBRA batteries, and the most recently developed liquid-metal batteries (LMBs) and solid electrolyte-based liquid Li (SELL) batteries.…”

Competing forces in liquid metal electrodes and batteries

“…1a). Typical chemistries include Ca||Bi [5,6], Ca||Sb [7,8], K||Hg [9], Li||Bi [10,11], Li||Cd [12], Li||Pb [4,12], Li||Sb [4], Li||Se [13,14], Li||Sn [15,16], Li||Te [17], Li||Zn [12], Mg||Sb [18], Na||Bi [19,20], Na||Hg [21,22], Na||Pb [12], Na||Sb [3], Na||Sn [9,23,24], Na||Zn [25,26] and Zn||Bi,Sn,Pb [27,28] cells. The three liquid layers are selfsegregated based on density, which makes the manufacturing process simpler and less expensive compared to other batteries.…”

Microstructural Analysis of Effective Electrode Conductivity in Molten Salt, Na-ZnCl2 Batteries

“…Despite the disadvantages of using Zinc, such as problems with dendrite formation, 19 it has been estimated that usage of Zn would reduce the cost of the cathode metal by almost 90%. 20 Furthermore, the battery chemistry with Sodium has been demonstrated in a high-temperature all-liquid cell before. 21,22 One of the key challenges in the development of these batteries is the understanding of the multiphase cathodic region at different stages through the battery charge/discharge cycles.…”