PDF Publication Title:
Text from PDF Page: 041
III. Assessing capacity loss remediation methods for asymmetric redox flow battery chemistries using levelized cost of storage 1. Introduction As discussed previously, the unique architecture of RFBs enables excellent resiliency for maintaining their energy capacities. However, crossover losses (i.e., the transport of active species through the semi-permeable membranes separating the positive and negative electrodes, which are designed to allow for transport of supporting ions to maintain charge balance [94]) is crucial to minimize. If these membranes are not perfectly selective for the desired charge-carrier species, then RFBs experience capacity reductions via undesired permeation of active species, often referred to as crossover [95]. While crossover is not the sole cause of capacity decline within RFBs, it is often the largest contributor and may halve the accessible capacity within 100-200 cycles [12]. One strategy for mitigating the effects of crossover is the use of a “symmetric” redox chemistry, where all active species are based on a single parent compound [14]. In this case, crossover does not lead to cross-contamination and associated capacity losses are recoverable via periodic electrolyte rebalancing: the transfer and mixing of partial or full volumes of electrolyte between the two reservoirs to balance the concentrations of active species. Rebalancing is a powerful capacity-remediation tool, as it allows the electrolyte to be used indefinitely, assuming other non- crossover capacity losses can be managed and/or remediated as well, which significantly reduces maintenance costs [16]. A number of symmetric chemistries have been contemplated for RFBs leveraging inorganic [75], organic [96–99], and organometallic [100–102] active species, but vanadium remains the canonical example. Vanadium RFBs (VRFBs) are the most researched and commercialized RFB technology, primarily because vanadium has four stable and soluble oxidation states accessible within the electrochemical stability window of aqueous acidic electrolytes on carbon electrodes. This, in turn, allows for a symmetric chemistry (V2+/V3+ in the negative half-cell and V4+/V5+ in the positive half-cell) and continual recovery of crossover capacity losses via rebalancing. While the VRFB system benefits from reduced maintenance costs, it suffers from a high upfront cost, due, in part, to the price of the active species [24,25]. Vanadium prices have been relatively volatile since the 1980’s, and especially so in the last four years with a late 2018 peak of over ten-fold the price at 41PDF Image | Bringing Redox Flow Batteries to the Grid
PDF Search Title:
Bringing Redox Flow Batteries to the GridOriginal File Name Searched:
Rodby-krodby-phd-chemE-2022-thesis.pdfDIY PDF Search: Google It | Yahoo | Bing
Salgenx Redox Flow Battery Technology: Salt water flow battery technology with low cost and great energy density that can be used for power storage and thermal storage. Let us de-risk your production using our license. Our aqueous flow battery is less cost than Tesla Megapack and available faster. Redox flow battery. No membrane needed like with Vanadium, or Bromine. Salgenx flow battery
CONTACT TEL: 608-238-6001 Email: greg@salgenx.com (Standard Web Page)